Three-Phase Four-Wire Hybrid Active Power Filter for Mitigating

Harmonic Problems Caused by CFLs Lamps based on a Shunt Active

Power Filter SAPF in Parallel with a Passive Filter

MOHAMED HAJJEJ, LASSAAD SBITA

Process Laboratory, Energetic, Environment and Electrical System (PEESE),

National Engineering School of Gabès (ENIG),

University of Gabès,

TUNISIA

Abstract: - The widespread integration of nonlinear loads across industrial, commercial, and residential settings

has significantly exacerbated power quality issues within contemporary power distribution systems. An

example of such nonlinear loads is the prevalent use of compact fluorescent lamps (CFLs), intended as

replacements for incandescent lamps (ILs). CFLs have gained popularity owing to their reduced energy

consumption and extended lifespan, contributing to their extensive use across various applications. But those

lamps inject high harmonic current in the power system. To address this issue, a hybrid active power filter

HAPF based on a shunt active power filter SAPF in parallel with a passive filter (PF) is implemented in this

paper. The reference current is calculated based on the PQ theory, and the voltage source inverter VSI is

controlled via a simple hysteresis current controller (HCC). The results show that the PF is suitable to

compensate for the Hight harmonic generated by both the load and the switched device of the APF. Also, this

HAPF is well designed and implemented to mitigate all harmonic generated by CFL lamps on the power

system, and compensate the reactive power. The THD of the current is reduced from 90.75% before

compensation to 0.75% after compensation. This implies that the main injects only the Fundamental current to

the power.

Key-Words: - Shunt active power filter (SAPF), passive filter (PF), PQ theory, hysteresis current controller

(HCC), hybrid active power filter (HAPF), Harmonics, current compensation, THD.

Received: August 13, 2023. Revised: February 7, 2024. Accepted: March 5, 2024. Published: April 8, 2024.

1 Introduction

In recent years, the escalating use of semiconductor

devices and nonlinear loads across various

applications has made power quality issues a

significant concern in power systems. Such as

residential or industrial loads and in particular the

light loads that represent 25% of the total power

loads, [1]. The massive use of Compact fluorescent

lamps CFLs injects high harmonic current into the

main systems for all harmonic levels, [2]. So,

harmonic currents, in particular, have become a

major focus in this context. Passive power filters

(PFs) primarily composed of inductive and

capacitive elements (L-C) are considered the best

low-cost solutions that offer fixed current

compensation. Diverging from Active Power Filters

APFs that provide dynamic and adaptable solutions.

They proactively respond to power quality issues,

affording precise control while minimizing

resonance effects often associated with passive

filters. Additionally, Shunt APFs offer advantages in

terms of sizing and flexibility, making them the

preferred choice for addressing power quality

challenges, [3]. Shunt active power filters (SAPFs)

are widely employed to manage current harmonics,

reactive power compensation, and neutral current

compensation in distribution systems. Typically

installed at the Point of Common Coupling (PCC) as

presented in Figure 1, where nonlinear loads

connect with the utility grid, these filters are more

adept at mitigating current harmonics compared to

passive power filters (PFs), which offer fixed

compensation and are limited by factors like

resonance effects and specific sizing, [4].

Presently, the attention of researchers and

developers is directed toward both the design and

control aspects of SAPFs tailored for three-phase

four-wire (3ph-4W) nonlinear loads. So, various

SAPF topologies have emerged to tackle these

challenges, including the four-leg (4L) configuration

[5], the split capacitor or two capacitors (2C)

approach [6] and the three H-bridges (3-HB)

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

topology, each H-bridge comprising four switches

arranged in an H shape [7], which is illustrated in

Figure 2.

In the split capacitor topology, the neutral wire

resides between two capacitors, necessitating an

additional control loop to maintain the DC voltage

balance between the capacitors. In contrast, the 4L

configuration introduces two active switches to the

fourth leg (neutral wire) to balance the neutral

current, resulting in superior performance compared

to the 2C topology. This configuration has been

extensively explored in various research studies, [8],

[9]. Conversely, the 3-HB inverter topology

employs three full H-bridges sharing a DC-link

capacitor, requiring three single-phase isolated

transformers to connect the 3-HB filter to the system

and more switches than other configurations.

While those researchers are focusing on

optimizing and creating various parallel active filter

topologies, others delve into perfecting the control

aspect, which represents the "heart" of these filters.

The efficacy of the filtering process is closely tied to

the reference current extraction algorithm. These

methodologies typically fall into two main

categories: frequency domain methods and time

domain methods.

Frequency domain methods, such as the fast

Fourier transform (FFT), extract harmonic

components from distorted voltage and current

signals. Despite providing precise values of

harmonic amplitude and phases, these techniques

suffer from aliasing effects, spectral leakage, and

slow response times due to heavy computational

loads, necessitating complex systems for real-time

operation.

Conversely, time domain methods, including the

p-q theory, instantaneous reactive power theory,

synchronous reference frame theory (SRF), and p-q-

r theory, have gained attention. SRF employing a

phase-locked loop (PLL) system, ensures

undistorted transformation angles even under

unbalanced source conditions, enabling its usage for

voltage and current reference generation. The

reference currents serve as inputs to the power

switch control block.

Hysteresis control algorithms (HCA) represent

simple and practical techniques for SAPF and power

switch device control. HCA operates with two

predefined bands, ensuring the modulated currents

remain within specified limits, resulting in close

tracking of the compensating current to the

reference current. HCA determines the VSI

(Voltage Source Inverter) switches' "ON" and

"OFF" states, leading to straightforward

implementation, robustness, and high performance.

However, HCA is constrained by a limited

frequency range and nonlinear effects. Addressing

these limitations, researchers have introduced a new

technique called pulse width modulation (PWM)

control, which generates a modulation signal to

adjust the duty cycle of power electronic switches,

[10], in wish is not the subject of this paper.

Moreover, and based on previous experimental

and simulation research, we found that the load

generates high harmonics for both low and high

harmonic levels. Also, it is noticed that the

switching devices of the APF may inject some

harmonic and in particular high frequency. So, as a

solution to mitigate both harmonics generated by

CFL and APF in high frequency levels a Hybrid

active power filter HAPF is proposed in this paper.

