阅读说明：本技术 一种集成磁悬浮飞轮储能的风力发电机组 (Wind generating set integrated with magnetic suspension flywheel energy storage ) 是由 鲁晓军 王华军 陶守元 肖军 叶磊 黄涵 简巍 黄灿灿 王乙斐 段涛 于 2020-12-24 设计创作，主要内容包括：本发明公开了一种集成磁悬浮飞轮储能的风力发电机组。它包括风力发电机组和磁悬浮飞轮储能系统；所述磁悬浮飞轮储能系统安装于风力发电机组的塔筒底部；风力发电机组与磁悬浮飞轮储能系统并联连接；磁悬浮飞轮储能系统为采用磁悬浮轴承的超高速飞轮储能系统；磁悬浮飞轮储能系统辅助维护电力系统安全稳定运行。本发明克服了现有技术由于储能单元控制器与交流系统无直接联系,需要建立交流系统频率与每一台风电机组内部储能控制单元的通讯；超级电容的使用寿命尚远小于风电机组的寿命等缺点；具有辅助实现一次调频、无功调节等有利于维护电力系统安全稳定运行；通过合理选择飞轮储能方案及安装形式,降低系统维护成本,提高系统可靠性和经济性。(The invention discloses a wind generating set integrated with magnetic suspension flywheel energy storage. The system comprises a wind generating set and a magnetic suspension flywheel energy storage system; the magnetic suspension flywheel energy storage system is arranged at the bottom of a tower barrel of the wind generating set; the wind generating set is connected with the magnetic suspension flywheel energy storage system in parallel; the magnetic suspension flywheel energy storage system is an ultra-high speed flywheel energy storage system adopting a magnetic suspension bearing; the magnetic suspension flywheel energy storage system assists in maintaining safe and stable operation of the power system. The invention overcomes the defects that in the prior art, because the energy storage unit controller is not directly connected with the alternating current system, the communication between the frequency of the alternating current system and the energy storage control unit in each wind turbine generator set needs to be established; the service life of the super capacitor is far shorter than that of the wind turbine generator and the like; the method has the advantages that the method assists in realizing primary frequency modulation, reactive power regulation and the like, and is beneficial to maintaining safe and stable operation of the power system; by reasonably selecting the flywheel energy storage scheme and the installation form, the system maintenance cost is reduced, and the system reliability and the economy are improved.)

1. A wind generating set integrated with magnetic suspension flywheel energy storage is characterized in that: comprises a wind generating set (1) and a magnetic suspension flywheel energy storage system (2);

the magnetic suspension flywheel energy storage system (2) is arranged at the bottom of a tower barrel (1.1) of the wind generating set (1);

the wind generating set (1) is connected with the magnetic suspension flywheel energy storage system (2) in parallel;

the magnetic suspension flywheel energy storage system (2) is an ultra-high speed flywheel energy storage system adopting a magnetic suspension bearing;

the magnetic suspension flywheel energy storage system (2) assists in maintaining safe and stable operation of the power system.

2. An integrated magnetic suspension flywheel energy storage wind generating set according to claim 1, characterized in that: the magnetic suspension flywheel energy storage system (2) comprises a magnetic suspension bearing (2.1), a flywheel (2.2), a high-speed permanent magnet synchronous generator (2.3), a rectifier (2.4), an inverter (2.5), a vacuum sealing cavity (2.6) and a vacuum pump (2.7);

the magnetic suspension bearing (2.1) and the flywheel (2.2) are in no contact, and the flywheel (2.2) is coaxially connected with a rotor of the high-speed permanent magnet synchronous generator (2.3) and is jointly installed in the vacuum seal cavity (2.6); the vacuum pump (2.7) is connected with the vacuum seal cavity (2.6);

the three-phase output of the stator of the high-speed permanent magnet synchronous generator (2.3) is connected to the alternating current side of the rectifier (2.4);

the rectifier (2.4) is connected to the DC side of the inverter (2.5) on the DC side via a capacitor;

the AC side of the inverter (2.5) is directly connected with the AC side of the grid-side inverter of the wind generating set (1).

3. An integrated magnetic suspension flywheel energy storage wind generating set according to claim 2, characterized in that: the wind generating set (1) is selected from a permanent magnet synchronous wind generating set or a double-fed induction wind generating set.

4. An integrated magnetic suspension flywheel energy storage wind generating set according to claim 3, characterized in that: the power grade of the magnetic suspension flywheel energy storage system (2) is matched with the power grade of the single wind generating set (1) according to a certain proportion; the capacity ratio of the magnetic suspension flywheel energy storage system (2) is smaller than that of the wind generating set (1).

