Knowledge point 1: flywheel energy storage principle
The working principle of flywheel energy storage is that in the case of abundant power, electric energy drives the flywheel to rotate at high speed, converting electric energy into mechanical energy for storage; When the system needs it, the flywheel slows down, and the motor works as a generator to convert the kinetic energy of the flywheel into electric energy for users to use. Flywheel energy storage realizes the storage and release of electric energy through the acceleration and deceleration of the rotor.
Knowledge point 2: flywheel energy storage structure
The basic structure of flywheel energy storage system includes the following five components:
Flywheel:
Generally, it is composed of high-strength composite fiber material, which is wound on the metal wheel integrated with the motor rotor in a certain winding way.
Bearing:
The flywheel is supported by permanent magnet bearings, electromagnetic bearings, superconducting suspension bearings or other low-friction and low-power bearings, and adopts mechanical protection bearings.
Motor generator:
Generally, it is a DC permanent magnet brushless synchronous motor to generate reciprocating bidirectional motors.
Power converter:
It is a key component that converts the input electric energy into direct current and supplies it to the motor, and the output electric energy is supplied to the load after frequency modulation rectification.
Vacuum chamber:
In order to reduce the wind loss and prevent the safety accident of high-speed rotating flywheel, the flywheel system is placed in a high-vacuum sealed protective sleeve.
Knowledge point 3: Advantages of flywheel energy storage
As a new type of physical energy storage, flywheel energy storage has the following advantages compared with traditional chemical batteries:
1) fast charge and discharge.
The time from receiving the regulation signal from the power grid side to the reaction of the flywheel energy storage system is extremely short, and the charging/discharging process of the whole system can be completed in the next few minutes, which meets the short-time response and regulation requirements of the power grid, and the charging/discharging time is faster than that of batteries, pumped storage and compressed air.
2) high working efficiency.
The working efficiency of general flywheel energy storage system can reach about 90%, which has obvious advantages compared with 60% of pumped storage and 70% of battery energy storage, while the working efficiency of magnetic bearing flywheel energy storage system is higher, close to 95%.
3) Long service life.
Although the flywheel energy storage system is expensive, it is well-designed, and the average annual maintenance cost is extremely low. The charging and discharging times are obviously better than that of battery energy storage, reaching the order of one million, and the maintenance-free time generally exceeds 10a.
4) Environmental protection and no pollution.
Because it is mechanical energy storage, flywheel energy storage will not emit substances that pollute the environment, and it is an environmentally friendly green energy storage technology. In addition, the flywheel energy storage system also has the advantages of modularization, short construction time and little impact of accident consequences.
Knowledge point 4: flywheel energy storage should be? use
The application of flywheel energy storage technology mainly focuses on energy storage and peak power consumption. The specific application is as follows:
1)UPS uninterruptible power supply.
Uninterruptible power supply (UPS) is a kind of equipment that uses energy storage devices to provide high-quality electric energy to loads, and is widely used in medical equipment, communication and computer systems. At present, UPS gradually tends to use new energy storage equipment such as flywheel energy storage device, which not only reduces environmental pollution, prolongs service life, but also improves work efficiency.
2) Save energy.
Energy efficiency has always been a topic of concern to us, and energy conservation has also been widely recognized. Traditional mechanical devices, after mechanical braking, energy is converted into heat energy and dissipated, resulting in a certain degree of waste and reducing the efficiency of energy utilization. Therefore, the flywheel energy storage device can convert this energy into kinetic energy, store it and output it to the system when necessary, which can reduce energy loss and improve energy utilization. At present, the main application fields are concentrated in new energy vehicles and urban rail transit.
3) Traditional power system.
Flywheel energy storage technology is applied to traditional power system, which can better adjust active power, peak load and valley load, improve power factor, stabilize voltage and frequency, and has a good effect on improving power quality and stabilizing load. Transient stability has always been the focus of stable operation and analysis of power system. Relying on the characteristics of flywheel energy storage, such as large instantaneous power, fast response and short charging and discharging completion time, it can quickly and actively participate in the dynamic process of power system, eliminate the transient process of disturbance and contraction, avoid the occurrence of dangerous situations such as voltage collapse and low-frequency oscillation as much as possible, and play a positive role in restoring stable operation of power system.
4) Microgrid.
At present, as a small power generation and distribution system, microgrid can realize self-monitoring and self-adjustment, and can be connected to the grid or run independently. Therefore, compared with the traditional large power grid, microgrid needs the support of energy storage system because of its many distributed power sources, flexible location and dispersion. When the microgrid energy is sufficient, the flywheel energy storage system stores excess energy to stabilize the terminal voltage; When the microgrid fails or lacks power, the stored energy is released, which enhances the reliability of local power supply and maintains the frequency stability of the microgrid.
5) Renewable energy is connected to the grid.
A key application field of flywheel energy storage technology is the grid connection of renewable energy. At present, new energy sources such as wind power generation and photovoltaic power generation have attracted more and more attention because of their clean, huge and renewable advantages. However, due to the intermittence and fluctuation of renewable energy such as wind and light, the impact on the power grid after grid connection is increased, which has a certain impact on the safe and stable operation of the power system. As a flexible active power supply, flywheel energy storage system can stabilize the grid-connected frequency and voltage, reduce the fluctuation of renewable energy, reduce the impact on the power grid, effectively improve the power quality problems caused by grid-connected renewable energy and ensure safety and reliability.
About micro-control new energy
Shenzhen Micro-control New Energy Technology Co., Ltd. (referred to as micro-control or micro-control new energy) is a global leader in physical energy storage technology. The company is headquartered in Shenzhen, covering North America, Europe, Asia, Latin America and other regions. With the "safe, reliable and efficient" global leading magnetic levitation energy technology, its products and services are widely trusted by many Fortune 500 companies such as Huawei, GE, ABB, Siemens and Emerson.
Facing the three major trends of "cleaner, high-density and digital" energy in the future, the company continues to provide systematic solutions for energy transportation, storage, recycling and data management for strategic emerging industries.