风电基地经特高压直流送出系统换相失败故障(二):送端风电机组暂态无功电压特性与作用机理分析

Commutation Failure of UHVDC System for Wind Farm Integration(Part Ⅱ):Characteristics and Mechanism Analysis of Transient Reactive Power and Voltage of Wind Powers in Sending Terminal Grid

实际运行与现场试验发现在同样特高压直流(ultra high voltage direct current,UHVDC)出口暂态电压作用下,直驱风电机组(permanent magnet synchronous generator,PMSG)与双馈风电机组(doubly-fed induction generator,DFIG)机端暂态电压响应存在较大差别,UHVDC与PMSG、DFIG不同类型风电机组暂态无功电压作用机理亟需研究。结合PMSG与DFIG控制硬件在环(control hardware-inthe-loop,CHIL)暂态无功响应特性试验曲线,该文将系列文章第1篇PMSG与DFIG机组暂态无功响应解析模型分解为暂态电压、功率控制、初始状态3个暂态无功分量的叠加,明确了暂态电压分量是PMSG与DFIG暂态无功响应特性存在差别的关键因素;建立PMSG与DFIG在UHVDC换相失败下机端暂态电压响应数学模型,对比分析各暂态无功响应分量对机端电压影响,揭示PMSG与DFIG不同类型机组与UHVDC暂态无功电压作用机理;依托系列文章第1篇CHIL实时仿真实验平台,验证该文揭示的PMSG与DFIG不同类型风电机组与UHVDC暂态无功电压作用机理的合理性。

There is a significant difference in transient voltage response between permanent magnet synchronous generators(PMSGs)and doubly-fed induction generators(DFIGs)under the same transient voltage in ultra high voltage direct current(UHVDC)transmission system both in real operation and field test.The transient reactive power and voltage mechanism of UHVDC,PMSG,DFIG wind turbines need to be studied.Considering the control hardware-in-theloop(CHIL)based transient reactive power testing results of PMSG and DFIG,this paper decomposed the transient reactive power response analytical model of PMSG and DFIG into the superposition of transient voltage,power control,and initial state in the first the series paper.The transient voltage component is the key factor of the differences in transient reactive power characteristics between PMSG and DFIG.The transient voltage mathematical model of PMSG and DFIG under UHVDC commutation failure were established,the influence of each transient reactive power component on voltage was analyzed,and the transient reactive power and voltage mechanism of PMSG,DFIG,UHVDC were revealed.Based on the CHIL real-time simulation platform in the first of the series paper,the rationality of the transient reactive power and the voltage mechanism of PMSG,DFIG,UHVDC revealed was verified.