Hybrid energy storage and power generation combined power control system and method

Abstract

The invention belongs to the field of energy storage and power generation combination, and provides a hybrid energy storage and power generation combined power control system and method, and the system comprises a power generation unit, a hybrid energy storage unit, a detection unit, a dynamic frequency response unit, a self-adaptive median calibration unit, and a combined system cooperative control unit. The dynamic frequency response unit dynamically distributes a power instruction based on a power grid frequency deviation delta f and a real-time inertia constant H: when delta f / delta fthgt; one hour power type energy storage is 100% in response; 0.5 lt; when delta f / delta fth is less than or equal to 1, distributing according to a ratio of 7: 3; and when delta f / delta fth is less than or equal to 0.5, the power type energy storage bears all delta P. The self-adaptive median calibration unit adjusts an SOC target value in real time through a dynamic median generator, and power type energy storage out-of-limit locking is avoided in combination with a deviation integrator and a safety boundary protector. And the combined control unit cooperates with multi-source output to realize economic dispatching and frequency stability. The problems of hybrid energy storage dynamic distribution, SOC real-time calibration and multi-source cooperative control are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage and power generation combined control, and particularly relates to a hybrid energy storage and power generation combined power control system and method. BACKGROUND

[0002] With the continuous increase of new energy generation proportion, the power system is facing challenges such as deterioration of frequency stability and decline of inertia support capability. The traditional power grid relies on the rotational inertia of synchronous generator units to suppress frequency fluctuations, but wind power, photovoltaic and other new energy units cannot provide equivalent inertia response, resulting in a significant decrease in system disturbance resistance. To make up for the deficiency of new energy, energy storage systems are widely used in frequency regulation due to their fast response characteristics. The existing technology mainly has the following defects: single energy storage type cannot balance frequency regulation performance and economic benefits, power type energy storage (such as super capacitor, flywheel) has fast response speed (≤100 ms), but has limited capacity and insufficient sustained support capability, and frequent charging and discharging can easily lead to life attenuation; energy type energy storage (such as lithium battery, flow battery) has large capacity, but has response delay (usually ≥500 ms), and cannot meet the demand of high dynamic frequency fluctuation. The existing scheme mainly uses fixed proportion to allocate power command, and does not consider the coupling relationship between real-time inertia change and frequency deviation of the power grid, resulting in over-compensation or under-compensation of regulation. Static energy storage operating parameters cause safety risks The state of charge (SOC) of power type energy storage is prone to cumulative deviation in frequent frequency regulation, and the existing system mainly uses fixed median value (such as 50% SOC) control. However, under the conditions of new energy output fluctuation and load mutation, the static median value will cause the SOC to continuously deviate from the safe interval, triggering protective lockout, which in turn aggravates the risk of system instability. The coordination mechanism between power generation units and energy storage is missing The frequency modulation of thermal power units has a climbing rate limit (usually ≤2% / s), which is difficult to match with the millisecond-level response of energy storage. The current joint control system only simply superimposes the output of power generation and energy storage, and does not establish a multi-time scale dynamic power distribution strategy, resulting in economic degradation (such as excessive use of energy storage increasing life loss) or insufficient frequency regulation reserve capacity. There is no real-time inertia sensing technology for regional inertia The inertia time constant (H) of the power grid is a core parameter for frequency control, but the existing system mainly uses the design reference value (fixed at 4-5 seconds). In actual operation, the H value dynamically decreases with the increase of new energy penetration rate, and the static H value causes unreasonable setting of the frequency threshold, which aggravates the number of energy storage actions.

[0003] The existing technology has the following defects: (1) Dynamic power distribution of hybrid energy storage - how to adaptively adjust the response proportion of power type / energy type energy storage according to the frequency deviation magnitude and real-time inertia of the power grid; (2) Real-time calibration of SOC of power type energy storage - how to dynamically correct the target median value according to the working condition to avoid over-limit lockout and cause the bottleneck of unavailable time; (3) Multi-source collaborative economic stability control - how to coordinate the complementary mechanism of slow frequency adjustment of thermal power and fast frequency adjustment of energy storage to achieve optimal operation in all working conditions.

[0004] Therefore, a hybrid energy storage and power generation combined power control system and method are proposed to solve the above problems. SUMMARY

[0005] Therefore, the purpose of the present application is to provide a hybrid energy storage and power generation combined power control system and method to at least solve the above problems.

[0006] The technical solution adopted by the first aspect of the present application is as follows: A hybrid energy storage and power generation combined power control system, the system comprising: A power generation unit, including wind power, photovoltaic, thermal power unit, for providing basic power transmission; A hybrid energy storage unit, composed of power type energy storage device and energy type energy storage device in parallel, connected in parallel with the power generation unit.

