Design And Verification Of The High And Low Grid Fault Voltage Emulator

As the most valuable large-scale renewable energy, wind and photovoltaic power have characteristics as high-efficiency and cleanness, but their operating stability becomes a hot point. Among all other issues, the Fault Ride Through (FRT) is one of the major concern. This paper is supported by (2011BAA07B05) "Integration Testing Technology and Equipment Development of Wind Power and Photovoltaic" from National Key Technology R&D Program and "Construction and Promotion of Basic Research Platform and testing capacity" from SGCC science and technology projects. It mainly focused on the design and verification of the high and low grid fault voltage emulator for FRT. The contents are as follows:(1) The comparison between different fault voltage simulating principles is studied. On the basis of resistor inductance voltage-dividing simulating scheme, inductance & capacitance simulating systematic high and low grid fault voltage scheme is raised. The key parameters for the scheme are adjusted; The possible surge and resonance in this scheme are analyzed. A detailed simulating fault voltage model is built and verified aiming at high voltage, low voltage and chain for high & low voltage fault.(2) The key components and integrated design for the high and low grid fault voltage emulator are researched based on the inductance & capacitance simulating systematic scheme. Based on reactor time-sharing multiplexing, a current-limiting and short-circuit reactance systematic dispatching scheme is proposed. The problem of impulse voltage and operating over voltage of reactor is discussed. The function deployment of the complex control system of the high and low grid fault voltage emulator is researched with the design of complex control system logic and safety chain criteria finished. For the needs of field test, movable integrated fault voltage simulate modular scheme is formulated.(3) The function of high and low grid fault voltage emulator has been tested by simulating the grid high and low voltage fault. The result shows that the emulator has features such as wide range, high accuracy and can fully meet the requirements of FRT test unit in accordance with gird codes home and abroad.