Computer Model of Thyratron TGI1-270/12

MIKHAIL PUSTOVETOV

Department of Electrical and Electronics Engineering,

Don State Technical University,

344000, Rostov region, Rostov-on-Don, Gagarin sq., 1,

RUSSIA

Abstract: - The issues of developing the computer model of a thyratron - an electronic tube triode operating in a

Key-Words: - thyratron, computer model, simulation, pulse voltage, OrCAD, test circuit

Received: March 25, 2023. Revised: October 28, 2023. Accepted: December 11, 2023. Published: December 31, 2023.

1 Introduction

In the technological chain of production of traction

electric machines, there is a place for testing

electrical insulation with pulsed voltage. Pulse

the industrial one is possible.

2 Problem Formulation

Often, a pulse voltage generator is built based on a

thyratron, [1] - a tube triode with a specific dynamic

characteristic - in the thyratron, from the moment of

ignition, the anode current avalanche-like reaches

the saturation current value and then does not

depend on the voltage on the grid, [2], [3].

pulse voltage test benches is reliable computer

modeling, which in turn poses the task of

developing a computer model (CM) of the thyratron.

An example of solving such a problem for the

TGI1-270/12 thyratron using OrCAD - one of the

modern widely used tools for the simulation

electronic and electrical circuits and devices, [5] - is

given in this article.

is, the TGI1-270/12 type thyratron, is shown in

The CM of a single-grid thyratron was developed in

the form of a hierarchical block, [5] based on

materials, [2], [3], [6], [7], [8]. The author,

unfortunately, was unable to find in published

sources, [2], [3], [4], [9], [10], [11], [12], a system

of differential equations describing the physical

processes occurring in the thyratron, which could

simplify the structure of the CM. Issues of cathode

heating in CM were not considered. The test circuit

for testing the CM thyratron is shown in Figure 2.

grid (unidirectional input port named gr), are used

as ports of the hierarchical block, [4].

hierarchical block, those listed in Table 1 are

displayed. Between the anode and cathode of the

thyratron, a capacitance C1 with a rated value of 2

nF and a resistance Rload1 with a rated value of 1

Ohm are connected in series. The initial voltage on

capacitor C1 is set equal to zero.

C1 is charged from a high (here 12 kV) DC

voltage source V2 through Rload1 by turning on

switch S1, controlled by a pulsed voltage source

V11.

the grid voltage has not yet been removed by

reducing the anode-cathode voltage to 150 V. Then

the whole cycle is repeated.

The structure of the hierarchical block is shown

in Figure 3. In the anode-cathode circuit, the

following are connected in series: a voltage-

controlled switch; inductance Lthyr; and a diode that

ensures unidirectional current from the anode to the

cathode. For the diode, the Dbreak element was

used, [5], in which the active resistance Rs is

Table 1. Customizable parameters of the thyratron

plates of the capacitor Cout and the DC bias voltage,

limited to 0...1000 V.

voltage in the anode-cathode circuit, for ignition and

continuation of combustion, the product of the

derivative exceeds 1000. A zero derivative threshold

value was not used to avoid the output signal of

block 3 bouncing near zero.

voltage is less than 300 V, then the output value is

“0”, otherwise “1”. Multiplying the output signal of

block 4 by the grid voltage prohibits turning on the

switch, that is, turning on the thyratron until the grid

voltage reaches the value of the ignition pulse.

150 V.

negative signal from the output of block 6 to the

input of block 8 with a positive voltage of the

anode-cathode circuit greater than 2000 V.

Fig. 3: Internal structure of the hierarchical block of the CM of the thyratron

Block 7. Tabular assignment of the transfer

function. Sets the type of nonlinear dependence that

of block 8 provides a fictitious anode voltage value

sufficient to maintain the thyratron combustion if

the thyratron is already ignited, and the anode-

cathode voltage value is less than 2000 V, but more

than 150 V. That is, the switch is kept “on”.

Block 9. Constant voltage source. Generates a

bias voltage (here assumed to be 2000 V). In

general, the value of the bias voltage depends on the

duration of the ignition pulse: as the pulse duration

decreases, the value of the bias voltage increases.

Fig. 5: Simulation results for the test circuit in

Figure 2. Currents and voltages of the thyratron

during the formation of a high voltage pulse

Fig. 6: Simulation results for the test circuit in

Figure 2. Currents and voltages during thyratron

quenching

Fig. 7: Simulation results for the test circuit in

Figure 2. Dynamic characteristics of a thyratron:

anode current as a function of the

4 Conclusion

From Figure 5, Figure 7 and Figure 8 there is a good

correspondence of the maximum value of the anode

electronic circuits and devices to simulate their

operating modes.

[2] A.V. Akimov, P.V. Logachev, V.D. Bochkov,

[3] Thyratron Working Principle, [Online].

[6] V.D. Bochkov, D.V. Botchkov, V.M.

[7] Thyratron TGI1-700/25, [Online].

[8] Pulse modulator thyratron TGI1-270/12,

[10] Yan Jiaqi, Shen Saikang, Sun Guoxiang, Ding

[12] V.D. Bochkov, D.V. Bochkov, I.N. Gnedin,

Contribution of Individual Author to the

Creation of a Scientific Article (Ghostwriting

problem to the final findings and solution.

No funding was received for conducting this study.

The author has no conflicts of interest to declare.

(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

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