The HAPF consists of a second-order high-pass

passive filter in parallel with an APF. The overall

system is estimated, and implemented by MATLAB

Simulink software. This is crucial to comply with

relevant national and international harmonic

standards, including NTF 15-520 and IEC61000-3-

2, [11], [12]. Also, Shunt Active Power Filters can

be used in industrial setups where Variable

Frequency Drives are employed. VFDs often

introduce harmonic distortion into the power

system, and SAPFs can help mitigate these

harmonics, ensuring a cleaner and more stable

power supply.

This paper employs the PQ theory for

calculating reference currents and utilizes hysteresis

current controllers HCC for pulse signal generation

to control the switching device of the SAPF.

Moreover, the research introduces a parallel-

operating Shunt Active Power Filter (SAPF) aimed

at mitigating high-order harmonic currents within

the load, significantly enhancing power quality

while diminishing disruptions caused by harmonic

distortions. The prevalence of nonlinear loads in

industrial, commercial, and residential systems has

precipitated substantial power quality challenges in

modern power distribution systems. Notably,

harmonic currents and reactive power emerge as

pivotal concerns among these issues.

The paper's structure is delineated as follows:

Section 2 provides a brief description of the CFL

load used and presents the experimental impact of

the massive use of these loads on the power system.

Section 3 intricately details the three-phase four-

wire Shunt Hybrid Power Filter SHPF with a four-

leg configuration and split capacitor topology. This

section also offers insights into the design and

modeling of Passive Filter. Also, it provides a

detailed analysis of the application of the PQ theory

for calculating compensation current and the Fixed

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

Hysteresis Control method implemented to manage

the switching devices of the APF. Furthermore,

Section 4 presents an exhaustive analysis of

simulation results and the effectiveness of harmonic

mitigation strategies. Finally, Section 5 concludes

the paper by summarizing the findings and

contributions of this research pursuit.

Fig. 1: Bloc diagram of the SAPF connected to the

distribution network

Fig. 2: Harmonic current compensation

classification based on the power circuit

2 Investigation of the Impact of CFL

Loads based on Experimental Tests

To quantify the effect of the massive use of CFL

loads on the distribution network many

experimental previous tests were carried out, [13].

Figure 3 shows the general scheme proposed in the

experimental setup for a large number of GE CFL

lamps powered by a three-phase system, this figure

includes 75 lamps distributed across 3 AC-50Hz

phases (25 lamps in parallel for each phase). A

power analyzer, C. A 8336, is used to obtain data

related to electrical parameters for any given point.

The analyzer is configured in three-phase mode.

This device is used to visualize data on-site and

store it in digital form, which can be later retrieved

using a computer and software provided by the

manufacturer of the power analyzer. Therefore, it is

important to note that all experimental figures in this

research work are generated using the software

provided by the manufacturing company (the latest

version), called “Power Pad III” designed for all

Chauvin Arnoux CA 8331, 8335, and 8336 devices,

[14].

















Fig. 3: Experimental setup for harmonic CFL

investigations

Chauvin Arnoux CA 8331, 8335, and 8336

devices, [15], utilize equation (1) to compute the

various harmonics (XTHD) for both voltage and

current. Additionally, equation (2) is employed to

determine the corresponding angle (φk) in degrees

(°) relative to the fundamental. It is important to

highlight that these calculations are executed

through a 16-bit FFT with 1024 data points covering

four cycles, and a rectangular window is applied

following the specifications outlined in IEC61000-

4-7. The harmonic factor for each phase (j) and

order (h) is then derived from the real parts (bk) and

imaginary parts (ak) expressed in equation (3).

(1)

(2)

where, X denotes the signal captured by the device,

representing either the current (A) or the voltage (V)

of the load. X[j][1] specifically signifies the

fundamental signal for each phase j (where 1≤j≤3),

and the variable h corresponds to the harmonic

index.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

(3)

In this context, Fs represents the sampled signal

at the fundamental frequency f4, and k stands for the

index of the spectral spike. It's essential to note that

the order of the harmonic component is directly

related to k/4.

From the founded results in [13], it is easy to

observe that the current waveforms of CFLs are not

sinusoidal for all three phases and are not in phase

with the source voltages. Also, the neutral current is

not equal to zero. The harmonic spectrum of CFLs,

summarizes the origins of these disturbances and the

non-linearity of the load. This load acts as a

generator of significant harmonic currents that

propagate back to the distribution source, potentially

affecting other loads connected to the same network.

Various parameters measured by the power analyzer

are illustrated in Table 1.

Table 1. Main measured parameters with C.A 8336

P (kW)

Phase

« a »

Phase

« b »

Phase

« c »

Phase

« a »

Phase

« b »

Phase

« c »

0.5013

0.4943

0.668

0.655

0.647

S (kVA)

I_rms (A)

Phase

« a »

Phase

« b »

Phase

« c »

Phase

« a »

Phase

« b »

Phase

« c »

0.7507

0.7793

0.7636

3.16

3.27

3.2

V_rms (V)

φ (°)

Phase

« a »

Phase

« b »

Phase

« c »

Phase

« a »

Phase

« b »

Phase

« c »

237.5

238.1

237.4

ATHD (%)

VTHD (%)

Phase

« a »

Phase

« b »

Phase

« c »

Phase

« a »

Phase

« b »

Phase

« c »

86.2

88.5

90.4

5.4

5.3

For instance, the total powers absorbed by 75

GE LFC 20W lamps distributed across phases a, b,

and c are respectively P(a) = 501.3W, P(b) =

501.3W, and P(c) = 494.3W. Additionally, poor

power factors of 0.668, 0.665, and 0.647 are

observed for the three phases. Despite the low active

power consumed by these CFLs, the reactive power

consumed is significantly considerable for phases a,

b, and c, with S(a) = 0.7507 kVA, S(b) = 0.7793

kVA, and S(c) = 0.7636 kVA.

Figure 4 presents the experimental results of the

effect of harmonic distortion of voltages as a

function of the number of lamps for phase a. Also,

as depicted in Table 1 and Figure 4, an increase in

voltage THD V_THD from 3.4% to 5.3%. This value

is outside the order of the international standards,

[11], [12]. It provides a detailed measurement for

the three-line source. For instance, the A_THD for the

three phases a, b and c are 86.2%, 88.5%, and

90.4%, respectively. From Table 1 it can be also

seen that the CFL current was delayed to the voltage

of 24° for the three phases, which may have harmful

effects on the distribution network.