5. An integrated magnetic suspension flywheel energy storage wind generating set according to claim 4, characterized in that: a coordinated operation method of a magnetic suspension flywheel energy storage system (2) and a wind generating set (1) in a wind generating set integrating magnetic suspension flywheel energy storage comprises the following steps:

s1: the magnetic field generated by the magnetic suspension bearing (2.1) bears the gravity of the flywheel (2.2), and the flywheel (2.2) is suspended in the vacuum sealed cavity (2.6); the vacuum pump (2.7) monitors and maintains the vacuum degree of the vacuum seal cavity (2.6), the flywheel (2.2) is coaxially connected with the rotor of the high-speed permanent magnet synchronous generator (2.3), the flywheel (2.2) drives the rotor of the high-speed permanent magnet synchronous generator (2.3) to rotate, and alternating current voltage and current are induced in the stator;

s2: the three-phase output of the stator of the high-speed permanent magnet synchronous generator (2.3) is connected to the alternating current side of the rectifier (2.4), and the rectifier (2.4) converts alternating voltage and alternating current generated by the stator of the high-speed permanent magnet synchronous generator (2.3) into direct voltage and direct current;

s3: the rectifier (2.4) is connected with the direct current side of the inverter (2.5) through a capacitor at the direct current side, and the inverter (2.5) converts direct current voltage and direct current into power frequency alternating current voltage and alternating current;

s4: the AC side of the inverter (2.5) is directly connected with the AC side of a grid-side inverter of the wind generating set (1) to directly measure the frequency of the AC side or measure the voltage amplitude of the AC side.

6. An integrated magnetic suspension flywheel energy storage wind generating set according to claim 5, characterized in that: in S4, the inverter (2.5) directly measures the frequency of the AC side, and actively or after receiving the instruction of the upper control system, participates in the frequency modulation process of the AC system;

when the deviation of the frequency of the alternating current side and the power frequency of 50Hz is monitored to be lower than a frequency control dead zone or an active power increasing instruction sent by an upper control system is received, the inverter (2.5) adjusts the active power of the alternating current side, the active power is injected into the alternating current side of the wind generating set (1) from the magnetic suspension flywheel energy storage system (2), the active power output to an alternating current power grid by the wind generating set (1) is increased, and the frequency of the alternating current power grid is assisted to be recovered to a normal state;

when the deviation between the frequency of the alternating current side and the power frequency of 50Hz is higher than a frequency control dead zone or an active power reduction instruction sent by an upper control system is received, the inverter (2.5) adjusts the active power of the alternating current side, the active power is injected into the magnetic suspension flywheel energy storage system (2) from the wind generating set (1), the active power output to an alternating current power grid by the wind generating set (1) is reduced, and the frequency of the alternating current power grid is assisted to be recovered to a normal state.

7. An integrated magnetic suspension flywheel energy storage wind generating set according to claim 5, characterized in that: in S4, the inverter (2.5) directly measures the voltage amplitude of the AC side, and actively or after receiving the instruction of an upper control system, participates in the reactive power regulation process of the AC system;

when the deviation between the voltage amplitude at the alternating current side and a rated value is lower than an amplitude control dead zone or an instruction sent by an upper control system is received, the inverter (2.5) provides capacitive reactive power for the alternating current side of the wind generating set (1) to assist the alternating current voltage to rise back to a normal value;

when the deviation between the voltage amplitude of the alternating current side and the rated value is higher than the amplitude control dead zone or an instruction sent by an upper control system is received, the inverter (2.5) provides inductive reactive power for the alternating current side of the wind generating set (1) to assist the alternating current voltage to fall back to a normal value.

Technical Field

The invention relates to the technical field of new energy power generation of a power system, in particular to a wind generating set integrated with magnetic suspension flywheel energy storage.

Background

In recent years, as the ratio of new energy power generation stations represented by photovoltaic power generation and wind power generation in a power supply of a power system is gradually increased, the frequency inertia of the power system is remarkably reduced, the frequency modulation and peak shaving pressure of a conventional thermal power generating unit are increased greatly, and the safe and stable operation of the power system is threatened. The national and local energy management organizations issue documents in sequence, and provide functional requirements beneficial to safe and stable operation of a system for a new energy power station for grid-connected power generation, wherein an energy storage technology is provided for many times:

the Liaoning province reform Committee printed 'Liaoning province wind power project construction scheme' requires that Liaoning wind power project construction preferentially considers projects with attached energy storage facilities and favorable peak shaving; the Jilin energy agency issues a 'reporting guidance scheme for wind power and photovoltaic power generation projects in the Jilin province of 2020', and points out that strategic emerging industrial projects with energy storage and the like are to be supported vigorously; the Henan development committee issues a notice about the organization developing the construction of a project for wind power generation and photovoltaic power generation in 2020, and points out that the project for newly adding flat wind power generation and photovoltaic power generation configured with energy storage is supported preferentially; the Hunan development of a Notification about the release of a whole province 2020-plus 2021-year new energy consumption early warning result is committed to require that measures such as energy storage facility construction and the like are researched by a power grid enterprise to improve the new energy consumption and delivery capacity; the energy resource agency of Guizhou issues a notice about reporting a photovoltaic power generation project plan of 2021, and indicates that 10% of stored energy needs to be allocated in a project of sending out a project with limited consumption; the Hubei energy agency issues a 'competition configuration working scheme for an annual average price wind power project of 2020 in Hubei province', points out that the promise of 'combining wind power field and energy storage' needs to be filled in the project declaration of the wind power field, and the energy storage capacity allocated to the wind power project is not less than 10% of the configuration capacity of the wind power project; a power dispatching control center of a Shanxi power company in the state of network issues a notice about developing primary frequency modulation transformation work of a new energy station, and points out that the new energy (a wind power station and a photovoltaic power station) realizes a primary frequency modulation function by reserving active standby or configuring energy storage equipment.

