A primary frequency modulation method and system for a flywheel energy storage power station

Abstract

The present invention discloses a primary frequency regulation method and system for a flywheel energy storage power station, which belongs to the field of electrical engineering. The method comprises: detecting the voltage, frequency and PCS initial power of the grid connection point, and determining whether to perform speed balancing or primary frequency regulation operation according to whether the frequency is within the dead zone. The frequency regulation power is preferentially allocated to the flywheel energy storage. When it is insufficient, the participation of wind and solar power is considered and allocated in proportion. The pre-allocated power of a single machine is calculated based on the flywheel speed, safety status and power constraints, the speed at future moments is estimated, and the safety status and power limit check are performed. If there is a power shortage and the flywheel has not reached the maximum power, the power is reallocated and the calculation is repeated until there is no shortage or the flywheel is at full power, and finally the allocated power of each unit is output. While the wind, solar and storage quickly respond to the primary frequency regulation demand, the present invention realizes the optimized management of the flywheel speed and power in the flywheel array and verifies the safety status of the single flywheel.

Description

Technical Field

[0001] The present invention belongs to the field of electrical engineering and mainly relates to a primary frequency modulation method and system for a flywheel energy storage power station. Background Art

[0002] As the proportion of new energy sources and power electronics devices in new power systems continues to increase, the grid's demand for high-frequency frequency regulation is growing. Compared to new energy storage technologies such as electrochemical energy storage, flywheel energy storage offers advantages such as high charge and discharge frequency, long service life, and high power generation efficiency, making it suitable for participating in grid primary frequency regulation. Flywheel energy storage is subject to self-discharge. After long-term operation, speed inconsistencies between individual flywheel units can occur, affecting the overall output and control performance of the flywheel array. Speed ​​recovery and adjustment of the flywheel units are required to ensure speed consistency. Furthermore, high-speed flywheels with speeds exceeding 10,000 rpm can cause runaway accidents with serious consequences if improperly controlled. Currently, most operating flywheel energy storage power stations use control strategies that ensure consistent state of charge for individual units or evenly distribute power commands. There is a lack of coordinated control methods for flywheel arrays that consider factors such as flywheel speed balance and self-recovery, as well as flywheel safe operation constraints. Summary of the Invention

[0003] In order to overcome the above-mentioned shortcomings of the existing technology, the present invention provides a primary frequency regulation method and system for a flywheel energy storage power station. While the wind, solar and storage systems quickly respond to the primary frequency regulation needs, the present invention achieves optimized management of the flywheel speed and power in the flywheel array and verifies the safety status of the single flywheel unit.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] In a first aspect, the present invention provides a primary frequency regulation method for a flywheel energy storage power station that takes into account both speed regulation and state safety, comprising:

[0006] S1: Initialization of high-speed flywheel array parameters, including: flywheel single unit speed ni, charge and discharge safety status Start-stop state, power constraint;

[0007] S2: Obtain the voltage, frequency, and PCS initial power of the grid connection point. Based on the voltage, frequency, and PCS initial power of the grid connection point, calculate the power demand ΔP in two cases. f : First, when the frequency is in the dead zone, the flywheel speed balancing operation is performed, and the speed balancing power ΔP re ; Second, when the frequency exceeds the dead zone, a frequency modulation operation is performed, ΔP f is the primary frequency modulation power;

[0008] S3: ΔP is the frequency modulation power requirement fAllocate to flywheel energy storage, wind power, and photovoltaics; prioritize flywheel energy storage frequency regulation, and then allocate wind and solar frequency regulation power proportionally based on the real-time output of wind and solar power;

[0009] S4: Frequency modulation power demand ΔP f After allocation, the power of the high-speed flywheel unit in response to the primary frequency regulation of the grid is set to ΔP FESS ; According to the speed n of the high-speed flywheel energy storage unit i , safe state of charge and discharge Power constraint, calculate the pre-allocated power of a single flywheel unit;

[0010] S5: Estimate the speed of each flywheel at time t+T based on the pre-allocated power;

[0011] S6: Perform safety status verification at the estimated speed of each flywheel at time t+T, and adjust the power of the flywheel energy storage unit whose safety status is less than 1;

[0012] S7: After the power is adjusted, a power over-limit check is performed and the power shortage is calculated;

[0013] S8: Determine whether the power shortage is less than the threshold value. If not, redistribute the power shortage to the high-speed flywheel whose speed does not exceed the limit, return to S5, and repeat until there is no frequency regulation power shortage or each flywheel energy storage unit reaches the maximum power; if less than, output the allocated power to each unit.

