Voltage harmonic compensation control for a stand-alone single phase inverter-based fuel cell

Abstract

In recent years, Fuel Cells (FC) have gained interest as energy source for stand-alone and grid connected applications, because they are very high-efficiency and multi-fuel power generators that require neither the burning of conventional fuels nor the mechanical equipment of conventional power generators. When FC are used with inverters for supplying AC loads, harmonic distortion in the supply voltage results in increased heating losses in loads, excite resonances and overload customer power factor correction equipment. Sensitivity of customer equipment to voltage distortion may be dependent on both the magnitude of the distortion levels and the specific harmonic components. For these reasons, it is important to keep the voltage harmonics within recommended levels. This paper presents a new method for voltage harmonic compensation of a stand-alone single phase inverter-based FC. The system under study is composed of: 1) ProtonExchange-Membrane (PEM) FC including a unidirectional DC/DC converter, which converts the DC voltage delivered by the FC to the DC bus voltage; 2) single-phase pulse width modulated (PWM) inverter; 3) transformer; 4) L passive filter; and 5) linear and non-linear loads. The dynamic model of this system and the control applied to the PWM inverter for voltage regulation and harmonic compensation are detailed in this paper. Simulation results show the effectiveness of the purposed method for voltage harmonic compensation to acceptable levels defined in grid codes.