Research On1kVA Two-stage Aeronautical Static Inverter

As the increasingly higher demands of power supply for onboard electrical equipments.TheASI has a small weight and volume and a high efficiency. This paper researches the two-stage ASI,and does further studies to decrease the weight and volume, improve its efficiency.The instantaneous output power of two-stage single phase inverters contains a two-octave pulsewhich frequency is twice of the output voltage. The pulse power is reflected in the input current ripple,affects the power supply and the converter itself. An inverter with different topologies and differentcontrol strategies can have different manifestations and transmission mechanisms. Through adding anotch filter in the control loop, the input current ripples of the inverter are rejected well. And in orderto adapt different inverters, specific applications of the notch filters are also provided. The experimentresults show that the low frequency pulse in the input current is decreased under5%, the dynamicresponse is favorable and the efficiency is improved.The DBI filtering inductor is so heavy and large, and a three-inductor DBI filter is proposed inthe thesis. One of the three inductors is an AC inductor separated from the primary inductors, it candecrease the filter’s weight and volume, simplify the control loop. This paper also analyses theoperating principle of three-inductor DBI in detail, provides the design principle of the filter,compares the two SPWM control strategies which can realize zero-offset current in the three-inductorDBI. The simulations verify that the bipolar SPWM can have a better reliability. In order to improvethe external characteristics of the inverter, a PR controller is added to the control loop.In order to expand the application of three-inductance DBI, a cascade three-inductor DBI isproposed in this paper. Choose the CPS control to double the equivalent switch frequency on theinductor, that can halve the primary inductor in the theory, also elimilate the distortion of the outputvoltage across zero. The model of the three-inductor is built, and the stability and dynamics areanalysed. What’s more, this paper also make detailed loss analysis of the three-inductor DBI and thecascade three-inductor DBI. The results of the two inverters’ loss analysis, have laid a good fundationof optimization design for the inverter’s efficiency.Two1kVA prototypes have been developed. The experiment results have proved the theoryanalysis.