Control Method Of Mine 1140V Of Static Var Generator

With the deepening of coal mining depth, the length of underground power lines is growing. Moreover, it is used that high power three phase asynchronous motor and power electronic equipment. These have resulted in the low power factor of coal mine power supply system, and other power quality problems, such as low voltage and flicker of load side voltage. Because of that, it is difficult to start large underground mining equipment and active power loss of power lines is growing. The production efficiency and mining safety of coal mining enterprises are affected. The most traditional reactive power compensation methods is based on the centralized switching capacitor witch only mainly balances reactive power between the power grid and main circuit of coal mine power supply system. For stabilizing the load side voltage and improving the power factor of the branch, it is presented in this paper that static var generator (SVG) with distributed local compensation for mine 1140V. This will get a great significance for energy-saving and consumption reducing, and for mining safety of coal mining enterprises.In this paper, mining 1140V voltage level as the background, using the instantaneous reactive power theory ip-iq detection methods, and the introduction of DC voltage negative feedback, to detect reactive command signal, stable dual purpose SVG DC capacitor voltage. With inductive load being starting and stopping frequently in mining 1140V system, it is adopted that hysteresis comparison direct current control to improve response speed to reactive power change and robustness of the system. The control strategy can accurately compensate the reactive power and stabilize load side voltage of the system, which has the favorable dynamic real-time performance and the compensation effect.Firstly, this paper design the part of SVG’s hardware and software respectively, For main circuit, firstly, it is determined that the parameters of the connected reactance and capacitance between the AC and DC side of the main circuit. Secondly, IGBT specification is selected, and the parameters of its buffer circuit element. Hardware part of the control circuit involves in the selection of control chips, and its peripheral power supply, detection and drive circuit design. The software part mainly involves in the initial design of the main control program, sampling subroutine and PWM wave output subroutine by using flowchart. Then the SVG is built and simulated in MATLAB/Simulink, which is the model of 1140V three-phase three wire (neutral point not grounded). The simulation results show that the system can accurately compensate reactive power at load side of underground power grid in real time, and has a certain ability to stabilizing voltage. The feasibility and effectiveness of the proposed scheme are verified by the simulation and the intended purpose is achieved.