Quasi-Z-Source Network-Based Hybrid Power Supply System for Aluminum Electrolysis Industry

Abstract

A hybrid power supply system (HPSS) based on the quasi-Z-source network is proposed for aluminum electrolysis, which can reduce energy consuming and carbon emission through the use of renewable energy. An ac–dc integrate controller is designed in the HPSS that contains a two-layer control. The first layer control is responsible for maintaining the dc bus voltage and current, which can mitigate negative effects caused by anode effect in aluminum electrolysis. The independent maximum power tracking for PV array and the dc-bus voltage balance for each quasi-Z-source dc–dc converter can be achieved by using the PV-voltage controller and dc-bus voltage controller for the PV System. To maintain the voltage of dc bus within the require voltage range of aluminum electrolysis production and ensure high input power quality of ac System, the quasi-Z-rectifier controller is employed, which can reduce the harmonic injection. The power allocation is addressed in the second control layer and a power scheme algorithm (PSA) is carried out to maximize the system efficiency and economic benefit. At last, the simulation and experimental results are provided to verify the effectiveness of the designed HPSS and the proposed PSA.