At present, the country and the place put rigid demands on the primary frequency modulation capability of a new energy station: GB 38755) 2019, the safety and stability guide of electric power systems, the two rules printed by the State energy administration of China supervision agency (the rules for implementing grid-connected operation management of power plants in China and the rules for implementing auxiliary service management of grid-connected power plants in China), and the local energy supervision authorities such as the State energy administration of North China supervision agency and the like all require that new energy stations have a primary frequency modulation function. The primary frequency modulation means that when the frequency of the power system deviates from the target frequency, the generator set automatically adjusts the output force to enable the system frequency to be recovered to be normal, and plays an important role in guaranteeing the safe and stable operation of the power system. Taking wind power generation as an example, in order to realize a primary frequency modulation function, if additional power sources such as energy storage and the like are not configured, when the system frequency falls out of an artificial frequency dead zone, a certain amount of spare power generation capacity needs to be reserved in a wind power plant to realize the rapid support of wind power; when the system frequency exceeds the artificial frequency dead zone, the captured wind energy is reduced through the adjustment of mechanical devices such as pitch angle control and the like, and the reduction of the wind power is realized. The former can cause the loss of generating capacity, and the economy is poor when the generator runs for a long time; the latter has the advantages of low regulation speed on one hand, and mechanical abrasion possibly increased by frequent action of a mechanical device on the other hand, so that the maintenance risk of the fan is increased, and the service life of the wind turbine generator is shortened. Therefore, a certain amount of energy storage devices are configured in the wind power project, so that the power of the wind power grid-connected point can be quickly adjusted, and the scheme has a wide application prospect.

The energy storage technology mainly comprises the forms of electrochemical energy storage, mechanical energy storage and the like, wherein the electrochemical energy storage is represented by a lithium battery, and the mechanical energy storage is represented by flywheel energy storage. At present, the energy storage of the lithium battery has the cost advantage and the energy density is large, but the lithium battery faces the safety risk of fire and explosion, and has the problems of high operation and maintenance cost, low recovery value, great environmental pollution, greatly shortened service life when being frequently used and the like, and the difficulty of cyclic investment is also faced when the battery is irregularly replaced. With the development of the flywheel energy storage technology, the magnetic suspension flywheel technology breaks through the technical bottleneck (Jiangwalie, Chenguang) of the traditional flywheel mechanical bearing, and the pulse power supply system design [ J ] Zhejiang electric power, 2020,39(05):50-54.) based on the magnetic suspension flywheel energy storage is adopted, so that the cross-magnitude promotion of the flywheel rotating speed is realized, the energy density and the conversion efficiency are obviously improved, and the volume of the flywheel energy storage device is reduced. Although the magnetic suspension flywheel energy storage one-time investment cost is large, the service life is long, and the circular investment burden is avoided. In addition, the flywheel body can realize cyclic utilization, and has high recovery value and small environmental pressure.

At present, a scheme for applying energy storage to primary frequency modulation of a wind power plant comprises a centralized scheme (Wenqui, Panyan, Chengjie and Lichenhao. the patent publication number is CN102412590A, the patent name is 'wind power plant group modular direct current grid-connected topology with an energy storage device') and a distributed scheme (Yanxiangwu, Cuisen and Changfei. a primary frequency modulation control strategy of a double-fed induction generator considering energy storage self-adaptive adjustment [ J ]. electrotechnical science and 2020). The prior publication No. CN202971050U, the patent name is "a wind power generation device", the wind power generator disclosed therein is connected in series with a flywheel system, the power levels of a fan and an energy storage system are equal, namely, the fan generates electricity and drives a direct current motor to drive the flywheel to rotate, and then the flywheel drives the generator to rotate to generate alternating current; the flywheel energy storage device is used for continuously and stably discharging, night wind power generation and daytime power utilization are connected by utilizing flywheel energy storage, short-period energy storage is achieved, and the flywheel energy storage device is a centralized scheme.

