Desenvolvimento e análise de um sistema multifatorial fotovoltaico-filtro ativo de potência de estágio único submetido a sombreamento parcial e carga não linear

Abstract

Distributed solar photovoltaic (PV) generation is becoming more popular. Similarly, the amount of electronic loads has increased along with the need to improve the power quality. The PV- Shunt Active Filter (PV-SAF) combines the renewable energy generation and power conditioners benefits in microgeneration systems, is a system capable of injecting the PV power generated in the electrical grid and eliminating harmonics of current and reactive power of the local installation load. In the single-stage topology, the PV array is connected directly to the SAF DC bus, without the need for an intermediate DC-DC converter. In this work, a three- phase three-wire single-stage PV-SAF system is evaluated in partial shading conditions and in the presence of nonlinear loads in the local installation. For this, is proposed a Global Maximum Power Point Tracking (GMPPT) technique capable of tracking the point of maximum power quickly even in the presence of several power peaks in the power-voltage curve of the PV array. A permissible voltage range is designed for the converter DC bus, for GMPPT to be executed by varying the DC bus voltage while still ensuring the converter current controllability. A nighttime mode is also implemented for system operation only as an active filter with the fixed DC bus voltage when there is no PV generation. The instantaneous powers theory is used to calculate the converter reference currents, which shows reliable performances. The adaptive hysteresis band current controller is used to control the converter output current and generate the converter switching signals. The sizing of the PV array and the converter components used, as well as the design of the controllers used is also presented. The results obtained through a computer simulation in PSIM software and a laboratory-based experimental prototype show that the PV-SAF system with the adopted control strategies is capable of simultaneously injecting into the electric grid the maximum power available by the PV system, even in the case of partial shading, and compensating load current harmonics and reactive power.