Research On Active Damping Of Three Phase Current Source PWM Rectifier

With the improvement of grid power quality requirements, PWM Rectifier been more extensively studied. Current Source PWM rectifier is based BUCK type of step-down circuit, DC voltage is below the rated value, the DC side current easy to control, and smoothing the DC side of the anti-beneficial short-circuit protection, suitable for high-power metal heat treatment, SMES, electric vehicle charging and other occasions. Current Rectifier network side using LC filter, is easy to oscillations. Commonly used to suppress the current oscillations methods are passive and active damping. In summary, current-mode PWM Rectifier active damping control in-depth research and analysis.1. Analysis of the main circuit of the current PWM Rectifier, respectively, a mathematical model abc coordinates and dq coordinates. Study the main control method of current source rectifier, compare the advantages and disadvantages of various control methods.2. To reduce the power loss of power device such as the current source rectifier(CSR) during hard switching process, an indirect control energy-saving strategy is proposed. To decrease total power loss of the device and maintain the quality of the current at grid side in the meanwhile, a control strategy, in which only the valves of two bridge arms in the three-phase bridge are circularly conducted within the 2/3 cycle. Results of simulation and experiments show that using the proposed control strategy, the loss in power device can be greatly reduced while the switching times of the valves are decreased, that is, the switching frequency of the valves are decreased, thus the service life of power devices can be prolonged. The proposed control strategy is suitable for high power applications3. Analysis of the inhibition of passive LC oscillation damping and active damping control principle. Proposed inductor voltage feedback input shaping and hybrid damping control. Not only can suppress the current command line current oscillation caused by changes in value, but also effective in suppressing distortion outside interference network side current. This control method can effectively improve the performance of the control system.4. A digital prototyape Curent Source PWM Rectifier based on FPGA is designed. Three-phase sinusoidal signal generator, the triangular carrier generation, sampling signal, LC damping control and generate trigger has completed. Experimental verification of the performance of current digital rectifier, and verified the effectiven ess of hybrid damping control strategy.