Self-adaptive charging and discharging coordination control method and system for energy storage battery

Abstract

The invention discloses a self-adaptive charging and discharging coordination control method and system for an energy storage battery, and relates to the technical field of charging and discharging control of the energy storage battery. The method comprises the following steps: correcting a maximum allowable current based on a real-time collected SOC and a preset battery low charge threshold, a battery high charge threshold, a reference coefficient, a first attenuation coefficient and a second attenuation coefficient to obtain an inner loop current amplitude limit; judging whether the current system reaches current saturation or voltage saturation, and marking a corresponding saturation mark; calculating a saturation difference value and a saturation direction angle based on the current value controlled and output by the inner ring and the current value actually output by the inner ring; according to the saturation mark, the saturation difference value and the inner loop current amplitude limit are used for correcting the preset outer layer reference power, the corrected reference power is obtained, the integration gain in the preset integration link is corrected, and the saturation state is relieved; stability and reliability of charging and discharging control of the energy storage system are guaranteed, power control precision is improved, service life of equipment is prolonged, and energy conversion efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage battery charging and discharging control technology, and more specifically, to an adaptive charging and discharging coordinated control method and system for energy storage batteries. Background Technology

[0002] In scenarios where energy storage battery systems operate in grid-connected environments or cope with complex load changes, dynamic power adjustment is often achieved through multi-level control loops to match real-time changes in grid dispatch commands or load demands. These energy storage battery systems typically include an outer control loop with a slower response time, used to generate a reference trajectory based on long-term power requirements or optimization goals; a middle-level droop control loop responsible for converting the outer reference into power commands; and an inner current loop with the fastest response time directly driving the power conversion circuit to execute current output. Each control loop achieves the connection from macroscopic goals to microscopic execution by progressively transmitting commands. Its technical principle is based on the dynamic response allocation at different time scales to balance control accuracy and system stability.

[0003] However, when the system experiences grid-connected current limiting, insufficient DC bus voltage, or excessive point of common coupling voltage, the inner current loop may enter a saturation state due to physical constraints. If the outer control loop fails to detect this state in time, it will continue to integrate and advance commands according to the preset reference trajectory, leading to a loss of coordination between the control loops. Since existing technologies lack cross-loop anti-saturation scheduling logic, the saturation state of the faster-responding inner control loop cannot be promptly fed back to the slower-responding outer control loop, causing phase lag and accumulated deviations between commands and actual execution capabilities. This results in overshoot or oscillation in system power output, causing equipment to frequently enter current-limiting protection states, and in severe cases, even triggering malfunctions. This affects the stable interaction between the energy storage system and the grid or load, shortens equipment lifespan, and reduces energy conversion efficiency.

[0004] In view of this, the present invention proposes an adaptive charge and discharge coordinated control method and system for energy storage batteries to solve the above problems. Summary of the Invention

[0005] To overcome the aforementioned deficiencies of the prior art and achieve the above objectives, the present invention provides the following technical solution: an adaptive charge-discharge coordinated control method for energy storage batteries, comprising:

[0006] The maximum allowable current is corrected based on the real-time collected SOC and preset low battery charge threshold, high battery charge threshold, reference coefficient, first attenuation coefficient and second attenuation coefficient to obtain the inner loop current limit.

[0007] Determine whether the current system has reached current saturation or voltage saturation, and mark the corresponding saturation flag; calculate the saturation difference and saturation direction angle based on the current value output by the inner loop control and the actual current value output by the inner loop.

[0008] Based on the saturation flag, the preset outer reference power is corrected using the saturation difference and inner loop current limiting to obtain the corrected reference power, and the integral gain in the preset integrator is corrected to remove the saturation state.

[0009] The corrected reference power is converted into a base current value, and feedforward compensation is added to correct the base current value to obtain the corrected current value.

[0010] Furthermore, methods for obtaining inner loop current limiting include:

[0011] When the SOC is less than or equal to the low charge threshold of the battery, the maximum allowable current = the current maximum allowable current × (first attenuation coefficient + second attenuation coefficient × SOC).

[0012] When the SOC is greater than or equal to the battery high charge threshold, the maximum allowable current = the current maximum allowable current × (base coefficient - second attenuation coefficient × SOC).

[0013] When the SOC is greater than the low charge threshold of the battery and less than the high charge threshold of the battery, the maximum allowable current remains unchanged.

[0014] Use the maximum allowable current as the inner loop current limit.

[0015] Furthermore, methods for determining whether the current system has reached current saturation or voltage saturation and marking the corresponding saturation flags include:

[0016] If the absolute value of the collected active current value is continuously greater than the inner loop current limit, or the absolute value of the collected reactive current value is continuously greater than the inner loop current limit, and the duration reaches the preset first continuous control cycle number, then it is determined that the current saturation has been reached, and the saturation flag is marked as 1a.

