Flywheel grid-connected management control system

Abstract

The invention provides a flywheel grid-connected management control system, and the system comprises a frequency modulation control system which calculates the frequency modulation power difference of all flywheel arrays according to the total expected output power and the total actual output power of all flywheel arrays; the cooperative controller is used for determining array expected output power corresponding to each group of flywheel arrays according to the frequency modulation power difference values of all the flywheel arrays and the actual working power of each group of flywheel arrays; each energy management system corresponds to one group of flywheel array, receives array expected output power for the corresponding flywheel array from the cooperative controller, and calculates the output power of the flywheel array according to the array expected output power corresponding to each group of flywheel array and the actual rotating speed of each flywheel in each group of flywheel array; and determining flywheel expected output power corresponding to each flywheel in each group of flywheel arrays, and controlling each flywheel in each group of flywheel arrays to operate according to the expected output power. According to the invention, the stability of flywheel grid connection is improved.

Description

Technical Field

[0001] The present application relates to the technical field of power grid frequency regulation, and in particular to a flywheel grid-connected management and control system. Background Art

[0002] At present, with the continuous expansion of the scale of intermittent new energy sources such as wind power and photovoltaic power grid connection, the volatility and randomness of their output power have brought huge challenges to the frequency stability of the power system. Flywheel energy storage has attracted much attention due to its characteristics of bidirectional output, instantaneous response and precise tracking of power generation instructions. Integrating flywheel energy storage into grid operation has become one of the effective ways to provide frequency regulation auxiliary services. Flywheel grid connection refers to the process of connecting the flywheel energy storage system to the grid and operating in coordination. The flywheel energy storage system uses high-speed rotating mechanical rotational inertia to store and release electrical energy, and flywheel grid connection is the key link for the system to exchange energy and work in coordination with the grid.

[0003] Generally, the power and capacity of a single flywheel unit are easily limited. When in use, a flywheel array system is usually composed of multiple flywheel units for grid-connected control. Although control strategies exist for single flywheel units in large flywheel array systems, they do not fully consider the actual engineering conditions, especially the lack of substantive explanation of the energy replenishment and protection control of the single flywheel unit, which limits the grid-connected application of large-scale flywheel array systems. Summary of the invention

[0004] In view of this, the purpose of the present application is to provide a flywheel grid-connected management and control system to overcome at least one of the above-mentioned defects.

[0005] In a first aspect, an embodiment of the present application provides a flywheel grid-connected management and control system, the system comprising: a frequency regulation control system, which obtains a total expected output power of the grid, and calculates the frequency regulation power difference of all flywheel arrays based on the total expected output power and the total actual output power of all flywheel arrays; a collaborative controller, which receives the frequency regulation power difference for all flywheel arrays from the frequency regulation control system, and determines the array expected output power corresponding to each group of flywheel arrays based on the frequency regulation power difference for all flywheel arrays and the actual working power of each group of flywheel arrays; a plurality of energy management systems, each energy management system corresponding to a group of flywheel arrays, which receives the array expected output power for the corresponding flywheel array from the collaborative controller, determines the flywheel expected output power corresponding to each flywheel in each group of flywheel arrays based on the array expected output power corresponding to each group of flywheel arrays and the actual rotational speed of each flywheel in each group of flywheel arrays, and controls each flywheel in each group of flywheel arrays to operate according to the expected output power.

[0006] In an optional embodiment of the present application, the frequency modulation control system determines the frequency modulation power difference of all flywheel arrays in the following manner: determine the grid-connected object, and select the corresponding frequency modulation function according to the grid-connected object to obtain the total expected output power of the grid; obtain the total actual output power of all flywheel arrays from the collaborative controller, and determine the difference between the total expected output power and the total actual output power as the frequency modulation power difference of all flywheel arrays.

[0007] In an optional embodiment of the present application, the collaborative controller determines the expected array output power corresponding to each group of flywheel arrays in the following manner: determine the sum of the actual working powers of all flywheel arrays; determine whether the frequency modulation power difference of all flywheel arrays is greater than the power sum; if the frequency modulation power difference of all flywheel arrays is greater than the power sum, then determine the actual working power of each group of flywheel arrays as the array expected output power of the flywheel array; if the frequency modulation power difference of all flywheel arrays is not greater than the power sum, calculate the proportion of the actual working power of each group of flywheel arrays to the power sum, and determine the product of the proportion and the frequency modulation power difference as the array expected output power of the flywheel array.