Fig. 4: Voltage THD as a function of the number of

lamps (Experimental setup)

To improve the power quality and to cancel the

harmonics generated by these non-linear loads on

the mains side, we will present in the next two

sections the proposed filter. At first, a passive power

filter for some special harmonic currents ranks

compensations applied for the same load. Second,

an active power filter will be applied to attenuate all

other harmonics and for reactive current

compensation. Both filters are connected in parallel

with the load.

3 Shunt Hybrid Power Filter

When both voltage and current are causing

problems and distortion in the power system, more

sophisticated filters are employed. These filters,

known as hybrid filters, [16], are a combination of

active and passive filters. Designing a passive filter

necessitates a thorough understanding of the

harmonic-producing load and the power system.

Passive filters, because they always provide reactive

compensation to a certain extent depending on the

volt-ampere rating and voltage of the capacitor bank

used, can be designed to serve the dual purpose of

filtering and power factor correction to the desired

level, [17]. As a result, passive filter design must

consider potential increases in harmonic current

sources or load reconfiguration, as these factors can

lead to overloading, which can develop quickly.

3.1 Passive Filter

Passive filters are electrical devices that reduce the

propagation of harmonics produced by non-linear

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

loads. A passive filter is installed in parallel to the

power grid as shown in Figure 5, providing a very

low impedance around the frequency to be filtered.

Two types of passive filters can be distinguished:

the resonant passive filter, and the damped passive

filter or high-pass filter, [18]. They are presented

respectively, by Figure 6(a) and Figure 6(b) The

primary components of a passive filter include

inductance L, capacitance C, and resistance R.

Compared to other harmonic elimination methods;

passive filters are relatively inexpensive. Their

applications include shunting harmonic currents

away from the power line or blocking their flow

between system components by tuning the elements

to resonate at a selected harmonic frequency, [19].

Fig. 5: Basic single-line diagram of a passive

compensator

a) Resonant passive filter

b) Damped passive filter

Fig. 6: Types of Passive Filter

 Resonant passive filter: It is a very selective

filter. It can be connected in parallel with

other resonant filters.

 Damped passive filter: It is the preferred

choice for attenuating a whole frequency

band.

These devices are used to prevent harmonic

currents from propagating in electrical grids. They

can also be used to compensate for reactive power.

Despite their widespread use in industry due to their

ease of installation, these devices can present many

disadvantages, such as their short lifespan and very

little flexibility;

 Lack of flexibility to adapt to network and

load variations.

 Bulky equipment.

 Resonance problems with network

impedance.

The presence of multiple harmonic orders,

including the 3rd, 5th, 7th, and 11th, in the

measured current necessitates the implementation of

harmonic filtering. Two filter configurations are

viable options: a single second-order, C-type high-

pass filter or a combination of parallel-connected

single-tuned filters. A comprehensive analysis

conducted in [20], revealed that employing a set of

combined single-tuned filters, each tuned to the

respective 5th, 7th, and 11th harmonic orders, is the

most effective strategy for mitigating these three

harmonic orders. In contrast, a second-order high-

pass filter is utilized to address harmonics ranging

from the 17th to the 49th orders.

3.2 Passive Filter Design Parameters

In a three-phase system with loads like compact

fluorescent lamps, the utilization of parallel passive

filters proves to be a critical solution for mitigating

harmonic distortions. These filters are designed to

control specific harmonics generated by these non-

linear loads, thus significantly improving the power

quality. Mathematically, the design of these parallel

passive filters involves the use of fundamental

equations based on the passive filter topology.

3.2.1 Single-tuned (Resonant) Filter Design

For instance, in a parallel RLC filter, the filter

impedance can be determined by equation (4), [21].

(4)

where Z represents the impedance, j is the imaginary

unit, is the frequency, C is the capacitance of the

capacitor, and L denotes the coil's inductance. These

filters selectively divert undesirable harmonics to

enhance current quality and ensure a more stable

operation of the three-phase electrical system.

The sizing of the different parameters R, L, and

C is done by the following equations (5)-(9)

(5)

(6)

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

(7)

(8)

(9)

In this context, X represents the reactance of

either the inductor or the capacitor at the resonant

frequency. Also, it should be noted that a typical

range for Q must be between 30 and 60.

3.2.2 Single Tuned (Resonant) Filter Design

The second-order high-pass filter resembles a

single-tuned filter, with the key difference being the

parallel arrangement of inductors (L) and resistors

(R) instead of the series arrangement observed in

single-tuned filters (Figure 6(b)). This configuration

offers enhanced filtering performance and reduces

energy losses at the fundamental frequency.

The impedance of this filter is given by equation

10:

(10)

But the quality factor is different compared to

the single tuned filter, it is given by 11:

(11)

3.3 Shunt Active Power Filter

The active filter connected in parallel to the

network, as shown in Figure 1, [22], [23], is most

often controlled as a current generator. It injects into

the network disruptive currents equal to those

absorbed by the polluting load but in phase

opposition with them, in order to restore the electric

network current to a sinusoidal shape, as illustrated

in Figure 7(c). It prevents disruptive currents

(harmonics, reactive, and unbalanced currents)

produced by polluting loads from flowing through

the impedance of the network, located upstream of

the active filter connection point. Figure 1

represents the general structure of the parallel active

filter, which consists of a single block. Only the

power parts were presented. The control-command

part will be presented in the next section. The power

part is composed of the:

1. A voltage inverter based on power switches,

controllable at initiation and blocking (GTO,

IGBT, etc.) with anti-parallel diodes.

