System for measuring the angle required for switching off current inverter thyristors.

摘要

The system is designed for measuring the angle required for switching off current inverter thyristors. The first inputs of the group of comparators are connected to the cathodes and to the shared anode of the anode group of the inverter thyristors, while the second inputs of the group of voltage comparators are connected to the anodes and to the shared cathode of the cathode group of the inverter. Unique characteristics: The shared output (3) of the comparators (KN1) of the anode group, galvanically-insulated from the high-current circuits of the inverter, is connected to the controlling inputs of the first integrating circuit (UC1) and two analogue electronic keys (K1) and (K2), which are normally opened. The first analogue key (K1) is connected between the input of the first integrating circuit (UC1) and the first terminal of the first capacitor (C1). The second key (K2) is connected between the first terminal of the output capacitor (C3) and the output of the voltage follower (W2) in the line of the cathode group (GK). The first terminal of the first capacitor (C1) is also connected to the input of the voltage follower (W1) in the line of the anode group (GA). The shared output (3) of the comparators (KN2) of the cathode group (GK), galvanically-insulated from the high-current circuits of the inverter, is connected to the controlling inputs of the integrating circuit (UC2) and the successive - the third and the fourth - analogue electronic keys (K3) and (K4), which are normally opened. The third analogue key (K3) is connected between the output of the second integrating circuit (UC2) and the first terminal of the second capacitor (C2). The fourth key (K4) is connected between the first terminal of the output capacitor (C3) and the output of the voltage follower (W1) in the line of the anode group (GA). The first terminal of the second capacitor (C2) is also connected to the input of the voltage follower (W2) in the line of the cathode group (GK). The second input of both integrating circuits (UC1) and (UC2) are connected to the output of the system (UF), which generates the voltage proportionate to the inverter operating frequency.