[0014] As a further improvement of the present invention, in S2: the power demand ΔP is calculated in two cases f , specifically:

[0015]

[0016] The first case: when f min ≤f≤f max When frequency modulation is not required, the speed n of the flywheel energy storage system is adjusted to the reference value. When the flywheel speed is close to the maximum and minimum speed in the frequency modulation dead zone, the balanced power ΔP re Balance the speed of the flywheel energy storage system to the reference value

[0017] The second case: When the frequency f exceeds the dead zone, a frequency modulation operation is required, using the power demand ΔP f Perform a frequency regulation operation, where δ% is the frequency regulation rate of the new energy station, P N is the rated power of the new energy station, f is the real-time frequency of the grid connection point, and m is the frequency modulation adaptive coefficient.

[0018] As a further improvement of the present invention, the speed reference value Determined based on the highest or lowest speed of a single unit in the flywheel energy storage array;

[0019] First, the flywheel speed is divided into n min ,n l ,n h ,n max , lower than n l or higher than n h Need to Based on the relationship between speed and energy, the balanced power ΔP of the i-th flywheel unit is set. adj,i for:

[0020]

[0021] Where n i is the speed of the i-th unit; α is the balance coefficient; P fess,N is the rated power of the flywheel; when n h <n i ≤n max When the speed needs to be lowered, ΔP adj,i is positive, discharge; when n min <n i ≤n l When the speed needs to be increased, ΔP adj,i is negative, charging the energy storage;

[0022] Define the power change boundary value ΔP av , ΔP av Determined by the frequency modulation dead zone boundary value, the energy storage is ΔP av Charging and discharging does not cause the frequency to exceed the dead zone, and the power ΔP is balanced re Need to be adjusted to ΔP adj and ΔP av The smaller value of , that is:

[0023]

[0024] As a further improvement of the present invention, the frequency modulation adaptive coefficient m increases when the frequency approaches the limit value, and when the frequency exceeds the limit value, the frequency modulation is no longer responded.

[0025] As a further improvement of the present invention, in S4, the charging and discharging safety state is determined according to the speed ni of the high-speed flywheel energy storage unit. Calculate the pre-allocated power of a single flywheel unit based on parameters such as power constraints; including:

[0026]

[0027] Where, is the charging power pre-allocated to the i-th flywheel, is the discharge power pre-allocated to the i-th flywheel, K is the number of flywheel units, is the power demand allocated to the flywheel array at time t, is the speed of the i-th flywheel unit at time t, n i,max is the maximum speed of the i-th flywheel unit, Represent the safe status of charge and discharge respectively.

[0028] As a further improvement of the present invention, in S5: estimating the rotational speed of each high-speed flywheel unit at time t+T based on the pre-allocated power includes:

[0029]

[0030] Where, is the charging power allocated to the i-th flywheel at time t, which is a negative value; is the discharge power allocated to the i-th flywheel at time t, which is a positive value; E N,i is the rated energy of the i-th flywheel, p i T represents the energy stored in i flywheels after T cycles.

[0031] As a further improvement of the present invention, in S6, a security status check is performed, including:

[0032] 1) Charging safety status

[0033]

[0034] Where n i,N is the rated speed of the i-th flywheel unit; in the charging state, when the speed is less than or equal to 95% of the rated speed, it is considered to be in a completely safe state, and the corresponding safety value is 1; when the speed is in the range of 95%-100% of the rated speed, the safety state gradually decreases;

[0035] 2) Discharge safety state

[0036]

[0037] In the discharge state, when the speed is greater than or equal to 5% of the rated speed, it is a completely safe state, and the corresponding safety value is 1; when the speed is in the rated speed range of 5%-0%, the safety state gradually decreases.

[0038] As a further improvement of the present invention, the power of the flywheel energy storage unit with a safety status less than 1 is adjusted:

[0039]

[0040] Where p B is the power limit.

