【作者】 邢洲；

【导师】 谢克明；

【作者基本信息】 太原理工大学 ， 控制理论与控制工程， 2005， 硕士

【摘要】 随着电力系统的发展和电力用户自动化水平的提高,对电网供电质量的要求也越来越高。而电力系统参数变化及波动性负荷会造成局部电网电压不稳及功率因数恶化,影响电能质量和降低电器设备的寿命,制约企业生产效率的提高,同时企业还可能因为电能质量未达标而承受线损及电力部门罚款等经济损失。低压电容补偿装置作为解决此类问题的一种设备应运而生。这种装置适用于变电站、冶金矿热炉等连续运行的大容量用电设备,可以提高电网功率因数、减少网络损耗,而且顺应电器设备智能化的潮流,近年来在电网中应用日益广泛。 但目前在国内冶炼行业,对矿热炉的低压无功补偿几乎是个空白。究其原因,一是因为矿热炉工作在140V左右的低电压下,并且电极电流高达几万安培,要对这么大的电流进行无功补偿,不仅耗资巨大,而且存在许多接触工艺上的困难,给控制上提出许多难题,稍不注意,便会出现大面积的设备烧毁及人身伤亡事故;二是因为大电流产生的强大的磁场使得导线经过之处的钢铁材料因涡流而发热,除造成大量的能量损耗、给现场施工带来许多困难外,还带来严重的电磁干扰,对于电容补偿装置的抗干扰性也是个严峻的考验。以上原因导致目前国内补偿成功的案例非常少,但实际的市场需求却非常大。若能开发出适合矿热炉的低压无功补更多还原

【Abstract】 With the development of electric power system and electric power user, people call for high quality of power supply, and the desire becomes more and more exigent. But the parametric variation in clectric power system and load of wave nature would cause mains voltage nonsteady, deteriorate power factor, affect quality of power supply and decrease the service life of wiring. This would restrict the production efficiency of the enterprise, and the enterprise might be fined by electric department and endure line loss because of not reaching the standards of electric department. The Low Voltage Capacitance Compensating Device, as a device for answering this kind of problem, emerges as the times require. Such device applies to large and continuouse running consumer, such as transformer substation and smelting furnace. Drifting with the crowd that electric apparatus become intelligentized, this kind of device becomes increasingly extensive in electric network.However, in smelting industry at home, reactive power compensating aiming at smelting furnace is all but a blankness. The reason lies in two points: firstly, the running voltage of smelting furnace is under 140 volt, but electrode current is as high as several thousands ampere. Not only does the reactive power compensating cost large quantities of money, but much difficult problem of contact technology also exists. If people lose track of it, large numbers of devices would be burned out. It also could cause personal injury. Secondly, the strong magnetic field which is brought by heavy current can result in high heat in ferrous material that around the conductor because of eddy current. This may bring about great deal of energy loss and much trouble to site operation. Furthermore, the strong electromagnetic interference is a baptism to capacitance compensating device. Above reasons make the successful compensating case at home very few, but the actual market demand is very large. If we could develop the intelligent control device of Low Voltage Capacitance Compensating that applies to smelting furnace, we can improve the power factor, enhance the output and reduce the current drain. The social and economic benefit are all extraordinary ramarkable.Firstly, this paper introduce the researching status quo in reactive power compensating area. Secondly, it recite some technical problem in the manufactureing practice about ferroalloy. Then it elaborate the reactive power compensating in theory. And Then it elaborate the operating principle,algorithm, antijamming measure, hardware and software structure of the the Intelligent Control device of Low Voltage Capacitance Compensating on the basis of Motorola’s MCU— —MC68HC912DG128A which is the control center of the device. This paper put forward an algorithm of extraction of square root based on the MCU’s hardware instruction CPU12, and the algorithm had been successfully applied to the device. Such algorithm solve the problem of evolution efficiently, the computing speed and calculating precision can meet a demand. For the moment, this device had been installed in Da Tong Jin Guang corporation. After the device were brought into use, power factor has been improved, current drain has been reduced > active power the output has been enhanced over 10%, and output has been increased 10%. It measures with the desired result and achieve consummation.更多还原