Superconducting magnetic energy storage (SMES) system is having increased attention in power system application because of its higher efficiency and faster response. This paper proposes a high quality power conditioning system (PCS) for the SMES system operation. The PCS consists of a voltage source converter using IGBT (Insulated Gate Bipolar Transistor). In order to compensate several problems such as voltage sag and harmonic current flowing into utility, active filter systems could be a good solution method. SMES is a promising source due to the high response time of charge and discharge. This paper presents a simulation technique for a decision making of the specification of the active filter system combined with SMES system. Through the results of several analyses and simulations carried out by PSCAD/EMTDC, this paper demonstrates the significant effect of SMES on the improvement of power system performance. Based on this simulation, the author developed a PCS connected to the utility system. It was shown that the developed PCS was well-designed and effective.