[0008] In an optional embodiment of the present application, each energy management system is used to perform the following processing: for each group of flywheel arrays corresponding to the energy management system, determine whether there is a speed difference in the flywheel array corresponding to the energy management system; if there is no speed difference in the flywheel array, determine the quotient of the array expected output power of the flywheel array and the total number of flywheels in the flywheel array as the flywheel expected output power of the flywheel array; if there is a speed difference in the flywheel array, calculate the quotient of the array expected output power of the flywheel array and the total number of flywheel arrays, and determine the sum of the quotient and the speed power compensation value of the target flywheel in the flywheel array as the flywheel expected output power of the target flywheel in the flywheel array.

[0009] In an optional embodiment of the present application, each energy management system is also used to perform the following processing: for each group of flywheel arrays with a speed difference, calculating the actual speed average value of all flywheels in the flywheel array; for each flywheel in the flywheel array, calculating the difference between the actual speed of the flywheel and the actual speed average value, and multiplying the difference by the compensation coefficient to determine the speed power compensation amount of the flywheel.

[0010] In an optional embodiment of the present application, the flywheel corresponds to a flywheel speed range, and the flywheel speed range includes an upper limit and a lower limit, wherein each energy management system is also used to perform the following processing: determine whether there is a flywheel with an actual speed lower than the lower limit of the range; if there is a flywheel with an actual speed lower than the lower limit of the range, determine the energy replenishment power, and send the energy replenishment power to the flywheel to perform a speed protection mechanism for the flywheel, so that the flywheel speed works within the range of the flywheel speed range, and the energy replenishment power is the difference between the lower limit of the range and the actual speed of the flywheel.

[0011] In an optional embodiment of the present application, each energy management system is also used to perform the following processing: determine whether there is a flywheel with an actual speed higher than the upper limit of the interval; if there is a flywheel with an actual speed higher than the upper limit of the interval, determine the energy release power, and send the energy release power to the flywheel to perform a speed protection mechanism for the flywheel, so that the flywheel speed operates within the range of the flywheel speed interval, and the energy release power is the difference between the actual speed of the flywheel and the upper limit of the interval.

[0012] In an optional embodiment of the present application, each energy management system corresponds to multiple flywheel management systems, each flywheel array group includes an energy management system, multiple flywheel management systems and the same number of flywheels as the flywheel management system, and each flywheel management system corresponds to a flywheel.

[0013] In an optional embodiment of the present application, the frequency control system and the collaborative controller are connected via an Ethernet bus using a first power system protocol, the collaborative controller and each energy management system are connected via an Ethernet bus using a second power system, and each energy management system and its corresponding multiple flywheel management systems are connected via an Ethernet bus using a protocol protocol.

[0014] In an optional embodiment of the present application, each flywheel includes a grid-side converter and a machine-side converter, and is uniformly controlled by a flywheel management system corresponding to the flywheel, wherein each flywheel management system is used to perform the following processing: receiving the expected flywheel output power corresponding to each flywheel in each group of flywheel arrays from the corresponding energy management system; sending the expected flywheel output power corresponding to the flywheel to the grid-side converter and the machine-side converter corresponding to the flywheel, so that each flywheel in each group of flywheel arrays operates according to the expected output power.

[0015] The flywheel grid-connected management and control system provided by the embodiment of the present application, wherein the frequency modulation control system calculates the frequency modulation power difference of all flywheel arrays according to the total expected output power and the total actual output power of all flywheel arrays; the collaborative controller receives the frequency modulation power difference for all flywheel arrays from the frequency modulation control system, and determines the array expected output power corresponding to each group of flywheel arrays according to the frequency modulation power difference of all flywheel arrays and the actual working power of each group of flywheel arrays; each energy management system corresponds to a group of flywheel arrays, and multiple energy management systems receive the array expected output power for the corresponding flywheel array from the collaborative controller, and determine the flywheel expected output power corresponding to each flywheel in each group of flywheel arrays according to the array expected output power corresponding to each group of flywheel arrays and the actual speed of each flywheel in each group of flywheel arrays, and control each flywheel in each group of flywheel arrays to operate according to the expected output power. Through this application, the stability of flywheel grid connection is improved.

