Research On Static Var Compensator For Low-voltage Power Grid

With the increasing varieties of modern users' electricity load and the complexity of load characteristics,the reactive components in the power supply system are very complex and diverse.Which has great influence on grid voltage and quality of the transmission power.The real-time monitoring and dynamic accurately compensation of reactive power in low voltage distribution network is an effective way to solve the power quality problem of low-voltage distribution grid.Therefore,it is of great significance to study the static var compensator for the low voltage power grid to stabilize the voltage of the power grid,reduce the loss of the system,improve the power factor,and improve the power transmission efficiency and load capacity of the system.In this paper,based on the analysis of reactive power compensation demand in low voltage distribution network,the TCR+TSC type SVC design scheme is adopted to design the software and hardware system of the whole device.And the BP-PID controller in its control system is optimized.Finally,the optimization performance and reactive power compensation effect of the design device is tested by simulation experiment and the built experimental prototype.The main contents of this paper are as follows:(1)Aimed at the traditional PID controller used in the reactive power compensator performing undesirably at stabilizing the voltage and setting the parameters of the nonlinear and time-varying object.A two order differential control link is introduced to the BP-PID controller to improve the control accuracy and response speed of the system.And a BP neural network with compact structure and good generalization performance is constructed automatically by the HDPSO algorithm to realize the optimization of BP-PID controller,its control performance is verified by simulation experiments.(2)The TMS320LF2407 A type DSP chip is chosen as the processing and control core of the hardware system,and the hardware system of the reactive power compensation device is built.Including the signal conditioning and sampling,three phase voltage synchronization signal acquisition,switching signal inputting and outputting,thyristor trigger and communication module.And the modular design idea is used to design its software system,including the data acquisition and processing,device protection and reactive power compensation control module.(3)Finally,the whole reactive power compensation system is modeled and simulated,and the voltage stability function and dynamic compensation performance of the system are verified and the experimental prototype of the 380 V static var compensator is built.The experimental results show that the TCR+TSC type low-voltage power grid static var compensator designed in this paper can quickly and accurately compensate the reactive power in the low voltage power grid,and effectively stabilize the voltage of the power grid under various load characteristics,and its practical application effect is ideal.