Experimental Evaluation of DG's Dynamic Voltage Support Capability Improving Short-Term Voltage Stability on Power System Loads

High DG penetration will seriously degrade the short-term voltage stability of the load in bulk power systems. Simulation results in previous studies by the authors have shown that the dynamic voltage support (DVS) capability of a DG improves stability, but experimental evaluation does not yet exist. This paper presents the effects of the DVS capability of a DG on an experimental circuit consisting of an induction motor, a resistance load, and a compensation capacitor behind a reactance. First, an experimental setup that causes voltage instability without DVS is set up. Second, an improvement in DG inverter control is made in order to achieve a low-voltage ride-through (LVRT) capability and DVS capability, and the DG's performance is confirmed by voltage sag tests. Finally, the tests on the experimental setup demonstrate that the DVS capability greatly improves the short-term voltage stability of power system loads, and the experimental results agree well with the simulation results. (C) 2010 Wiley Periodicals, Inc. Electr Eng Jpn, 172(2): 28-36, 2010; Published online in Wiley Inter Science (www.interscience.wiley.com). DOT 10.1002/eej.20914