[0007] A detection unit, according to the operation data of the power generation unit, the hybrid energy storage unit and the PMU, detects the grid frequency and the regional inertia time constant, the energy storage state parameter, for providing basic data for the energy storage and power generation combined system control; A dynamic frequency response unit for dynamically distributing the power instructions of the power type energy storage and the energy type energy storage of the hybrid energy storage unit according to the grid frequency deviation and the regional inertia time constant; An adaptive median calibration unit, including a deviation integrator, a compensation controller and a dynamic median generator, for dynamically adjusting the operating parameters of the power type energy storage, and interlocking with the dynamic frequency response unit, to lock the power type energy storage in emergency working conditions; A combined system cooperative control unit for cooperative control of the power generation unit, the hybrid energy storage unit, the dynamic frequency response module and the adaptive median calibration module, to realize the cooperative control of the hybrid energy storage and power generation combined system.

[0008] Further, the response time of the power type energy storage device of the hybrid energy storage unit is ≤100ms, and the response time of the energy type energy storage device is dynamically adjusted according to the frequency deviation; The response time is dynamically adjusted according to the frequency deviation: response time adjustment function: response time And the grid frequency deviation Satisfies the relationship ; Wherein The preset maximum response time is 1 second to 10 seconds, The adjustable coefficient is 0.1~10s / Hz; Dynamic adjustment trigger condition: when the frequency deviation The dynamic adjustment is started; The response time dynamic adjustment is realized by adjusting the power adjustment instruction control period of the energy type energy storage device, and output adjustment instructions are sent to the power converter of the energy type energy storage device.

[0009] Further, the grid area inertia time constant H is obtained by recording the frequency dynamic process of the hybrid energy storage and power generation combined system at the grid connection point by using the PMU data, combined with the load fluctuation, and is obtained by data fitting and backstepping, and the calculation formula is: Where ΔP is the disturbance power (MW); f N is the rated power; df / dt: the frequency change rate (Hz / s) in the initial stage of disturbance, is the load capacity in the area.

[0010] Further, the energy storage state parameters include: state of charge SOC, grid-connected power, charge / discharge state, average temperature of energy storage units, and energy storage locking state.

[0011] Further, the combined system cooperative control unit comprises: A power distribution coordinator for dynamically adjusting the power distribution ratio between the power generation unit and the energy storage unit according to the real-time power demand of the grid; A state monitoring module for obtaining detection unit data to monitor the operating state of the power generation unit, the energy storage unit and the grid in real time, including frequency, voltage, power fluctuation; A strategy optimization module for dynamically optimizing the control strategy according to the grid operating state, load prediction and energy storage SOC state information to realize the economy and stability of system operation; A communication interface for data interaction with external grid dispatching system, energy storage management system and power generation control system to realize remote monitoring and control.

[0012] Further, the control strategy of the combined system cooperative control unit under different working conditions is as follows: Normal working condition: Give priority to using wind power and photovoltaic output, and the energy storage system is charged and discharged under the set conditions; Grid frequency fluctuation working condition: A dynamic frequency response unit is started, which is quickly responded by the power type energy storage device to maintain the stability of the grid frequency; Extreme weather or fault working condition: Activate the frequency modulation standby mode, and the power generation unit provides power support to ensure the continuous operation of the system.

[0013] The technical solution adopted by the first aspect of the application is as follows: A hybrid energy storage and power generation combined power control method, the method is applied to the system of the first aspect, the dynamic frequency response module is configured to: When the frequency deviation Δf> Δfthis detected, in The power type energy storage is started within 20ms to compensate 100% of the power shortage ΔP, and the shortage part is supplemented by the energy type energy storage; When 0.5<|Δf / Δfth|≤1, ΔP is allocated to the power type / energy type energy storage device in a ratio of 7:3; When |Δf / Δfth|≤0.5, 100% ΔP is allocated to the power type energy storage; wherein the dynamic threshold Δfth=Δfbase×(1+H / Href), wherein H is the measured inertia constant of the power grid, Href is the design reference inertia constant of the power grid, and the value is 4.0-5.0 seconds, Δfbase is determined according to the annual statistical average of system frequency deviation, and the set range is 0.05~0.15Hz.

