基于AVC系统的省地电网关口无功功率协调控制方法

An AVC System Based Coordinated Control Method for Reactive Power at Gateway Between Provincial and Regional Power Grids

定量评估省级电网的无功调控能力以确定关口无功功率控制范围,是大电网自动电压控制(automatic voltage control,AVC)的关键。基于电网分层解耦的理念,首先给出了平均协调功率因数限值(average coordination power factor limits,ACPF)的定义来评价省级电网的无功承受极限,并求解ACPF的优化数学模型,得到ACPF与省级电网下送负荷水平的相关性曲线;接着根据各500 kV变电站负荷的差异性,近似线性化计算上游关口协调功率因数限值,并以其为约束条件建立下游关口协调功率因数下限值的计算模型及其快速估算方法,实现AVC系统参数的动态整定;最后给出了AVC系统省地协调的关口无功功率控制实现方法。应用到广东某区域电网的仿真结果表明,所提的方法在节能降损、提升电压质量、提高省级电网电压无功安全裕度以及挖掘片区变电容量等方面优势更加明显。

It is the key problem in automatic voltage control（AVC） of large-scale power grids to quantitatively assess the reactive power regulation capability of provincial power grid to determine the control range of reactive power at the gateway of provincial power grid. Based on the idea of layered decoupling, firstly the definition of average coordination power factor limits（ACPF） is given to evaluate the limit of provincial power grid to withstand the reactive power, and the optimized mathematical model of ACPF is solved to obtain the correlation curve between ACPF and load level transmitted from provincial power grid to subordinate power networks; then based on the differences among loads of 500kV substations, the approximate linearization calculation of limit value of the coordinated power factor at main gateway is performed, and taking it as the constraint a calculation model and its fast estimation method for the lower limit value of coordinated power factor at subordinate gateway are established to implement dynamic setting of parameters of AVC system; finally a method to implement the AVC system based coordinated reactive power control at the gateway between provincial power grid and regional power grid is given. Simulation results of applying the proposed method to a certain regional power grid in Guangdong power grid show that the proposed method is favorable for energy-saving and loss-reduction, improving voltage quality, enhancing security margin of voltage and reactive power in provincial power grid and bringing the potential of area substation capacity into play.