The control system for uninterruptible power supply

It is necessary to develop uninterruptible power supplies (UPS) forming a sinusoidal voltage. This article is devoted to working out of the control system for a UPS. During of realization of the project we've worked out the control system for UPS. By means of the system it is possible to form the sinusoidal voltage on the output of the UPS. The system uses only one microcontroller and hardware, which had been reduced to the minimum. The microcontroller forms two types of impulses. At first, there are impulses, which enter to one of the pins of the microcontroller with frequency 50 Hz. Other ones are WPM-impulses, which enter one of the pins of microcontroller with frequency 4 kHz. These impulses are enforced and enter to the keys of the inverter, which converts the DC of the accumulator into the sinusoidal voltage, which is transferred to the load in case the AC line is absent. The principle of operation of the control system is described. The control system uses the method of asymmetrical control. The method provides the possibility to form sinusoidal voltage by means of only two impulses entered from microcontroller which is very convenient for working out both software and hardware. This method is also described.