The centralized scheme is only used for configuring energy storage at a grid-connected point of the wind power plant, and the distributed scheme can be used for configuring the energy storage to a single wind turbine. The centralized scheme focuses on the frequency fluctuation of the wind power grid-connected point, ignores the internal condition of the wind power plant, and has higher safety and reliability risk than distributed energy storage. In the distributed energy storage scheme, if the lithium battery is configured in a single wind turbine, the fire and explosion risks of the lithium battery can greatly harm the safety of the wind turbine, especially the offshore wind turbine, and huge loss can be caused. In addition, the service life of a single wind turbine generator is 20 years at present, the service life of energy storage of a lithium battery is often low, the maintenance time windows in the whole life cycle of the two wind turbine generators are not uniform, and the operation and maintenance cost is high. The number of times of the flywheel energy storage is far greater than that of the lithium battery energy storage, the service life of the flywheel energy storage is long, the maintenance cost in the whole life cycle is low, the synchronous maintenance of the flywheel energy storage and the wind turbine generator can be realized, and the operation and maintenance cost is further reduced.

It can be seen that how to select an energy storage configuration scheme with flexible control, safety, reliability and excellent economy in a large-scale wind power plant, especially an offshore wind power plant with expensive construction and operation and maintenance costs is a problem to be solved urgently in the current engineering.

Disclosure of Invention

The invention aims to provide a wind generating set integrated with a magnetic suspension flywheel for energy storage, which can realize auxiliary services such as primary frequency modulation and reactive power regulation which are beneficial to maintaining the safe and stable operation of an electric power system; on the other hand, by reasonably selecting the flywheel energy storage scheme and the installation form, the system maintenance cost is reduced, and the system reliability and the economy are improved.

In order to achieve the purpose, the technical scheme of the invention is as follows: a wind generating set integrated with magnetic suspension flywheel energy storage is characterized in that: the system comprises a wind generating set and a magnetic suspension flywheel energy storage system;

the magnetic suspension flywheel energy storage system is arranged at the bottom of a tower barrel of the wind generating set;

the wind generating set is connected with the magnetic suspension flywheel energy storage system in parallel;

the magnetic suspension flywheel energy storage system is an ultra-high speed flywheel energy storage system adopting a magnetic suspension bearing; the magnetic suspension flywheel energy storage system assists in maintaining safe and stable operation of the power system.

In the technical scheme, the magnetic suspension flywheel energy storage system comprises a magnetic suspension bearing, a flywheel, a high-speed permanent magnet synchronous generator, a rectifier, an inverter, a vacuum seal cavity and a vacuum pump;

the magnetic suspension bearing is in no contact with the flywheel, and the flywheel is coaxially connected with a rotor of the high-speed permanent magnet synchronous generator and is jointly installed in the vacuum seal cavity; the vacuum pump is connected with the vacuum seal cavity;

the three-phase output of the stator of the high-speed permanent magnet synchronous generator is connected to the alternating current side of the rectifier;

the rectifier is connected with the direct current side of the inverter through a capacitor at the direct current side;

and the alternating current side of the inverter is directly connected with the alternating current side of a grid-side inverter of the wind generating set.

In the technical scheme, the wind generating set is selected from a permanent magnet synchronous wind generating set or a double-fed induction wind generating set.

In the technical scheme, the power grade of the magnetic suspension flywheel energy storage system and the power grade of a single wind generating set are proportioned according to a certain proportion; the capacity ratio of the magnetic suspension flywheel energy storage system is smaller than that of the wind generating set.

In the above technical solution, the coordinated operation method of the magnetic suspension flywheel energy storage system and the wind generating set in the wind generating set integrated with the magnetic suspension flywheel energy storage comprises the following steps:

s1: the magnetic field generated by the magnetic suspension bearing bears the gravity of the flywheel and enables the flywheel to be suspended in the vacuum seal cavity; the vacuum pump monitors and maintains the vacuum degree of the vacuum sealed cavity, the flywheel is coaxially connected with a rotor of the high-speed permanent magnet synchronous generator, the flywheel drives the rotor of the high-speed permanent magnet synchronous generator to rotate, and alternating current voltage and current are induced in the stator;

s2: the three-phase output of the stator of the high-speed permanent magnet synchronous generator is connected to the alternating current side of the rectifier, and the rectifier converts alternating voltage and alternating current generated by the stator of the high-speed permanent magnet synchronous generator into direct voltage and direct current;

s3: the rectifier is connected with the direct current side of the inverter through a capacitor at the direct current side, and the inverter converts direct current voltage and direct current into power frequency alternating current voltage and alternating current;

s4: and the alternating current side of the inverter is directly connected with the alternating current side of a grid-side inverter of the wind generating set, and the frequency of the alternating current side or the voltage amplitude of the alternating current side is directly measured.

