Design And Research For Emergency Power Supply Of Auxilary Engine System In Compressor Station

The auxiliary engine system of natural gas compressor station is critical to the compressor's stable operation.Once the loss of electricity happens,the stable operation of auxiliary engine system will be greatly interrupted,which will even cause serious accidents.In such cases,equipping a high performance emergency power supply(EPS)is very important to such kind of load.Compressor station auxiliary system could be seen as a motor type load,when using as diesel generators as emergency power supply,it takes tens of seconds for diesel generators to start supporting power supply,which is easily to make damage to the equipment without electricity.A new kind of emergency power supply should be desined,the emergency power supply should be able to ensure a period of time to the auxiliary system of emergency power supply,and ultimately smooth switch to the diesel generator power supply or re-switched to the main power supply.In this paper,a kind of parallel type of emergency power system(EPS)using super capacitor as energy storage structure is researched by considering the characteristics of the impulse current in the auxiliary system of the compressor station,especially the power supply of the auxiliary load switching.The new EPS are different from the traditional UPS,which is always in the online state.Because the emergency power supply is connected in parallel in the system,the normal state in the sleep state,but can release energy when there is a power failure.So it can effectively reduce the running costAs the emergency power supply system needs make stable voltage to maintain the load power supply,and the supercapacitor and the general discharge characteristics is similar to the way of release energy of the normal capacitor,super capacitor's voltage drops rapidly,so it cannot be used as a constant voltage power supply directly connected to the load,so DC / DC converter should be desighed,in orther that the DC output can provide a stable voltage,and theb through the DC / AC convert into AC power for the auxiliary load.In this thesis,the emergency power system is designed to convert the AC to DC for charging the supercapacitor through the current limited resistor.The supercapacitor enters to the float mode when the super capacitor is fully charged.When it comes to discharge state,the DC voltage output module is based on the DSP-based voltage negative feedback BOOST circuit,for the super capacitor discharge voltage change characteristics,and constantly raise the BOOST circuit when the boost ratio of the output always maintain a constant voltage output.According to the above design,a low-power emergency power system is built.By simulation and experiment,the load of different power is connected to test the key points,and the internal loss and stable voltage output time under different load conditions are analyzed in detail.And it was proved that the supercapacitor can be used as an emergency power storage module to load the power supply,and can have good working characteristics.Finally,according to the actual investigation of the compressor station,based on the actual compressor station auxiliary system's load requirements and cost controlling considerations,a supercapacitor and supercapacitor/battery hybrid power of the comparative study and analysis of the advantages and disadvantages of the two,through Simulink software A simulation model of the parallel type emergency power supply of the compressor station was built,and the size of the battery and the supercapacitor required by different power supply configurations were estimated according to the simulation model.