[0014] Further, the adaptive median calibration unit includes a deviation integrator, a compensation controller, a dynamic median generator, and a safety boundary protector, which are configured to: The deviation integrator is used to calculate the net energy deviation ΔQ of the power type energy storage within the time window Tw;

[0015] Wherein is the actual power of the power type energy storage within Tw; The compensation controller, when , wherein is the rated capacity of the power type energy storage, and the compensation instruction output to the energy type energy storage is:

[0016] The compensation instruction output to the power type energy storage is:

[0017] Wherein and are the maximum power instructions of the energy type and power type energy storage during compensation, respectively, and the compensation instruction execution time is Tw, and compensation is performed in the next calculation time window; the dynamic median generator adjusts the target SOC value in real time according to the load rate η of the hybrid energy storage system:

[0018] Wherein, α=0.1% / ℃, which is used for temperature compensation; Temperature compensation mechanism: When the ambient temperature is lower than -10℃, the value of α is adjusted from 0.1 to 0.15 to adapt to the change of energy storage performance in low temperature environment; Safety boundary protector, when the SOC of the power-type energy storage device deviates from ±15%, triggers interlocking with the dynamic frequency response module, and the power-type energy storage device preferentially executes compensation instructions in the next Tw time window:

[0019] The interlocking is released when the following conditions are met: |dSOC / dt|<1% / min; and the duration is ≥5 minutes.

[0020] Further, the compensation controller activates the frequency modulation standby mode of the power generation unit when the energy-type energy storage is unavailable, and the output change rate is limited to:

[0021] wherein, is the power change rate limit of the power generation unit, is the percentage of the change in rated power per second.

[0022] Further, the control strategy of the joint system cooperative control unit is based on the following formula:

[0023] wherein, is the total system output power, is the power generation unit output power, and is the power smoothing amount, which is provided by the hybrid energy storage.

[0024] Compared with the prior art, the beneficial effects of the present application are: 1. Dynamic power distribution optimization: based on the frequency deviation magnitude and the real-time inertia of the power grid, the output ratio of the power-type / energy-type energy storage is dynamically distributed, solving the problem of insufficient response or over-compensation of single energy storage. The power-type energy storage quickly suppresses high-frequency fluctuations, and the energy-type energy storage dynamically adjusts the response time, balancing the frequency modulation speed and economy, and further improving the frequency regulation accuracy.

[0025] 2. Real-time calibration of power-type energy storage SOC: through the dynamic median generator, the target SOC is corrected in real time based on the load rate η and the ambient temperature, and a deviation integrator is designed to accumulate the net charge-discharge energy ΔQ, triggering bidirectional compensation. The safety boundary protector locks the power-type energy storage frequency modulation when the SOC deviates from ±15%, preferentially executes compensation instructions, and avoids the problem of "unavailable during use" caused by SOC exceeding the limit.

[0026] 3. Multi-source coordinated economic stability control: the joint control unit coordinates the slow frequency regulation of thermal power and the fast frequency regulation of energy storage, and in normal conditions, new energy output is preferred, and in extreme conditions, thermal power frequency regulation backup is activated. Through the power smoothing quantity ΔPsmooth, economic optimization is achieved in all conditions, thereby reducing the energy storage calling loss, and the frequency regulation backup capacity utilization rate is further improved. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only preferred embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0028] Figure 1 It is a kind of mixed energy storage and power generation combined power control system overall structure schematic diagram provided by an embodiment of the present application. DETAILED DESCRIPTION

[0029] The principles and characteristics of the present application will be described below in conjunction with the drawings, and the listed embodiments are only used to explain the present application, and are not used to limit the scope of the present application.

[0030] Referring to Figure 1 , an embodiment of the present application provides a kind of mixed energy storage and power generation combined power control system, the system includes: Power generation unit, including wind power, photovoltaic, thermal power unit, for providing basic power transmission; Mixed energy storage unit, which is connected in parallel by power type energy storage device and energy type energy storage device, and is connected in parallel with the power generation unit.

[0031] Detection unit, according to the operation data of power generation unit, mixed energy storage unit and PMU, detect grid frequency and regional inertia time constant, energy storage state parameter, for providing basic data for energy storage and power generation combined system control; Dynamic frequency response unit, for dynamically distributing the power instruction of power type energy storage and energy type energy storage of mixed energy storage unit according to grid frequency deviation and regional inertia time constant; Adaptive median calibration unit, including deviation integrator, compensation controller, dynamic median generator, for dynamically adjusting the operating parameters of power type energy storage, and interlocking with dynamic frequency response unit, to lock power type energy storage in emergency conditions; Joint system cooperative control unit, for cooperative control of power generation unit, mixed energy storage unit and dynamic frequency response module and adaptive median calibration module, to realize the cooperative control of mixed energy storage and power generation combined system.

[0032] For example, this application addresses the challenges of frequency stability and inertia support brought about by the increased proportion of renewable energy generation through multi-unit collaborative control. In dynamic power allocation, the response ratio of power-type energy storage (such as supercapacitors) and energy-type energy storage (such as lithium batteries) can be adaptively adjusted based on grid frequency deviation and regional inertia time constant, balancing frequency regulation speed and economy. In real-time SOC calibration, the target SOC of power-type energy storage can be corrected by a dynamic median generator combined with load factor and ambient temperature, avoiding energy storage lockout due to SOC exceeding limits. In multi-source collaborative control, power generation units and hybrid energy storage units can be combined to achieve economic dispatch and increased frequency regulation reserve capacity under all operating conditions. The specific functions and interaction logic of each unit are as follows: The power generation unit consists of wind power, photovoltaic power, and thermal power units, providing basic power transmission. In terms of coordination, it is connected in parallel with the hybrid energy storage unit. Under normal operating conditions, it prioritizes the use of new energy sources, while under extreme operating conditions, the thermal power units provide power support.

