A Design Of UPS Inversion Control System Based On DSP

UPS (Uninterrupted Power Supply) is an electrical equipment that can provide emergent power supply by use of storage battery when power failure. In addition, UPS can improve the quality of mains power supply. Our country has large demand for UPS. The annual sales of UPS reach to 6 billion yuan. The demand is continuously large in the field of telecommunication and finance and begins to rise in the field of manufacturing, transportation and energy source.This dissertation introduces the structure of UPS, analyzes the function and operation principle of each part of UPS and studies the key technique for UPS inversion control. The UPS inversion control system based on DSP is put forward. The system is combined with hardware design and software design and is suitable for digital accurate control.In terms of the hardware design of UPS inversion control system, TMS320F2808, the 32-bit DSP manufactured by TI, is used to control inverter and generate drive signal for IGBT and SCR. EPM240T100C, the high performance and low power consumption manufactured by Altera, is used for interface extension and phase shift of drive signal. The schematics and printed circuit board are designed in the environment of Altium Designer. Anti-interference methods are adopted to enhance system stability.The software design focuses on programming for DSP and CPLD. DSP generates SPWM signal and SCR rectification signal, samples analog parameter of input and output to monitor system state. CPLD shifts the signal generated by DSP. The software achieves soft start, drive signal generation, analog parameter acquisition and system protection.After hardware design and software design, the control board is joint-tested with UPS. The waveform is recorded in the state of open-loop and close-loop. The result shows that under the coordination of UPS inversion control system designed in this dissertation, IGBT drive signal and SCR control signal can be correctly generated so that UPS can work normally. The output signal can accurately trace the frequency of mains power supply, keeping the phase consistent. What's more, the output signal improves the quality of mains power supply by reducing high harmonic wave.The UPS inversion control system designed in this dissertation is general to various types of UPS. The control board can be used in both three-phase-input three-phase-output UPS and three-phase-input one-phase-output UPS, while the software should be modified only a little. The control system is not restricted by the power of UPS and can be applicable for both large-power UPS and small-power UPS.