Research On The Suppression Of Current Mutation And Ripple Produced By The Accelerator Power Supply

Shanghai Synchrotron Radiation Facility(SSRF)is a third generation synchrotron radiation light source of high performance.It is the largest scientific device and big scientific platform in China so far and has a widely applied value in the scientific and industrial circles.The synchrotron radiation source has very high requirement for the long-term stability,as well as the stability of magnetic field needs the fluctuation of excitation current in a reasonable range as a guarantee.Voltage collapse has a significant effect on the output of the power supply.In order to ensure the stability of the excitation current,a compensatory method of dynamic current based on the load side is proposed.This method can compensate for the current immediately when the abrupt current appeared.It's different from the active power filter(APF)parallel with the bus,but directly parallel connected with the load,so its power is smaller and the response speed is faster.The compensator uses a deep negative feedback control based on Pulse-Width Modulation(PWM): Firstly,its extract the AC signals from the output of power supply;Secondly,made the extractive negative,then as the reference signal of compensator;Finally,through the proportional integral(PI)control get the control signal of PWM which can control insulated gate bipolar transistor(IGBT)of inverter,then complete the compensation.In this paper,in order to verify the feasibility of the method,the hardware structure and parameters of the current compensator are designed with the corrected power supply as the experimental object.The qualification of the current compensator is put forward,by the parameters of the corrected power supply,and the theoretical element parameters of the current compensator are calculated.Then the stability is carried out with the loop control part analysis and the reasonable control parameters are obtained.The Simulink is used to simulate the current compensator and prove it is feasible,and the design parameters also meet the requirements of the target.Finally,an experimental platform is built,and a prototype of the current compensator is made by using the corrected power supply,which carried out the actual sudden current compensation experiment.After experimental debugging,the abrupt current is suppressed.