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CN-122026401-A - Energy storage power station primary frequency modulation control method and system based on SOC balance

CN122026401ACN 122026401 ACN122026401 ACN 122026401ACN-122026401-A

Abstract

The invention discloses an energy storage power station primary frequency modulation control method and system based on SOC balance, and particularly relates to the technical field of power system control, which is applicable to a large-scale power grid side pure energy storage system of 100MW level and above. The system acquires data such as power grid frequency, energy storage unit SOC and the like through 100Hz high frequency, distributes frequency modulation power through a double-factor self-adaptive algorithm of SOC deviation-frequency deviation change rate after preprocessing, realizes SOC balance by combining unit level-group level-station level hierarchical closed-loop control, and guarantees stable operation through 5G+ optical fiber dual-mode communication and an abnormal fault tolerance mechanism. The invention has the advantages that the frequency modulation response time is less than or equal to 20ms, the SOC balance error is less than or equal to 2%, the reliability and the expansibility are outstanding, the power grid frequency fluctuation can be quickly stabilized, the service life of the energy storage unit is prolonged, and the primary frequency modulation requirement of a large-scale energy storage power station is met.

Inventors

  • HE JIANRONG
  • WANG YONG

Assignees

  • 合邦电力科技有限公司

Dates

Publication Date
20260512
Application Date
20260413

Claims (10)

