Power Control of Permanent Magnet Synchronous Generator-Based Wind Energy Conversion Systems with Higher-Order Sliding-Mode Observer

摘要

Real-time rotor position and speed feedback is essential for the effective power control of permanent magnet synchronous generator-based wind energy conversion systems. The presence of encoders or resolvers can increase the size, cost and complexity, but also reduce the overall system's reliability, and life-time. To provide a more reliable sensorless wind generator control scheme and eliminate the reliance on encoders or resolvers, this paper presents a novel higher-order sliding mode observer for power electronics control of a grid-connected permanent magnet synchronous generator-based wind energy conversion system. Comparing with a first-order sliding mode observer, a higher-order sliding mode observer shows superior estimation accuracy with significantly chattering reduction. A three-level neutral-point-clamped space-vector pulse-width-modulation based power converter is used to reduce the voltage stress on power switching devices and produce less harmonics in the output waveforms compared with a traditional 2-level inverter. Computer simulation results have shown the superior performance of the higher-order sliding mode observer in wind turbine power control applications.