[0017] If the modulation ratio derived from the voltage value is continuously greater than the preset modulation ratio safety factor, and the duration reaches the preset second consecutive control cycle number, then it is determined that voltage saturation has been reached, and the saturation flag is marked as 1b.

[0018] If current saturation or voltage saturation is not reached, the saturation flag is set to 0;

[0019] The saturation flag can be labeled as 1a and 1b simultaneously.

[0020] Furthermore, the method for calculating the modulation ratio includes:

[0021] Based on the collected AC grid voltage phase, the inverter's maximum output phase voltage peak value, and the preset modulation ratio safety factor, the voltage limit corresponding to the maximum active current and the voltage limit corresponding to the maximum reactive current are calculated.

[0022] Add the voltage limit corresponding to the maximum active current to the voltage limit corresponding to the maximum reactive current, and then divide by 2 to obtain the first voltage value.

[0023] The modulation ratio is obtained by taking the square root of the sum of the squares of the acquired d-axis and q-axis voltage values ​​and then calculating the ratio with the first voltage value.

[0024] Furthermore, methods for calculating the saturation difference and saturation direction angle include:

[0025] Calculate the difference between the current value output by the d-axis inner loop control and the actual current value output by the d-axis inner loop to obtain the first difference;

[0026] Calculate the difference between the current value output by the q-axis inner loop control and the actual current value output by the q-axis inner loop to obtain the second difference;

[0027] Calculate the square root of the sum of the squares of the first difference and the second difference to obtain the saturation difference;

[0028] The saturation direction angle is the arctangent of the ratio of the first difference to the second difference.

[0029] Furthermore, the method for modifying the preset outer layer reference power includes:

[0030] Calculate the product of the preset voltage correction and the saturation difference to obtain the first product;

[0031] If the saturation flag is 0, then the current outer reference power remains unchanged;

[0032] If the saturation flag includes 1a, and the direction of the saturation direction angle is such that active power output needs to be reduced, then the reference active power in the current outer reference power is subtracted from the first product to obtain the adjusted reference active power, while keeping the reference reactive power in the current outer reference power unchanged; if the direction of the saturation direction angle is such that reactive power output needs to be reduced, then the reference reactive power in the current outer reference power is subtracted from the first product to obtain the adjusted reference reactive power, while keeping the reference active power in the current outer reference power unchanged.

[0033] If the saturation flag includes 1b, then the reference active power in the current outer layer reference power is frozen as the actual active power, and the ratio of the saturation difference to the inner loop current limit is calculated to obtain the first ratio. The reference reactive power in the current outer layer reference power is multiplied by 1 and the difference between the first ratio to obtain the adjusted reference reactive power.

[0034] Furthermore, methods for determining the direction of the saturation direction angle include:

[0035] If the absolute value of the saturation direction angle is less than the preset threshold angle, then the direction of the saturation direction angle is to reduce the active power output.

[0036] If the absolute value of the saturation direction angle is greater than or equal to the difference between 90° and the threshold angle, then the direction of the saturation direction angle is such that reactive power output needs to be reduced.

[0037] Furthermore, methods for modifying the integral gain in the preset integral stage include:

[0038] If the saturation flag is 0, the integral gain in the integral stage remains unchanged;

[0039] If the saturation flag contains 1a or 1b, the integral gain in the integral stage is multiplied by the difference between 1 and the first ratio to obtain the corrected integral gain; if the saturation direction angle is in the same direction as the integral error, the integration stops; if the saturation direction angle is in the opposite direction to the integral error, the integration continues according to the corrected integral gain.

[0040] Furthermore, methods for determining the direction of integration error include:

[0041] The active power integral error is the difference between the reference active power and the actual active power. If the reference active power is greater than the actual active power, the active power integral error is positive, and the direction of the integral error is that the active power output needs to be increased. If the reference active power is less than the actual active power, the active power integral error is negative, and the direction of the integral error is that the active power output needs to be reduced.

[0042] The reactive power integral error is the difference between the reference reactive power and the actual reactive power. If the reference reactive power is greater than the actual reactive power, the reactive power integral error is positive, and the direction of the integral error indicates that reactive power output needs to be increased. If the reference reactive power is less than the actual reactive power, the reactive power integral error is negative, and the direction of the integral error indicates that reactive power output needs to be reduced.

[0043] Furthermore, methods for obtaining the corrected current value include:

[0044] Based on the preset power-current conversion model, the corrected reference power is converted into the base current value;

[0045] Based on the vector decomposition principle of trigonometric functions, the saturation difference is decomposed into compensation components corresponding to the active and reactive directions, and the decomposed compensation components are multiplied by a preset feedforward weight coefficient to obtain the negative feedback quantity.

