Concept study of microgrid dispatch strategy for solar thermal power plant with thermal storage

Complex grid systems have been gradually replaced by smaller and simpler grid systems called Microgrids. Integration of a solar thermal power generation systems into Microgrids open a new horizon of renewable energy power generation to achieve the supply and demand balance of electricity. Microgrid dispatch strategy is a control method of energy balance between power generation and electricity consumption. A thermal storage integrated into the system buffers the intermittency of solar radiation used as the heat source of the power generation system. The daily starting time for the power generation is determined by the dispatch strategy in search of minimum power from the conventional grid and maximum electricity generation from the solar thermal power generation system. In the simulation stage, the heat energy available for power generation and amount of thermal energy saved in the thermal storage is calculated at each time step using measured solar radiation data as the heat source and load profile data as the consumption required. Based on the simulation result, the power generation starting time for the next day is determined. The effectiveness of the proposed dispatch strategy is demonstrated by obtaining the best starting time and identifying minimum power requiredfrom the conventional grid. The power supply from the conventional grid is reduced by 10% by applying the proposed methodology

Black box modelling and simulating the dynamic indoor air temperature of a laboratory using autoregressive–moving-average (ARMA) model

Mathematical model representing the dynamic indoor air temperature of a building is important for reducing the time and cost required to test any proposed thermal comfort control algorithm and strategy for that building through computer simulation. There are many types of mathematical model, and each type has its strength(s) and weakness(es). An autoregressive-moving-average (ARMA) model, a type of black box model is used to represent the dynamic indoor air temperature behaviour of industrial instrumentation laboratory at Malaysia-Japan international institute of technology (MJIIT), Universiti Teknologi Malaysia (UTM) Kuala Lumpur based on the recorded data from the laboratory and minimal physical characteristics knowledge of the laboratory. The ARMA model?s output developed in this research is compared with the actual data recorded from the laboratory for performance measurement. The obtained result shows that the ARMA model is sufficient for modelling and simulating the dynamic indoor air temperature behaviour of the laboratory

Comparative study of series and parallel schemes for stabilization of a microgrid integrated with a solar thermal cogeneration system using virtual synchronous generator control

When a solar thermal cogeneration system is located close to energy consumers, the electricity loss caused by transportation can be largely reduced and the low-temperature thermal energy can be utilized for air conditioning. In this case, a microgrid is introduced to connect a solar thermal cogeneration system and a conventional grid to switch between islanded and grid-connected modes. A new technology for stabilizing the system is required to handle the relatively slow response of the solar thermal cogeneration system for this configuration. Virtual synchronous generator (VSG) control can enhance the power system stability by mimicking steady-state and transient behaviors of synchronous generators (SGs). A swing equation in the VSG control identifies the virtual inertial property of SGs to rapidly adjust to a steady-state frequency. In this work, the transient responses of the VSG series and parallel configurations incorporated into a microgrid are compared. The transient behaviors of rotor angular speed and voltage are simulated for loading and tripping operations. The analysis results suggest that the VSG series configuration suppresses fluctuations better than the parallel configuration and enables stable network operation