An innovative series connected power flow controller, Magnetic Energy Recovery Switch (MERS)

A new power flow controller called the magnetic energy recovery switch (MERS) has been investigated. It consists of four active switches per phase and a dc-capacitor. The MERS is capable of injecting zero to rated voltage within the current rating. The device can from a power flow control point of view be regarded as a capacitive reactance in series with a controllable voltage source. A control algorithm has been developed in order to facilitate power flow control with these combined characteristics. The control has been optimized in order to reduce injection of voltage harmonics. Experimental results have shown high speed control characteristics and smooth transition from reactance control area to series voltage control area. Additionally, the sub-harmonic characteristics have been found to be good. In summary, the MERS seems to be a promising future power flow controller.