[0016] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 One of the structural schematic diagrams of the flywheel grid-connected management and control system provided in the embodiment of the present application;

[0019] Figure 2 This is the second structural schematic diagram of the flywheel grid-connected management and control system provided in the embodiment of the present application. DETAILED DESCRIPTION

[0020] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. The components of the embodiments of the present application usually described and shown in the drawings here can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the application claimed for protection, but merely represents the selected embodiments of the present application. Based on the embodiments of the present application, each other embodiment obtained by those skilled in the art without making creative work belongs to the scope of protection of the present application.

[0021] First, the application scenarios to which the present application is applicable are introduced. The present application can be applied to the field of power grid frequency modulation technology.

[0022] Research has found that the power and capacity of a single flywheel unit are generally easily limited. When in use, a flywheel array system is usually composed of multiple flywheel units for grid-connected control. Although there are control strategies for single flywheels in large flywheel array systems, none of them fully considers the actual engineering conditions, especially the lack of substantive explanation of the energy replenishment and protection control of the flywheel unit, which limits the grid-connected application of large-scale flywheel array systems.

[0023] Based on this, the embodiment of the present application provides a flywheel grid-connected management and control system, wherein the frequency modulation control system calculates the frequency modulation power difference of all flywheel arrays according to the total expected output power and the total actual output power of all flywheel arrays; the collaborative controller receives the frequency modulation power difference for all flywheel arrays from the frequency modulation control system, and determines the array expected output power corresponding to each group of flywheel arrays according to the frequency modulation power difference of all flywheel arrays and the actual working power of each group of flywheel arrays; each energy management system corresponds to a group of flywheel arrays, and multiple energy management systems receive the array expected output power for the corresponding flywheel array from the collaborative controller, and determine the flywheel expected output power corresponding to each flywheel in each group of flywheel arrays according to the array expected output power corresponding to each group of flywheel arrays and the actual speed of each flywheel in each group of flywheel arrays, and control each flywheel in each group of flywheel arrays to operate according to the expected output power. Through this application, the stability of flywheel grid connection is improved.

[0024] See also Figure 1 , Figure 1 This is a schematic diagram of the structure of the flywheel grid-connected management and control system provided in the embodiment of the present application. Figure 1 As shown in , the flywheel grid-connected management and control system 100 provided in the embodiment of the present application includes: a frequency regulation control system 11, a collaborative controller 12 and multiple energy management systems 13.

[0025] Here, the frequency control system 11 and the cooperative controller 12 are connected via an Ethernet bus using a first power system protocol, and the cooperative controller 12 and each energy management system 13 are connected via an Ethernet bus using a second power system protocol.

[0026] In an optional embodiment, the first power system protocol may be a power system 61850 protocol, and the second power system protocol may be a power system 104 protocol.

[0027] Specifically, the frequency regulation control system 11 is used to obtain the total expected output power of the grid, and calculate the frequency regulation power difference of all flywheel arrays according to the total expected output power and the total actual output power of all flywheel arrays.

[0028] Specifically, the frequency modulation control system 11 determines the frequency modulation power difference of all flywheel arrays in the following manner:

[0029] Determine the grid-connected object, and select the corresponding frequency modulation function according to the grid-connected object to obtain the total expected output power of the grid.

[0030] In an optional embodiment, the frequency control system 11 runs a grid-connected frequency control algorithm. When the flywheel runs to provide energy for a new energy object when connected to the grid, a primary frequency regulation algorithm is run. When the flywheel runs to provide energy for an independent energy storage power station or a thermal power combined frequency regulation when connected to the grid, a secondary frequency regulation algorithm is run.

[0031] Here, the primary frequency regulation algorithm refers to the process in which the control system of the units in the power grid automatically adjusts its active power output according to the change in frequency to maintain the stability of the power grid frequency when the power grid frequency deviates from the rated value. Primary frequency regulation is a fast and indiscriminate response that mainly relies on the frequency regulation control system.

[0032] The primary frequency regulation algorithm for new energy objects (such as wind power, photovoltaic power, etc.) is mainly based on the relationship between their power generation and grid frequency. When the grid frequency drops, the new energy object will try to increase its power generation to make up for the power shortage in the grid; conversely, when the grid frequency rises, the new energy object will try to reduce its power generation to avoid grid overload.

[0033] The secondary frequency regulation algorithm is to further optimize the frequency and power distribution of the power grid by adjusting the output of each unit in the power grid on the basis of the primary frequency regulation to meet the economic and safety requirements of the power grid. Secondary frequency regulation usually requires a centralized control system to monitor the frequency of the power grid and the output of each unit, and adjust the output of each unit according to certain algorithms and strategies.

