High-Power Current-Pulse Generator Based on a Reverse Thyristor Converter

Abstract

In metal processing by powerful current pulses, there is a need for adjustment of both the pulse repetition rate and amplitude. This paper describes a powerful current-pulse generator with a controlled thyristor converter, which is used as a power source for a charging device for regulating the voltage (pulse amplitude) of a capacitor charge. The disadvantages of the generators associated with the current spike in the capacitor charge modes that reduces the supply network quality are discussed. The application of a reverse thyristor converter (RTC) as a power supply is considered to reduce the transient time at a voltage decrease on the capacitors. The generator’s structural diagram that consists of a reversible thyristor converter with separate control, a power unit, a capacitor recharge device, an automatic control system (ACS) for the charger parameters, and a capacitor charging control system is presented. The regulator parameters of the ACS are calculated. To obtain optimal transients, a standard methodology for regulator tuning according to a modular optimum is employed. In order to reduce overadjustment at the disturbance time reaching 100% and higher, the so-called logical device is introduced into the ACS. The latter blocks the control pulses on the converter thyristors and simultaneously reduces the signal at the output of the current regulator to zero. A simulation model of a powerful current pulse generator is synthesized in the MatLab-Simulink environment. The model is analyzed, and plots explaining the device’s operation principle and transients in various operating modes are shown. The use of a generator will allow high-performance adjustments of the current pulse amplitude and obtain sufficiently high-quality capacitor charge (discharge) transients, which will have a beneficial effect on the power supply network. The application of higher quality converters will significantly increase the current pulse repetition rate.