[0041] As a further improvement of the present invention, in S7: determining whether the charge and discharge power of each flywheel exceeds the power limit and calculating the power shortage specifically includes:

[0042]

[0043] In a second aspect, the present invention provides a primary frequency regulation system for a flywheel energy storage power station that takes into account both speed regulation and state safety, comprising:

[0044] Includes: dispatching layer, station control layer, and on-site layer;

[0045] Wherein, the dispatching layer refers to the grid dispatching;

[0046] The station control layer includes energy storage primary frequency regulation control device, energy storage monitoring, wind and solar station monitoring module, network switch, and energy storage communication management machine;

[0047] The present formation is a flywheel array composed of multiple high-speed flywheel machines;

[0048] The energy storage primary frequency modulation device is connected to the grid connection point and is used to detect frequency changes at the grid connection point and calculate the power required by each flywheel based on the preset frequency dead zone and the speed and charge and discharge authority of each flywheel. The energy storage monitoring system is capable of monitoring the status information of each flywheel and managing the flywheel group. The flywheel array receives upper-level grid dispatch, automatic primary frequency modulation or speed balancing instructions, and the primary frequency modulation instructions have higher priority than the dispatch instructions.

[0049] The wind and solar station monitoring module is used to control the wind turbine power generation and photovoltaic power generation to respond to the frequency modulation power;

[0050] Each device communicates with each other through a local area network formed by a network switch;

[0051] The energy storage communication management machine is used to perform communication management of the flywheel array.

[0052] In a third aspect, the present invention provides an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety is implemented.

[0053] In a fourth aspect, the present invention provides a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety.

[0054] In a fifth aspect, the present invention provides a computer program product, which includes computer instructions, and the computer instructions instruct a computer to execute the primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety.

[0055] The beneficial effects of the present invention compared to the prior art are:

[0056] In response to the shortcomings of MW-class high-speed flywheels in practical applications, the present invention proposes a primary frequency regulation method for flywheel energy storage power stations that takes into account both speed regulation and state safety. This method can effectively improve the frequency regulation capability and operating efficiency of flywheel energy storage arrays in new power systems by optimizing the control strategy, especially while meeting the high-frequency frequency regulation requirements, significantly improving the safety and stability of the system. Moreover, even when the initial speeds of individual flywheel units vary greatly, the speeds of individual units can be quickly converged through collaborative control to ensure that the total speed of the flywheel array remains near the reference value for a long time. This optimization strategy not only improves the energy utilization efficiency of the entire system, but also reduces energy loss during the frequency regulation process. In addition, the present invention adopts a real-time safety status verification mechanism, combined with the dynamic adjustment of the speed and the charge and discharge state, to effectively ensure the safety of the flywheel unit and the system as a whole, and reduce the safety risks that may be caused by high-speed operation. This technology can also be applied to a variety of application scenarios, including wind storage, solar storage and other joint operation modes, and has a wide range of applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following introduction is made to the drawings of the embodiments of the present invention or the related technical solutions in the prior art. It should be understood that the drawings introduced below are only for the convenience of clearly describing some embodiments of the technical solutions of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative work.

[0058] Figure 1 It is a schematic diagram of a frequency modulation curve;

[0059] Figure 2 Provides a frequency regulation control architecture for flywheel energy storage in conjunction with wind and solar power stations;

[0060] Figure 3 A flow chart for frequency regulation of flywheel energy storage in coordination with wind and solar power stations;

[0061] Figure 4 Schematic diagram of the calculation curve of the frequency modulation adaptive coefficient m. DETAILED DESCRIPTION

[0062] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided for ease of explanation only and do not limit the order of the steps. The order of execution of the steps in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0063] In the description of the present invention, unless otherwise clearly defined, terms such as setting, installing, and connecting should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in the present invention based on the specific content of the technical solution.

[0064] In order to achieve the control requirements of flywheel single-machine speed consistency, flywheel energy state balanced regulation, and flywheel safe operation in the control process of flywheel energy storage power station, the present invention proposes a flywheel energy storage power station primary frequency adaptive method, system and device that take into account both speed adjustment and state safety.

[0065] Specifically, if Figure 3 As shown, the first object of the present invention is to provide a primary frequency regulation method for a flywheel energy storage power station that takes into account both speed regulation and state safety. The method comprises the following steps:

[0066] Step 1: Initialize the high-speed flywheel array parameters, including: flywheel single unit speed ni, charge and discharge safety status (1 means safe, 0 means unsafe), start / stop status, power constraint, etc.

[0067] Step 2: The device detects the voltage, frequency, PCS initial power and other signals of the grid connection point, and calculates the power demand ΔP in two cases f : First, when the frequency is in the dead zone, the flywheel speed balancing operation is performed, and the speed balancing power ΔP re ; Second, when the frequency exceeds the dead zone, a frequency modulation operation is performed, ΔP f is the primary FM power.