[0033] The hybrid energy storage unit consists of power-type energy storage (response time ≤ 100ms) and energy-type energy storage (response time 1-10 seconds) connected in parallel, with an adjustable parallel ratio. Functionally, the power-type energy storage quickly smooths out high-frequency fluctuations, while the energy-type energy storage provides continuous support. In terms of coordination, it receives power commands from the dynamic frequency response unit and operates in parallel with the power generation unit.

[0034] The detection unit functions to collect data from power generation, energy storage, and PMU, and to detect parameters such as grid frequency, inertia time constant, and energy storage SOC. In terms of coordination, it provides data support for dynamic frequency response, adaptive calibration, and the coordinated control unit.

[0035] Dynamic frequency response unit function: Generates power commands based on frequency deviation and inertia data: When there is a high frequency deviation, the power type energy storage responds 100%; when there is a medium deviation, it is allocated according to a 7:3 ratio; when there is a low frequency deviation, the power type energy storage undertakes all the adjustments; In terms of coordination: Output commands to the hybrid energy storage unit and interlock with the adaptive calibration unit.

[0036] The adaptive median calibration unit consists of: a deviation integrator, a compensation controller, a dynamic median generator, and a safety boundary protector. Functionally, it dynamically adjusts the target SOC of power-type energy storage and triggers bidirectional compensation by accumulating net energy deviation through deviation integration. The safety boundary protector locks out energy storage when the SOC deviates by ±15%. In terms of coordination, it is interlocked with the dynamic frequency response unit and prioritizes the execution of compensation commands in emergency situations.

[0037] The joint system collaborative control unit functions to: globally coordinate power generation, energy storage and control units; achieve economic dispatch and frequency stability through power distribution coordinator, status monitoring module and strategy optimization module; and interact with external systems through communication interface.

[0038] The synergistic relationship between each unit is embodied as follows: Data flow synergy: the detection unit transmits real-time data to each control unit to support control strategy decision-making; power instruction synergy: the dynamic frequency response unit generates power instructions, and the adaptive calibration unit corrects energy storage parameters to ensure safe operation; global optimization synergy: the joint control unit dynamically adjusts power distribution between power generation and energy storage, combined with load prediction optimization strategy; interlock protection synergy: the adaptive calibration unit and the dynamic frequency response unit are interlocked, and the power-type energy storage is locked in emergency conditions to avoid system instability.

[0039] In this application, the dynamic power distribution mechanism is used to improve the frequency regulation accuracy; the SOC real-time calibration technology is used to improve the availability of energy storage; and the multi-source synergy strategy is used to realize the complementary advantages of thermal power and energy storage, which can provide an efficient frequency stability and inertia support solution for new energy power systems.

[0040] The response time of the power-type energy storage device of the hybrid energy storage unit is ≤100 ms, and the response time of the energy-type energy storage device is dynamically adjusted according to the frequency deviation; The response time is dynamically adjusted according to the frequency deviation: response time adjustment function: response time and the grid frequency deviation satisfies the relationship ; wherein is a preset maximum response time, with a value range of 1 second to 10 seconds, is an adjustable coefficient, with a range of 0.1-10 s / Hz; Dynamic adjustment trigger condition: when the frequency deviation , the dynamic adjustment is started; The dynamic adjustment of the response time is realized by adjusting the power regulation instruction control period of the energy-type energy storage device, and the output regulation instruction is output to the power converter of the energy-type energy storage device.

[0041] For example, a differentiated control strategy is proposed for the response characteristics of the two types of energy storage devices in the hybrid energy storage unit, which realizes the coordinated frequency regulation with the power-type energy storage by dynamically adjusting the response time of the energy-type energy storage. On the power-type energy storage (such as super capacitor, flywheel): the response time is required to be ≤100 ms to ensure that the power is immediately output when the grid frequency fluctuates rapidly (such as sudden load change), and to make up for the instantaneous power gap; on the energy-type energy storage (such as lithium battery, flow battery): the basic response time is longer (1-10 seconds), but the response time can be shortened through the dynamic adjustment mechanism to balance the economy and frequency regulation demand.

[0042] In the dynamic adjustment mechanism, the response time of the energy-type energy storage is dynamically changed according to the grid frequency deviation (Δf), and the adjustment logic implementation example is as follows: Initial setting: set the maximum response time of energy storage to 5 seconds, and the adjustable coefficient to 1s / Hz.

