A pumped storage power plant is a hydroelectric power plant that stores electrical energy.
Process: use energy from the power grid when the load is low, pump water from the lower tank to the upper tank to store energy, and when the power grid is under peak load, release the water. to the hydroelectric power station where the lower reservoir produces electricity. Also known as a hydroelectric energy storage plant.
Methods to achieve benefits: In many power grids, due to the expansion of peak-valley differences and various economic reasons, there is an urgent need for power electric peak shaving. Pumped storage power plants are both good sources of energy for peak attenuation and offer great flexibility in grid dispatch. Related tox conventional hydroelectric power plants, in addition to having the same peak regulation, phase regulation and backup functions, it can also use energy during low valley periods (called valley filling) to convert electricity low-cost grid to high-cost energy. , sold electricity. This can bring economic benefits to the entire power grid due to its high price for peak electricity.
Pumped-storage unit: A three-phase salient-pole synchronous motor used in pumped-storage power plants. It can be used to regulate system load in electrical systems. When there is excess electricity in the system, the pumped storage motor operates as an electric motor, driving a water pump (turbine) to pump water downstream into the tank, converting the electrical energy in potential energy of the eto and storing it. When there is a peak load in the system, water is released from the reservoir and the hydraulic turbine drives the pumped storage motor to operate as a generator, converting the potential energy of the water from the reservoir of electrical energy to supply the network. . In small pumped storage power plants, the pumped storage motor can be connected to the turbine and the water pump simultaneously, which is called a series unit. This pumped storage motor is not much different from a general synchronous motor. In large pumped-storage power plants, the pumped-storage motor is often connected to a single type of hydraulic machinery, called a reversible unit. When this type of hydraulic machine works as a water turbine and a water pump, not only its rotation direction is different, but also to improve the operating efficiency ofFor a water pump, the rotation speed must be increased appropriately compared to that of a water turbine. Therefore, the pumped storage motor must not only rotate forward and reverse, but also. The number of poles of the motor can be changed accordingly to change the speed according to its operating conditions.
Actually, the storage method is: electrical energy -> potential energy -> electrical energy. In some places, when load demand is high (like after everyone goes home in the evening), fill up. electricity cannot be satisfied, but once the peak passes (when people sleep in the middle of the night), electricity consumption drops significantly. Heat engines (thermal power plants) operate continuously and take several hours to start and stop (which costs money). Consequently, thermal enginesThey generally rarely stop except to meet dispatching needs. When load demand is low, excess electrical energy cannot be used. If it is wasted, the pumped storage plant can use the excess electricity to pump water, store water, and use that water to produce electricity during peak periods.