[0068] Step 3: Convert the frequency modulation power demand ΔP f Distributed to flywheel energy storage, wind power, and photovoltaics. Since most wind power and photovoltaic units use the maximum power point tracking (MPPT) control method, wind and photovoltaic units cannot increase power when the frequency of the grid connection point drops. In order to improve the absorption of wind and light, flywheel energy storage frequency regulation is preferred. When flywheel energy storage cannot meet the frequency regulation demand, wind and solar power are selected to participate in the frequency regulation. Then, according to the real-time output of wind and light, the frequency regulation power of wind and light is proportionally allocated;

[0069] Step 4: Set the power of the high-speed flywheel unit in response to the grid primary frequency regulation to ΔP FESS , according to the speed n of the high-speed flywheel energy storage unit i , safe state of charge and discharge Calculate the pre-allocated power of a single flywheel unit based on parameters such as power constraints;

[0070] Step 5: Estimate the speed of each flywheel at time t+T based on the pre-allocated power;

[0071] Step 6: Perform safety status verification and adjust the power of the flywheel energy storage unit whose safety status is less than 1;

[0072] Step 7: Perform power limit check and calculate power shortage;

[0073] Step 8: Determine whether the power shortage is less than the threshold. If not, redistribute the power shortage to the high-speed flywheel whose speed does not exceed the limit. Return to step 5 and repeat the above calculation until there is no frequency regulation power shortage or each flywheel energy storage unit reaches the maximum power. If it is less than the threshold, output the allocated power to each unit.

[0074] The present invention first initializes the flywheel parameters, including speed, charge and discharge safety status, start and stop status, and power constraints. Then, the grid connection point voltage, frequency, and PCS initial power are detected, and speed balancing or a frequency modulation operation is performed based on whether the frequency is within the dead zone. The frequency modulation power is allocated to the flywheel energy storage first. If it is insufficient, wind and solar power will be considered for participation and allocated proportionally. The pre-allocated power of a single machine is calculated based on the flywheel speed, safety status, and power constraints, the speed at future times is estimated, and the safety status and power limit checks are performed. If there is a power shortage and the flywheel has not reached the maximum power, the power is reallocated and the calculation is repeated until there is no shortage or the flywheel is at full power. Finally, the allocated power of each unit is output. This process ensures the stability of the grid frequency, improves the absorption of wind and solar power, and at the same time guarantees the safe operation of the flywheel energy storage unit.

[0075] Furthermore, by optimizing the power distribution and speed recovery management of the flywheel array, it is possible to quickly respond to the primary frequency regulation needs of the power grid while achieving efficient coordinated control of the flywheel array with new energy sources such as wind and solar power, thereby improving the energy utilization efficiency and operational safety of the system.

[0076] Therefore, in the frontier flywheel energy storage technology, the present invention takes high-speed MW-class flywheel single units as the mainstream direction. Moreover, with the large-scale new energy grid connection, the power system's demand for high rotational inertia and high-frequency frequency modulation is increasing. The large-scale flywheel energy storage array composed of MW-class flywheel single units can give full play to the flywheel's long life and fast response operating characteristics to support grid frequency modulation.

[0077] like Figure 2Another object of the present invention is to provide a system and device for primary frequency regulation of a flywheel energy storage power station that balances speed regulation and state safety, comprising a dispatching layer, a station control layer, and a ground layer. The dispatching layer refers to power grid dispatching, the station control layer comprises an energy storage primary frequency regulation control device, energy storage monitoring, a wind and solar station monitoring module, a network switch, and an energy storage communication management unit. The ground layer is a flywheel array consisting of multiple high-speed flywheels.

[0078] The energy storage primary frequency control device is responsible for detecting frequency changes at the grid connection point and calculating the power required of each flywheel based on the preset frequency deadband, as well as information such as the flywheel's speed and charge / discharge limits. The energy storage monitoring system monitors the status of each flywheel and manages the flywheel assembly. The flywheel array can receive upper-level grid dispatch, automatic primary frequency regulation, or speed balancing commands, with primary frequency regulation commands taking precedence over dispatch commands.

[0079] In the above scheme, the dispatching layer is responsible for overall grid dispatching and command issuance, ensuring frequency stability and safe operation. The station control layer includes energy storage primary frequency regulation control devices, energy storage monitoring, wind and solar station monitoring modules, network switches, and energy storage communication management units. This layer bridges the dispatching layer and the field layer, responsible for receiving dispatching commands, monitoring flywheel status, and calculating power allocation. The field layer, consisting of a flywheel array consisting of multiple high-speed flywheels, is responsible for actually executing frequency regulation commands, supporting the grid frequency by adjusting its speed.

