Algorithm for Asymmetric Control of Power Transistors in DC-DC Converter with Series-Resonant Inverter for Solar Power Plants

DC-DC converters with series-resonant inverter (SRI) may arouse interest among scientists and converter equipment designers due to their applicability at solar power plants (SPP) in particular. Zero-current switching (ZCS) and/or zero-voltage switching (ZVS) of semiconductor devices could be easily implemented in such DC-DC converters. This could allow reducing power losses when switching devices considerably as well as operating DC-DC converters at higher frequencies with high efficiency. A basic diagram for the power section of the bridge DC-DC converter as well as the operating principle of this section in DC-DC converters with SRI for SPP is discussed in the Theory Section of the paper. There are a great number of analog control units on serial chips to control resonant DC-DC converters, but they are intended for symmetric control only. The paper provides a scheme for implementing the algorithm for asymmetric control of the resonant DC-DC converter power transistors on discrete components in the form of a virtual model in the Matlab/Simulink environment. So far, the asymmetric control method is described only in one foreign paper providing current oscilloscope patterns of the resonant circuit and control voltages across MOSFET transistor gates of the DC-DC converter as well as the control system flowchart. The experimental part of the article presents the simulation results (transient, steady state, external characteristics, dependences for the efficiency of the converter). The obtained characteristics are consistent with the results of theoretical calculations presented in previous papers of the authors.