[0034] The secondary frequency regulation algorithm for independent energy storage power stations or thermal power combined frequency regulation is mainly adjusted based on the frequency deviation of the power grid, the output of each unit, and the economic and safety requirements of the power grid. By adjusting the charging and discharging power of the energy storage power station or the output of the thermal power unit, the frequency and power distribution of the power grid can be further optimized, and the stability and economy of the power grid can be improved.

[0035] In summary, primary frequency regulation and secondary frequency regulation are important measures to maintain frequency stability in power systems. In the flywheel grid-connected management and control system, by running different frequency regulation algorithms, effective control of new energy objects, independent energy storage power stations or thermal power combined frequency regulation can be achieved.

[0036] The total actual output power of all flywheel arrays is obtained from the cooperative controller 12, and the difference between the total expected output power and the total actual output power is determined as the frequency modulation power difference of all flywheel arrays.

[0037] Specifically, the frequency modulation power difference of all flywheel arrays is determined by the following formula:

[0038] dP=Pt-Pf

[0039] Wherein, dP represents the frequency modulation power difference of all flywheel arrays, Pt represents the total expected output power of all flywheel arrays, and Pf represents the total actual output power of all flywheel arrays.

[0040] The collaborative controller 12 receives the frequency modulation power difference for all flywheel arrays from the frequency modulation control system 11, and determines the expected array output power corresponding to each flywheel array according to the frequency modulation power difference of all flywheel arrays and the actual working power of each flywheel array.

[0041] Specifically, the collaborative controller 12 determines the expected array output power corresponding to each group of flywheel arrays in the following manner:

[0042] Determine the sum of the powers of all flywheel arrays to determine their actual operating power.

[0043] The collaborative controller 12 obtains the actual working power of the flywheel array corresponding to each energy management system from the multiple energy management systems 13, and calculates the sum of the actual working powers of all the flywheel arrays.

[0044] Determine whether the frequency modulation power difference of all flywheel arrays is greater than the total power;

[0045] If the frequency modulation power difference of all flywheel arrays is greater than the total power, the actual working power of each group of flywheel arrays is determined as the array expected output power of the flywheel array; if the frequency modulation power difference of all flywheel arrays is not greater than the total power, the ratio of the actual working power of each group of flywheel arrays to the total power is calculated, and the product of the ratio and the frequency modulation power difference is determined as the array expected output power of the flywheel array.

[0046] In an optional embodiment, taking the flywheel grid-connected management and control system including flywheel array 1, flywheel array 2 and flywheel array 3 as an example, the actual working power of the flywheel arrays corresponding to all energy management systems can be recorded as the actual working efficiency P1 corresponding to flywheel array 1, the actual working efficiency P2 corresponding to flywheel array 2 and the actual working efficiency P3 corresponding to flywheel array 3.

[0047] If dP>(P1+P2+P3), the expected array output power PT1 of flywheel array 1 is P1, the expected array output power PT2 of flywheel array 2 is P2, and the expected array output power PT3 of flywheel array 3 is P3.

[0048] If dP≤(P1+P2+P3), the expected array output power PT1 of the flywheel array 1, the expected array output power PT2 of the flywheel array 2, and the expected array output power PT3 of the flywheel array 3 are calculated by the following formula.

[0049]

[0050]

[0051] Among them, PT1 represents the expected array output power of flywheel array 1, PT2 represents the expected array output power of flywheel array 2, PT3 represents the expected array output power of flywheel array 3, dP represents the frequency modulation power difference of all flywheel arrays, P1 represents the actual working efficiency corresponding to flywheel array 1, P2 represents the actual working efficiency corresponding to flywheel array 2, and P3 represents the actual working efficiency corresponding to flywheel array 3.

[0052] Here, through the frequency modulation control system and the power allocation principle of the cooperative controller, the system can achieve rapid response and precise adjustment of the grid frequency. This can not only improve the stability and reliability of the grid, but also effectively reduce the power loss caused by frequency fluctuations. At the same time, the cooperative controller can ensure the power balance of each flywheel during the charging and discharging process, avoid overload or underload, and thus extend the service life of the flywheel.

[0053] Multiple energy management systems 13, each energy management system corresponds to a group of flywheel arrays, receive the array expected output power for the corresponding flywheel array from the collaborative controller 12, determine the flywheel expected output power corresponding to each flywheel in each flywheel array according to the array expected output power corresponding to each flywheel array and the actual rotational speed of each flywheel in each flywheel array, and control each flywheel in each flywheel array to operate according to the expected output power.