  1. 1. The primary frequency modulation control method of the energy storage power station based on SOC balance is suitable for a large-scale power grid side pure energy storage system of 100MW level and above, and is characterized by comprising the following steps of continuously and circularly executing: S1, collecting high-frequency data through a distributed collecting module (1), wherein the distributed collecting module (1) comprises an SOC collecting unit (101), a frequency collecting unit (102) and a power collecting unit (103), and the frequency of a public connection point of a power grid is collected in real time at 100Hz frequency State of charge of each energy storage unit Output power Terminal voltage The acquired data is transmitted to a central controller through a 5G+ optical fiber dual-mode communication module (4), and the transmission delay is less than or equal to 10ms; S2, preprocessing data, namely filtering and denoising the acquired data by adopting a Kalman filtering algorithm, setting an abnormal value threshold value, marking and linearly interpolating and supplementing the data exceeding the threshold value, and simultaneously calculating the power grid frequency deviation by adopting a central controller SOC deviation of each energy storage unit Rate of change of frequency deviation ; S3, frequency modulation triggering judgment, namely setting a frequency modulation dead zone If = ± 0.03Hz < The energy storage power station maintains the standby state if ≥ Triggering a primary frequency modulation process; S4, double-factor self-adaptive power distribution, namely calculating the frequency modulation power distribution coefficient of each energy storage unit based on the double factors of the SOC deviation and the frequency deviation change rate The distribution coefficient formula is: ; Wherein, the Distributing coefficients for the base power; The SOC balance adjustment coefficient is used; adjusting coefficients for the frequency response; To satisfy 0 <) ≤1.2; S5, calculating and issuing the frequency modulation power, namely calculating the total frequency modulation power according to a sagging control formula Recombination of distribution coefficients Calculating the target output power of each energy storage unit Amount of power adjustment Will be The instruction is issued to a local controller of each energy storage unit; S6, hierarchical closed-loop SOC balance control, namely adopting unit-group-station three-layer closed-loop control to adjust the output of each energy storage unit in real time, and ensuring that the total station SOC balance error is less than or equal to 2%; S7, abnormal fault tolerance and resetting, namely when a sensor fault, communication interruption or energy storage unit fault occurs, starting a fault tolerance mechanism, removing a fault unit and reallocating power, automatically resetting the fault unit after abnormal release, and continuously executing SOC balance control until reaching standards after the system is restored to a dead zone after the power grid frequency is restored to normal operation, and then restoring a standby state.
  2. 2. The method of claim 1, wherein in step S1, the SOC acquisition unit (101) adopts an SOC sensor, the frequency acquisition unit (102) adopts a power analyzer, the power acquisition unit (103) adopts a Hall current sensor, and each energy storage unit is correspondingly provided with 1 set of SOC acquisition unit (101) and power acquisition unit (103).
  3. 3. The method according to claim 1, wherein in step S2, the threshold value of the abnormal value is set to be SOC 5% or more and 95% or more, and the frequency deviation is set to be equal to or less ≥±0.5Hz; Grid frequency deviation , Rated frequency of 50Hz for the power grid; SOC deviation of each energy storage unit , The SOC average value for all the energy storage units.
  4. 4. The method according to claim 1, wherein in step S4, The range of the value of (2) is 0.2-0.4, and the large-scale energy storage system defaults =0.3; The value range of (2) is 0.1-0.3, and the large-scale energy storage system defaults =0.2; Basic power distribution coefficient Wherein Is the first The power rating of the individual energy storage units, And (5) the total rated power of the energy storage power station.
  5. 5. The method of claim 1, wherein in step S5, the droop control formula is , The frequency modulation sagging coefficient is in the value range of 10-20MW/Hz and can be dynamically adjusted according to the power grid dispatching requirement; power adjustment of each energy storage unit , And outputting power for each energy storage unit.
  6. 6. The method according to claim 1, wherein in step S6, the specific process of hierarchical closed-loop SOC balance control is: unit level local controller real-time monitoring local unit If the dynamic threshold value is exceeded, the frequency modulation output is suspended, only SOC balance adjustment is executed, and the dynamic threshold value is based on The adjustment is carried out so that the adjustment is carried out, When the temperature is more than or equal to 0.2Hz, the upper limit of the SOC is 85 percent, the lower limit is 25 percent, At <0.2Hz, the SOC threshold value is restored to 20% -80%; dividing the energy storage power station into a plurality of energy storage groups, wherein each group comprises 10-20 energy storage units, and if the average value deviation of the SOC between the groups is more than or equal to 5%, adjusting the power distribution coefficient between the groups to reduce the deviation between the groups; Station level, central controller real-time monitoring all energy storage units If single unit SOC deviates Not less than 3%, continuously adjusting the unit Coefficients up to <3%。
  7. 7. An energy storage power station primary frequency modulation control system based on SOC balance is used for realizing the control method of any one of claims 1-6, and is characterized by comprising a distributed acquisition module (1), a central control module (2), a local control module (3), a communication module (4), a charge and discharge execution module (5) and a monitoring and scheduling module (6), wherein the specific structure is as follows: The distributed acquisition module (1) comprises an SOC acquisition unit (101), a frequency acquisition unit (102) and a power acquisition unit (103), which are respectively used for acquiring the SOC value of each energy storage unit, the power grid frequency and the output power of each energy storage unit and supporting 100Hz high-frequency acquisition; the central control module (2) adopts an industrial PLC controller, and is internally provided with a data preprocessing module, a frequency modulation triggering judgment module, a double-factor self-adaptive power distribution module, a layered closed-loop balanced control module and an abnormal fault tolerance module, so that multitasking parallel processing is supported, and the response time is less than or equal to 10ms; The local control module (3) is used for configuring 1 local controller for each energy storage unit, receiving the instruction of the central controller, controlling the charge and discharge power of the energy storage unit, and simultaneously collecting and uploading the operation data of the unit; The communication module (4) adopts a 5 G+optical fiber dual-mode communication architecture, and a communication protocol accords with IEC 61850 standard, so that high-speed stable transmission of data is ensured, and the optical fiber is automatically switched to 5G communication when interrupted; Each energy storage unit is provided with 1 set of IGBT inverter, which is used for receiving a local controller instruction to adjust charging and discharging power, the response time is less than or equal to 5ms, and the energy storage unit has overcurrent, overvoltage and overtemperature protection functions; The monitoring and dispatching module (6) comprises an industrial monitoring host and monitoring software, can display the running state of the system, set control parameters and check fault records in real time, and supports the butt joint with the power grid dispatching center to realize cooperative dispatching.
  8. 8. The system of claim 7, wherein the built-in memory capacity of the central control module (2) is more than or equal to 16GB, the built-in memory capacity is used for storing collected data, control parameters and fault records, and the local control module (3) is directly connected with the IGBT inverter of the corresponding energy storage unit and the collection unit.
  9. 9. The system of claim 7, wherein in the communication module (4), the transmission rate of optical fiber communication is more than or equal to 1000Mbps, the delay is less than or equal to 5ms,5G communication adopts an industrial grade 5G module, SA independent networking is supported, the transmission rate is more than or equal to 100Mbps, and the data transmission requirement of the distributed layout of the large-scale energy storage system is ensured.
  10. 10. The system according to claim 7, wherein the IGBT inverter in the charge-discharge execution module (5) has a rated voltage of 380V/10kV, and is flexibly adjustable according to the specification of the energy storage unit, and the industrial monitoring host of the monitoring and dispatching module (6) supports manual setting 、 、 And SOC threshold value and other control parameters, and remote scheduling control is realized.