2. An energy storage circuit, often capacitive.

3. An output filter.

a) injected current

b) load current

c) Source current

Fig. 7: Source current at different points of APF

applied to a 3 phases rectifier connected to an RL

load

3.3.1 Mathematical Fundamentals of the

Harmonic Detection Technique

The load current is influenced by the line impedance

connected to the power sources during steady-state

conditions and the equations for calculating the load

current can be derived as follows, [24]:

(12)

Where :

, and

It is clear from equation (12) that the variables

, and represent the

fundamental active current, fundamental reactive

current, and the harmonic current of the Three-

Phases Four-wires load respectively. To compensate

the harmonic and reactive currents, the active

current can be isolated from the equation. Thus, the

required compensation currents (13) that the active

power filter must generate are those that need to be

injected.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

(13)

The overall efficiency of the Active Power

Filter (APF) was discovered to hinge on both the

accuracy of the reference current extraction method

and the control of Voltage Source Inverter (VSI)

switching devices. To extract reference currents, an

algorithm rooted in the PQ technique was devised

and implemented. This algorithm facilitated the

real-time extraction of harmonics produced by

Compact Fluorescent Lamps (CFLs) from the power

source. These extracted currents were sensed

through four strategically placed sensors on the load

side. The compensation currents were then

compared to the actual currents supplied by the VSI

at the Point of Common Coupling (PCC). Any

disparities detected were treated as error currents

and employed in the Fixed Hysteresis Control

Algorithm (HCA) to generate switching signals for

the VSI via Insulated Gate Bipolar Transistor

(IGBT) switches.

3.3.2 Algorithm for Current Identification

Typically, the primary function of a Shunt Active

Power Filter (SAPF) involves filtering or

compensating for disturbances (harmonic, reactive,

unbalanced, etc.) originating from both linear and

non-linear loads on the electrical grid. The

identification method serves to calculate perturbing

currents that the Voltage Source Inverter (VSI) will

inject, via the output filter, into the Point of

Common Coupling (PCC) in a phase opposite to the

disturbance. Consequently, the electrical grid side is

maintained in a clean state, exhibiting sinusoidal

current and voltage patterns.

3.3.3 Review of the Instantaneous Reactive

Power Theory (PQ Theory)

The prevailing identification method, widely

adopted, is the instantaneous real and imaginary

powers approach, [3]. This technique presents the

benefit of simultaneously and precisely

compensating for harmonic currents, unbalanced

currents, and reactive power, either partially or

selectively. It achieves this accuracy swiftly and

with ease. It was implemented in 1983, [25]. They

introduced the "Generalized Theory of the

Instantaneous Reactive Power in Three-Phase

Circuits," commonly known as the instantaneous

power theory or PQ theory. This theory is based on

instantaneous values in three-phase power systems

with or without neutral wire, and can be applied to

steady-state or transitory operations with various

voltage and current waveforms. The PQ theory

involves transforming the three-phase voltages and

currents in the (a-b-c) coordinates to the (α-β-0)

coordinates using the Clarke transformation as

presented in equations (14) and (15), and then

calculating the PQ theory instantaneous power

components, [26].

The PQ theory's advantage is that it separates

the zero sequence components which do not

contribute to the alpha and beta components.

Therefore, it can be neglected in a balanced system.

Figure 8 represents the block diagram of the

proposed methodology.

Fig. 8: Block diagram of the PQ theory

122

2 3 3

3 2 2

111

222









   



   



   



   





(14)

122

2 3 3

3 2 2

111

222









   



   



   



   





(15)

The power components p and q are related to

the same α-β voltages and currents and can be

written together:

V V i

  

  

   



   

 

    

(16)

Where p0 = v0

⋅

i0 instantaneous zero-sequence

power. The harmonics component can be eliminated

by using a Low Pass Filter (LPF). After selecting

and eliminating the harmonic current, it is necessary

to apply the inverse of Clarke transformation

(Equation 17) to calculate the reference current in

the (a,b,c) frame.

( , , )

110

2 1 3

* * 1

3 2 2

*1 1 3

a b c b

c c c

i i i











 



 

   

 



 

 







(17)

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

3.3.4 Advantage of the PQ theory in SAPF

The control of active filters can be achieved using

various methods, including the p-q theory. The p-q

theory has notable advantages such as being

inherently designed for three-phase systems,

regardless of their balance or unbalance, with or

without harmonic distortions in both voltages and

currents. Additionally, it relies on instantaneous

values, enabling a high level of dynamic response.

Furthermore, its computations are relatively

straightforward, utilizing only algebraic expressions

that can be implemented using standard processors.

Lastly, it offers two control strategies, namely

constant instantaneous supply power and sinusoidal

supply current. It is applicable for all industrial and

residential loads applications.

3.3.5 Conventional Fixed Hysteresis Band

The conventional hysteresis fixed band technique

employs two bands, namely the upper band and the

lower band represented by ∆+ and ∆-, respectively.

The modulated current is confined between these

two bands. When the error current approaches the

upper band ∆+, the upper IGBT switch , is

switched off while the lower switch is switched

on, and vice versa for the lower band ∆-. This

ensures that the compensating current

tracks the reference current , this achieving

robustness and good dynamic performance

compared to other compensation methods. Figure

9(a) and Figure 9(b) illustrate the block diagram of

the conventional hysteresis control and the

waveform of the control signals for a single phase

(phase a). It is to be noted that the lower side of the

inverter is controlled by the same signal but with a

NOT logic gate.

Fig. 9: Block diagram of the constant hysteresis

modulation and their principle of generating control

signals

The fixed hysteresis band has certain

advantages, such as:

 Simplicity: A fixed hysteresis band is

relatively simple to implement because it

does not require additional components such

as sensors or microcontrollers.

 Quick Response: it can allow a quick

response of the filter in case of variation of

load or source conditions, which can improve

the quality of the output signal.

 Low distortion: it can reduce signal

distortion by limiting variations in filter

resonance frequency.

 Low cost: Fixed hysteresis band does not

require expensive components, which can

reduce the cost of manufacturing the filter.

However, it is important to note that these

benefits may vary depending on filter specifications

and operating conditions. Also, while this method

has some advantages, it has several disadvantages,

including:

 Limited range Frequency: The fixed

hysteresis band is suitable for a limited

frequency range. If the source frequency

exceeds this range, the filter may not function

properly, which may cause signal distortion.

 Sensitivity to temperature variations: The

properties of the electronic components that

make up the filter can vary with temperature

changes. This can result in the drift of

resonant frequencies and affect the accuracy

of the fixed hysteresis band.

 Non-linear effects: The fixed hysteresis band

can also produce non-linear effects that can

alter the waveform of the output signal. These

non-linear effects may be due to interactions

between filter components or saturation of the

feedback circuit.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

As presented previously to improve the

performance, and mitigate the disadvantages

mentioned below we can use a PWM controller

instead of an HCC. But this is not the subject of this

paper.

