Abstract
Photovoltaic energy has become an increasingly competitive source delivering electricity with a steadily cost decline. Alongside the deployment of this sustainable energy system, the power supply stability should be thoroughly examined especially in off-grid systems when electricity storage becomes a constraint. The work presented in this paper proposes a practical solution for the DC bus voltage stabilization in a stand-alone photovoltaic generator devoid of an energy storage system. In order to achieve this objective, a new control strategy applied to the DC/DC converter installed on the PV terminals is investigated. Specifically, the proposed method consists of a modified control in the PWM signal driving the boost converter. Four different modes were considered according to the difference levels between the reference and the measured voltage. Furthermore, this simple and effective technique circumvents the absence of a storage system and ensures the DC bus voltage stability despite the unpredictable operating conditions. An experimental test bench was developed in order to prove the high performance of the proposed control method which is corroborated by the obtained results in particular the DC bus voltage stabilization to the reference value.
•A novel control strategy for a stand-alone PV generator is proposed.•The DC bus voltage is regulated without using an energy storage system.•The PWM control signal of the DC/DC converter is adapted according to each load variation.•A correction term of the PWM signal duty cycle is determined according to four modes.