| Work Detail |
A group of Chinese researchers has developed an energy management system for modular gravity storage. Compared with single block gravity storage, the modular counterpart offers more flexibility in power output, ease of mass production of related equipment and greater flexibility in weight selection.
A group of researchers led by Chinas State Grid Smart Grid Research Institute has developed a plant control system for modular gravity energy storage (M-GES).
“Our work represents the first attempt to create an energy control strategy with excellent performance for M-GES power plants,” lead author of the research Wenxuan Tong told pv magazine . “We proposed and validated for the first time the control of maximum height difference. “A detailed mathematical model of the energy management system of the M-GES plant is also presented for the first time.”
M-GES differs from monolithic GES in that it uses several standardized blocks instead of a single giant block. According to the researchers, the use of modular weights offers more flexibility in power output, ease of mass production of related equipment, and greater flexibility in weight selection.
“Currently, most studies in the field of M-GES focus on the proposal of new technological routes and the preliminary verification of technical feasibility,” the researchers explain. “However, M-GES plants need a deeper study of their control technology to apply it to the real electrical grid with its function as grid power regulator.”
In the study “ Energy management system for modular-gravity energy storage plant ,” published in the Journal of Energy Storage, the research team explains that the system The management system consists of three different parts: the monitoring prediction system (MPS), the energy management system (EMS) and the power control system (PCS). The three parts communicate with each other through the supervisory control and data acquisition (SCADA) system.
The MPS monitors the network status in real time and receives information from the dispatch center based on that status. It is responsible for the optimal interaction between the M-GES plant and the network. The PCS is responsible for balancing the power and coordinating the operation of the M-GES plant units.
The EMS coordinates the operation of the different blocks of the GES plant. “The EMS of an M-GES plant will be more complex than that of a GES plant based on independent blocks due to the implication of coordinated control between multiple blocks,” the academics say.
The EMS also reportedly addresses one of the main obstacles that module-based gravity storage has to deal with, which is its state of charge (SOC). SOC is the amount of energy stored in an energy storage system relative to its total capacity. To solve this problem, the research team adopted a SOC model and maximum height difference (MHC) power control strategy.
“Losses are generated whenever the unit is turned on and off, including inherent losses during starting and stopping, the overall operating efficiency of the unit can be improved by extending the stable operating time of the unit,” scientists explain.” Adopting an energy control strategy with a longer unit operating cycle is appropriate from the units perspective.”
The researchers validated their approach on the MATLAB/Simulink platform and discovered that the MHC improves the energy stability and efficiency of an M-GES plant by keeping the SOC above half, an advantage that becomes more relevant as the SOC.
“The proposed energy management system works well in natural energy systems,” says Tong. |
