Study On Single-phase Power Electonic Load With Energy Feedback

With the development of power electronics technology, different power electronic devices are applied in more and more areas. AC power utilities such as UPS, generators, power inverters are widely used in people's life. Thus,These devices need to be strictly tested before they are put into use. Conventional tests using real components, such as resistors,capacitors and inductance and their mix,is inflexible, and cause energy loss, which can hardly meet the requirements of the various testing occasions. Based on full-controlled switching devices, this paper proposes a novel equipment named PEL(Power Electronics Load). The ac current can be easily set to simulate conventional real load, including common linea and non-linear load, active load, moreover, the energy absorbed from the tested utilities can be effectively fed back to grid.This paper firstly introduces the structure of the PEL and its development at home and abroad. As the ac current can be fully controled and have a Four-quadrant operation, this paper uses DC link AC-DC-AC PWM rectifier to constitute the topology of PEL. Secondly,this paper illustrates the application of parabolic PWM method, which features a reasonably fast response, outstanding performance of current tracking. Then, the theroy of PEL are elaborated, using DLL to control the reference current. With regard to the three-phase three-wire PEL system, a strategy named virtual zero sequence current decoupling are established.In PSIM, both the single phase and three phase's closed-loop simulation model are built, the simulation results denotes the feasibility. Based on the simulation,the op amp circuit model of PEL is built, the control board using TMS320F28335 as the CPU, and hardware circuit are built, codes are developped at the CCStudio V3.3 platform. The testing work is being done.