Specified structure mixed H2=H∞ control-based robust frequency stabilization in a smart grid by plug-in hybrid electric vehicles

In the future smart grid, the penetration of wind power tends to increase significantly. This may cause the tie-line power and frequency fluctuations in the power grid. On the other hand, the plug-in hybrid electric vehicles (PHEV) are highly expected to be installed in the customer side. The bidirectional power control of PHEV can be applied to stabilize the power and frequency fluctuations. This paper proposes the specified structure mixed H2=H∞ control design of bidirectional power controller of PHEV for robust frequency stabilization of the smart grid with large wind farms. System uncertainties are represented by the multiplicative perturbation model. The structure of power controller is specified as a proportional integral (PI) with single input. The PI parameters optimization problem is formulated based on the enhancement of control performance and robustness against system uncertainties. Without the difficulty of weighting functions selection as in a mixed H2=H∞ control, the PI parameters are automatically tuned by particle swarm optimization. Simulation results confirm that the proposed robust controller is much superior to the conventional controller in terms of control performance and robustness against various uncertainties. © 2013 ICIC International.