[0043] Adjustment process: scene 1 (Δf = 0.05Hz, small deviation): the response time remains close to 5 seconds, and the economy is preferred, and the number of charging and discharging is reduced.

[0044] Scene 2 (Δf = 0.3Hz, medium deviation): the response time is shortened to 2 seconds (5s / (1x0.3) ≈ 16.7s, which needs to be adjusted in combination with the actual threshold).

[0045] Scene 3 (Δf = 0.6Hz, large deviation): the response time is further shortened to within 1 second, and the frequency modulation support is quickly provided.

[0046] Effect verification: compare the frequency fluctuation suppression effect before and after adjustment through actual operation data, and confirm whether the energy storage can effectively make up the power gap in the key period.

[0047] In the present application, the energy storage considers economy and flexibility through the mechanism: when the frequency deviation is small, unnecessary charging and discharging is reduced, and the equipment life is prolonged; when the deviation increases, the response is fast, and the “fast-slow” complementation with the power storage is formed, and the overall frequency modulation capability is improved. The present application matches the response time and the frequency deviation dynamically, and the system can optimize the utilization of energy storage resources under different working conditions, and balance stability and economy.

[0048] The grid area inertia time constant H is obtained by recording the frequency dynamic process of the grid-connected point of the hybrid energy storage and power generation combined system by using the PMU data, and is obtained by data fitting and back calculation combined with the load fluctuation, and the calculation formula is: Where ΔP is the disturbance power (MW); f N is the rated power; df / dt: frequency change rate (Hz / s) in the initial disturbance, is the load capacity in the area.

[0049] For example, for real-time calculation of the grid inertia time constant H, the grid-connected point frequency dynamic data can be collected by a synchronous phasor measurement unit PMU, combined with the load fluctuation, and the formula:

[0050] The grid area inertia time constant is back calculated, so that the traditional fixed inertia design can be broken through, and dynamic perception of the inertia parameter can be realized.

[0051] The energy storage state parameters include: state of charge SOC, grid-connected power, charging / discharging state, average temperature of energy storage unit, and energy storage locking state.

[0052] The combined system cooperative control unit includes: A power distribution coordinator for dynamically adjusting the power distribution ratio between the power generation unit and the energy storage unit according to the real-time power demand of the power grid; A state monitoring module for obtaining detection unit data to monitor the operating state of the power generation unit, the energy storage unit, and the power grid in real time, including frequency, voltage, and power fluctuation; A strategy optimization module for dynamically optimizing the control strategy based on the operating state of the power grid, load prediction, and energy storage SOC state information to achieve the economy and stability of system operation; A communication interface for data interaction with external power grid dispatching system, energy storage management system, and power generation control system to realize remote monitoring and control.

[0053] For example, in the joint system cooperative control unit, the power distribution coordinator can dynamically adjust the power distribution ratio between the power generation unit (such as wind power / photovoltaic) and the energy storage unit (power type / energy type) according to the real-time power demand of the power grid; the state monitoring module can obtain frequency, voltage, power fluctuation, and other data through the detection unit to monitor the system operating state in real time; the strategy optimization module can dynamically optimize the control strategy to balance economy and stability by combining the state of the power grid, load prediction, and energy storage SOC (state of charge) information; the communication interface can realize data interaction with the external power grid dispatching system, energy storage management system, and power generation control system to support remote monitoring and control. Specific example: during the period of high wind power generation, the power distribution coordinator can increase the charging ratio of the energy storage unit to store excess power; when the power grid load increases suddenly, the strategy optimization module will preferentially call the power type energy storage for rapid discharge, and at the same time the communication interface will synchronize the real-time data to the power grid dispatching center to ensure system response and global dispatching coordination.

[0054] The control strategy of the joint system cooperative control unit under different working conditions is as follows: Normal working condition: Give priority to using wind power and photovoltaic output for economy, and the energy storage system performs charging and discharging adjustment under certain conditions; Power grid frequency fluctuation working condition: Start the dynamic frequency response unit, which is quickly responded by the power type energy storage device to maintain the stability of the power grid frequency; Extreme weather or fault working condition: Activate the frequency modulation standby mode, which is provided by the power generation unit to ensure the continuous operation of the system.

