Adjoint least mean square control for solar photovoltaic array grid‐connected energy generating system

Abstract

Abstract This study deals with a new control for a double‐stage grid‐integrated solar photovoltaic array (SPVA)‐based energy generation system, which is based on adjoint least mean square (ALMS) control. This ALMS control algorithm has some new features: (1) it provides a fast rate of convergence, (2) harmonics mitigation ability, and (3) ease of implementation. The solar PV energy generating system includes a DC–DC boost converter, a voltage source converter (VSC), a ripple filter, a three‐phase grid, and local non‐linear loads. The VSC is controlled for feeding the active power from the solar array to the grid and three‐phase non‐linear loads. Moreover, VSC control is used to improve the grid current quality. A DC–DC boost converter is coupled between the photovoltaic array and the DC‐link capacitor, which tracks the maximum SPVA power from the SPV array by using perturb & observe algorithm. Here, the main goals of SPVA generating system are to eradicate power quality problems caused by unbalanced and non‐linear loads and to provide sinusoidal grid currents at solar PV array irradiance variation. Moreover, a comparison of ALMS control is made with other control algorithms. Performance of this ALMS control is studied at varying non‐linear loads and under different environmental conditions on a developed prototype in the laboratory. The simulated results of the system are validated with test results. Detailed behaviour of the grid‐integrated SPV system and harmonics spectrum of grid currents are given here while meeting the IEEE 519 Standard.

Keywords

• power converters
• power supply quality
• renewable energy sources
• robust control