Adaptive Grid-Voltage Feedforward for Three-Phase Inverters Applying Perturb and Observe Algorithm to Minimize Current THD

Abstract

As the amount of renewable energy increases rapidly, power systems will face novel challenges to maintain power quality. Power quality issues, which usually arise from the grid connection through power-electronic devices, can be reduced by proper control strategies. Grid-connected devices are conventionally optimized into a single operating point, but real performance is affected by the interfaced grid conditions. As the grid conditions change over time, the control performance varies, as does the quality of the power produced. To tackle this issue, the adaptive grid-voltage feedforward is introduced to the control system. The adaptive method, applying a perturb-and-observe algorithm, improves the produced power quality in real time by taking the control system characteristics and the grid conditions into account. The results show the improved power quality in various grid conditions when comparing the adaptive grid-voltage feedforward and the conventional implementations.