【作者】 吴艳娟；

【导师】 李林川；

【作者基本信息】 天津大学 ， 电力系统及其自动化， 2013， 博士

【摘要】 大型风电场并网，给电网的安全稳定运行造成一定隐患，因此研究风电场并网系统的安全稳定性受到了关注。FACTS在电力系统中的成功应用，表明FACTS是提高风电场并网系统安全稳定性的有效措施。本文重点对FACTS提高含大型风电场互联系统输电线路传输能力、抑制含风电场互联系统的低频振荡、提高风电场并网的暂态电压稳定性以及补偿风电场并网无功功率等问题进行研究。主要创新点如下：（1）针对风电场发电容量迅速增加与相对薄弱的输电网络之间的矛盾问题，提出了在风电场并网输电线上安装TCSC可变阻抗控制器，并设计了考虑暂态稳定约束的附加Bang-Bang控制策略。该控制器能实时跟踪风电场随风速变化的有功输出，通过实时灵活地调节传输线路的阻抗，实时调节输电线路的传输能力，可有效提高系统的暂态稳定极限，增强风电场故障后电压的恢复能力，提高风能利用率。（2）针对TCSC保护装置会因为短路电流大，积累能量多而导致保护误动作，减弱TCSC阻尼控制器的抑制效果等问题。详细研究了含大型风电场的互联系统联络线修正能量函数与TCSC模式转换时刻的对应关系，提出了基于联络线修正能量函数的TCSC分段阻尼控制器及其控制策略。该控制器在静态运行时采用电压电流双环闭环控制，保证线路的有功潮流稳定在期望值。而在系统发生故障时，采用基于联络线修正能量函数的附加控制，增强了含风电场的互联系统承受大扰动的能力，提高系统稳定性。（3）由于系统受到大扰动或故障时，风电场需要从电网吸收大量的无功功率，导致并网电压迅速降低，极易造成系统电压崩溃，而采取风电场切机措施又极易引起系统振荡。结合STATCOM具有瞬时调节无功，快速回复故障电压的能力。提出了在风电场并网母线处安装STATCOM自适应电压电流双环控制器，并给出了控制策略。通过与其它控制方法的仿真比较，验证了该控制器在提高风电场并网的暂态电压稳定性、增强风电场低电压穿越能力方面具有明显的优势。（4）针对STATCOM无功补偿迅速灵活，但是造价昂贵，而固定并联电容器组造价低廉，但是不能进行实时平滑补偿的问题，提出了应用STATCOM与自动投切并联电容器（APFC）联合对风电场进行实时、平滑无功功率补偿的协调优化配置方案。以无功补偿设备投资最小作为目标函数，对补偿设备的容量进行寻优。应用APFC对不同工作风速下系统静态稳定运行时的风电场无功功率进行阶梯式补偿。应用STATCOM对APFC投切间隙进行动态实时补偿和故障后的风电场暂态无功功率补偿。由于综合考虑了补偿设备运行的经济性、风电场在不同工作风速下并网运行的静态稳定性以及系统的暂态稳定性，因此，该方案是满足经济性和安全可靠性的无功优化配置方案。更多还原

【Abstract】 Potential threats for security and stability of the power system will be caused bylarge-capacity wind farm integration (LWFI). So the security and stability of thepower system containing large-capacity wind farm (PSCLWF) has been paid greatattention. The successful application of flexible ac transmission system (FACTS) inpower system shows that FACTS is effective measures to improve the security andstability of PSCLWF. This paper makes researches on available transfer capability(ATC) improvement of the PSCLWF transmission line, inhibition ability of lowfrequency oscillation of PSCLWF, transient voltage stability improvement of LWFIand reactive power compensation of LWFI. The main achievements are as follows:(1) It is a contradiction in the rapid increase of wind power generation capacityand the relatively weak transmission network. Therefore, it is proposed that the TCSCvariable impedance controller added a Bang-Bang transient stability control canimprove obviously ATC of LWFI transmission line. The controller’s advantage is thatcan real-time track the active output change with wind speed of wind farms, andreal-time flexibly adjust the impedance of the transmission lines in order to real-timeadjust the active power of transmission line. The controller can improve effectivelythe transient stability limit of ATC, enhance the low-voltage though ability of LWFI,and increase the efficiency of wind energy.(2) The excess energy accumulated by high short circuit current in protectiondevice can cause TCSC protection misoperation. This will weaken the dampingeffectiveness of TCSC damping controller. The corresponding relation between thecorrection energy function of PSCLWF tie-line and the model transformation momentof TCSC is analyzed in detail. A segmented TCSC damping controller based ontie-line correction energy function and its control strategy are proposed. The TCSCcontroller uses the voltage and current double closed-loop control during stablecondition to guarantee the active power flow being in expectation. But it uses thetransient stability control based on tie-line correction energy function to improve theability to endure large disturbance and improve the transient stability of the grid.(3) When a large disturbance or a failure occurs, the large-capacity wind farmneeds to absorb a lot of reactive power. This will cause easily voltage collapse of thepower system. Furthermore, large-scale wind farm tripping is easy to cause the systemoscillation. Combining with the advantages of STATCOM in adjusting instantaneously reactive power and restoring rapidly voltage after fault, a adaptiveSTATCOM controller and its control strategy are proposed to realize transient voltagestability control of LWFI. By comparing with other control method simulation, theeffectiveness of the controller is proved to improve the transient voltage stability andstrengthen low voltage though ability of wind farm integration.(4) STATCOM can compensate reactive power rapidly and flexibly, but its costis too high. The cost of the parallel capacitor groups is low, but it can’t compensatereactive power smoothly and real-time. A coordination optimization reactive powercompensation scheme using STATCOM and auto-switching parallel capacitorgroups(APFC) is proposed. Its control strategy is proposed also. APFC compensatethe static reactive power under different working wind speed during stable condition.STATCOM compensates the dynamic reactive power during the switching gap ofAPFC and the transient reactive power during fault condition. The control scheme isbased on economy of reactive power compensation equipments, static stability andtransient stability. It is a coordination optimization reactive power compensationscheme because of considering economy, security and stability at the same time.更多还原