Research And Design Of Controllable Phase Shifted Inverter Based On Series Compensation Technology

Electric power is one of the most important energy.With the increase in the number of users,the number and species of equipment which access to the power grid is also increasing.These non-linear loads reduce the power factor of the grid and affect the power quality of the grid.And a stable grid voltage is the important guarantee of safe and stable equipment and power grid.In the above-mentioned background,this dessertation studies a controlled phase-shifting inverter,which is applied in series compensation.The device consists of the former Boost APFC circuit and the latter stage single-phase inverter circuit.In this dessertation,working condition and control algorithm of the pre-stage circuit is described and a control algorithm based on duty cycle prediction is proposed.The post-stage inverter circuit is modeled and analyzed.The control algorithm under the virtual vector is given and the algorithm is simulated by MATLAB/Simulink and the system Bode diagram is drawn.Moreover,the important components of the hardware circuit of the device are calculated in detail and the selection results are given.Considering the high-speed information processing ability of digital control,the device uses a digital control based on the TMS320F28335 chip.Finally,a 1kW experimental prototype was developed and verified experimentally.The experimental results show that the input power factor of the device reaches 0.98,and can output a stable sinusoidal alternating voltage,which can reduce the voltage drop of the distribution line by controlling the phase and amplitude of the output waveform,in order to achieve the purpose of voltage compensation.