Description

Energy storage power station primary frequency modulation control method and system based on SOC balance Technical Field The invention relates to the technical field of power system control, in particular to an energy storage power station primary frequency modulation control method and system based on SOC balance. Background With the large-scale grid connection of new energy sources such as wind power, photovoltaic and the like, the fluctuation and intermittence of the output of the energy storage power station lead to the aggravation of the fluctuation of the frequency of a power grid, and the frequency stability of a power system is provided with a serious challenge, so that the energy storage power station has become a core regulation resource of primary frequency modulation of the power grid due to the characteristics of high response speed and flexible charge and discharge. The core complaint of primary frequency modulation is that the frequency deviation of a power grid is responded quickly, and meanwhile, the state of charge of each energy storage unit in the energy storage power station is required to be balanced, so that the service life is shortened or the system is failed due to overcharge and overdischarge of part of units. However, the prior art has obvious defects that part of schemes depend on multi-energy coupling such as wind storage, optical storage and the like, cannot adapt to a large-scale grid side pure energy storage scene, part of schemes adopt single factor power distribution, frequency modulation response speed and SOC balance accuracy are difficult to consider, most of schemes are designed for medium and small scale, a layered closed loop architecture is lacking, expansibility is poor, a communication mode is single, frequency modulation is easy to break, and other schemes only depend on hardware improvement, are not optimized cooperatively from an algorithm level, and are poor in universality and economy. In summary, the prior art cannot meet the comprehensive requirements of a large-scale power grid side pure energy storage system of 100MW level and above on primary frequency modulation response speed, SOC balance precision and system reliability, and a control method and a system which are high in efficiency response, accurate in balance and stable and reliable are needed. Disclosure of Invention In order to overcome the defects in the prior art, the invention provides a primary frequency modulation control method and system for an energy storage power station based on SOC balance, which are used for solving the problems in the background art. In order to achieve the above purpose, the present invention provides the following technical solutions: On the one hand, the invention provides an energy storage power station primary frequency modulation control method based on SOC balance, which is suitable for a large-scale power grid side pure energy storage system of 100MW level and above, and comprises the following steps of continuously and circularly executing: s1, collecting high-frequency data through a distributed collecting module, wherein the distributed collecting module comprises an SOC collecting unit, a frequency collecting unit and a power collecting unit, and the frequency of a public connection point of a power grid is collected in real time at 100Hz frequency State of charge of each energy storage unitOutput powerTerminal voltageThe acquired data are transmitted to the central controller through the 5G+ optical fiber dual-mode communication module, and the transmission delay is less than or equal to 10ms; S2, preprocessing data, namely filtering and denoising the acquired data by adopting a Kalman filtering algorithm, setting an abnormal value threshold value, marking and linearly interpolating and supplementing the data exceeding the threshold value, and simultaneously calculating the power grid frequency deviation by adopting a central controller SOC deviation of each energy storage unitRate of change of frequency deviation; S3, frequency modulation triggering judgment, namely setting a frequency modulation dead zoneIf = ± 0.03Hz<The energy storage power station maintains the standby state if≥Triggering a primary frequency modulation process; S4, double-factor self-adaptive power distribution, namely calculating the frequency modulation power distribution coefficient of each energy storage unit based on the double factors of the SOC deviation and the frequency deviation change rate The distribution coefficient formula is: ; Wherein, the Distributing coefficients for the base power; The SOC balance adjustment coefficient is used; adjusting coefficients for the frequency response; To satisfy 0 <) ≤1.2; S5, calculating and issuing the frequency modulation power, namely calculating the total frequency modulation power according to a sagging control formulaRecombination of distribution coefficientsCalculating the target output power of each energy storage unitAmount of