[0055] For example, the joint system cooperative control unit can formulate differentiated control strategies for three types of working conditions. For normal working conditions, the economic efficiency is targeted, renewable energy power generation is preferentially utilized, and the energy storage system charges and discharges according to preset conditions. For power grid frequency fluctuation conditions, the dynamic frequency response unit is started, and the power type energy storage (such as a super capacitor) quickly responds to the frequency deviation. For extreme weather or fault conditions, the frequency modulation standby mode is activated, and the power generation unit (such as a thermal power unit) provides main power support. Specific examples are as follows. For normal working conditions, when the photovoltaic output is sufficient, the energy type energy storage (such as a lithium battery) is charged according to the plan, and the power type energy storage remains standby. For frequency fluctuation, when the power grid frequency deviation exceeds the threshold value, the power type energy storage outputs compensation power within 1 second to stabilize the frequency to the normal range. For extreme weather, when a typhoon causes photovoltaic disconnection, the thermal power unit immediately increases the output, and the energy type energy storage releases the reserved electric energy to ensure continuous power supply of the system. The above explanations highlight the adaptability and cooperative control logic of the system under different conditions in combination with the technical solutions and actual application scenarios.

[0056] Another embodiment of the present application provides a hybrid energy storage and power generation combined power control method, which is applied to a hybrid energy storage and power generation combined power control system. The dynamic frequency response module is configured to: When the frequency deviation Δf > Δfth is detected, the power type energy storage is started within 20 ms to compensate for the power shortage ΔP by 100%, and the energy type energy storage supplements the shortage part. 20 ms within the power type energy storage 100% compensates for the power shortage ΔP, and the energy type energy storage supplements the shortage part. When 0.5 < |Δf / Δfth| ≤ 1, ΔP is allocated to the power type / energy type energy storage device in a ratio of 7:3. When |Δf / Δfth| ≤ 0.5, 100% ΔP is allocated to the power type energy storage; wherein the dynamic threshold Δfth = Δfbase × (1 + H / Href), wherein H is the measured inertia constant of the power grid, Href is the design reference inertia constant of the power grid, the value is 4.0-5.0 seconds, Δfbase is determined according to the annual statistical average of the system frequency deviation, and the set range is 0.05-0.15 Hz.

[0057] For example, the method in the present application can realize accurate allocation of power through the dynamic frequency response module. When the frequency deviation Δf > Δfth is detected, the power type energy storage device is immediately started, and the power type energy storage compensates for the power shortage by 100% within 20 ms, and the energy type energy storage supplements the shortage part. For example, if the power grid frequency drops due to sudden load increase, the power type energy storage can quickly output power to stabilize the frequency, and the energy type energy storage then provides continuous support. When 0.5<|Δf / Δfth|≤1, the system allocates the power shortage to the power-type and energy-type energy storage devices in a 7:3 ratio. For example, if the deviation is 70% of the threshold, the power-type energy storage undertakes 70% of the rapid response task, and the energy-type energy storage undertakes 30% of the continuous power supply task, balancing response speed and economy.

[0058] When |Δf / Δfth|≤0.5, the system allocates all the power shortage to the power-type energy storage device. For example, when there is a slight load fluctuation, only the power-type energy storage needs to output for a short time to suppress the fluctuation, avoiding frequent start-stop of the energy-type energy storage and reducing device loss.

[0059] The method solves the problems of low response accuracy, poor economy, and weak adaptability in the traditional scheme by dynamically allocating power in different scenarios and adaptively adjusting the threshold, and significantly improves the regulation and control capability of the hybrid energy storage system in a complex power grid environment.

[0060] The adaptive median calibration unit includes a deviation integrator, a compensation controller, a dynamic median generator, and a safety boundary protector, and is configured to: The deviation integrator is configured to calculate the net energy deviation ΔQ of the power-type energy storage in a time window Tw.

[0061] Wherein is the actual power of the power-type energy storage in Tw; The compensation controller is configured to output a compensation instruction to the energy-type energy storage when , wherein is the rated capacity of the power-type energy storage, and the output compensation instruction to the energy-type energy storage is:

[0062] The output compensation instruction to the power-type energy storage is:

[0063] Wherein and are the maximum power instructions of the energy-type and power-type energy storage during the compensation process, respectively, and the compensation instruction execution duration is Tw, and the compensation is performed in the next calculation time window; The dynamic median generator adjusts the target SOC value in real time according to the load rate η of the hybrid energy storage system:

[0064] Wherein, α=0.1% / ℃, for temperature compensation; Temperature compensation mechanism: When the ambient temperature is lower than -10℃, the α value is adjusted from 0.1 to 0.15 to adapt to the change in energy storage performance in a low-temperature environment. Safety boundary protector, when the SOC of a power storage device deviates from... When the error exceeds ±15%, an interlock with the dynamic frequency response module is triggered, and the power-type energy storage device will prioritize executing the compensation command in the next Tw time window.

[0065] The following conditions must be met for the interlock to be released: |dSOC / dt|<1% / min; And the duration is ≥5 minutes.

