Can Be Fed Electronic Load

With the development of social economy, people pay more and more attention on energy source problem. The electronic power load is a new type power electronic instrument that can run with the same function as resistors in the test of all kinds of DC power source. The electronic load transforms the DC power into AC power and sends it into the utility power system. Electronic load can save power and space because it is lighter and smaller.This paper discusses the difficulty of the power load system, and proposes a preferable design project. The system has two parts: DC-DC converter and DC-AC grid-connected inverter. They select full-bridge converter. Taking into account soft switching, The DC-DC converter select Phase-Shifted control strategy realized by UC3879.This paper detailed analysis of its control objectives and control mode, the control algorithm is in-depth study. The entire system, the tracking control of grid-connected current it is very critical. The DC-AC converter select hysteresis current control strategy realized by C8051F020. It has fast transient response and high stability. The combination of analog control and digital control can make the design and the debugging of the control system easy, and also can improve the reliability of the whole system. It is easy for this kind of structure to expand its functions in the future, which has strong adaptability.This paper presents design and calculation methods of the main components in the circuit. The main circuit switching elements is IGBT. Design of the drive and protection circuit is given. The diagram of hysteresis current control is given.The simulation results verify that the electronic load is well designed. The electronic load can be regards as a resistor whose value change smoothly. Required performance is obtained: unit power factor and the grid-connected current that is close to sinusoidal.