Dynamic Simulation Technology of Wind Turbine Based on Virtual Inertia

The comprehensive ground testing of the offshore wind turbine generator (WTG) has become more and more difficult as the capacity of the wind turbine continues rising. The wind turbine is absent in the ground testing of the WTG. Thus, a major problem in the ground testing is how to simulate and compensate the inertia of the wind turbine by controlling the drag motor. This paper summarizes the relevant inertia compensation methods and analyzes the existing problems of mainstream methods. There are two main kinds of inertia compensation method. One is torque control-based method, the other is speed control-based method. The torque control-based method has the problem of measuring noise of speed differential when simulating a large inertia, while the speed control-based method has the problem of slow control dynamic when simulating a small inertia. In this paper, the improvement methods of the two compensation methods are proposed respectively. For the torque control-based method, the accuracy of the control is improved by optimizing the Luenberger observer parameters. For the speed control-based method, an additional torque feedforward is added to improve the speed tracking performance. The simulation results verify the effectiveness of the proposed improvement measures to help solve the existing problems of the two kinds of inertia compensation method.