[0080] The frequency modulation principle includes the following steps:

[0081] Frequency detection: The energy storage primary frequency regulation control device detects the frequency changes of the grid connection point (i.e. the connection point between the flywheel energy storage power station and the power grid) in real time.

[0082] Power calculation: Based on the preset frequency dead zone (i.e. the allowable frequency fluctuation range) and information such as the speed, charge and discharge authority of each flywheel, the power that each flywheel needs to bear is calculated.

[0083] Instruction issuance: The calculated power instruction is sent to the flywheel array in the ground layer through the station control layer.

[0084] Execution adjustment: The flywheel array adjusts the speed according to the received instructions, thereby supporting and regulating the grid frequency.

[0085] Priority processing: Primary frequency modulation instructions take precedence over dispatch instructions. When the grid frequency fluctuates significantly, the system can quickly respond and execute the primary frequency modulation instructions, ensuring the safe and stable operation of the grid.

[0086] As an example, the flywheel energy storage power station of the embodiment of the present invention has the characteristics of fast response speed, and can adjust the rotation speed and support the grid frequency in a very short time. Through the calculation and distribution of the energy storage primary frequency regulation control device, the power distribution can be flexibly adjusted according to the actual situation of each flywheel to ensure the optimization of the frequency regulation effect. The system has complete monitoring and management functions, which can monitor the flywheel status information and manage the flywheel unit in real time. At the same time, the priority setting of the primary frequency regulation instruction ensures the safe and stable operation of the power grid in emergency situations. The system can monitor and coordinate with other new energy sites (such as wind farms, photovoltaic power stations, etc.) to improve the flexibility and stability of the entire power grid.

[0087] The control method and system of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0088] Figure 1 is the active power-frequency characteristic curve of the energy storage equipped with the new energy station participating in the primary frequency regulation, where is the active power limiting coefficient β, i.e. [f min ,f max ] is the dead zone of grid frequency regulation, [f n ,f m ] are the upper and lower limits of a frequency modulation.

[0089] like Figure 2 As shown in the figure, the flywheel energy storage coordinated wind and solar power station frequency regulation control architecture consists of grid dispatching, energy storage primary frequency regulation device, energy storage monitoring, wind turbine monitoring, energy storage communication management machine, and high-speed flywheel array. Among them, the energy storage primary frequency regulation device is connected to the grid connection point and is responsible for detecting frequency changes at the grid connection point and issuing primary frequency regulation or speed balancing instructions; the energy storage monitoring system is responsible for monitoring the status information of the flywheel unit and managing the flywheel array; the wind and solar power station monitoring module is used to control the wind turbine power generation and photovoltaic power generation to respond to the frequency regulation power; the various devices communicate with each other through a local area network formed by a network switch, supporting the IEC104 / 61850-MMS protocol.

[0090] Figure 3 This is a control method and implementation block diagram for primary frequency regulation using flywheel energy storage in conjunction with wind and solar power stations. Specifically, it includes the following steps:

[0091] Step 1: Initialize the high-speed flywheel array parameters, including: flywheel single unit speed ni, charge and discharge safety status Start / stop status, power constraints, etc.

[0092] Step 2: The energy storage primary frequency control device detects the voltage, frequency, PCS initial power and other signals at the grid connection point, and calculates the power demand ΔP in two cases. f:First, when the frequency is in the dead zone, the flywheel speed balancing operation is performed; second, when the frequency exceeds the dead zone, a frequency modulation operation is performed, ΔP f is the primary FM power.

[0093] Furthermore, in step 2: calculate the power demand ΔP in two cases f for

[0094]

[0095] (1) When f min ≤f≤f max When frequency modulation is not required, the speed n of the flywheel energy storage system can be adjusted to the reference value Therefore, the speed reference value is defined as When the flywheel speed is close to the maximum and minimum speed in the frequency modulation dead zone, the balanced power ΔP re Balance the speed of the flywheel energy storage system to the reference value The speed reference value Determined based on the highest or lowest speed of a single unit in the flywheel energy storage array. First, the flywheel speed is divided into n min ,n l ,n h ,n max , which is lower than n l or higher than n h , need to Based on the relationship between speed and energy, the balanced power ΔP of the i-th flywheel unit is first set. adj,i for:

[0096]

[0097]

[0098] Where n i is the speed of the i-th unit; α is the balance coefficient; P fess,N is the rated power of the flywheel. h <n i ≤n max When the speed needs to be lowered, ΔP adj,i is positive, discharge; when n min <n i ≤n l When the speed needs to be increased, ΔP adj,i Negative, that is, charging the energy storage.

