IMPROVING POWER QUALITY OF A PV-INVERTER FOR THREE-PHASE SOLAR ENERGY CONVERSION SYSTEM WITH LEAKAGE CURRENT SUPPRESSION

Abstract

The improved power quality solar photovoltaic (PV) inverter that
allows for the reduction of common-mode leakage current is presented
in this work. This study examines a three-phase transformer-less solar
energy conversion system (SECS), which provides grid reactive
power support and peak active power production from photovoltaic
arrays. It also ensures various power quality improvement capabilities,
including grid current harmonic mitigation and grid current balancing.
This approach, in contrast to traditional power quality inverters, is
resilient to anomalies in grid voltages at distant radial ends and does
not jeopardize the leakage currents brought on by the parasitic
capacitance of the PV array with ground. PV leakage-currents are
often ignored in PV inverter power quality management, despite the
fact that they negatively impact system performance by lowering
power quality and endangering operating staff safety. Therefore, the
transformer-less PV systems are required to function with leakage
current within the 300mA range per the standards VDE-00126 and
NB/T-32004. Numerous test and simulation results demonstrate the
offered strategy's good performance even in the presence of numerous
grid-side anomalies. The efficiency of the method is shown by a
comparison examination using cutting-edge techniques. The PV
leakage currents are kept well within the range advised by the VDE00126 standard, while the harmonics in the grid currents are noted
within limitations as per the IEEE-519 and IEC-61727 standards under
all test situations.