In the above technical solution, in S4, the inverter directly measures the frequency of the ac side, and actively or after receiving an instruction from the upper control system, participates in the frequency modulation process of the ac system;

when the deviation of the frequency of the alternating current side and the power frequency of 50Hz is monitored to be lower than a frequency control dead zone or an active power increasing instruction sent by an upper control system is received, the inverter adjusts the active power of the alternating current side, the active power is injected into the alternating current side of the wind generating set from the magnetic suspension flywheel energy storage system, the active power output to an alternating current power grid by the wind generating set is increased, and the frequency of the alternating current power grid is assisted to be recovered to a normal state;

when the deviation between the frequency of the alternating current side and the power frequency of 50Hz is higher than a frequency control dead zone or an active power reduction instruction sent by an upper control system is received, the inverter adjusts the active power of the alternating current side, the active power is injected into the magnetic suspension flywheel energy storage system from the wind generating set, the active power output to the alternating current power grid by the wind generating set is reduced, and the frequency of the alternating current power grid is assisted to be recovered to a normal state.

In the above technical solution, in S4, the inverter directly measures the voltage amplitude at the ac side, and actively or after receiving an instruction from the upper control system, participates in the reactive power regulation process of the ac system;

when the deviation between the voltage amplitude of the alternating current side and the rated value is lower than an amplitude control dead zone or an instruction sent by an upper control system is received, the inverter provides capacitive reactive power to the alternating current side of the wind generating set to assist the alternating current voltage to rise back to a normal value;

when the deviation between the voltage amplitude of the alternating current side and the rated value is higher than the amplitude control dead zone or an instruction sent by an upper control system is received, the inverter provides inductive reactive power to the alternating current side of the wind generating set to assist the alternating current voltage to fall back to a normal value.

Compared with the existing wind turbine generator distributed energy storage scheme, the method has the following advantages:

(1) the magnetic suspension flywheel energy storage scheme is adopted, so that the safety and the reliability are realized, and the risk of fire and explosion does not exist;

(2) the magnetic suspension flywheel energy storage system has the advantages that the flywheel rotating speed is high, the energy density and the power density are high, the size is small, the magnetic suspension flywheel energy storage system can be integrally installed on an equipment platform in the tower of the wind generating set, an energy storage device platform does not need to be additionally built, and the construction cost is low;

(3) the flywheel of the magnetic suspension flywheel energy storage system has no friction loss of a mechanical bearing, low operation loss, high energy conversion efficiency and low operation cost;

(4) the circulating operation frequency of the flywheel of the magnetic suspension flywheel energy storage system can reach the million order, the whole life cycle is long, the operation life of the flywheel has the same order of magnitude as that of the wind generating set, and the synchronous maintenance can be realized, so the maintenance cost is low;

(5) the magnetic suspension flywheel energy storage system is directly connected with the alternating current side of the wind turbine generator system grid-side inverter, so that double regulation control of active power and reactive power of the alternating current side of the wind turbine generator system can be realized, and the auxiliary service requirements of primary frequency modulation and reactive power regulation are met;

(6) the circulating operation times of the magnetic suspension flywheel energy storage system are almost not limited, so that the worry of frequent operation and shortening of the service life of the magnetic suspension flywheel energy storage system does not exist, the magnetic suspension flywheel energy storage system can actively participate in paid auxiliary service projects such as system frequency modulation and reactive compensation, and the economic benefit of a wind power plant is improved;

(7) the magnetic suspension flywheel energy storage system directly acquires local alternating current frequency and voltage amplitude signals and performs spontaneous active power and reactive power control, an energy management system is not needed to communicate the energy storage scheme of each wind turbine generator, and the operation control is flexible and reliable;

(8) when the wind turbine generator set needs to generate active power in application scenes such as primary frequency modulation, the magnetic suspension flywheel energy storage system can quickly respond and output the active power to the alternating current side of the wind turbine generator set;

(9) when the wind turbine generator is required to reduce active power in application scenes such as primary frequency modulation, the magnetic suspension flywheel energy storage system can absorb the active power from the alternating current side of the wind turbine generator, convert wind energy into kinetic energy of a flywheel, store the kinetic energy in a high efficiency mode, and finally feed the kinetic energy back to the alternating current system, so that waste of the wind energy is avoided, overvoltage of a direct current side capacitor of a grid side inverter can be avoided, the use frequency of an energy consumption resistor is reduced, even the energy consumption resistor can be cancelled, and the manufacturing cost of a fan is reduced;

(10) in the application scene of reactive power regulation, the inverter of the magnetic suspension flywheel energy storage system can realize flexible and bidirectional reactive power control by regulating the phase of the output alternating voltage and alternating current, has little influence on the energy stored in the flywheel and hardly influences the stored energy.

Drawings

FIG. 1 is a schematic diagram of the structural position relationship between the energy storage of the magnetic suspension flywheel and the wind turbine generator set.

FIG. 2 is a schematic diagram of the electrical connection between the magnetic suspension flywheel energy storage system and a wind turbine generator of the permanent magnet synchronous generator type.

FIG. 3 is a schematic diagram of the electrical connection between the magnetic suspension flywheel energy storage system and a wind turbine generator set adopting a doubly-fed generator type.

Fig. 4 is a schematic diagram of the present invention participating in a frequency modulation process.

FIG. 5 is a schematic diagram of an example of the present invention participating in a voltage regulation process.

