Research On The Parallel Inverters Mimicking Synchronous Generators

Along with the rapid development of China railway transport, Locomotive electrical equipment type and quantity increased significantly, Locomotive power supply puts forward higher request for capacity and stability. The parallel operation become one of the development trend of locomotive power. Locomotive power has the characters of high power, wide range of high DC input voltage, higher requirements of the output voltage waveform quality and the auxiliary inverter scattered layout, working with environment electromagnetic noise. Aiming at the locomotive of the power supply characteristics, This paper studied the control method of the parallel locomotive auxiliary power supply.In this paper, the relationship of synchronous generator between output active power and the output voltage frequencies is analyzed. The similarity between the inverter drop control and the characteristic of synchronization generator is analyzed .The mathematical modeling of three-phase inverter is established .This paper analyzes and Design of a voltage and current double closed-loop controlled Three Phase Inverter which is based on Rotating coordinate transformation . The power calculation for three-phase inverter is researched, this calculation is accuracy and timeliness . The power control parameters calculation method is given. The influence of parallel inductance is analyzed. The model of the parallel system is simulated in Matlab/Simulink software. The key influencing factors of the parallel three-phase inverters without connection is analyzed. Power calculation, single control system performance, the power control parameter calculation are very important. On the basis of theoretical analysis, the parallel system prototype of two 35KW three-phase inverters is build, the software and hardware design of experiments introduced. Experimental results demonstrate the feasibility of the paralleling control strategy without interconnection in high power application.