电网技术2012，Vol.36Issue(1)：72-78,7.
电网电压不平衡时全功率风电并网变流器的控制策略
A Control Strategy for Grid-Connecting Full Power Converter of Wind Power Generation System Under Unbalanced Grid Voltage
廖勇 1庄凯 1姚骏1
作者信息
- 1. 输配电装备及系统安全与新技术国家重点实验室重庆大学,重庆市沙坪坝区400044
- 折叠
摘要
Abstract
When grid voltage is unbalanced, the negative sequence component of grid voltage leads to harmonics with twice as much as power frequency in DC side voltage of full power grid-connecting converters for direct drive permanent magnet synchronous generators （PMSG）, and it will evidently affect the service life of capacitors at DC side of the converter and jeopardize stable operation of wind power generating units while such an operating condition is persistent. A mathematical model of the full power grid-connecting converter at grid side is built, and on the basis of taking the influence of grid-connecting impedance on active power into account, a control strategy, which takes the enhancement of DC side voltage stability as the object, is proposed. In the proposed control strategy, by means of ensuring no double-frequency oscillation in active power flow between DC side capacitor and grid-connecting converter the positive and negative current instructions are obtained, thus it is unnecessary to solve complex high-order matrix for the calculation of the instructions and there are not more variables to be led in as well The effectiveness of the proposed voltage control strategy is verified by simulation results of direct drive PMSG. Comparing with traditional balanced control strategy, the proposed control strategy can effectively suppress the double-frequency oscillation in the active power transmitted to power grid while the DC side voltage stability control is implemented, thus the ability of uninterrupted secure and stable operation of direct drive PMSG under unbalanced grid voltage is improved.关键词
风力发电/全功率变流器/不平衡电网电压/直流/侧电压控制/谐波Key words
wind power generation/full power converter/unbalanced grid voltage/DC side voltage control/harmonics分类
信息技术与安全科学引用本文复制引用
廖勇,庄凯,姚骏..电网电压不平衡时全功率风电并网变流器的控制策略[J].电网技术,2012,36(1):72-78,7.
