Modelling and simulation of a multifunctional PV electrochemical storage system

Abstract

In this thesis the simulation and modelling of a Multifunctional PV Electrochemical Storage System is performed. This system lies under the umbrella term Hybrid Energy Storage System (HESS) due to presence of two DC power sources. This household HESS system is also connected to the LV grid. As the main focus of the thesis all the component level controlling schemes are implemented in order to equip HESS system with functionalities which helps to achieve the following objectives: - Extract the maximum available PV power under temperature and irradiance variations - Fully control the battery energy storage system (BESS) charge-discharge operation - Controlling the grid tied inverter power flow - Grid power injection-absorption (GPIA) control - Grid frequency-voltage regulation (GFVR) by the means of household HESS These objectives are achieved by implementing the following controllers and algorithms in Matlab-Simulink environment: - PV Maximum Power Point Tracking (MPPT) - BESS charge-discharge management (CDM) - BESS charge-discharge controller (CDC) - DC link pre-charge controller (DCC) - DC link voltage controller (DCVC) - Inverter current control (ICC) - Combined GPIA and GFVR controller Moreover the following component models are presented in details: - Single diode PV model - Generic BESS model - DC-DC PV boost converter model - Bidirectional Buck-Boost BESS converter - DC link model - Three-phase three-level neutral point clamped (NPC) inverter - RL and LCL grid filter models - Household load model - Ideal LV grid model