并网双馈风电机组低电压穿越能力研究

详细分析了双馈风电机组LVRT功能的实现原理，并在电力系统仿真分析软件PSASP中建立双馈风电机组的LVRT功能模型，采用地理接线图直观地表示风电场外部系统发生短路故障瞬间对风电机组端电压的影响，并以我国某地区电网为例来分析在风电场接入方式不同的情况下系统短路故障对风电机组的影响，根据仿真结果给出风电机组LVRT能力的最低电压限值要求。最后提出了利用串联制动电阻来提高风电机组的LVRT能力的新方法。分析结果表明，串联制动电阻能够可观地提高风电机组的低电压穿越能力，具有较高LVRT能力的风电机组，可以节省一定的投资费用，在一定程度上降低了风电的上网电价。

Studies on the LVRT Capability of Integrating DFIG

This paper presents a detailed analysis of the low voltage ride-through(LVRT) functions of the doubly-fed induction generator (DFIG).The model and control strategy of the doubly-fed induction generator with LVRT are established on the power system simulation tool PSASP.The geographic wiring diagram used intuitively indicates the impacts on the terminal voltages of wind turbine generators at the moment when a short circuit takes place in the power grid. And taking a regional power grid as an example, analysis is made on the impact of the short circuit happened in the external power grid under different patterns of connecting with the wind farm, and based on the simulation result, and the minimum voltage limit of LVRT of wind turbines is given. Finally, the paper introduces a new method to increase the LVRT of wind turbines by means of series dynamic braking resistors. Analysis results show that the series dynamic braking resistors can considerably increase the LVRT of wind turbines. Wind turbines of higher LVRT capability help reduce the investment costs, and to a certain extent, give rise to a reduction of the wind power electricity price.