Fig. 6 is an electrical connection schematic diagram of the magnetic suspension flywheel energy storage system in the invention.

In fig. 1, a indicates an equipment platform inside a tower of a wind turbine generator system.

In the figure, 1-a wind generating set, 1.1-a tower cylinder, 2-a magnetic suspension flywheel energy storage system, 2.1-a magnetic suspension bearing, 2.2-a flywheel, 2.3-a high-speed permanent magnet synchronous generator, 2.4-a rectifier, 2.5-an inverter, 2.6-a vacuum sealing cavity and 2.7-a vacuum pump.

Detailed Description

The embodiments of the present invention will be described in detail with reference to the accompanying drawings, which are not intended to limit the present invention, but are merely exemplary. While the advantages of the invention will be clear and readily understood by the description.

The distributed energy storage configuration scheme based on a single wind turbine generator is adopted, reliability and safety are considered, reasonable connection is carried out on the electrical relation to realize multiple functions of primary frequency modulation, reactive power regulation and the like, reasonable planning is carried out on the structure to reduce the platform construction and operation and maintenance cost, and reasonable design is carried out on control to improve the operation flexibility and stability of the system; the method overcomes the defects that in the existing distributed energy storage technical scheme based on a single wind turbine generator, a super capacitor is adopted in an energy storage mode, and the super capacitor is directly connected to the direct current side of a double-fed wind turbine generator inverter through a DC/DC (direct current/direct current), so that only the support of active power can be provided, and the regulation of reactive power cannot be considered; because the energy storage unit controller is not directly connected with the alternating current system, the communication between the frequency of the alternating current system and the energy storage control unit in each wind turbine generator set needs to be established, and the cost is higher; how to structurally integrate the energy storage and the wind turbine generator is not considered; the cycle number of the super capacitor is high, but the service life of the super capacitor is far shorter than the 20-year service life of the wind turbine generator.

With reference to the accompanying drawings: a wind generating set integrated with magnetic suspension flywheel energy storage comprises a wind generating set 1 and a magnetic suspension flywheel energy storage system 2;

install magnetic suspension flywheel energy storage system 2 in tower section of thick bamboo 1.1 of wind generating set 1, and arrange on the equipment platform of tower section of thick bamboo 1.1 bottom, because the rotational speed of magnetic suspension flywheel is high, consequently, the power and the energy density of unit mass are great, and the magnetic suspension flywheel does not contain mechanical bearing, place in vacuum environment, mechanical friction and air friction loss are minimum, need not to be equipped with solitary heat-radiating equipment, therefore compact structure, area and volume are not big, can directly settle on the inside equipment platform of wind turbine tower section of thick bamboo, with original converter cabinet etc. put together on the equipment platform, realize the assembly that integrates of wind generating set and flywheel energy storage device, need not additionally to build the platform for energy storage device: the land wind power can be reduced in floor area; for offshore wind power, an offshore platform does not need to be built for the energy storage device or the load of the existing platform is not needed to be increased, sea wind and rainwater erosion is avoided in the tower barrel, and the service life is prolonged;

the wind generating set 1 is connected with the magnetic suspension flywheel energy storage system 2 in parallel; the magnetic suspension flywheel energy storage system 2 is an ultra-high speed flywheel energy storage system adopting a magnetic suspension bearing; the magnetic suspension flywheel energy storage system 2 assists in realizing services such as primary frequency modulation and reactive power regulation which are beneficial to maintaining safe and stable operation of the power system.

Further, the magnetic suspension flywheel energy storage system 2 comprises a magnetic suspension bearing 2.1, a flywheel 2.2, a high-speed permanent magnet synchronous generator 2.3, a rectifier 2.4 and an inverter 2.5 based on a full-control device, a vacuum seal cavity 2.6 and a vacuum pump 2.7;

the magnetic suspension bearing 2.1 and the flywheel 2.2 are in no contact, the flywheel 2.2 is coaxially connected with a rotor of the high-speed permanent magnet synchronous generator 2.3, and the magnetic suspension bearing 2.1, the flywheel 2.2 and the high-speed permanent magnet synchronous generator 2.3 are jointly arranged in the vacuum seal cavity 2.6; the vacuum pump 2.7 is connected with the vacuum seal cavity 2.6; the magnetic suspension bearing 2.1 bears the gravity of the flywheel 2.2, and is arranged in the vacuum seal cavity 2.6 together with the high-speed permanent magnet synchronous generator 2.3, the vacuum pump 2.7 monitors and maintains the vacuum degree of the vacuum seal cavity 2.6, so that the friction loss and the heating problem caused by the friction loss do not exist in the high-speed rotation process of the flywheel, the service life is greatly prolonged, the service life as same as that of a wind generating set can be achieved, the synchronous maintenance is realized, and the maintenance cost is reduced;

the three-phase output of the stator of the high-speed permanent magnet synchronous generator 2.3 is connected to the alternating current side of the rectifier 2.4;

the rectifier 2.4 is connected on the dc side to the dc side of the inverter 2.5 via a capacitor;

the ac side of the inverter 2.5 is directly connected to the ac side of the grid-side inverter of the wind turbine generator system 1 (as shown in fig. 1, 2, 3, 6); because the inverter 2.5 can directly measure the frequency and the voltage amplitude of the alternating current side, the invention can spontaneously adjust the active power and the reactive power which are injected into the alternating current side of the wind turbine generator by the flywheel energy storage system without communication, and realize the auxiliary services of primary frequency modulation, reactive power adjustment and the like.

