RU1777211C - Controlled thyristor switch - Google Patents

Abstract

Summary of the invention: if it is necessary to turn on the power thyristor 1, the controlled key 3 is turned on. Due to the voltage difference across the capacitors 7 and 10, the anode circuit of the power thyristor is first unloaded, and when the voltage across the capacitors is equalized, the lockable thyristor is turned off by the control circuit. 1 ill.

Description

The invention relates to electrical engineering and may find application in converter technology: autonomous inverters, frequency converters, proximity switches of electrical circuits, etc.

An object of the invention is to increase the speed of a thyristor controlled key without complicating the design of the control system.

The drawing shows a circuit diagram of a thyristor controlled key.

The thyristor controlled key contains a power thyristor 1, made in the form of a lockable thyristor, the anode and cathode of which are used as the outputs of the thyristor controlled key, and the control electrode is designed to connect to the output of the formation of the pulse pulses of the control system 2. To connect to the output of the formation locking pulses is intended for the control input of the controlled key 3, the first output of which is connected to the cathode of the power thyristor 1 and the first output of the recharge circuit 4 made in the form of a interconnected by a cut-off diode 5 and a bypass choke 6. The second terminal of the bypass circuit is connected to the first terminal of the switching capacitor 7, the second terminal of which is connected to the anode of the power thyristor 1. The thyristor controlled key also includes two isolation diodes 8 and 9 and a voltage source 10 made in the form of a pre-charged storage capacitor. The control output of the power thyristor 1 is connected to the anode for the first time00

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dividing diode 8. whose cathode is connected to the second pin of the controlled key 3 - | the cathode of the second isolation diode 9. The anode of the isolation diode 9 is connected to the first output of the switching capacitor 7. The thyristor controlled key operates as follows.

In the initial state, the power lockable thyristor 1 and the controlled switch 3 are closed, the capacitor 10 is charged to a voltage not exceeding that acceptable for the lockable thyristor.

 3 and & off, 3op

with the polarity shown in the drawing, the switching capacitor 7 is charged to the voltage of the power supply Uj with the polarity shown in the drawing without brackets. At time c, a lockable thyristor 1 is turned on. The voltage of the power supply is applied to the load (the load and power supply are not shown in the drawing, since they are not part of the thyristor controlled key). The capacitor 7 is recharged along circuit k to the opposite fullness. At time tg, the recharging process ends. The duration of the open state of the power thyristor 1 is determined by the algorithm of operation of the thyristor controlled key in a specific converter device and is determined by the control system. If necessary, turn off the power thyristor 1 at time t turns on controlled softkey 3. Then, since the voltage of the capacitor 7 is greater than the voltage of the capacitor 10

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the isolation diode 8 is closed and the diode 9 is opened. The voltage of the capacitor 7 is applied to the lockable thyristor 1, it closes, and the load current passes to the switching circuit along the anode. The capacitor 7 is discharged by the load current. At time d, when the voltage levels on the capacitors were compared, the diode 8 opens and the simultaneous flow of two processes begins: firstly, under the action of the voltage of the capacitor 10, the main

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minority carriers from the emitter layer of the lockable thyristor 1, and secondly, under the action of a voltage equal to the sum of the voltages of the capacitor 10 and the power source, minority charge carriers are removed from the thicknesses of the p-base of the lockable thyristor 1, which contributes to its rapid recovery in the forward direction. Turning off the power lockable thyristor 1 along the control electrode circuit occurs with a significant decrease in its anode current, therefore, the structure is restored to a non-conductive state in a short time at a low level of power loss in the structure of the thyristor, –t controls the process of turning off the power lockable thyristor 1 is carried out using one controlled key 3, which does not require complicating the control system. At time t, the turn off of the power thyristor 1 is completed, and the capacitor 7 continues to be recharged by the load current to the voltage of the power supply with the polarity shown in the drawing without brackets. The slew rate of the voltage acting on the lockable thyristor 1 is equal to the slew rate of the voltage on the capacitor 7. Therefore, its capacitance is chosen so that at the maximum possible load current, the slew rate of the anode voltage does not exceed the allowable burden of the thyristor 1

dU / dt, - dU / dt on

In this case, the capacitor 7 also performs the function of protecting the power thyristor from the effect dl / d -. At time t, the voltage across the capacitor 7 reaches the voltage level of the power supply and the control switch 3 is turned off. At time t7, in accordance with the operation algorithm of the thyristor controlled key, the power thyristor 1 is turned on and then all the processes in the circuit are repeated. Compared with the prototype, the proposed technical solution allows to obtain the following advantages:

- increasing the frequency properties of the thyristor controlled key for

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due to the fact that the power thyristor is made on a lockable thyristor, and the frequency properties of two-operation thyristors are better than the frequency properties of single-operation thyristors;

-increasing the frequency properties of the thyristor controlled key due to the fact that two switching circuits act on the power lockable thyristor and the result of their combined effect is a decrease in heat generation in the structure of the power thyristor, limiting the frequency of possible switching;

- simplification of the control algorithm for the process of switching a power lockable thyristor along two switching circuits by introducing into the circuit two isolation diodes and connecting them to the rest of the circuit elements in the indicated order;

- simplification of the design of the thyristor controlled key due to the fact that the switching thyristor is excluded from its circuit, and the switching process is controlled by one controlled key;

- simplification of the design of the thyristor controlled key due to the fact that it does not require the use of a special circuit to protect the power lockable thyristor from the dU / dt element, so

how a switching capacitor exhibits protective properties with respect to a power thyristor;

 the complication of the thyristor controlled key control system due to the exclusion of the switching thyristor from its circuit is excluded.

Thus, the frequency properties of the thyristor controlled key can be increased without complicating

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thyristor controlled key management systems.

Claims (1)

SUMMARY OF THE INVENTION A thyristor controlled key containing a power thyristor, the anode and cathode of which are used as the terminals of the thyristor controlled key, and the control electrode is designed to connect to the output of the trigger pulses of the control system, to connect to the output of the formation of the locking pulses of which the control input is intended controlled key, the first output of which is connected to the cathode of the power thyristor and the first output of the overcharge circuit, made in the form of series-connected compartment a connecting diode and a recharging throttle, the second output of which is connected to the first output of the switching capacitor, the second output of which is connected to the anode of the power thyristor, characterized in that, in order to increase the speed, two isolation diodes and a voltage source, made in the form of pre-charged zhennogo storage capacitor, and the power thyristor is made in the form of a lockable thyristor, and the control electrode of the power thyristor is connected to the first output of the voltage source, the second output of which the second is connected to the anode of the first isolation diode, the cathode of which is connected to the second terminal of the controlled key and the cathode of the second isolation diode, the anode of which is connected to the first output of the switching capacitor. 10 o qtf J 7 3 + 11H W 4 5 5 rvv-4- $ j