Coordinated control of MTDC-based microgrid with wind turbines

A DC microgrid using multi-terminal DC system (MTDC) is an effective solution to integrate wind turbines with distribution network, due to the low investment and the flexible system power flow distribution. A four-terminal DC microgrid composed of permanent magnet synchronous wind generators, power distribution grid, energy storage battery, and passive loads is used to validate the reasonability of the system configuration firstly. And then a power management scheme based on the above configuration is proposed to keep the power balance and stable operation. In addition, the control strategy of constant DC voltage for the proposed MTDC-based microgrid to coordinate various terminal converters is studied. Finally, the validity of the control strategy is demonstrated by simulations on a four-terminal DC microgrid with wind turbines using MATLAB/Simulink in different operation modes, considering various operating conditions, such as variations of wind speed and load. The system shows the satisfactory operation performances, and power balance and constant DC voltage are maintained automatically.