液体火箭发动机地面试验控制电路的设计与分析

Aiming at the problems that the liquid rocket engine ground test control system must suppress the pulse noise at the input end of the control circuit, the peak inverse voltage at the output end and the low measurement accuracy of the control current, a control drive and control current measurement circuit based on printed board solid state relay is designed through the application of circuit simulation and amplification circuit methods. The control drive circuit applied the "diode + zener diode" module to reduce the peak reverse voltage and speed up the reset time. An optocoupler isolation module is integrated at the output of solid state relay (SSR) of the control drive circuit to feed back the control signal. The Hall effect current sensing module and operational amplifier make up the majority of the control current measurement circuit, which is designed to provide high-precision control current measurement. The dynamic and static characteristics of the peak inverse voltage suppression module of the control drive circuit and the control current measurement circuit are simulated and analyzed. The simulation and measurement results show that the intrinsic error of the control current measurement circuit is 6.66%±1.80%, with a circuit rise time less than 0.3 ms and a fall time less than 0.5 ms. Control drive circuit can be used to construct high precision ground test control system of liquid rocket engine, with turn-on and turn-off time less than 2 μs and 0.5 ms, respectively. The control drive circuit can efficiently suppress peak inverse voltage with the help of a "standard recovery diode + zener diode" module.