Design Of Protective Circuit For DC High-Voltage Power Supply

With the development of science and technology,high voltage power supply occupies an important position in medical and agricultural,military and scientific fields.Nowadays,high voltage power supply is optimizing and developing in the direction of improving power and reducing volume.In the process of continuous optimization of high voltage power supply,the safety performance of power supply has received widespread attention.Good circuit structure design and equipment selection can improve system safety,and the design of protection circuit is irreplaceable,which provides a double guarantee for the safety performance of the power supply.The article introduces the knowledge about high-voltage power supply,including rectifier filter circuit,inverter circuit,high-frequency booster and voltage doubling rectifier circuit,etc.The technical indexes of the power system are analyzed in detail.For the DC high-voltage power supply system,three types of protection circuits are designed: beam current regulation protection circuit,sparkling protection circuit and self-restoring sparkling protection circuit.Multiple protection measures are adopted in the beam current adjustment protection circuit to realize the absorption of strong interference by the capacitor and the protection of op-amp by voltage clamp of varistor and diode limiting circuit.The beam current sampling signal is compared with the protection voltage through the operational amplifier,and the overcurrent signal is output to control the work of the relay,so as to achieve the purpose of power circuit protection.Applying the principle of mutual inductance to design a new type of overcurrent protection circuit that detects the ignition signal through the magnetic ring,namely the ignition protection circuit.The circuit can be connected to the power supply terminal or high-voltage sampling terminal to protect the power supply circuit.On the basis of the ignition protection circuit,an ignition protection self-recovery circuit is designed.The ignition signal turns on the relay,so that the subtractor connected to the high-voltage PID operates,which is then connected to the signal-adjusting power supply through the slow-start circuit,followed by inverter and follower into the negative high-voltage sampling of the high-voltage PID.The overvoltage protection circuit that realizes self-recovery suppression of high-voltage transients replaces the traditional overvoltage protection circuit.Simulation and experimental results show that the above circuits can realize their protection functions in a reasonable,sensitive,and reliable manner,which provides an effective guarantee for the safe operation of the power circuit system.