[0046] Subtract the negative feedback value from the base current value to obtain the corrected current value.

[0047] An adaptive charge-discharge coordinated control system for energy storage batteries, comprising:

[0048] The current limiting calculation module corrects the maximum allowable current based on the real-time collected SOC and preset low battery charge threshold, high battery charge threshold, reference coefficient, first attenuation coefficient and second attenuation coefficient to obtain the inner loop current limiting.

[0049] The saturation detection module is used to determine whether the current system has reached current saturation or voltage saturation, and to mark the corresponding saturation flag.

[0050] The saturation calculation module calculates the saturation difference and saturation direction angle based on the current value output by the inner loop control and the actual current value output by the inner loop.

[0051] The saturation correction module, based on the saturation flag, uses the saturation difference and inner loop current limiting to correct the preset outer reference power, obtain the corrected reference power, and correct the integral gain in the preset integrator to remove the saturation state.

[0052] The feedforward compensation module is used to convert the corrected reference power into a base current value, and then correct the base current value through feedforward compensation to obtain the corrected current value.

[0053] Compared with the prior art, the technical effects and advantages of the adaptive charge and discharge coordinated control method and system for energy storage batteries of the present invention are as follows:

[0054] This invention corrects the maximum allowable current based on real-time acquired SOC and preset battery low charge threshold, high charge threshold, reference coefficient, first attenuation coefficient, and second attenuation coefficient to obtain inner-loop current limiting. It then determines whether the system has reached current saturation or voltage saturation and marks the corresponding saturation flag. Simultaneously, it calculates the saturation difference and saturation direction angle based on the current values ​​of the inner-loop control output and the actual output. Next, based on the saturation flag, it uses the saturation difference and inner-loop current limiting to correct the preset outer-layer reference power to obtain the corrected reference power, and corrects the integral gain of the integrator to desaturate the system. Finally, it converts the corrected reference power into a base current value, adds feedforward compensation to correct the base current value, and obtains the corrected current value. Furthermore, after the system desaturates, it can dynamically determine the recovery slope based on the recovery margin, allowing the reference power to smoothly recover to the original target reference power.

[0055] This invention addresses the problems in existing technologies where the outer control loop fails to detect saturation in the inner current loop in a timely manner, lacks cross-loop anti-saturation scheduling logic, leading to phase lag and accumulated deviations between commands and actual execution capabilities. This results in system power overshoot or oscillation, frequent current-limiting protection activation by equipment, impacts on the stable interaction between the energy storage system and the grid or load, shortened equipment lifespan, and reduced energy conversion efficiency. Its advantages include: dynamic adjustment of current limiting based on battery SOC to prevent overcharging and over-discharging; precise saturation judgment and correction to ensure voltage and current commands remain within safe ranges, preventing inverter overmodulation; dynamic adjustment and direction correction of integral gain to prevent excessive integral accumulation, facilitating rapid system exit from saturation; and the addition of feedforward compensation to reduce the deviation between commands and actual execution capabilities, lowering the probability of secondary saturation. Overall, it ensures the stability and reliability of energy storage system charge and discharge control, improves power control accuracy, extends equipment lifespan, and increases energy conversion efficiency. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of an adaptive charging and discharging coordinated control system for an energy storage battery according to an embodiment of the present invention.

[0057] Figure 2 This is a flowchart of an adaptive charge and discharge coordinated control method for an energy storage battery according to an embodiment of the present invention.

[0058] Figure 3 This is a flowchart of a method for determining whether the current system has reached current saturation or voltage saturation and marking the corresponding saturation flag according to an embodiment of the present invention.

[0059] Figure 4 This is a flowchart illustrating a method for modifying a preset outer layer reference power according to an embodiment of the present invention. Detailed Implementation

[0060] To further clarify the specific implementation methods of this application, the relevant technical principles will be explained before proceeding with the specific implementation methods.

[0061] The core of the inverter's coordinated control logic in the energy storage battery charging and discharging control system is to achieve effective regulation of AC quantities through coordinate system transformation, ensure that control commands are within physical constraints through dynamic limiting, and identify whether the system exceeds its regulation capacity through saturation judgment. Specifically, the three-phase AC grid voltage needs to be transformed to the α-β stationary coordinate system through Clark transformation, and then to the dq synchronous rotating coordinate system through Park transformation, so as to convert the AC components into DC components that are easy to regulate; the inverter's voltage and current limiting are used to define the safe boundaries of voltage and current values ​​to prevent exceeding the inverter's modulation capability or the battery's charging and discharging capability; saturation judgment is used to identify whether the current or voltage value exceeds the corresponding limit, providing a basis for subsequent control adjustments.

