Design Of Reactive Power Compensator Based On ARM

With the increasing of power capacity and the electric equipment, therequirement of reactive power grows day by day. Reactive power will cause the dropof power factor and voltage, the decline of capability of network transmission, andthe increase of active power loss, so the equipments can not be sufficiently utilized,even be damaged. Therefore more and more attention has been paid to reactive powercompensation. Due to the limited operation ability of main controller, the traditionalreactive power compensator is difficult to analyze real-time signal effectively andthus impacts the result of compensation.The paper analyzes the basic principle and control method of reactive powercompensation, and compares advantages and defects of all kinds of reactive powermethods. Then a low-voltage intelligent reactive power compensator based on ARMhas been designed for the present electrical power market. The reactive powercompensation controller satisfies the requests of high speed and control precision.In hardware design, LPC2132(ARM7)is used in the compensator, which carriesout the functions such as sampling and calculating, regulating the reactive powerautomatically, giving an alarm and protection in case of faults, saving data etc.Multi-frequency circuit is applied to track electric harmonic. A zero triggered circuitis used to restrict the inrush current in the cast-cut equipment. The controller carriesout switching of capacitors by special 8421 mode. Furthermore, the controller candisplay the system parameters momentarily with liquid crystal display.In software design, the paper completes the design of reactive powercompensation controller with ARM software development platform.The paperpresents the whole project on the embedded Real Time Operation SystemμC/OS-Ⅱ.The paper also particularly describes the porting ofμC/OS-Ⅱon LPC2132, thearrangement of the function and the mission scheduling. According to the softwarefunction, with the thought of three layers software ofμC/OS-Ⅱoperating system,users design the middleware level and the task level. The work of phase locking andsynchronous sampling is completed by A/D and CD4046 chip. The power factors areobtained by LPC2132 processes with calculating. In communication design, RS486and GPRS communication system is adopted, which is used for data transmission.In theoretical studies, the control strategy of reactive power compensationcombines the power factor with the reactive power controlling method. And PID isused for improving its performance. By preserving the best interests, this method ofreactive power compensation is simple in principle and also efficient in calculatingand superior in effect.In the end, the paper presentes some shortcoming of the compensator whichneed be amended in future. The controller integrates reactive power compensating,power monitoring, data transmiting and saving, and other functions. This reactivepower compensator has reasonable design and steady performance, which can realizethe functions anticipated.