Research On 3KW Energy Feedback Power Electronic Load

With the continuous development of industrial automation and power electronic technology in modern society, different types of power supply are used for people's life and production in all aspects, therefore the people's living quality nowadays is closely related to the quality of electric power. It is necessary to do the power performance verification for different kinds of power supply equipment. The traditional power calibration equipment is composed of linear electrical components and power electronic devices, which needs to consume a large amount of active power at work and always leads to the waste of both energy and space. This paper uses power electronic load to evaluate the performance of the power supply, which saves a lot of energy and works environmentally friendly. In addition, the simulation types of this equipment can be both linear and nonlinear, the amplitude and power can achieve stepless adjustment and the operation process is simple.The equipment is based on the three-phase half bridge back-to-back topology. The load circuit model is established, different operation modes of the load are analyzed, and the calculation method of command current in load mode is analyzed. In order to improve the output current waveform of the system, LCL filter is used and the component parameters are determined according to the power and the filtering effect of the system.The fixed switching frequency triangle wave comparison method is used in this paper. In order to meet the requirements for the load and fed side's bandwidth and precision, two kinds of current controller are designed:P control, PI+repetitive control.With the simplified algorithm of SVPWM, the utilization ratio of DC side voltage is improved. The power electronic load is modeled and simulated with PSIM. In the case of 10% system voltage fluctuation, the current waveform of the system is observed in the constant current, constant power and constant impedance operation mode separately.On the basis of the research work, a power electronic load device is designed and developed. The operation results show the excellent steady state performance of power electronic load. Experimental results verify the effectiveness and wide range applicability of the proposed current control strategy.