[0099] In order to ensure that the charging and discharging behavior during the energy storage balancing process does not have a significant impact on the access point frequency, the power change boundary value ΔP is defined av, this value is determined by the frequency modulation dead zone boundary value. The energy storage is charged and discharged at this value without causing the frequency to exceed the dead zone, so the balanced power ΔP re Need to be adjusted to ΔP adj and ΔP av The smaller value of , that is:

[0100]

[0101] (2) When the frequency f exceeds the dead zone, a frequency modulation operation is required. The power requirement of the frequency modulation is shown in formula (1), where δ% is the frequency modulation difference rate of the new energy station, P N is the rated power of the new energy station, f is the real-time frequency of the grid connection point, m is the frequency modulation adaptive coefficient, and the value of m is as follows: Figure 4 As shown. Figure 4 As shown in FIG, the frequency modulation adaptive coefficient m increases when the frequency approaches the limit value, which plays a role in accelerating the frequency regulation; when the frequency exceeds the limit value, the system will no longer respond to the frequency modulation.

[0102] Step 3: Frequency regulation power allocation. Since wind power and photovoltaic units often operate in maximum power point tracking (MPPT) control mode and have no active reserve capacity, wind and photovoltaic units cannot generate additional power when the frequency at the grid connection point drops. Flywheel energy storage is used for frequency regulation first. When flywheel energy storage cannot meet the frequency regulation demand, wind power and photovoltaic units participate in frequency regulation and only respond to downward frequency regulation. Based on the real-time output of wind and photovoltaic units, the abandoned wind and photovoltaic power are allocated according to the real-time power generation ratio.

[0103] Step 4: Set the power of the high-speed flywheel array in response to the grid primary frequency modulation to P FESS , the power control period is T, according to the speed ni of the high-speed flywheel energy storage unit, the charging and discharging safety state Calculate the pre-allocated power of a single flywheel unit based on parameters such as power constraints;

[0104] Further, in step 4: according to the speed ni of the high-speed flywheel energy storage unit, the charging and discharging safety state The pre-allocated power of a single flywheel unit is calculated based on parameters such as power constraints:

[0105]

[0106] Where, is the charging power pre-allocated to the i-th flywheel, is the discharge power pre-allocated to the i-th flywheel, K is the number of flywheel units, is the power demand allocated to the flywheel array at time t, is the speed of the i-th flywheel unit at time t, n i,max is the maximum speed of the i-th flywheel unit, Represent the safe status of charge and discharge respectively.

[0107] Step 5: Estimate the speed of each flywheel at time t+T based on the pre-allocated power;

[0108] Furthermore, in step 5: the speed of each high-speed flywheel unit at time t+T is estimated based on the pre-allocated power.

[0109]

[0110] Where, is the charging power allocated to the i-th flywheel at time t, which is a negative value; is the discharge power allocated to the i-th flywheel at time t, which is a positive value; E N,i is the rated energy of the i-th flywheel. In this example, the control mode of the flywheel is to charge and discharge at constant power through PCS, so p is used. i T represents the energy stored in i flywheels after T cycles.

[0111] Step 6: Perform safety status verification and adjust the power of the flywheel energy storage unit whose safety status is less than 1;

[0112] Further, in step 6: perform security status verification

[0113] (1) Charging safety status

[0114]

[0115] Where n i,N is the rated speed of the i-th flywheel unit. During charging, when the speed is less than or equal to 95% of the rated speed, it is considered to be completely safe, with a corresponding safety value of 1. When the speed is between 95% and 100% of the rated speed, the safety status gradually decreases.

[0116] (2) Discharge safety status

[0117]

[0118] In the discharge state, when the speed is greater than or equal to 5% of the rated speed, it is considered to be in a completely safe state, and the corresponding safety value is 1; when the speed is in the rated speed range of 5%-0%, the safety state gradually decreases.

[0119] And adjust the power of the flywheel energy storage unit whose safety status is less than 1:

[0120]

[0121] Where p B is the power limit, which is set according to the charge and discharge status.

[0122] Step 7: Perform power limit check and calculate power shortage;

[0123] Furthermore, in step 7: determine whether the charge and discharge power of each flywheel exceeds the power limit, and calculate the power shortage

[0124]

[0125] Step 8: Determine whether the power shortage is less than the threshold. If not, redistribute the power shortage to the high-speed flywheel whose speed does not exceed the limit. Return to step 5 and repeat the above calculation until there is no frequency regulation power shortage or each flywheel energy storage unit reaches the maximum power. If it is less than the threshold, output the allocated power to each unit.

