Research On Dynamic Reactive Power Devices’ Optimization And Its Coordination Control Application

Due to the unbalanced distribution of energy and economic development, high-voltage, high-capacity, long-distance transmission and interconnection of large power grids has become one of the major trends in the development of countries in the world of modern power systems. It has caused great concern in domestic and foreign scholars how to ensure the safety and reliability and operational stability of the power grid. The birth and development of dynamic reactive power compensation device with real-time tracking compensation load changes provides a new and effective means of control to achieve this goal. To the end of the grid for the actual large-scale, the support effectiveness of dynamic device for reactive power largely depends on its configuration points, the capacity to select and coordinate with the traditional means of voltage and reactive power control method in the grid is reasonable or not.The present situation and problems of dynamic reactive power compensation optimization studies are analyzed at home and abroad, and we launch a study by the end of the actual characteristics of the grid. The main contents and results are as follows:Based on basic principles, functional properties of typical dynamic reactive power compensation devices such as improving static voltage stability, transfer capability and transient stability of power systems are introduced and their respective scope is obtained. Analysis and pointe out that the dynamic reactive power compensation technology has unique advantage in improving system transient stability,which lay a theoretical foundation for the installation point and installation capacity of reactive power compensation considering transient stability and dynamic system.From the perspective of improving both transient angle stability and transient voltage stability and combining the evaluation index of transient stability margin and limit the opening time, the optimization of dynamic reactive power compensation device configuration considering system transient stability is proposed. First, apply EEAC to calculate transient stability margin describing quantitatively the transient angle stability in a particular disturbance of the system,which can be used to determine the weak areas of transient stability in the system. Then analysis and indicate clearing time limit can approximately measure transient voltage stability of the system under certain conditions,and dynamic reactive power sources extend the index.At last,sensitivity index is used to reflect the impact on the transient stability margin dynamic from the compensate volume changes of reactive power compensation device.Based on hierarchical and regional balance and local compensation of reactive power, a method to determine the reactive power compensation capacity limit value considering the transient stability of system is proposed.The sensitivity relationship between transient stability margin and reactive compensation capacity is deducted.Then the strict function relationship between the active power loss and reactive compensation capacity is deserved with the economic pressure difference method to obtain the dynamic reactive power compensation capacity interval. Finally, limit value is modified with the interval,which can improve the system transient stability and reduce active power loss.For coordinating dynamic reactive power compensation device and the traditional discreteequipment,a coordinated control strategy of dynamicreactivepowerdevices and traditio nal control means is put forward based on the different running condition. We set a dead zone module coordination dynamic compensation device and load tap running. Dynamic reactive power devices and capacitor banks distribute reactive follow the principle of “discrete equipment basic support, continuous equipment fine tuning”. This strategy not only to maximize played a transient support capacity, but also can coordinate with the discrete devices to achieve the goal of fast, accurate and economical reactive power compensation.Finally, through the simulation of actual grid computing, a complete set of dynamic reactive power optimization device configuration and its coordinated control program with the traditional means of voltage and reactive power control is got, Verifying the effectiveness and practicality of the proposed method and providing a theoretical analysis basis and specific guidance for engineering decisions.