The Research Of Thyristor Self-powered Drive Circuit And Detection Circuit

The triggering and detection circuit of thyristor is an indispensable part of the thyristor application circuit.The reliable power supply is the guarantee for the normal operation of the thyristor.The power supply of the triggering and detection circuit of thyristor for special applications(high voltage,series,etc.)often require isolation or special treatment.Using self-powered technology is a common solution.To that end,the paper aims at solving existing problems in current triggering and detection self-power supply circuit of thyristor,and carries out research as follows:(1)Through analysis of thyristor principle,use occasions and a variety of energy-capturing circuits,the paper takes into account various factors such as circuit complexity and reliability,the RC buffer-energy-capturing circuit is selected as a prototype for improvement,and an improved RC energy-capturing is proposed.The improved RC-buffered energy-acquisition circuit uses a full-wave rectifier bridge for energy-capturing,which avoids the problem that the half-wave energy-capturing circuit is easily affected by the conduction angle with the low energy-capturing efficiency and poor load capacity.The simulation results of the established simulation model prove the effectiveness of the improved circuit.(2)For the common ground problem caused by the full-wave energy rectification by using a rectifier bridge,a thyristor trigger circuit,a detection circuit,and an optoelectronic signal transmission circuit adapted to the requirements of the new self-power supply are designed.The trigger circuit adopts pulse transformer as the core component to isolate and trigger the thyristor,which solve the common ground problem caused by full-wave energy acquisition.The detection circuit uses the temperature sensor DS18B20 and the humidity sensor HS1101 in conjunction with the single-chip microcomputer to carry out real-time detection of thyristor temperature and ambient humidity.The paper uses DS18B20 "one-line bus" protocol to detect the temperature of six thyristors in real time,which increases the applicability and anti-interference ability of the detection circuit;photoelectric signal transmission circuit uses optical fiber to transmit the trigger signal and detected temperature and humidity data,and has higher Voltage isolation level to avoid signal distortion caused by electromagnetic interference during signal transmission.(3)According to the performance index requirements of the self-powered circuit,a hardware circuit is set up,and the hardware circuit is tested.The test results meet the design requirements.