[0062] The α-β stationary coordinate system is a two-phase stationary coordinate system used to convert three-phase AC quantities into two-phase orthogonal AC components. The α-axis coincides with the A-phase axis in the three-phase coordinate system, and the β-axis is perpendicular to the α-axis. This conversion simplifies the mathematical model of the three-phase system. The dq synchronous rotating coordinate system is a two-phase rotating coordinate system whose rotation speed is the same as the angular frequency of the grid voltage. The d-axis is usually aligned with the direction of the grid voltage vector, while the q-axis is perpendicular to the d-axis and leads the d-axis by 90 electrical degrees. This rotating coordinate system can convert AC components into DC components, facilitating the use of proportional-integral regulators to achieve zero steady-state error control.

[0063] The technical solutions of the embodiments of the present invention will be described in detail, clearly, and completely below with reference to the accompanying drawings. It should be particularly noted that the specific embodiments described below are only for better illustrating and explaining the technical solutions of the present invention, and are intended to enable those skilled in the art to better understand and implement the present invention, and should not be construed as limiting the scope of protection of the present invention. Without departing from the spirit and substance of the present invention, those skilled in the art can modify, adjust, or make equivalent substitutions based on the content disclosed in the present invention, and these should all be considered within the scope of protection of the present invention.

[0064] Example 1:

[0065] Please see Figure 1 As shown in the figure, this embodiment discloses an adaptive charge and discharge coordinated control system for energy storage batteries, including a limiting calculation module, a saturation judgment module, a saturation calculation module, a saturation correction module, a feedforward compensation module, and a progressive recovery module. Each module is connected by wires and / or wirelessly to realize data transmission.

[0066] The current limiting calculation module corrects the maximum allowable current based on the real-time collected SOC and preset low battery charge threshold, high battery charge threshold, reference coefficient, first attenuation coefficient, and second attenuation coefficient to obtain the inner loop current limiting. Here, SOC refers to the battery state of charge.

[0067] First, calculate the inverter's voltage limit based on the inverter's modulation limit. The maximum peak output phase voltage of the inverter is... / 2, the three-phase AC grid voltage is transformed into voltage components in the α-β stationary coordinate system via Clarke transform, and then transformed into voltage components in the dq synchronous rotating coordinate system via Park transform. A proportional-integral (PI) controller tracks the d-axis voltage component and brings the q-axis voltage component close to zero. The output of the PI controller is then the phase θ of the AC grid voltage. The AC grid voltage is measured by an AC-side voltage sensor and used to estimate the limitations of grid-side conditions on the output capability.

[0068] Since the inner loop control needs to adjust the active and reactive currents to control the charging and discharging power of the energy storage battery, and the adjustment of the active and reactive currents corresponds to the output voltage values ​​on the d-axis and q-axis respectively, the maximum voltage value is limited by the inverter's modulation capability and the physical constraints of the grid voltage. If the voltage value exceeds this limit, the inverter will enter an overmodulation state, causing output voltage distortion, reduced power control accuracy, or even damage to power devices. Therefore, it is necessary to calculate the voltage limit corresponding to the maximum output active current by combining the AC grid voltage phase θ. Voltage limiting corresponding to maximum reactive current This ensures that the d-axis and q-axis voltage values ​​remain within a safe range, guaranteeing the stability and reliability of the inner-loop control. Based on the AC grid voltage phase, the voltage limit corresponding to the maximum output active current is calculated. Voltage limiting corresponding to maximum reactive current :

[0069] ;

[0070] ;

[0071] In the formula, θ is the phase of the grid voltage; The modulation ratio safety factor is set to 0.95 in this embodiment to avoid overmodulation, and can be adjusted according to actual needs; min(˙) is the minimum value function; This refers to the AC mains voltage.

[0072] Voltage limiting must simultaneously satisfy two physical constraints; the smaller of the two values ​​must be taken to ensure that neither constraint is exceeded: voltage limiting corresponding to the maximum active current. , This reflects the constraint of grid voltage on the active direction voltage value, that is, the additional voltage margin that can be output in the active direction after considering grid voltage. This reflects the constraint on the inverter's modulation capability, that is, the maximum voltage value that the inverter can output within a safe range. The smaller of these two values ​​is taken as... This ensures that the d-axis voltage value neither exceeds the margin limit imposed by the grid voltage nor exceeds the inverter's safe modulation capability. For q-axis voltage limiting... , This reflects the constraint of the grid voltage on the voltage value in the reactive direction, that is, the voltage margin that can be output in the reactive direction; This also applies to the inverter's modulation capability constraint. The smaller of the two values ​​is taken as... This ensures that the q-axis voltage value simultaneously meets the dual constraints of grid voltage margin and inverter safety modulation capability, ultimately keeping both the d-axis and q-axis voltage values ​​within a safe range.