[0126] Due to the adoption of the above-mentioned technical solution, the present invention can achieve optimized management of the power and speed of the flywheel array while rapidly responding to power demands. Even when the initial speeds of individual flywheels are highly discrete, the speeds of each flywheel can be adjusted to maintain consistency within a short period of time, and the total speed of the flywheel array can be kept near the reference value for most of the time, facilitating the charging or discharging of the flywheel energy storage array, thereby improving the energy utilization efficiency of the entire system. Furthermore, the inclusion of inertial flywheels in the hybrid flywheel array can provide inertia support for the new power system, improving system stability.

[0127] A third objective of an embodiment of the present invention is to provide an electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the aforementioned method for primary frequency regulation of a flywheel energy storage power station that balances speed regulation and state safety. The electronic device also includes a communication interface and a bus.

[0128] A fourth object of an embodiment of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, implements the primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety.

[0129] A fifth object of an embodiment of the present invention is to provide a computer program product, which includes computer instructions, and the computer instructions instruct a computer to execute the above-mentioned primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety.

[0130] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1The function specified in one or more boxes.

[0131] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0132] The present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, readable storage media, optical storage, etc.) containing computer-usable program code.

[0133] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowcharts and / or block diagrams. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0134] Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0135] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A primary frequency regulation method for a flywheel energy storage power station that takes into account both speed regulation and state safety, characterized in that: include: S1: Initialize high-speed flywheel array parameters, including: single flywheel speed , safe state of charge and discharge 、 , start-stop state, power constraint; S2: Obtain the voltage, frequency, and PCS initial power of the grid connection point, and calculate the power demand in two cases based on the voltage, frequency, and PCS initial power of the grid connection point. : First, when the frequency is in the dead zone, the flywheel speed is balanced and the speed balance power ; Second, when the frequency exceeds the dead zone, a frequency modulation operation is performed. is the primary frequency modulation power; S3: FM power demand Allocate to flywheel energy storage, wind power, and photovoltaics; prioritize flywheel energy storage frequency regulation. If frequency regulation power is insufficient, the wind and solar frequency regulation power will be allocated proportionally based on the real-time output of wind and solar power. S4: Power demand in FM After allocation, the power of the high-speed flywheel unit in response to the primary frequency regulation of the grid is set to ; According to the speed of the high-speed flywheel energy storage unit , safe state of charge and discharge 、 , power constraint, calculate the pre-allocated power of a single flywheel machine; S5: Estimate the speed of each flywheel at time t+T based on the pre-allocated power; S6: Perform safety status verification at the estimated speed of each flywheel at time t+T, and adjust the power of the flywheel energy storage unit whose safety status is less than 1; S7: After the power is adjusted, a power over-limit check is performed and the power shortage is calculated; S8: Determine whether the power shortage is less than the threshold. If not, redistribute the power shortage to the high-speed flywheel whose speed does not exceed the limit, return to S5, and repeat until there is no frequency modulation power shortage or each flywheel energy storage unit reaches the maximum power. If less than the threshold, output the power allocated to each unit. In S6, a security status check is performed, including: 1) Charging safety status Where, For the i The rated speed of the flywheel unit; in the charging state, when the speed is less than or equal to 95% of the rated speed, it is considered to be in a completely safe state, and the corresponding safety value is 1; when the speed is in the range of 95%-100% of the rated speed, the safety state gradually decreases; 2) Discharge safety state In the discharge state, when the speed is greater than or equal to 5% of the rated speed, it is a completely safe state, and the corresponding safety value is 1; when the speed is in the rated speed range of 5%-0%, the safety state gradually decreases.

2. A flywheel energy storage power station primary frequency modulation method that takes into account both speed adjustment and state safety according to claim 1, characterized in that: In S2: Calculate power requirements in two cases , specifically: The first case: When When frequency modulation is not required, the speed n of the flywheel energy storage system is adjusted to the speed reference value. When the flywheel speed is close to the maximum and minimum speed in the frequency modulation dead zone, the balanced power Balance the speed of the flywheel energy storage system to the speed reference value ; The second case: When the frequency When crossing the dead zone, a frequency modulation operation is required, using the power requirement Perform a frequency modulation operation, where It is the frequency regulation rate of the new energy station. is the rated power of the new energy station, The real-time frequency of the grid connection point, is the FM adaptive coefficient.

