Study On Energy Feedback Type Electronic Load Based On Soft Switching Technology

With the development of social economy, people paid more and more attention on energy source problem. The electronic power load is a new type power electronics instrument that can run with the same function as resistors in the test of all kinds of DC power source. The power load transforms the DC power into AC power and sends it into the utility power system. Power load can save power and space because it is lighter and smaller. In order to increase the power density and output efficiency, the soft switching techniques is the key and important. So it is necessary to use soft switching in electronic power load.The paper discusses the difficulty of the power load system, and proposes a preferable design project. The system includes two parts: DC/DC converter and DC/AC inverter. In the design, the converter select Phase-Shifted Full-Bridge zero-voltage-switched technology converter. The loss of duty cycle is greatly reduced. The adoption of saturated inductance and auxiliary resonant circuit resolves the conflict between realizing ZVS in a wide range of load and serious loss of duty cycle in low voltage and high current input condition; the inverter is implemented with assistant zero-current-switched technology. The merit of this circuit is little inductance losses and simple control way. IGBT is chosen as the power electronics element.To achieve a good performance both statically and dynamically in electronic power load, DC/DC converter takes advantage of a double closed-loop control method based on average-current mode. In the way, it improves the performance of the converter and can get a steady output voltage. The tracking control of grid-connected current is the central technology in the all system. This paper has studied the method of zero-error of current tracking. Using this method, the shape of current wave is improved. The simulation model of system is established, and simulations are carried out.Its operation principle and critical parameters are analyzed. At last, the computer simulation of the proposed project is given the excellent proof to feasibility and validity as electronic power load. The output current that is close to sinusoidal. Its harmonious is very low. Power factor is close to unit.