3.4 Filters Selection

From previous experimental research carried out to

investigate the effect of harmonics generated by

CLFs at the side of the main. We can notice that at

lower harmonic frequencies, most waveforms have

a high percentage of harmonic distortion compared

to the harmonic frequency. Hence CFLs are

characterized by the high harmonic emission for low

and high harmonic order frequency, therefore, a

2nd-order high-pass filter is used to remove the

higher-order frequencies injected by CFL and by the

switched device of the APF, as shown in Figure 10.

So, that’s why in this research we interest only for

the 2nd order high-pass filter filters for high

harmonic current 21th to 49th) and the other

harmonics will be mitigated by the SAPF.

Fig. 10: Basic single-line diagram of a hybrid active

power filter topology based on a passive filter in

parallel with an active power filter

4 Simulations and Results

The studied shunt hybrid system is simulated using

Matlab/Simulink software, by using the Simscape

power system library toolbox. The load is

constituted of 75 equivalent models of 20W lamps

distributed over the 3 AC phases. A passive filter is

connected in parallel to attenuate the high harmonic

rank (from harmonic 21st). Also, a three-phase four-

wire SAPF with three legs and the ford leg

connected to a split capacitor (2C topologies) is

connected in parallel with the load. Table 2

summarizes the simulation parameters. The circuit

diagram of the full part of the HAPF is presented in

Figure 11. The passive filter is connected at

t=0.04s, and the HAPF is connected to PCC at time

instant t = 0.08 seconds.

Table 2. Power System Parameters.

Parameters

Symbol

Values

Grid

System

frequency

50 HZ

Source voltage

Vrms

230V

Source

resistance

2mΩ

Source

inductance

1mH

Passive

filter

PF capacitance

CPF

nF, µF

PF inductance

LPF

PF resistance

RPF

4.7Ω

Shunt

active

power

filter

SAPF

Filter resistance

1mΩ

Filter

inductance

0.1µH

DC side

capacitance

C1, C2

2200µF

Reference

voltage

Vdc

600V

Fig. 11: Circuit diagram of a three-phase four-wire

HAPF with PQ and Hysteresis Controller

Where , , and are the

load currents before compensation, the

compensating current injected by the power device

(the SAPF), the source currents after compensation,

and the source voltage, respectively.

4.1 Simulation Result before Compensation

The simulated results of the source voltage

and currents waveforms before connecting

the PF and the APF to the system the three-line

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

system are presented in Figure 12(a) and Figure

12(b), respectively.

Fig. 12: Source voltage and current waveforms

before compensation

The current waveforms generated by CFLs

deviate from sinusoidal shapes across all three

phases and are not synchronized with the source

voltages. Furthermore, the neutral current is

different to zero. The harmonic spectrum of CFLs

presented in Figure 13 serves to encapsulate the

sources of these disruptions, highlighting the non-

linear behavior of the load. Essentially, this load

functions as a generator of notable harmonic

currents with , which have the

potential to propagate back to the distribution

source, thereby impacting other loads connected to

the same network. Also, it should be noted that all

simulated parameters are almost identical to the

experimental simulation carried out in [13]. Wish

means that the current waveforms of the real model

and the simulation model reproduce the same

waveforms and also the same FFT components.

Fig. 13: FFT components of the load current before

compensation

4.2 Performance of the Passive Filter

The passive filter is suggested for its simplicity,

cost-effectiveness, and dependable performance.

Utilizing system parameters and measured

harmonics. A 2nd order high-pass filter is used to

remove the higher-order frequencies injected by

CFLs and by the switched devices of the APF. After

connecting the PF at t=0.04s we can notice that the

THD is reduced from 90.75% to 71.22% (as

presented in Table 3); which means that the PF is

well designed for attenuated those high harmonic

orders frequency. However, the power quality still

contains the low harmonic frequency and noise, and

the full system is still outside the national and

international standards, [11], [12]. So, a force needs

an SAPF to attenuate others' harmonic rank. Wish is

implemented in the next section to make the source

current and voltage align with predefined

international standards.

Table 3. THD Percentage Comparison

THD without PF Filters

THD with PF Filter

90.75%

71.22%

Figure 14(a) and Figure 14(b), represent

respectively, the current waveforms of the

compensations current and the source current before

and after connecting the APF to the system at

t=0.08. Also, Figure 15 represents the source current

FFT after connecting the SHPF.

Fig. 14: Current waveforms before and after

compensation at different points

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

Fig. 15: FFT components of the source current after

compensation (a) with APF, and (b) with HAPF

As shown in Figure 15(a) and Figure 14(a)

represent the FFT component and the current

waveforms of the CFLs before connecting the

SAPF, it can be noticed that the THD of the current

, and the THD of the voltage

. Moreover, Figure 14(a) and Figure

14(c) show that the system corresponds to a poor

factor due to the phase shift between the current and

voltage. According to the international, [11], [12],

standards, these results are outside of the allowed

limits and can cause harmful effects on the

distribution network. As result of this work, and

after connecting the SHPF at t=0.06s to the system,

it is clear from Figure 14(b) and Figure 14(c) that

the currents waveforms of the source ,

become almost sinusoidal, which attests that the

conventional algorithm used in this paper has

succeeded in compensating harmonic currents; by

injecting equal but opposite harmonic current to the

power network. In addition, the source currents and

voltage are in phase as presented in the same figure,

which results in obtaining a good power factor PF

close to 1. Figure 15(a) shows that the THD of the

current after compensation becomes equal to

1.75%, (a good reduction in THD is noticed) with a

APF and to 0.75% with a HAPF (Figure 15(b)).

Also, the fundamental current values for phase “a”

remain almost the same before and after connecting

the HAPF to the system where

and . This implies that the filter

injects only harmonic currents, while the network

injects only the fundamental component of the load

current.