[0073] The maximum allowable current is corrected based on the battery's current state of charge (SOC) and preset low-charge threshold, high-charge threshold, reference coefficient, first attenuation coefficient, and second attenuation coefficient. The SOC is obtained through the battery management system. The maximum allowable current is given by the device rating or protection settings, representing the saturation threshold of the inner-loop current control. The low-charge threshold and high-charge threshold are preset according to the battery type, battery cycle life requirements, and system safety requirements. The reference coefficient, first attenuation coefficient, and second attenuation coefficient are pre-calibrated based on the battery's charge / discharge rate limits at different SOCs, capacity decay characteristics, and system power requirements. When the State of Charge (SOC) is less than or equal to the battery's low charge threshold, the maximum allowable current = the current maximum allowable current × (first attenuation coefficient + second attenuation coefficient × SOC); when the SOC is greater than or equal to the battery's high charge threshold, the maximum allowable current = the current maximum allowable current × (base coefficient - second attenuation coefficient × SOC); when the SOC is greater than the battery's low charge threshold but less than the battery's high charge threshold, the maximum allowable current remains unchanged. The maximum allowable current corrected according to different SOC ranges is used as the upper limit of the inner loop current control, thus obtaining the inner loop current limit. This ensures that the current output of the inner loop does not exceed the battery's safe charging and discharging capacity under the current SOC, thus avoiding performance degradation or safety risks caused by overcurrent.

[0074] The saturation detection module is used to determine whether the current system has reached current saturation or voltage saturation, and to mark the corresponding saturation flag.

[0075] Please see Figure 3 As shown, the methods for determining whether the current system has reached current saturation or voltage saturation and marking the corresponding saturation flags include:

[0076] Methods for determining whether current saturation has been reached include: if the absolute value of the active current continuously exceeds the inner loop current limit. Or the absolute value of the reactive current is continuously greater than the inner loop current limit. If this state persists for a preset first consecutive control cycle number, it is considered current saturation. The preset first consecutive control cycle number is pre-set based on system response speed requirements and anti-interference needs. Current saturation indicates that the current value exceeds the physical capacity of the battery or inverter, and the actual current cannot follow the changes in the commanded current. Without intervention, this can lead to decreased power control accuracy, increased power output deviation, and even system oscillation. Therefore, determining current saturation provides an adjustment basis for subsequent outer loop control, ensuring stable system operation. The active current value is the current value output by the inner loop control to regulate the active power of the energy storage battery; specifically, it is the current value output by the d-axis inner loop control. Its value is obtained through a power-current conversion model (P=3 / 2× × Q = 3 / 2 × × The active power is obtained by converting it from the reference active power in the outer reference power. The conversion formula is as follows: =2× / (3× ), This refers to the reference active power in the outer layer reference power; the reactive current value is the current value output by the inner loop control to achieve reactive power regulation of the energy storage battery, specifically the current value output by the q-axis inner loop control. Its value is obtained by converting the reference reactive power in the outer reference power through a power-current conversion model. The conversion formula is as follows: =2× / (3× ), This refers to the reference reactive power in the outer layer reference power. Both active and reactive current values ​​are current physical quantities, and their units are the same as those of the inner loop current limit. Since they are consistent, the absolute values ​​of the active current and reactive current can be compared with the inner loop current limit, respectively. In the power-current conversion model, P is the power to be calculated. This represents the corresponding current value along the d-axis. The coefficient "3" represents the corresponding current value on the q-axis. The coefficient "3" originates from the power calculation characteristics of a three-phase system. The total power of a three-phase system is the sum of the individual powers of phases A, B, and C. The coefficient "3" reflects the cumulative relationship of the three-phase power. The coefficient "2" originates from the transformation nature of the dq synchronous rotating coordinate system. When three-phase AC quantities are converted into two-phase orthogonal DC components on the d and q axes through the Clark and Park transformations, coefficient "2" is introduced to ensure power conservation before and after the transformation, achieving equivalent conversion between three-phase and two-phase quantities. The inner loop control output is the control command calculated by the inner current controller, such as the inverter's dq-axis voltage value, provided by the controller's internal variables. The outer reference power is the power reference value given by the outer control, such as the active / reactive power command generated by model predictive control or the expected output of droop control, provided by the upper controller.