[0054] Here, each energy management system corresponds to multiple flywheel management systems.

[0055] Each flywheel array includes an energy management system, a plurality of flywheel management systems and a number of flywheels equal to the number of the flywheel management systems, and each flywheel management system corresponds to a flywheel.

[0056] For example, a flywheel array includes an energy management system, three flywheel management systems and three flywheels. Figure 2 , Figure 2This is the second structural diagram of the flywheel grid-connected management and control system provided in the embodiment of the present application. Figure 2 As shown in the figure, the flywheel grid-connected management and control system 100 provided in the embodiment of the present application includes: a frequency modulation control system 11, a collaborative controller 12, a plurality of energy management systems 13, a plurality of flywheel management systems 14 and a plurality of flywheels 15.

[0057] In an optional embodiment, the energy management system 13 and the flywheel management system 14 are connected via an Ethernet bus, using the Modbus TCPIP protocol.

[0058] Each energy management system is used to perform the following processes:

[0059] For each group of flywheel arrays corresponding to the energy management system, determining whether there is a speed difference in the flywheel array corresponding to the energy management system;

[0060] If there is no speed difference in the flywheel array, the quotient of the expected array output power of the flywheel array and the total number of flywheels in the flywheel array is determined as the expected flywheel output power of the flywheel array; if there is a speed difference in the flywheel array, the quotient of the expected array output power of the flywheel array and the total number of flywheel arrays is calculated, and the sum of the quotient and the speed power compensation value of the target flywheel in the flywheel array is determined as the expected flywheel output power of the target flywheel in the flywheel array.

[0061] Here, taking flywheel array 1 as an example, an average value is calculated according to the actual rotational speed of each flywheel in flywheel array 1, and the average value is used as the rotational speed threshold in flywheel array 1. If the actual rotational speed of each flywheel in flywheel array 1 is less than the rotational speed threshold, it is considered that there is no rotational speed difference in flywheel array 1. If there is no rotational speed difference in flywheel array 1, the quotient of the array expected output power of flywheel array 1 and the total number of flywheels in flywheel array 1 is determined as the flywheel expected output power of flywheel array 1.

[0062] Preferably, the expected flywheel output power when there is no speed difference in the flywheel array 1 is determined by the following formula:

[0063]

[0064] Wherein, PE1 represents the expected output power of the flywheel of the flywheel array 1, PT1 represents the expected array output power of the flywheel array 1, and A represents the total number of all flywheels in the flywheel array 1.

[0065] If the actual speed of any flywheel in the flywheel array 1 is greater than or equal to the speed threshold, it is considered that there is a speed difference in the flywheel array 1. If there is a speed difference in the flywheel array 1, the quotient of the expected array output power of the flywheel array 1 and the total number of flywheel arrays is calculated, and the sum of the quotient and the speed power compensation value of the target flywheel in the flywheel array 1 is determined as the flywheel expected output power of the target flywheel in the flywheel array 1.

[0066] Preferably, the expected flywheel output power when there is a speed difference in the flywheel array 1 is determined by the following formula:

[0067]

[0068] Among them, PE1 represents the expected output power of the flywheel of flywheel array 1, PT1 represents the expected array output power of flywheel array 1, A represents the total number of all flywheels in flywheel array 1, and dPN1 represents the speed power compensation value of the target flywheel in flywheel array 1.

[0069] Specifically, each energy management system determines the speed power compensation value of the target flywheel in the following manner:

[0070] For each group of flywheel arrays with speed difference, the average actual speed of all flywheels in the flywheel array is calculated; for each flywheel in the flywheel array, the difference between the actual speed of the flywheel and the average actual speed is calculated, and the product of the difference and the compensation coefficient is determined as the speed power compensation amount of the flywheel.

[0071] Specifically, the speed power compensation amount of each flywheel when there is a speed difference in the flywheel array 1 is determined by the following formula:

[0072]

[0073] Wherein, dPN1 represents the speed power compensation amount of the first flywheel in the flywheel array 1, N1 represents the actual speed of the first flywheel in the flywheel array 1, A represents the total number of all flywheels in the flywheel array 1, KN represents the compensation coefficient, and KN is a constant.

