Study On Energy Feedback Type AC Electronic Load

All kinds of AC power supply device (like AC regulated power supply, AC UPS, inverter and other) in the factory are experimental aging strict (24-72hours) and dynamic, steady state associated with loading experiment, using existing high resistive load discharge and energy consumption of AC electronic load to the old style, with no energy feedback function, will spend a lot of energy, and the construction of a conservation-oriented society. For saving energy, reducing consider heat and other aspects, this paper studies a with the function of energy feedback AC electronic load, it can simulate the real impedance load discharge effect, but also will be aging test of energy feedback to power grid, realize energy recycling.In this paper, a converter, analysis the test required by the load requirements, introduced the working principle of energy feedback AC electronic load, AC electronic load topology was proposed with intermediate DC link of the AC-DC-AC, on the basis of deep analysis of electronic load system the core of the three phase of VSR, established in the three-phase the static coordinate system (abc), a static coordinate system (αβ), two-phase rotating coordinate system(dq) of the mathematical model. Then to design the LC filter required converters in a test environment.According to the working principle of the system and the operation of the law, according to the way of controlling the electronic load is divided into load simulation unit and energy feedback unit. The load simulation unit with direct current loop control mode to fully guarantee the tracking accuracy and speed of the current; energy feedback unit adopts the traditional voltage and current double closed-loop control mode, which the stability of DC voltage and current unit power factor power regeneration; at the same time, two control unit using the SVPWM algorithm to solve the switching frequency is not fixed, the problems such as high sampling frequency AD. Then, according to the topology structure design and corresponding control strategy, build the simulation model of electronic load in the Matlab/Simlink2010b simulation environment, the controller parameter tuning each ring, and the electronic load function load simulation unit and energy feedback unit to realize the simulation, results show can be completed at the same time load characteristic simulation the energy feedback power electronic design load. Based on the realization of the need to project, designed specifically to start the process of electronic load, and verified in simulation.This paper designed a prototype system of electronic energy feedback unit load, with Mitsubishi power module PS21867as the power drive core, TI (TI) TMS320F2812series DSP as control core, the power board and a control board circuit design. The general design method of inductance on the AC side and DC side capacitor is presented and the main circuit of fuse and power devices selection. Then by using modular programming ideas, the preparation of the control procedures, including the main program, the grid voltage zero-crossing detection subroutine, T1interrupt service subroutine, AD interrupt service subroutine, interrupt processing program of fault response. Finally, we build the prototype, experimental waveforms are given, and the electronic load function experiment.