Output voltage control of 3-ϕ switched boost inverter for standalone renewable energy based distributed generation systems

The Switched Boost Inverter (SBI) can generate higher ac output voltage compared to the traditional voltage source inverter (VSI), by advantageously utilizing the shoot-through interval of the inverter phase legs. Also, the SBI has two control variables, namely, shoot-through duty ratio (D), and modulation index (M). Hence, the output voltage of the SBI can be regulated to a given reference value for wider range of input voltages. This paper presents an output voltage control strategy of 3-φ SBI for standalone renewable energy based distributed generation (DG) applications. The control system is designed in dq-reference frame, with an inner current controller and an outer voltage controller. The control strategy, described in the paper, requires measurement of voltage and current information in only one phase of the 3-φ SBL Also, the controller has been implemented in digital domain using Texas Instruments TMS320F28335 digital signal processor (DSP). A laboratory prototype of the 3-φ SBI has been used to verify the steady state and transient performances of the control system and the experimental results are presented in the paper.