DC-Current Sensor-Less MPPT Based Grid-Fed Single-Phase Photovoltaic (PV) Micro-Inverter

• Published in: Applied solar energy Vol. 56; no. 2; pp. 85 - 93
• Main Author: Bohra, Shabbir S
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.03.2020; Springer Nature B.V
• Subjects: Converters; Cost analysis; Cost effectiveness; Direct Conversion of Solar Energy into Electrical Energy; Direct current; Electrical Machines and Networks; Engineering; Harmonic distortion; Interactive systems; Inverters; Irradiation; Maximum power tracking; Photovoltaic cells; Photovoltaics; Power Electronics; Power management; Radiation; Roofs; Sensor arrays; Sensors; Solar energy; Tracking control; Voltage converters (DC to DC); DC-DC converter; maximum power point tracking (MPPT); micro-inverter; photovoltaic (PV) system
• ISSN: 0003-701X; 1934-9424
• DOI: 10.3103/S0003701X20020036

This paper presents grid-feeding type micro-inverter for a single-phase grid-interactive photovoltaic (PV) system. The system comprises of two stages, a step-up DC-DC converter with series resonant type voltage multiplier-a doubler and an inverter operating on single-switch modulation technique in order to improve efficiency of system. Use of single switch-modulating inverter helps in preventing shoot-through problem. The PV current from array is estimated without employing a DC current sensor to make system operate at maximum power point (MPP). A simulation for low power 300 W PV system without DC-current sensor maximum power point tracking (MPPT) control has been carried out to analyze cost effectiveness solution for small power rooftop applications. The simulation has been carried out on MATLAB®/Simulink platform under varying irradiation conditions to verify effectiveness of control technique and ripple present into injected grid current. The total harmonic distortion in grid current has been observed to be less than 5% even at as low as 0.25 G irradiation to comply IEEE standards.