4.3 Performance under Different Scenarios

To investigate and validate the performance of

conventional algorithms and the fixed hysteresis

controller, two distinct case studies have been

undertaken. This could involve essentially sudden

changes in the load part. Variations in source

voltage, or other external factors that might affect

system performance will be the case of another

future research anyways, these cases are outlined as

follows:

Case 1: Variable and Balanced Load of 100%

CFLs: In this scenario, a load of 99 Compact

Fluorescent Lamps (CFLs), with 33 lamps

connected per phase, is employed from t0=0s to

t2=0.14s. Subsequently, at t2=0.14s, the load is

doubled to 150 lamps, maintaining a balanced

distribution across the three phases.

Case 2: Unbalanced Load: This case involves an

unbalanced load configuration, with 75 lamps for

Phase A, 100 lamps for Phase B, and 120 lamps for

phase c.

Figure 16 and Figure 17 depict the current

waveforms of the Shunt Active Power Filter (SAPF)

both before and after compensation for Case 1 and

Case 2. Notably, the SAPF is activated at t1=0.04s

for Case 1, while Case 2 retains the same

configuration as previously established in the study.

These visual representations provide insights into

the SAPF's effectiveness in mitigating power quality

issues under varying load conditions, showcasing its

performance in both balanced and unbalanced load

scenarios.

Figure 16 displays simulation results with a

variable load of 100% CFLs. The SAPF effectively

adjusts to load variations, maintaining sinusoidal

source currents throughout load changes. The Total

Harmonic Distortion (THD) of the source decreases

from 89.66% to 2.18% with the connection of 99

lamps (from t1=0.04s to t2=0.14) and from 92.2% to

2.44% with 150 lamps connected (at t2=0.14s). The

fundamental currents for these configurations are

2.8A and 5.2A, respectively. Note that t0, t1, and t2

are arbitrarily chosen for this study.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

In Figure 17, the SAPF response to an unbalanced

load (75 lamps for Phase A, 100 lamps for Phase B,

and 120 lamps for Phase C) is presented. Although

the source currents are sinusoidal for each phase,

they are unfortunately not balanced with the simple

hysteresis controller. However, the THD is reduced

from 89% to 2.56% for Phase A, 90.3% to 2.67%

for Phase B, and 90.9% to 2.7% for phase c. The

fundamental currents for the three phases are 2.4 A,

2.6 A, and 2.8 A, respectively.

Fig. 16: Current waveforms before and after

compensation under case 1

Fig. 17: Current waveforms before and after

compensation under case 2

4.4 Performance under Different SAPF

Topologies:

In this section, we present the performance of the

shunt active power filter with three phase four wire

different active power filter topologies, respectively,

with the four legs topologies. With the four legs and

mid-point capacitor topologies and with 3 half-

bridge topologies presented in Figure 18(a), Figure

18(b) and Figure 18(c). These SAPF configurations

are widely employed to address power quality issues

in the grid or distribution medium, particularly in

higher power applications. Moreover, these

topologies can effectively mitigate issues related to

the duty cycle dv/dt of active switches.

Nevertheless, the primary drawbacks of these

configurations include a substantial number of

switching devices, intricate control techniques,

sizable physical dimensions, and elevated costs.

Fig. 18: Bloc diagram of the SAPF connected to

distribution network a) with four legs topologies, b)

with four legs and mid-point capacitor topologies,

and c) with 3 half-bridge topologies

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

As known that The THD of the current before

compensation of the load is equal to 90.75%. After

connecting the SAPF with the 2C topology, the

THD is reduced to 1.75%. With the four legs

topologies the THD of the source current is

improved to 1.25% and with the 3H bridge topology

to 1%. However, the three applied topologies show

their good application of filtering the harmonic

currents generated by the non-linear load. Which

implies that the network contains only the

fundamental current.

SAPFs are used in power systems to mitigate

harmonics and improve power quality. They are

commonly employed in various industrial

applications to address issues related to distorted

power waveforms, reactive power, and harmonic

currents. We can note some industrial applications

of SAPFs such as Variable Frequency Drives,

Industrial Automation and Robotics, Data Centers,

Textile Industry, and Pharmaceutical and Chemical

Industries. By installing SAPFs in these and other

industrial and residential applications, companies

can enhance power quality, reduce energy losses,

and comply with regulatory standards related to

harmonics and power factor correction.

4.5 Future Research

It's crucial to note that although the HCA method

has numerous advantages, it is prone to chattering,

resulting in inconsistent switching frequencies,

which remained unresolved. To counter this issue, a

Pulse Width Modulation (PWM) controller must be

integrated into the system in place of HCA. This

PWM controller served to stabilize the switching

frequency and alleviate associated harmonic losses.

Also, despite all the advantages of the SHPF, the

DC bus of this filter uses a three-phase rectifier to

provide the power energy to the capacitors to

compensate for the reactive power generated by the

nonlinear loads, which can create other problems of

harmonics in case of highly non-linear loads. To

overcome this issue, a hybrid active power filter

HAPF powered up with a PV system to power the

DC bus can be suggested for future work. Also, to

further test the effectiveness and applicability of the

suggested filter, different algorithms and scenarios

including balanced and unbalanced nonlinear loads

must be investigated and studied.

Finally, the integration of Computational

Intelligence (CI) and Artificial Intelligence (AI)

methods, such as Neural Networks, Fuzzy Logic,

Petri Nets, and Evolutionary Computing, into the

design of SAPF circuits in the context of PQ theory

and hysteresis controller presents an intriguing

avenue for enhancing performance and adaptability.

CI techniques have demonstrated effectiveness in

optimizing control strategies and mitigating power

quality issues in various applications. For instance,

neural networks have been employed for real-time

learning and adaptation in power systems, [27],

[28], while Petri nets and, fuzzy logic have shown

their success in nonlinear system control and for

multilevel inverter topology, they are offering

robustness in dealing with uncertainties inherent in

power electronics, [29], [30] and [31]. Evolutionary

computing, on the other hand, has proven valuable

in parameter tuning and optimization tasks in power

systems. By leveraging these CI methodologies, the

design of SAPF circuits could potentially benefit

from improved efficiency, adaptability, and

robustness, aligning with the current trends in power

electronics research. So, it is recommended to use

another intelligent control technique such as Petrie

net algorithms, or neuronal algorithms for the

current compensation calculation block. Wish is the

work of future research. We will take into account

the effect of the impedance of the cable even in

simulation mode, [32].