Further, the wind generating set 1 is a conventional wind generating set (the conventional wind generating set is a conventional wind generating set), and may be selected from a permanent magnet synchronous wind generating set or a double-fed induction wind generating set (wherein, the self-permanent magnet synchronous wind generating set or the double-fed induction wind generating set is the prior art); the inverter 2.4 of the magnetic suspension flywheel energy storage system 2 is directly connected with the alternating current side of the grid-side inverter of the wind generating set 1, and the grid-side inverter can be a grid-side inverter in a full-power converter in a permanent magnet synchronous wind generator or a grid-side inverter in a double-fed wind power generating set, so that the invention is suitable for the type of the conventional main-flow wind generating set.

Furthermore, the power level of the magnetic suspension flywheel energy storage system 2 and the power level of the single wind generating set 1 can be proportioned according to a certain proportion according to the use requirement; the capacity ratio of the magnetic suspension flywheel energy storage system 2 is smaller than that of the wind generating set 1; for example, the rated power of the magnetic suspension flywheel energy storage system is proportioned according to 10% of the rated power of a single wind turbine generator, so that the peak-to-valley power stabilizing requirement of +/-10% can be met; in the invention, the fan and the flywheel energy storage system are in parallel connection, and the magnetic suspension flywheel energy storage system assists in realizing primary frequency modulation, reactive power regulation and other services which are beneficial to maintaining the safe and stable operation of the power system.

The magnetic suspension flywheel energy storage system is in a hot standby state in a normal state; when the system needs auxiliary services such as primary frequency modulation and the like of a fan, the magnetic suspension flywheel energy storage system intervenes in power generation.

The invention relates to a coordinated operation method of a magnetic suspension flywheel energy storage system 2 and a wind generating set 1 in a wind generating set integrating magnetic suspension flywheel energy storage, which comprises the following steps:

s1: the magnetic field generated by the magnetic suspension bearing 2.1 bears the gravity of the flywheel 2.2, and enables the flywheel 2.2 to be suspended in the vacuum seal cavity 2.6, the vacuum pump 2.7 monitors and maintains the vacuum degree of the vacuum seal cavity 2.6, the flywheel 2.2 is coaxially connected with the rotor of the high-speed permanent magnet synchronous generator 2.3, the flywheel 2.2 drives the rotor of the high-speed permanent magnet synchronous generator 2.3 to rotate, and alternating current voltage and current are induced in the stator;

s2: the three-phase output of the stator of the high-speed permanent magnet synchronous generator 2.3 is connected to the alternating current side of the rectifier 2.4, and the rectifier 2.4 converts alternating voltage and alternating current generated by the stator of the high-speed permanent magnet synchronous generator 2.3 into direct voltage and direct current;

s3: the rectifier 2.4 is connected with the direct current side of the inverter 2.5 through a capacitor at the direct current side, and the inverter 2.5 converts the direct current voltage and the direct current into power frequency alternating current voltage and alternating current;

s4: the alternating current side of the inverter 2.5 is directly connected with the alternating current side of the grid-side inverter of the wind generating set 1, and the frequency of the alternating current side or the voltage amplitude of the alternating current side is directly measured.

Further, in S4, the inverter 2.5 directly measures the frequency on the ac side, and actively or after receiving the command from the upper control system, participates in the frequency modulation process of the ac system;

when the inverter 2.5 monitors that the deviation between the frequency at the alternating current side and the power frequency 50Hz is lower than a frequency control dead zone or receives an active power increasing instruction sent by an upper control system, the inverter 2.5 adjusts the active power at the alternating current side, and the active power is injected from the magnetic suspension flywheel energy storage system 2 to the alternating current side of the wind generating set 1, so that the active power output from the wind generating set 1 to an alternating current power grid is increased, and the frequency of the alternating current power grid is assisted to be recovered to a normal state;

when the inverter 2.5 monitors that the deviation between the frequency at the alternating current side and the power frequency 50Hz is higher than a frequency control dead zone or receives an active power reduction instruction sent by an upper control system, the inverter 2.5 adjusts the active power at the alternating current side to realize that the active power is injected into the magnetic suspension flywheel energy storage system 2 from the wind generating set 1, so that the active power output to an alternating current power grid by the wind generating set 1 is reduced, and the frequency of the alternating current power grid is assisted to be recovered to a normal state;

the upper control system instruction can refer to a primary frequency modulation instruction or an Automatic Generation (AGC) instruction sent by an energy management system of the wind power plant; in the process of frequency adjustment, when the magnetic suspension flywheel energy storage system 2 sends active power, the rotating speed of the flywheel 2.2 is gradually reduced; when the magnetic suspension flywheel energy storage system 2 absorbs active power, the rotation speed of the flywheel 2.2 will gradually increase.

