Research On Moment Inertia Features Of Voltage Source Inverter Based Simulator For Permanent Magnet Direct Drive Wind Generator System

The breakthroughs have been achieving constantly during the process of exploiting the wind energy in light of the principle of sustainable development. And as a result, the technological innovation of wind generation system (WGS) from both the hardware and software is on-going. To verify the correctness of relevant theories,the field test is the most effective means. However, the research based on field test is limited by the long-term nature of scientific research and the randomness of wind field’s operation condition, and this will prolong the update cycle of the technology. To issue the presented problem, this thesis intents to develop a permanent magnet direct-drive wind power system (PM-DD-WPS)based on voltage source inverter (VSI) to emulate the actual wind turbine in the laboratory conditions to carry out research.1.The software and hardware of the proposed wind power generation simulation system are both presented in this thesis.By controlling the inverter, simulator could realize the simulation of wind power generation system output. The research work focuses on the following aspects:The wind wheel, the transmission shaft and the permanent magnet synchronous generator (PMSG), which constitute an integral wind turbine system,are modeled respectively.. The aerodynamic torque characteristics of wind wheel is introduced firstly and the torque coefficient is obtained by the polynomial fitting method。Then the virtual rotate speed adjustment module is established based on the shaft transmission model. The virtualization of PMSG is achieved at last,2.A control strategy based on voltage and current double loop is presented in this thesis to simulate the actual wind turbine output characteristics accurately.According to the mathematical model of (PM-DD-WPS),the generator output voltage is calculated as a reference value of the inverter voltage vector using the inverter output current feedback value.Then the detail control strategy is analyzed in the d-q coordinates and the control parameters tuning is proceeded. The simulation platform is established, the dynamic and static response of the system under different conditions can be analyzed by using the simulation platform.3.Based on the relative mathematical models and control strategy, the software and hardware of the simulator are improved. In the aspect of software, the DSP program and PC monitoring program are written using the discrete model to control the state of the inverter and monitor system parameters. In the aspect of hardware the experiment platform is built after parts selection to verify the effectiveness of simulation system and the feasibility of control strategy...