[0077] The method for determining whether voltage saturation has been reached includes: if the modulation ratio derived from the voltage value is continuously greater than the modulation ratio safety factor, and this state lasts for a preset second consecutive control cycle number, then voltage saturation is determined. The preset second consecutive control cycle number is pre-set based on system response speed requirements and anti-interference needs. The modulation ratio derived from the voltage value is calculated using the d-axis and q-axis voltage values. Specifically, the calculation method is as follows: add the voltage limit corresponding to the maximum active current to the voltage limit corresponding to the maximum reactive current, divide by 2 to obtain the first voltage value; then, calculate the ratio of the square root of the sum of the squares of the d-axis and q-axis voltage values ​​to the first voltage value to obtain the modulation ratio. Voltage saturation indicates that the current voltage value is close to or has reached the inverter's modulation limit. Continuing to increase the voltage value will cause the inverter to enter an overmodulation state, leading to problems such as output voltage distortion and increased harmonic content, affecting power control accuracy and equipment safety. Therefore, determining whether voltage saturation is present is to limit the voltage value in a timely manner to avoid overmodulation.

[0078] The control cycle is the basic time unit for the system to perform a complete control calculation and command output. That is, the controller completes parameter acquisition, logic operation and control command update once every control cycle. The first number of consecutive control cycles and the second number of consecutive control cycles are both counting multiples based on the control cycle as the basic unit. For example, if the first number of consecutive control cycles is set to 3, it means that a specific state needs to be detected for 3 consecutive control cycles to be considered valid. The relationship between the two is that the latter is the sum of the former, which is used to filter out instantaneous interference signals and ensure the reliability of state judgment.

[0079] Define a saturation flag S. When S is 1, it indicates that the system is in a saturated state, and when S is 0, it indicates that the system is in a non-saturated state. When S is 1, it is necessary to distinguish whether the saturation state is current saturation (denoted as S=1a) or voltage saturation (denoted as S=1b). The saturation flag can be marked as 1a and 1b at the same time.

[0080] The saturation calculation module calculates the saturation difference and saturation direction angle based on the current value output by the inner loop control and the actual current value output by the inner loop.

[0081] The method for calculating the saturation difference ΔI is as follows:

[0082] ;

[0083] In the formula, and These are the current values ​​output by the inner loop control on the d-axis and q-axis, respectively. and These are the actual current values ​​output by the inner loops of the d-axis and q-axis, respectively. The actual output of the inner loop is the actual output value after limiting, such as the actual applied dq-axis voltage or actual output current, which can be obtained through the controller's limiting module output or sensor measurement. The calculation method for the saturation difference is based on the characteristics of the current vector in the dq synchronous rotating coordinate system. In the dq synchronous rotating coordinate system, the active current and reactive current correspond to the d-axis and q-axis components, respectively, forming a deviation vector in a two-dimensional plane. This deviation vector is composed of the d-axis deviation (…). Deviation from q-axis ( The calculation involves taking the square root of the sum of the squares of the deviations between the current value output by the control loop and the actual current value along the d-axis and q-axis. Essentially, this calculates the magnitude of the deviation vector, which comprehensively reflects the total deviation magnitude in both active and reactive directions, conforming to the mathematical principles of vector operations. The calculation of the saturation difference incorporates the two-dimensional characteristics of current control in the energy storage system. By quantifying the overall deviation, it allows subsequent outer-loop adjustment commands to be directly correlated with the total deviation, avoiding adjustment imbalances caused by single-direction deviation calculations. The saturation difference reflects the magnitude of the portion of the current value not realized by the actual current, quantifying the control deviation and providing a basis for subsequent outer-loop adjustment commands, ensuring that the adjustment magnitude matches the deviation degree.

[0084] The method for calculating the saturation direction angle φ is as follows:

[0085] ;

[0086] The calculation of the saturation direction angle is based on the angular characteristics of the deviation vector in the dq coordinate system. In a two-dimensional plane, the angle of the deviation vector is determined by the arctangent of the ratio of its q-axis component to its d-axis component. This angle can intuitively reflect the distribution and emphasis of the deviation vector in the active (d-axis) and reactive (q-axis) directions. The calculation method of the saturation direction angle is based on the conversion relationship between polar coordinates and rectangular coordinates. By clearly defining the dominant direction of the deviation, the outer loop adjustment can prioritize compensating for the direction with more significant deviation, avoiding efficiency losses caused by indiscriminate adjustment. Its design logic is directly matched with the directional characteristics of the current vector, ensuring the targeting and accuracy of the adjustment. The saturation direction angle reflects the degree of emphasis of the saturation state in the active and reactive directions. Its function is to provide a directional reference for the outer loop adjustment, enabling the adjustment to more specifically compensate for deviations in the corresponding directions.

[0087] The saturation correction module, based on the saturation flag, uses the saturation difference and inner loop current limiting to correct the preset outer reference power, obtains the corrected reference power, and corrects the integral gain in the preset integrator to remove the saturation state.