[0066] For example, the adaptive median calibration unit can achieve dynamic calibration and safety protection of the energy storage system's SOC through the collaboration of a deviation integrator, a compensation controller, a dynamic median generator, and a safety boundary protector. The deviation integrator can continuously calculate the net energy deviation ΔQ of the power storage within a set time window Tw, that is, the cumulative difference between the actual charging and discharging energy and the target value. For example, if the power storage's charging amount exceeds the target value by 10% within 1 hour, the integrator will record the deviation to provide data for subsequent adjustments.

[0067] The compensation controller can output compensation commands based on the ΔQ value to adjust the charging and discharging strategies of energy storage and power storage: when ΔQ exceeds the threshold (such as 5% of the rated capacity), energy storage takes priority to bear the low-frequency fluctuation power, and power storage supplements the high-frequency fluctuation. The execution time of the compensation command is Tw, and it is recalculated in the next cycle to form a closed-loop correction. For example, if ΔQ is +8% (overcharge), energy storage increases the discharge power, and power storage reduces the charging power until the deviation returns to zero.

[0068] The dynamic median generator can adjust the target SOC in real time based on the system load rate η and temperature: when the load rate is low (e.g., η<30%), the target SOC is increased to 60% (default 50%), reserving more energy to cope with sudden demand.

[0069] Temperature compensation: For every 10°C decrease in ambient temperature, the target SOC is increased by 1.5% (e.g., the target SOC is 63% at -20°C) to offset capacity decay at low temperatures.

[0070] The safety boundary protector can trigger an interlock when the SOC of power-type energy storage deviates from the target value by ±15%: suspend the dynamic frequency response command, prioritize the execution of the compensation command, and forcibly adjust the SOC to a safe range. The release condition is |dSOC / dt|<1% / min; and the duration is ≥5 minutes. The system then resumes automatic control. For example, if the SOC surges to 70% (exceeding +15%) due to a sudden load spike, the system immediately switches to compensation mode, the energy storage discharges at full capacity, and the power storage stops charging until the SOC falls back below 55%.

[0071] The compensation controller activates the frequency modulation standby mode of the power generation unit when the energy type energy storage is unavailable, and the output change rate is limited to:

[0072] wherein, the limit value of the power change rate of the power generation unit is set, the percentage of the change of the rated power per second.

[0073] The compensation controller can solve the problem of secondary frequency collapse of the traditional frequency modulation system when the energy storage fails by activating the frequency modulation standby mode of the power generation unit, and at the same time, reduce the mechanical loss of the power generation equipment, and improve the economy and safety of the system operation.

[0074] The control strategy of the joint system cooperative control unit is based on the following formula:

[0075] wherein, the total output power of the system, the output power of the power generation unit is, the power smoothing amount, which is provided by the hybrid energy storage.

[0076] Exemplarily, the joint system cooperative control unit can realize the dynamic power distribution of the power generation unit and the hybrid energy storage unit, and adaptively adjust the control strategy combined with the grid operating condition.

[0077] The above only describes the preferred embodiments of the present application, and is not intended to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A hybrid energy storage and generation combined power control system, characterized by, The system comprises: a power generation unit comprising wind power, photovoltaic power, and thermal power units, for providing basic power transmission; a hybrid energy storage unit comprising power-type energy storage devices and energy-type energy storage devices in parallel, connected in parallel with the power generation unit. a detection unit for detecting grid frequency and regional inertia time constant and energy storage state parameters based on operation data of the power generation unit, the hybrid energy storage unit, and the PMU, for providing basic data for energy storage and power generation combined system control; a dynamic frequency response unit for dynamically allocating power instructions of the power-type energy storage and the energy-type energy storage of the hybrid energy storage unit according to grid frequency deviation and regional inertia time constant; an adaptive median calibration unit comprising a deviation integrator, a compensation controller, and a dynamic median generator, for dynamically adjusting power-type energy storage operation parameters and interlocking with the dynamic frequency response unit to lock the power-type energy storage in an emergency working condition; a combined system cooperative control unit for cooperatively controlling the power generation unit, the hybrid energy storage unit, the dynamic frequency response module, and the adaptive median calibration module, to realize cooperative control of the hybrid energy storage and power generation combined system.

2. The hybrid energy storage and generation combined power control system of claim 1, wherein, The response time of the power-type energy storage device of the hybrid energy storage unit is ≤100 ms, and the response time of the energy-type energy storage device is dynamically adjusted according to frequency deviation. The response time is dynamically adjusted according to the frequency deviation: response time adjustment function: response time with the grid frequency deviation satisfies the relationship ; wherein is a preset maximum response time, ranging from 1 second to 10 seconds, is an adjustable coefficient, ranging from 0.1 to 10 s / Hz; Dynamic adjustment trigger condition: when the frequency deviation is started. The response time dynamic adjustment is realized by adjusting the power regulation instruction control period of the energy-type energy storage device, and outputting the regulation instruction to the power converter of the energy-type energy storage device.

