Three-phase four-leg type PCS with individual phase control algorithm for compensating unbalance loads using ESS

The power systems have encountered with a problem such as unbalance current due to loads unbalance. Particularly, the problem rises in the small scale grid such as a microgrid that is installed in remote country and island which are difficult to reach existing power grid. To solve the unbalance current of the grid, we usually use compensators for balancing the current of the grid. In this paper, the authors propose a power conditioning system (PCS) using energy storage system which has not only normal operation functions but also a compensation function of the unbalance current of the grid without special compensators. The proposed PCS is modeled and simulated using PSCAD/EMTDC to demonstrate the effectiveness of the system.