[0088] Please see Figure 4As shown, the method for obtaining the corrected reference power by correcting the preset outer layer reference power based on the saturation flag, using the saturation difference and inner loop current limiting includes:

[0089] When S=0, the actual output current value of the inner loop perfectly follows the output current value of the inner loop control, and the actual power remains consistent with the outer reference power, with no control deviation occurring in the inner loop. Adjusting the outer reference power at this time might disrupt the current control balance and cause unnecessary system fluctuations. Therefore, maintaining the original outer reference power ensures control stability and power output accuracy. The actual power refers to the actual output power value of the system, obtained by measuring the grid-side voltage and current and calculating the power.

[0090] When S includes 1a, the dominant saturation direction needs to be determined based on the deviation vector direction corresponding to the saturation difference. If the absolute value of the saturation direction angle φ is less than or equal to a preset threshold angle, it indicates that the direction of the deviation vector is close to the d-axis, meaning that saturation is mainly caused by the deviation in the active power direction, i.e., active power is dominant. The threshold angle is preset based on the system's sensitivity to deviations in the active and reactive power directions. At this time, the reference active power in the outer reference power is... Adjusted to -kp×ΔI yields the adjusted reference active power, where kp is the voltage correction amount pre-calibrated based on the system's dynamic response speed, stability requirements, and load characteristics, and its product with the saturation difference ΔI is the correction amount in power units. This refers to the actual active power. By reducing the command demand in the active direction, the deviation between the active current value and the actual active current is reduced, allowing the actual output current value of the inner loop to follow the command again, avoiding power overshoot or oscillation caused by the continuous accumulation of deviation. Since there is no significant deviation in the reactive direction, the reference reactive power in the outer reference power remains unchanged. If the absolute value of the saturation direction angle φ is greater than or equal to the difference between 90° and the threshold angle, it indicates that the direction of the deviation vector is close to the q-axis, and saturation is mainly caused by the deviation in the reactive direction, i.e., reactive power is dominant. In this case, the reference reactive power in the outer reference power is... Adjusted to -kp×ΔI yields the adjusted reference reactive power, where This represents the actual reactive power. Adjusting the reference reactive power in the outer layer reference power can reduce the deviation between the reactive current value and the actual reactive current, restoring the inner loop following capability. Since there is no significant deviation in the active power direction, the reference active power in the outer layer reference power remains unchanged. If the absolute value of the saturation direction angle φ is greater than the preset threshold angle but less than the difference between 90° and the threshold angle, no correction is required.

[0091] When S includes 1b, the active power output of the inverter needs to be driven by the d-axis voltage value. The maximum value of the d-axis voltage value is constrained by the inverter's modulation limit, that is, the maximum peak value of the inverter's output phase voltage is... / 2, considering the AC grid voltage phase and modulation ratio safety factor, the d-axis voltage value has a clear upper limit. If the active power output increases, the d-axis voltage value needs to increase synchronously to meet the power demand, easily leading to voltage saturation triggered by voltage limiting. Therefore, the correlation between voltage limiting and active power output is stronger. Based on this, the reference active power in the outer reference power is forcibly frozen to... This avoids further increases in active power commands that could cause the d-axis voltage to exceed the limit, thus preventing the voltage saturation state from deteriorating. Simultaneously, the q-axis voltage corresponding to reactive power also occupies the inverter's voltage margin. Maintaining the original reactive power reference would further compress the voltage margin. Therefore, the reference reactive power in the outer reference power is... according to ×(1-ΔI / The attenuation is used to obtain the adjusted reference reactive power. By reducing the q-axis voltage requirement, some voltage margin is released, thus alleviating voltage saturation pressure.

[0092] Furthermore, the corrected reference power needs to be converted into corresponding d-axis and q-axis current values ​​using a power-current conversion model to ensure that the converted current values ​​do not exceed the inner loop current limit. Specifically, the d-axis current value is calculated as follows: =2× / (3× The calculation method for the q-axis current value is as follows: =2× / (3× The calculated d-axis and q-axis current values ​​are both current values ​​and can be directly compared with the inner loop current limit to ensure that the absolute values ​​of the d-axis and q-axis current values ​​do not exceed the inner loop current limit. This guarantees that the current requirement corresponding to the corrected reference power is within the safe current range of the battery and inverter. Verification is performed in conjunction with the battery's current SOC. If the current SOC is less than or equal to the battery's low charge threshold, the charging current corresponding to the adjusted reference active power must not exceed the corrected maximum allowable current under the corresponding SOC to prevent overcharging damage to the battery. If the current SOC is greater than or equal to the battery's high charge threshold, the discharging current corresponding to the adjusted reference active power must not exceed the corrected maximum allowable current under the corresponding SOC to prevent over-discharge leading to battery capacity degradation. If the SOC is greater than the battery's low charge threshold but less than the battery's high charge threshold, the adjusted current value must not exceed the maximum allowable current to ensure that the reference power is always within the battery's safe charging and discharging capacity range, avoiding equipment failure or performance loss caused by exceeding physical limits.

