Design And Realization Of An Improved Low-voltage Reactive Power Compensation Device

Electric Power is the main secondary energy source in china, with the development of Chinese national economy, how to save energy source, reduce wastage and production-cost, is the goal in enterprises. In electric power system, many applications of nonlinear loads reduced the power factor, especially some large fluctuant loads, leaded to huge fluctuation of reactive power, affected voltage quality severely. This also made large wastage of using efficiency and benefit in electric power system. Therefore, how to reduce reactive power and increase power factor in electric network is an important problem in electronic technology and electric automation area, thus, it is getting more and more attention.According to the effects of former products of Wuhan network security company which were used in Guangdong, Guizou, Hubei province, this paper analyzed the principles of reactive power compensation, the advantages and disadvantages, and the application field of different kinds of reactive power compensation devices which were widely used at the present time.Based on this, an improved low-voltage reactive power compensation device with wireless data transmission was designed with STC89C516RD which worked as MCU. This paper analyzed the choice of system scheme, introduced the design and realization of hardware and software, including data collecting part, compensation controlling part, communication part, human-machine interface and so on. It also gave detailed circuit diagram and flow chart, including some program. Using GSM module TC35 to monitor electric network in long-distance, to control and communicate, was analyzed and studied particularly. Finally, we completed the system debugging and results analysis, it showed that the device was operating well.Aimed at the disadvantages of the domestic and international similar devices as below: without wireless long-distance monitor function, not intelligent enough and so on, this device made huge improvements, it's advantages as below: enhanced stability, high precision of measurement and control, better performance and lower price. It's main performance as below: adopted more reasonable control-strategy, chose combination switch to put into capacitors, had electric network monitor function, long-distance wireless communication capability, multiple protection capabilities. This device had passed the electromagnetism compatibility test and the technical verification of the Chinese National Quality-technology Supervision Part. After experiment in the real electric network system, the results showed that the design of the hardware and software was reasonable, it's performance was stable and reliable, thus it achieved the expected design requirements.