Low Voltage Ride Through Improvement of Machine Side and Grid Side Converters of PMSG-Wind Turbine Based on SMC

This paper presents a sliding mode control (SMC) method for a variable-speed wind turbine system based direct-drive Permanent Magnet Synchronous Generator (PMSG) during normal and grid fault conditions. In this control method at the normal conditions, Machine Side Converter (MSC) is used to satisfy maximum power point tracking (MPPT) of wind turbine and Grid Side Converter (GSC) controls the DC-link voltage and reactive power injected to the grid. In return, when grid faults happen to satisfy grid code requirements such as Low Voltage Ride Through (LVRT), MSC regulates the DC-link voltage instead of the GSC and GSC controls the active power as well as the reactive power. The results showed that the suggested method has better faster dynamic response under both balanced and unbalanced condition. Furthermore, while enhancing LVRT capability and injecting active power and reactive power, the proposed control system causes smaller spikes in the injected current and DC link voltage. To validate the results, simulations are performed in MATLAB/Simulink environment.