Reduced-order LPV controller for coordination of power sources within multi-source energy systems

In this paper an order-reduction approach for multi-variable LPV/H∞ controller is presented and applied to design a power source coordination strategy within a multi-source energy system. The energy system has three different kinds of power sources - fuel cell, battery and supercapacitor - which compose the power supply system of an electric vehicle. All sources are paralleled together with their associated DC-DC converters on a common DC- link coupled to vehicle’s electrical motor and its converter. DC-link voltage must be regulated in spite of load power variations corresponding the driving cycle. A reduced LPV controller is obtained using the ISTIA algorithm. It shows to have a special form consistent with the physical properties of the studied system. The MIMO LPV reduced controller is proved to ensure quadratic stability of the closed-loop system. Besides, this controller could be implemented with smaller computational burden. The nonlinear multi-source system is simulated in MATLAB®/Simulink® using the Normalized European Driving Cycle (NEDC) as load profile. Simulation shows good performance of the reduced-order LPV/H∞ controller to be used in power sharing strategy.