[0074] Here, through the energy balance control strategy of the energy management system, the system can monitor the energy status of each flywheel unit in real time and redistribute and dispatch energy as needed. This can not only improve the overall energy utilization efficiency of the flywheel energy storage system, but also avoid the degradation of system performance caused by energy imbalance. In addition, the energy management system can also intelligently adjust the charging and discharging strategy according to the needs of the power grid and the actual situation of the flywheel energy storage system to achieve the optimal operation of the system.

[0075] Specifically, the flywheel corresponds to a flywheel speed range, and the flywheel speed range includes an upper limit and a lower limit.

[0076] Each energy management system is also used to perform the following processes:

[0077] In an optional embodiment, it is determined whether there is an actual rotation speed of the flywheel lower than the lower limit of the interval;

[0078] If the actual speed of a flywheel is lower than the lower limit of the interval, the energy replenishment power is determined and sent to the flywheel to perform a speed protection mechanism for the flywheel so that the flywheel speed operates within the range of the flywheel speed interval.

[0079] The energy replenishment power is the difference between the lower limit of the interval and the actual speed of the flywheel.

[0080] Here, when the actual speed of a flywheel in the flywheel array 1 is lower than the lower limit of the interval, the corresponding energy management system will send energy supplement power to the flywheel until the actual speed of the flywheel rises to the lower limit of the interval, thereby performing speed protection control on each flywheel and always maintaining the actual speed of each flywheel within the working range of the flywheel speed interval.

[0081] In another optional embodiment, it is determined whether there is an actual rotation speed of the flywheel higher than the upper limit of the interval;

[0082] If the actual speed of a flywheel is higher than the upper limit of the interval, the energy release power is determined and sent to the flywheel to perform a speed protection mechanism for the flywheel so that the flywheel speed works within the range of the flywheel speed interval.

[0083] The energy release power is the difference between the actual speed of the flywheel and the upper limit of the range.

[0084] Here, when the actual speed of a flywheel in the flywheel array 1 is higher than the upper limit threshold, the corresponding energy management system will send energy to release power to the flywheel until the actual speed of the flywheel drops to the lower limit of the interval, thereby performing speed protection control on each flywheel and always maintaining the actual speed of each flywheel within the working range of the flywheel speed interval.

[0085] Here, through the single-machine speed compensation control strategy in the flywheel array, the system can monitor the speed status of each flywheel unit in real time, and compensate and adjust the speed as needed. This can not only ensure the speed balance of each flywheel unit during the charging and discharging process, but also avoid problems such as system vibration and noise caused by speed differences. At the same time, the speed compensation control strategy can also improve the overall response speed and dynamic performance of the flywheel energy storage system, so that it can better adapt to the changing needs of the power grid.

[0086] The present application provides the topology and composition of a complete flywheel grid-connected management and control system, including a frequency regulation control system 11, a collaborative controller 12, multiple energy management systems 13, multiple flywheel management systems 14 and a flywheel 15, wherein the flywheel 15 includes subsystems such as a grid-side converter, a machine-side converter, a magnetic bearing controller, a vacuum system, an auxiliary monitoring system, and a braking system.

[0087] In an optional embodiment, the machine-side converter plays a role in stabilizing the voltage on the flywheel motor side, the grid-side converter plays a role in grid-connected control, the flywheel management system plays a role in monitoring and auxiliary control of the flywheel unit, the energy management system plays a role in flywheel charging, discharging and energy control, the collaborative controller plays a role in executing the upper-level control logic, and the frequency regulation control system plays a role in running the grid-connected frequency regulation control algorithm.

[0088] Each flywheel includes a grid-side converter and a machine-side converter, and is controlled by the flywheel management system corresponding to the flywheel. The flywheel management system is connected to the grid-side converter, machine-side converter, magnetic bearing controller, vacuum system, braking system and auxiliary monitoring system through an Ethernet bus.

[0089] In an optional implementation, the flywheel management system is connected to the grid-side converter via an Ethernet bus, using the Modbus TCPIP protocol; the flywheel management system is connected to the machine-side converter via a high-speed optical fiber, using a synchronous serial clock communication protocol; the flywheel management system is connected to the magnetic bearing controller via a CAN bus, using a custom communication protocol; the flywheel management system is connected to the vacuum system via an RS485 bus, using the Modbus RTU protocol; the flywheel management system is connected to the braking system via an RS485 bus, using the Modbus RTU protocol; the flywheel management system is connected to the auxiliary monitoring system via an RS485 bus, using the Modbus RTU protocol.