Further, in S4, the inverter 2.5 directly measures the voltage amplitude at the ac side, and actively or after receiving the instruction from the upper control system, participates in the reactive power regulation process of the ac system;

when the inverter 2.5 monitors that the deviation of the voltage amplitude value of the alternating current side and the rated value is lower than the amplitude control dead zone or receives an instruction sent by an upper control system, the inverter 2.5 provides capacitive reactive power for the alternating current side of the wind generating set 1 to assist the alternating current voltage to rise back to a normal value;

when the inverter 2.5 monitors that the deviation between the amplitude of the voltage at the alternating current side and the rated value is higher than the amplitude control dead zone or receives an instruction sent by an upper control system, the inverter 2.5 provides inductive reactive power to the alternating current side of the wind generating set 1 to assist the alternating current voltage to fall back to a normal value;

the upper control system instruction can refer to an automatic voltage regulation (AVC) instruction or a reactive power regulation instruction sent by a wind power plant energy management system; in the reactive power regulation process, the rotating speed of the flywheel 2.2 in the magnetic suspension flywheel energy storage system 2 is almost unchanged, and the stored energy is almost unchanged.

Examples

The invention is explained in detail by taking the embodiment that the magnetic suspension flywheel energy storage system is applied to a certain permanent magnet synchronous wind generating set to form the wind generating set integrated with the magnetic suspension flywheel energy storage, and has the guiding function for the application of other forms of the invention.

Example 1

In this embodiment, a single 5MW permanent magnet synchronous wind turbine generator system is taken as an example, and a 500kW magnetic suspension flywheel energy storage system is integrally installed at the bottom of a tower according to a capacity ratio of 10%, where a rated rotation speed of a magnetic suspension flywheel is 30000 rpm. In the spatial relationship, the energy storage system cabinet and the fan converter cabinet are jointly installed on an equipment platform at the bottom of the tower (as shown in fig. 1); in the electrical connection, an alternating current output end of the magnetic suspension flywheel energy storage system is connected to an alternating current side of a grid-side inverter of the permanent magnet synchronous wind generating set (as shown in fig. 2). The frequency control dead zone of the magnetic suspension flywheel energy storage system is set to be +/-0.05 Hz, and the alternating current voltage amplitude control dead zone is set to be +/-5%.

As shown in fig. 4, at time t1, when the frequency of the alternating current system exceeds 50.05Hz, the magnetic suspension flywheel energy storage system absorbs active power from the alternating current side of the wind turbine generator, and the rotation speed of the flywheel gradually rises; at the time t2, the frequency of the alternating current system falls back into the frequency control dead zone, and the magnetic suspension flywheel energy storage system stops absorbing active power; at the time of t3, the frequency of the alternating current system is lower than 49.95Hz, the magnetic suspension flywheel energy storage system sends active power to the alternating current side of the wind turbine generator set, and the rotating speed of a flywheel of the magnetic suspension flywheel energy storage system gradually decreases; and at the time t4, the frequency of the alternating current system rises back to the frequency control dead zone, and the magnetic suspension flywheel energy storage system stops sending active power.

As shown in fig. 5, at time t5, when the voltage of the alternating current system exceeds 105%, the magnetic suspension flywheel energy storage system provides inductive reactive power to the alternating current side of the wind turbine generator set; at the time t6, the alternating-current voltage falls back to the amplitude control dead zone, and the magnetic suspension flywheel energy storage system stops reactive power regulation; at the time of t7, the alternating current voltage is lower than 95%, and the magnetic suspension flywheel energy storage system provides capacitive reactive power for the alternating current side of the wind turbine generator set; and at the time of t8, the alternating voltage rises back to the amplitude control dead zone, and the magnetic suspension flywheel energy storage system stops reactive power regulation. The flywheel speed hardly changes in this process.

It can be seen that the magnetic suspension flywheel energy storage system in this embodiment has four-quadrant operation capability, and can flexibly control active power and reactive power transmitted between the magnetic suspension flywheel energy storage system and the ac side of the wind turbine generator system, and provide frequency modulation and voltage regulation services for the ac system, so that the wind turbine generator system integrated with the magnetic suspension flywheel energy storage system is beneficial to maintaining the stability of the ac system.

Example 2

The connection relationship of the magnetic suspension flywheel energy storage system and the wind generating set in the embodiment on the space relationship and the electrical relationship is the same as that of the embodiment 1; the difference lies in that: the wind generating set in the embodiment adopts a double-fed induction wind generating set (as shown in fig. 3).

Other parts not described belong to the prior art.