3. The hybrid energy storage and generation combined power control system of claim 1, wherein, The power grid area inertia time constant H is obtained by combining load fluctuation through data fitting and backstepping by using the data record of the frequency dynamic process of the grid connection point of the hybrid energy storage and power generation combined system, and the calculation formula is: where ΔP is the disturbance power (MW); f N is the rated power; df / dt: the frequency change rate at the initial stage of disturbance (Hz / s), is the load capacity of the area where the disturbance occurs.

4. The hybrid energy storage and generation combined power control system of claim 1, wherein, The energy storage state parameters include state of charge (SOC), grid-connected power, charging / discharging state, average temperature of the energy storage unit, and energy storage lock state.

5. The hybrid energy storage and generation combined power control system of claim 1, wherein, The combined system cooperative control unit comprises: a power distribution coordinator for dynamically adjusting the power distribution ratio between the power generation unit and the energy storage unit according to real-time power demand of the grid; a state monitoring module for obtaining detection unit data to monitor the operation state of the power generation unit, the energy storage unit, and the grid in real time, including frequency, voltage, and power fluctuation; a strategy optimization module for dynamically optimizing control strategies according to grid operation state, load prediction, and energy storage SOC state information, to realize economy and stability of system operation; a communication interface for data interaction with external grid dispatching systems, energy storage management systems, and power generation control systems, to realize remote monitoring and control.

6. The hybrid energy storage and generation combined power control system of claim 1, wherein, The control strategies of the combined system cooperative control unit under different working conditions are as follows: Under normal working conditions: Give priority to wind power and photovoltaic power output, and the energy storage system performs charging and discharging regulation under certain conditions; Under grid frequency fluctuation working conditions: Start the dynamic frequency response unit, and the power-type energy storage device responds quickly to maintain grid frequency stability; Under extreme weather or fault working conditions: Activate the frequency modulation standby mode, and the power generation unit provides power support to ensure continuous operation of the system.

7. A hybrid energy storage and generation combined power control method, the method is applied to a hybrid energy storage and generation combined power control system, characterized in that, The dynamic frequency response module is configured to: When a frequency deviation Δf > Δfth is detected, Within 20ms, power-type energy storage can be activated to fully compensate for the power deficit ΔP, with the deficit being supplemented by energy-type energy storage. when 0.5<|Δf / Δfth|≤1, allocate ΔP to the power-type / energy-type energy storage devices in a 7:3 ratio; when |Δf / Δfth|≤0.5, allocate 100% ΔP to the power-type energy storage device; wherein the dynamic threshold Δfth=Δfbase×(1+H / Href), wherein H is the measured inertia constant of the power grid, Href is the design reference inertia constant of the power grid, and is taken as 4.0-5.0 seconds, Δfbase is determined according to the annual statistical average of the system frequency deviation, and is set in the range of 0.05-0.15 Hz.

8. The hybrid energy storage and power generation combined power control method of claim 7, wherein, The adaptive median calibration unit comprises a deviation integrator, a compensation controller, a dynamic median generator and a safety boundary protector, and is configured to: The deviation integrator is used to calculate the net energy deviation ΔQ of the power-type energy storage in a time window Tw; wherein Pact is the actual power of the power type energy storage within Tw. Compensation controller, when wherein is the power-type energy storage rated capacity, output to the energy-type energy storage compensation instruction: The output is a power-type energy storage compensation instruction: wherein with respectively the maximum power instruction of energy type and power type energy storage in compensation process, the compensation instruction execution time is Tw, compensation is carried out in the next calculation time window; dynamic median generator, the target SOC value is adjusted in real time according to the load rate η of hybrid energy storage system: Wherein, α=0.1% / ℃, for temperature compensation; Temperature compensation mechanism: When the ambient temperature is lower than-10℃, the value of α is adjusted from 0.1 to 0.15 to adapt to the change of energy storage performance in low temperature environment; A safety boundary protector, when the SOC of the power energy storage device deviates more than ± 15%, triggers interlocking with the dynamic frequency response module, and the power energy storage device preferentially executes compensation instructions at the next Tw time window: The following conditions must be met for interlocking release: |dSOC / dt| < 1% / min; And the duration is greater than or equal to 5 minutes.

9. The hybrid energy storage and power generation combined power control method of claim 7, wherein, The compensation controller activates the frequency regulation standby mode of the power generation unit when the energy-type energy storage is unavailable, and the output change rate is limited to: wherein, Set a limit for the power change rate of the power generation unit, Percentage of change in rated power per second.

10. The hybrid energy storage and power generation combined power control method of claim 7, wherein, The control strategy of the joint system cooperative control unit is based on the following formula: wherein, Ptotal is the total power output of the system, Pgen is the power output of the power generation unit, and Psmooth is the power smoothing quantity, provided by the hybrid energy storage.

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