[0090] Each flywheel management system is used to perform the following processes:

[0091] Receive the expected flywheel output power corresponding to each flywheel in each flywheel array from the corresponding energy management system; send the expected flywheel output power corresponding to the flywheel to the grid-side converter and the machine-side converter corresponding to the flywheel, so that each flywheel in each flywheel array operates according to the expected output power.

[0092] Specifically, the energy management system sends the expected flywheel output power of each flywheel to the flywheel management system corresponding to the flywheel, so that the flywheel management system controls the grid-side converter for charging and discharging control and the machine-side converter for DC voltage regulation control to meet the flywheel's operation according to the expected output power.

[0093] This application adopts the complete flywheel grid-connected management and control system, which can realize the grid-connected control of flywheel arrays and large systems, complete the primary and secondary frequency modulation control functions, achieve reasonable logic, simplicity and efficiency, without adding overly complex subsystems, and improve the integration of the overall system.

[0094] The flywheel grid-connected management and control system provided by the embodiment of the present application, the frequency control system calculates the frequency modulation power difference of all flywheel arrays according to the total expected output power and the total actual output power of all flywheel arrays; the collaborative controller receives the frequency modulation power difference for all flywheel arrays from the frequency modulation control system, and determines the array expected output power corresponding to each group of flywheel arrays according to the frequency modulation power difference of all flywheel arrays and the actual working power of each group of flywheel arrays; each energy management system corresponds to a group of flywheel arrays, and multiple energy management systems receive the array expected output power for the corresponding flywheel array from the collaborative controller, and determine the flywheel expected output power corresponding to each flywheel in each group of flywheel arrays according to the array expected output power corresponding to each group of flywheel arrays and the actual speed of each flywheel in each group of flywheel arrays, and control each flywheel in each group of flywheel arrays to operate according to the expected output power. Through this application, the stability of flywheel grid connection is improved.

[0095] This application fully considers the upper-level control logic of the frequency modulation control system and the collaborative controller, and provides the charging and discharging control strategy of the energy management system, while taking into account the speed protection control of the flywheel unit, ensuring the smooth grid-connected operation of the overall flywheel energy storage system, with strong practicality, improving the reliability of system operation, and facilitating engineering applications.

[0096] The present application provides the charge and discharge control logic of the flywheel grid-connected management and control system, including the power allocation principle of the frequency modulation control system and the collaborative controller, the energy balance control strategy of the energy management system, the single-machine speed compensation control strategy in the flywheel array, etc. It can not only realize the effective execution of the frequency modulation instructions, but also realize the energy balance control and speed protection control of the flywheel array, improve the power balance of the flywheel array, and maximize the charge and discharge capabilities of each flywheel in the flywheel array. It is simple and practical, and ensures the reliability and stability of the operation of the entire system.

[0097] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0098] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are merely schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some communication interfaces, and the indirect coupling or communication connection of devices or units can be electrical, mechanical or other forms.

[0099] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0101] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a non-volatile computer-readable storage medium that is executable by a processor. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0102] Finally, it should be noted that the above-described embodiments are only specific implementation methods of the present application, which are used to illustrate the technical solutions of the present application, rather than to limit them. The protection scope of the present application is not limited thereto. Although the present application is described in detail with reference to the above-mentioned embodiments, ordinary technicians in the field should understand that any technician familiar with the technical field can still modify the technical solutions recorded in the above-mentioned embodiments within the technical scope disclosed in the present application, or can easily think of changes, or make equivalent replacements for some of the technical features therein; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A flywheel grid-connected management and control system, characterized in that: include: The frequency modulation control system obtains the total expected output power of the grid, and calculates the frequency modulation power difference of all flywheel arrays according to the total expected output power and the total actual output power of all flywheel arrays; The collaborative controller receives the frequency modulation power difference values ​​for all flywheel arrays from the frequency modulation control system, and determines the array expected output power corresponding to each group of flywheel arrays according to the frequency modulation power difference values ​​of all flywheel arrays and the actual working power of each group of flywheel arrays; Multiple energy management systems, each energy management system corresponds to a group of flywheel arrays, receives the array expected output power for the corresponding flywheel array from the collaborative controller, determines the flywheel expected output power corresponding to each flywheel in each flywheel array according to the array expected output power corresponding to each flywheel array and the actual rotational speed of each flywheel in each flywheel array, and controls each flywheel in each flywheel array to operate according to the expected output power.

