The energy in the system is stored in (E) hydraulically or pneumatically and extracted from (E) when necessary. Since hydraulic pumps/motors tend to have a higher power density than pneumatic compressors/expanders, the hydraulic path is usually used for high-power transient events, such as gusts or a sudden power demand.
The hydraulic energy storage system enables the wind turbine to have the ability to quickly adjust the output power, effectively suppress the medium- and high-frequency components of wind power fluctuation, reduce the disturbance of the generator to the grid frequency, and improve the power quality of the generator.
This review will consider the state-of-the art in the storage of mechanical energy for hydraulic systems. It will begin by considering the traditional energy storage device, the hydro-pneumatic accumulator. Recent advances in the design of the hydraulic accumulator, as well as proposed novel architectures will be discussed.
This article mainly reviews the energy storage technology used in hydraulic wind power and summarizes the energy transmission and reuse principles of hydraulic accumulators, compressed air energy storage and flywheel energy storage technologies, combined with hydraulic wind turbines.
On one hand, introducing the energy storage system into hydraulic wind power solves the problems caused by the randomness and volatility of wind energy on achieving the unit’s own functions, such as speed control, power tracking control, power smoothing, and frequency modulation control.
4. The different forms of hydraulic storage We can distinguish three types of hydroelectric power stations capable of producing energy storage: the power stations of the so-called “lake” hydroelectric schemes, the power stations of the “run-of-river” hydroelectric schemes, and the pumping-turbine hydroelectric schemes (Read: Hydraulic works ).