Design, Development and Analysis of Microcontroller Based Constant Power Purifier

Abstract

Now a day’s electricity becomes necessary requirement in industry, home, office, and laboratory or in any other field. Most of the electrical equipments like computer, TV, FAX, heater, electrical motor etc. are designed to operate at constant voltage like 230V +5%. If voltage is above or below the rated voltage, electrical equipment may get damaged. We are mainly getting electric supply from generating station, which are far away from our working area. Voltage variation in the incoming supply is major problem of power engineering. Fluctuations are also produced in the incoming supply due to welding and other industry. Some times surges and spikes are found in the supply. This voltage variation may harmful to our valuable electrical equipment. Due to over voltage winding may get damage. Slight fluctuation in the supply is sufficient to damage program written in the computer. Under voltage is harmful to electrical motor and other machinery. Constant power purifier is a device, which give constant output voltage in spite of variation in the supply voltage. Its heart is microcontroller based voltage stabilizer, which stabilize the supply voltage. In addition, it also suppresses the surges and spikes by surge arrester circuit. Output voltage of stabilizer remains constant at 230 + 5%. Its input voltage range is 160V to 290V. In this project SCR are used as switching device and microcontroller is used as triggering device. Microcontroller is used to measure and to control voltage. It corrects the voltage at every half cycle of the supply voltage. In this project zero crossing switching technology is used. So very less harmonics are produced due to switching. Voltages are stepped up or down by autotransformer. Constant power purifier is applicable for computer, TV, CD player, FAX and all other laboratory and office equipment, which are sensitive to voltage changes.