ANALYSIS OF CIRCUITS WITH UNIFORM PHASE SHIFT OF INVERTER CELLS

The article discusses the methods of constructing an inverter with summation of the power conversion cell currents. A computer simulation of the proposed load current distribution schemes of a multicellular inverter with a phase shift of cells has been carried out. When considering the task of increasing the maximum power of the inverter, taking into account the existing element base, it becomes quite obvious that the design of high-power inverters to obtain high performance without load distribution on the flows is very difficult. One of the most important tasks of the organization of parallel operation of inverters is to ensure a uniform distribution of currents between the cells of inverters, they must be synchronized in all parameters (phase, frequency and amplitude). Synchronization must be operational in any modes (nominal, transient and emergency). The uniform distribution of the load current across the inverter cells depends on the phase shift of the output voltages caused by the non-synchronicity of the voltage frequencies generated at the outputs of the inverter cells. An imbalance of one degree between the phases of the output voltages of the two cells leads to a redistribution of power, which can reach over fifty percentages. If the output voltage of one cell shifts forward in phase, then it takes over most of the power of the total load, which in the case of the same output voltage amplitudes will indicate an increase in the current consumption of the leading cell. To ensure the energy balance of the two cells, it is necessary to add just the frequency of the output voltage of the cell with the leading phase. This balancing should occur with high speed. Keywords: power conversion, inverter, phase shift, high speed, distribution, parallel connection, transistors, synchronization.