Design of the feedback type energy-saving electronic load

Feedback Type Electronic Load is a load to simulate the characteristics of the new power electronic devices, which can be used as test equipment. The energy can be feedback to the utility power system with little loss and high power factor. This paper introduce a practical system. System consists of the control circuits, main circuits and detection circuits. Control circuit uses two ATMega128 controller for communication and display. The main circuit is mainly built with a MOSFET inverter H-bridge, which is used to convert DC into the AC. Detection circuits uses optocoupler devices which are used to get DC voltage and current. In the whole system, connecting to the grid is very important. After the analysis of control strategies, a phase-locked loop is used to make the inverted current and voltage into the same phase and frequency. To achieve constant current, constant resistance and constant power mode, we use PI regulator with fast transient response and high stability. System also has the under-voltage and over-current protecting function, which is used to improve system security. The device has the merit of energy-saving, small size, light weight, and it can save installation space and has the advantages of excellent performance.