5 Conclusion

The focus of this study is on power quality indices

related to a residential power rectifier functioning as

a nonlinear load. The analysis delves into harmonic

distortions present in both the source current and

voltage, considering both total and individual

harmonic distortions. The measured values surpass

the thresholds established by international standards

for both current and voltage. To address and

overcome this issue a SHPF based on a passive filter

in parallel with an APF is designed and

implemented. The APF is controlled with the PQ

theory and a simple Hysteresis controller. Matlab

simulation results validate the effectiveness of the

proposed hybrid filter design, demonstrating an

improvement in source current and voltage to meet

the accepted levels specified by the international

standard.

Beyond those traditional methods, the synergy

between a hybrid active power filter powered up

with a PV system offers a compelling avenue for

harmonic mitigation, unlocking additional benefits

that deserve dedicated exploration in future studies.

Their control part will be suggested based on the

current trend of Computational Intelligence such as

Neural Networks, Fuzzy Logic, or Intelligence

Artificial IA.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

Nomenclature:

Notation

Description

CFL

Compact Fluorescent Lamp

Passive Filter

APF

Active Power Filter

SAPF

Shunt Active Power Filter

HAPF

Hybrid Active Power Filter

VSI

Voltage Source Inverter

THD

Total Harmonic Distortion

PCC

Point of Common Coupling

HCA

Hysteresis control algorithms

FFT

Fast Fourier Transform

PFC

Power Factor Correction

PQ theory

References:

[1] İ. Kıyak, B. Oral, and V. Topuz, “Smart

indoor LED lighting design powered by

hybrid renewable energy systems,” Energy

Build., vol. 148, pp. 342–347, 2017, doi:

10.1016/j.enbuild.2017.05.016.

[2] P. Verma, N. Patel, and N.-K. C. Nair, “Power

quality impacts during CFL to LED

transition,” in Australasian Universities

Power Engineering Conference

(AUPEC),Brisbane, QLD, Australia, 2016,

pp. 1-6. doi: 10.1109/aupec.2016.7749339.

[3] K. Naftahi, A. Abouloifa, Z. Hekss, S.

Echalih, F. Ait Bellah, and I. Lachkar, “Three-

Phase Four-Wire Shunt Active Power Filter

Based on the Hybrid Automaton Control with

Instantaneous Reactive Power Theory,”

IFAC-PapersOnLine, vol. 55, no. 12, pp. 532–

537, 2022, doi: 10.1016/j.ifacol.2022.07.366.

[4] R. Arnold, “Solutions to the power quality

problem,” Power Eng. J., vol. 15, no. 2, pp.

65–73, 2001, doi: 10.1049/pe:20010202.

[5] A. Chebabhi, M. K. Fellah, A. Kessal, and M.

F. Benkhoris, “Comparative study of

reference currents and DC bus voltage control

for Three-Phase Four-Wire Four-Leg SAPF to

compensate harmonics and reactive power

with 3D SVM,” ISA Trans., vol. 57, pp. 360–

372, 2015, doi: 10.1016/j.isatra.2015.01.011.

[6] B. Deffaf, H. Farid, H. Benbouhenni, S.

Medjmadj, and N. Debdouche, “Synergetic

control for three-level voltage source inverter-

based shunt active power filter to improve

power quality,” Energy Reports, vol. 10, pp.

1013–1027, 2023, doi:

10.1016/j.egyr.2023.07.051.

[7] Z. Hekss, A. Abouloifa, I. Lachkar, F. Giri, S.

Echalih, and J. M. Guerrero, “Nonlinear

adaptive control design with average

performance analysis for photovoltaic system

based on half bridge shunt active power

filter,” Int. J. Electr. Power Energy Syst., vol.

125, p. 106478, 2021, doi:

10.1016/j.ijepes.2020.106478.

[8] B. Nagi Reddy, A. Pandian, O. Chandra

Sekhar, and M. Ramamoorty, “Performance

and dynamic analysis of single switch AC-DC

buck-boost buck converter,” Int. J. Innov.

Technol. Explor. Eng., vol. 8, no. 4, pp. 307–

313, 2019.

[9] Y. Ramachandra, M. Akhileshwar, A.

Pandian, R. Nalli, and K. Subbarao, “Analysis

of recent developments in brushless DC

motors controlling techniques,” Int. J. Innov.

Technol. Explor. Eng., vol. 8, no. 5, pp. 522–

526, 2019.

[10] A. H. Fahad and M. S. Reza, “Single-Phase

Shunt Active Power Filter Using Parabolic

PWM for Current Control,” in Proceedings of

the 7th International Conference on Smart

Energy Grid Engineering, SEGE,Oshawa,

ON, Canada, 2019, 2019, pp. 134–138. doi:

10.1109/SEGE.2019.8859868.

[11] GENELEC, Characteristics of the voltage

supplied by public distribution networks

“Caractéristiques de la tension fournie par

les réseaux publics de distribution”, EN 50

160, CLC/BTTF, vol. 68. 1994, p. 6.

[12] S. Emv, A. G. Corporate, and H. Nordstrasse,

“IEC 61000-3-2 Harmonics Standards

Overview,” Schaffner EMC Inc., Edsion, NJ,

USA, pp. 1–5, 2005, [Online].

http://www.teseq.tw/pdfinfo/05_AN_IEC6100

0-3-25.pdf (Accessed Date: March 29, 2024).

[13] H. Mohamed, N. Mohamed, and S. Lassaad,

“Experimental Investigations of a CFLs

Currents Harmonics Injection into an

Electrical Network Grid,” in 2021 4th

International Symposium on Advanced

Electrical and Communication Technologies,

ISAECT, Arabie Saoudi, 2021, IEEE, 2021,

pp. 1–5. doi:

10.1109/ISAECT53699.2021.9668434.

[14] Chauvin Arnoux, “Chauvin Arnoux

software.” [Online]. https://catalog.chauvin-

arnoux.com/fr_en/c-a-

8336.html?___from_store=fr_fr (Accessed

Date: March 8, 2023).

[15] Chauvin Arnoux Manyfactory,

“TECHNICAL DATA”, [Online].

https://www.chauvin-

arnoux.com/sites/default/files/HLHBXUP5.P

DF (Accessed Date: March 8, 2023).

[16] R. Bahrekazemi, “Assessment of Different

Compensation Strategies in Hybrid Active

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

Power Filters,” Int. J. Appl. Math. Comput.