3. A flywheel energy storage power station primary frequency modulation method that takes into account both speed regulation and state safety according to claim 2, characterized in that: The speed reference value Determined based on the highest or lowest speed of a single unit in the flywheel energy storage array; First, the flywheel speed is divided into , lower than or higher Need to Based on the relationship between speed and energy, set the i Balanced power of flywheel units for: Where, For the i Unit speed; is the equalization coefficient; is the rated power of the flywheel unit; when When the speed is lowered, is positive, discharge; when When the speed needs to be increased, is negative, charging the energy storage; Define power change boundaries , Determined by the frequency modulation dead zone boundary value, energy storage Charging and discharging does not cause the frequency to exceed the dead zone, and the power is balanced Need to be adjusted to and The smaller value of , that is: 。 4. A flywheel energy storage power station primary frequency modulation method that takes into account both speed regulation and state safety according to claim 2, characterized in that: The frequency modulation adaptive coefficient , when the frequency is close to the limit value, Increase, when the frequency exceeds the limit, it will no longer respond to frequency modulation.

5. A flywheel energy storage power station primary frequency regulation method that takes into account both speed regulation and state safety according to claim 1, characterized in that: In S4, according to the speed of the high-speed flywheel energy storage unit , safe state of charge and discharge 、 , power constraint calculation of the pre-allocated power of a single flywheel; include: Where, is the charging power pre-allocated to the i-th flywheel, is the discharge power pre-allocated to the i-th flywheel, K is the number of flywheel units, for t The power demand allocated to the flywheel array at any time, for t Moment i The speed of the flywheel unit, For the i The maximum speed of the flywheel unit, 、 Represent the safe status of charge and discharge respectively.

6. A flywheel energy storage power station primary frequency regulation method that takes into account both speed regulation and state safety according to claim 1, characterized in that: In S5: the speed of each high-speed flywheel unit at time t+T is estimated based on the pre-allocated power, including: Where, is the first i The charging power allocated to the flywheel is negative; is the first i The discharge power allocated to each flywheel is a positive value; It is i Rated energy of a flywheel, express The energy stored in a flywheel after T cycles.

7. A flywheel energy storage power station primary frequency regulation method that takes into account both speed regulation and state safety according to claim 1, characterized in that: It also includes power adjustment for flywheel energy storage units with a safety status less than 1: Where, is the power limit.

8. A primary frequency regulation method for a flywheel energy storage power station that takes into account both speed regulation and state safety according to claim 7, characterized in that: In S7: determining whether the charge and discharge power of each flywheel exceeds the power limit, and calculating the power deficit, specifically including: 。 9. A flywheel energy storage power station primary frequency regulation system that takes into account both speed regulation and state safety, realizing the flywheel energy storage power station primary frequency regulation method that takes into account both speed regulation and state safety as described in any one of claims 1-8; characterized in that: include: Dispatching layer, station control layer, and ground layer; Wherein, the dispatching layer refers to the grid dispatching; The station control layer includes an energy storage primary frequency regulation control device, an energy storage monitoring system, a wind and solar station monitoring module, a network switch, and an energy storage communication management machine; The present formation is a flywheel array composed of multiple high-speed flywheel machines; The energy storage primary frequency regulation control device is connected to the grid connection point and is used to detect frequency changes at the grid connection point and calculate the power required by each flywheel based on the preset frequency dead zone and the speed and charge and discharge authority of each flywheel. The energy storage monitoring system monitors the status information of each flywheel and manages the flywheel group. The flywheel array receives upper-level grid dispatch, automatic primary frequency regulation or speed balancing instructions, and the primary frequency regulation instructions have higher priority than the dispatch instructions. The wind and solar station monitoring module is used to control the wind turbine power generation and photovoltaic power generation to respond to the frequency modulation power; Each device communicates with each other through a local area network formed by a network switch; The energy storage communication management machine is used to perform communication management of the flywheel array.

10. An electronic device, characterized in that: The invention comprises a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the primary frequency regulation method of a flywheel energy storage power station taking into account both speed regulation and state safety as described in any one of claims 1 to 8 is implemented.

11. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety as described in any one of claims 1 to 8 is implemented.

12. A computer program product comprising computer instructions, characterized in that: The computer instructions instruct the computer to execute the primary frequency regulation method of a flywheel energy storage power station that takes into account both speed regulation and state safety as described in any one of claims 1-8.

Images