Renewable energy sources are widely available on Earth; hence they have attracted much interest in both research and practical applications. In the large scale renewable energy system, power quality into the grid, especially harmonics and flicker, impacts on grid system significantly. In recent years, magnetically controlled shunt reactors (MCSRs) have been widely used to solve the problems of the power quality caused a failure or malfunction of the end-user equipment. MCSR can simplify the system reactive power and voltage control in the super / special high-voltage power grid, suppress power frequency and operation over voltage, eliminating generator self excitation, dynamically compensate charging the power in a transmission line, suppress the secondary arc current, damping system resonance and so on, which can meet the various needs of the system, it has a very broad application prospects. This paper presents a comprehensive review of MCSR configurations, the control strategies, the selection of components, other related economic and technical considerations, and their selection for specific applications. It is aimed at providing a broad perspective on the status of MCSR technology to the researchers and the application engineers dealing with power quality issues. A list of more than 130 research publications on the subject is also appended for a quick reference.