Sci. Syst. Eng., pp. 34–39, 2013.

[17] S. R. Reddy, P. V Prasad, and G. N. Srinivas,

“Power Quality Improvement on 11kV/440V

Distribution System using DSTATCOM,” Int.

J. Electr. Eng. Comput. Sci., vol. 6, pp. 17–26,

2024.

[18] E. Kazemi-Robati and M. S. Sepasian,

“Passive harmonic filter planning considering

daily load variations and distribution system

reconfiguration,” Electr. Power Syst. Res.,

vol. 166, pp. 125–135, 2019, doi:

10.1016/j.epsr.2018.09.019.

[19] M. M. Swamy, G. R. Bisel, and S. L. Rossiter,

“Passive harmonic filter system for variable

frequency drives.” Google Patents, 1995.

[20] A. B. Nassif, W. Xu, and W. Freitas, “An

investigation on the selection of filter

topologies for passive filter applications,”

IEEE Trans. Power Deliv., vol. 24, no. 3, pp.

1710–1718, 2009.

[21] A. K. Mishra, P. K. Nanda, D. Das, A. K.

Patra, N. Nahak, and L. M. Sathapathy,

“Design and Analysis of Shunt Passive Filter

for Harmonic and Reactive Power

Compensation,” in 2023 International

Conference in Advances in Power, Signal, and

Information Technology, APSIT, India, 2023,

2023, pp. 347–352. doi:

10.1109/APSIT58554.2023.10201759.

[22] F. Zaro, “Power Quality Improvement using

Shunt Active Power Filter: An Industrial Zone

Case Study,” WSEAS Transactions on Power

Systems, vol. 18, pp. 179-185, 2023, doi:

10.37394/232016.2023.18.19.

[23] F. Zaro, “Shunt Active Power Filter for Power

Quality Improvement of Renewable Energy

Systems: A Case Study,” WSEAS

Transactions on Power Systems, vol. 18, no.

14, pp. 241-247, 2023, doi:

10.37394/232016.2023.18.25.

[24] A. Bouhouta, S. Moulahoum, N. Kabache, A.

Moualdia, and I. Colak, “Harmonics

Compensation of Grid-Connected PV Systems

Using a Novel M5P Model Tree Control,” in

11th International Conference on Smart Grid,

icSmartGrid,Parie France, 2023, 2023, pp. 1–

6. doi:

10.1109/icSmartGrid58556.2023.10170901.

[25] A. M. Sharaf, F. H. Gandoman, and B. Khaki,

“Active harmonic filters,” Power Qual. Futur.

Electr. Power Syst., vol. 93, no. 12, pp. 131–

163, 2017, doi: 10.1049/pbpo092e_ch4.

[26] O. T. Ibitoye, M. O. Onibonoje, and J. O.

Dada, “Analysis of Power Quality and

Technical Challenges in Grid-Tied Renewable

Energy,” WSEAS Transactions on Power

Systems, vol. 18, no. 608, pp. 248–258, 2023,

doi: 10.37394/232016.2023.18.26.

[27] Q. Jin, Z. Yao, and M. Guo, “A Control

Method of Shunt Active Power Filter for

System-wide Harmonic Suppression Based on

Complex-valued Neural Network,” in 2020

IEEE 9th International Power Electronics and

Motion Control Conference, IPEMC ECCE

Asia,Nanjing, China,2020, 2020, pp. 1543–

1548. doi: 10.1109/IPEMC-

ECCEAsia48364.2020.9368080.

[28] A. Y. Hatata, M. Eladawy, and K. Shebl,

“Parameter control scheme for active power

filter based on NARX neural network,”

WSEAS Transactions on Power Systems, vol.

13, no. Pt 1, pp. 118–124, 2018.

[29] P. P. Behera, D. A. Gadanayak, R. R.

Panigrahi, and M. Mishra, “A Mamdani Type

Fuzzy Controller with Mathematical

Morphology for Shunt Active Power Filters,”

in 2023 1st International Conference on

Circuits, Power, and Intelligent Systems,

CCPIS,Bhubaneswar, India, 2023, 2023, pp.

1–5. doi:

10.1109/CCPIS59145.2023.10291823.

[30] S. Othman, M. A. Alali, L. Sbita, J. P. Barbot,

and M. Ghanes, “Modeling and control design

based on petri nets tool for a serial three-phase

five-level multicellular inverter used as a

shunt active power filter,” Energies, vol. 14,

no. 17, 2021, doi: 10.3390/en14175335.

[31] S. Othman, J. P. Barbot, L. Sbita, M. A. Alali,

M. Ghanes, and A. Fekik, “Hybrid renewable

energy system based on Petri nets control for

a single-phase flying capacitor multilevel

DC–AC converter,” in Power Electronics

Converters and their Control for Renewable

Energy Applications, A. Fekik, M. Ghanes,

and H. Denoun, Eds., Academic Press, 2023,

pp. 145–166. doi: 10.1016/B978-0-323-

91941-8.00007-X.

[32] M. N. Iqbal, L. Kutt, B. Asad, and N. Shabbir,

“Impact of cable impedance on the harmonic

emission of LED lamps,” in Proceedings -

2020 21st International Scientific Conference

on Electric Power Engineering, EPE, Prague,

Czech Republic, 2020, 2020, pp. 1–5. doi:

10.1109/EPE51172.2020.9269271.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024

Contribution of Individual Authors to the

Creation of a Scientific Article (Ghostwriting

Policy)

The authors equally contributed to the present

research, at all stages from the formulation of the

problem to the final findings and solution.

Sources of Funding for Research Presented in a

Scientific Article or Scientific Article Itself

No funding was received for conducting this study.

Conflict of Interest

The authors have no conflicts of interest to declare.

Creative Commons Attribution License 4.0

(Attribution 4.0 International, CC BY 4.0)

This article is published under the terms of the

Creative Commons Attribution License 4.0

https://creativecommons.org/licenses/by/4.0/deed.en

_US.

WSEAS TRANSACTIONS on CIRCUITS and SYSTEMS

DOI: 10.37394/23201.2024.23.3

Mohamed Hajjej, Lassaad Sbita

E-ISSN: 2224-266X

Volume 23, 2024