2. The system according to claim 1, characterized in that The frequency modulation control system determines the frequency modulation power difference of all flywheel arrays in the following manner: Determine a grid-connected object, and select a corresponding frequency modulation function according to the grid-connected object to obtain a total expected output power of the grid; The total actual output power of all flywheel arrays is obtained from the cooperative controller, and the difference between the total expected output power and the total actual output power is determined as the frequency modulation power difference of all flywheel arrays.

3. The system according to claim 1, characterized in that The collaborative controller determines the expected array output power corresponding to each group of flywheel arrays in the following manner: Determine the sum of the actual operating powers of all flywheel arrays; Determining whether the frequency modulation power difference of all the flywheel arrays is greater than the power sum; If the frequency modulation power difference of all the flywheel arrays is greater than the power sum, the actual working power of each group of flywheel arrays is determined as the array expected output power of the flywheel array; If the frequency modulation power difference of all flywheel arrays is not greater than the total power, the ratio of the actual working power of each flywheel array to the total power is calculated, and the product of the ratio and the frequency modulation power difference is determined as the array expected output power of the flywheel array.

4. The system according to claim 1, characterized in that Each energy management system is used to perform the following processes: For each group of flywheel arrays corresponding to the energy management system, determining whether there is a speed difference in the flywheel array corresponding to the energy management system; If there is no speed difference in the flywheel array, the quotient of the array expected output power of the flywheel array and the total number of flywheels in the flywheel array is determined as the flywheel expected output power of the flywheel array; If there is a speed difference in the flywheel array, the quotient of the array expected output power of the flywheel array and the total number of flywheel arrays is calculated, and the sum of the quotient and the speed power compensation value of the target flywheel in the flywheel array is determined as the flywheel expected output power of the target flywheel in the flywheel array.

5. The system according to claim 4, characterized in that Each energy management system is also used to perform the following processes: For each group of flywheel arrays with a rotation speed difference, calculating the average actual rotation speed of all flywheels in the flywheel array; For each flywheel in the flywheel array, the difference between the actual rotation speed of the flywheel and the actual rotation speed average value is calculated, and the product of the difference and the compensation coefficient is determined as the speed power compensation amount of the flywheel.

6. The system according to claim 1, characterized in that The flywheel corresponds to a flywheel speed interval, and the flywheel speed interval includes an interval upper limit and an interval lower limit. Each energy management system is also used to perform the following processing: Determine whether there is an actual rotation speed of the flywheel lower than the lower limit of the interval; If the actual speed of the flywheel is lower than the lower limit of the interval, the energy replenishment power is determined and sent to the flywheel to perform a speed protection mechanism for the flywheel so that the flywheel speed works within the range of the flywheel speed interval. The energy replenishment power is the difference between the lower limit of the interval and the actual speed of the flywheel.

7. The system according to claim 6, characterized in that Each energy management system is also used to perform the following processes: Determine whether there is an actual rotation speed of the flywheel higher than the upper limit of the interval; If the actual speed of a flywheel is higher than the upper limit of the interval, the energy release power is determined and sent to the flywheel to perform a speed protection mechanism for the flywheel so that the flywheel speed works within the range of the flywheel speed interval. The energy release power is the difference between the actual speed of the flywheel and the upper limit of the interval.

8. The system according to claim 1, characterized in that Each energy management system corresponds to multiple flywheel management systems, each group of flywheel arrays includes an energy management system, multiple flywheel management systems and the same number of flywheels as the flywheel management systems, and each flywheel management system corresponds to a flywheel.

9. The system according to claim 8, characterized in that The frequency modulation control system and the cooperative controller are connected via an Ethernet bus using a first power system protocol, the cooperative controller and each energy management system are connected via an Ethernet bus using a second power system, and each energy management system and its corresponding multiple flywheel management systems are connected via an Ethernet bus using a protocol protocol.

10. The system according to claim 8, characterized in that Each flywheel includes a grid-side converter and a generator-side converter, which are uniformly controlled by the flywheel management system corresponding to the flywheel. Each flywheel management system is used to perform the following processes: Receiving the flywheel expected output power corresponding to each flywheel in each group of flywheel arrays from the corresponding energy management system; The flywheel expected output power corresponding to the flywheel is sent to the grid-side converter and the machine-side converter corresponding to the flywheel, so that each flywheel in each group of flywheel arrays operates according to the expected output power.

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