Research For The Control System Of Variable-frequency Mine Emergency Power Supply Based On DSP

Security has been widespread concerned in the dig working face of coal mine,particularly, the gas issues have an important impact on the safety of coal mine.In order toprevent the accumulation of gas and generate explosion, and the dig working face should bealways ensured proper ventilation in the production process. So, the power supply isparticularly important in the mine underground. At present, although the power linesunderground mine very well, but the underground environment is complexity, equipmentfailure or other reasons may cause power failure and the wind stopping, which cause theaccident.In order to ensure the reliability of the blower power supply, on the basis of theexisting power supply, addition emergency power supply(EPS), this can provide power forthe blower, when unexpected power outages caused by the accident. The main purpose ofthis study is design and development of high-power mine EPS, focusing on the controlsystem, including theoretical study of control scheme and design of control circuits.Firstly, on the basis of the principle of EPS, a charger was designed for the lithiumiron phosphate battery. The main circuit use three-phase voltage source inverter circuit andLC output filter.Secondly, establishing mathematical modeling of three-phase inverter and filter circuit,after coordinate transformation, design the voltage-current closed-loop control method andPI controller, then calculation the controller parameters.Thirdly, after analyzing the load characteristics of the blower and battery dischargecharacteristics, variable frequency scheme is designed for the system. The blower consumeless energy by frequency control, thus, the EPS has longer running time. After studyingSVPWM control technology, the method of achieving SVPWM is deduced and simulated inthis paper.Finally, experimental platform is established, it includes the main circuit, high-powerdrive circuit and peripheral circuits based on TMS320F2812digital signal processor. Afterprogramming, the system has been simulated and experimented. The results of simulationand experiment show the control and variable frequency scheme are good performance andpractical value.