[0093] When S=0, the integral link updates according to the conventional integral law. The main function of the integral link in a normal energy storage battery charge-discharge coordinated control system is to eliminate steady-state error. In systems using only proportional control, a fixed deviation, i.e., steady-state error, easily exists between the actual output and the reference value. The integral link continuously accumulates the integral error and converts it into a control adjustment quantity, gradually reducing this deviation until the actual output stably tracks the reference value, ensuring that the system power control accuracy meets operational requirements. The conventional integral law is the accumulation of integral error over time. Specifically, the integral value equals the current integral value plus the product of the integral gain and the integral error, multiplied by the control period. This continuous accumulation of error eliminates steady-state deviation. The integral error is the difference between the reference value and the actual value; the active power integral error is the difference between the reference active power and the actual active power; and the reactive power integral error is the difference between the reference reactive power and the actual reactive power. The integral gain remains unchanged because when the system is in a non-saturated state, the actual output can follow the reference command, allowing the integral link to function normally in eliminating steady-state error. Maintaining the original integral gain ensures that the system's dynamic response characteristics match its steady-state accuracy. The integral gain is the proportional coefficient of the integral element, used to control the strength of the integral action. The larger the integral gain, the stronger the integral action and the faster the steady-state error is eliminated.

[0094] When S contains 1a or 1b, the integral gain Dynamic attenuation, the calculation method for the attenuated integral gain Ki' is as follows:

[0095] ;

[0096] Since the actual output of the system cannot follow the reference command under saturation, if the original integral gain is maintained, the integral stage will continue to accumulate errors, leading to an excessive increase in the integral value, which in turn exacerbates the overshoot phenomenon after saturation. By introducing... As a decay factor, the more severe the saturation, the more... The larger the integral gain, the greater the attenuation, which weakens the integral action and prevents excessive accumulation of integrals. In this embodiment, the minimum attenuated integral gain is 0.2×Ki to retain the basic integral capability and prevent the complete loss of integral action, which would lead to the inability to eliminate subsequent steady-state errors.

[0097] The direction of integration correction needs to be determined by considering the relationship between the saturation direction angle corresponding to the saturation difference and the direction of the integration error. The direction of the integration error is indicated by its positive or negative value. For active power integration error, it is the difference between the reference active power and the actual active power. If the reference active power is greater than the actual active power, the difference is positive, indicating under-output in the active power direction, and the direction of the integration error is that active power output needs to be increased. If the reference active power is less than the actual active power, the difference is negative, indicating over-output in the active power direction, and the direction of the integration error is that active power output needs to be reduced. For reactive power integration error, it is the difference between the reference reactive power and the actual reactive power. If the reference reactive power is greater than the actual reactive power, the difference is positive, indicating under-output in the reactive power direction, and the direction of the integration error is that reactive power output needs to be increased. If the reference reactive power is less than the actual reactive power, the difference is negative, indicating over-output in the reactive power direction, and the direction of the integration error is that reactive power output needs to be reduced. If the saturation direction angle is in the same direction as the integral error, for example, if the integral error is positive and the component of the deviation vector in the corresponding axis of the saturation direction angle is positive, then integration is stopped to avoid further expansion of the deviation due to the accumulation of integrals in the same direction. If the direction of the deviation vector is opposite to the direction of the integral error, then integration continues according to the attenuated integral gain Ki', and the historical integral error is gradually offset by accumulating the reverse error, laying the foundation for the system to quickly recover its tracking capability after exiting saturation.

[0098] Finally, an integral state limit is applied, and the integral value must not exceed ±Pi× / Ki (effective), ±Pi× / Ki (no reactive power). Among them, The maximum active power that the system is allowed to output is determined by the inverter's rated active power and the battery's maximum charging and discharging active power. The maximum reactive power allowed to be output by the system is determined by the inverter's rated reactive power capacity and the grid's demand for reactive power regulation; Pi is the power proportionality coefficient. If the integral value exceeds the integral state limit range, the subsequent current value calculated based on the integral value will exceed the inner loop current limit or the system's power carrying capacity, thereby triggering power overshoot or equipment protection action. Therefore, it is necessary to... and An integral limit is set as a baseline. The preset power proportional coefficient is pre-set according to the system's maximum allowable integral range and stability requirements. For example, in this embodiment, it is set to 0.1, which can retain the ability of the integral link to eliminate steady-state errors while avoiding excessive accumulation of integral values ​​that could lead to abnormal control commands. The purpose of the integral state limit is to prevent the integral value from exceeding the reasonable range, avoid abnormal integral values ​​that could cause subsequent control commands to exceed physical constraints, and ensure that the integral link always operates within the effective range.

[0099] By dynamically adjusting the integral strength, optimizing the integral direction, and limiting the integral range, abnormal control factors under saturation conditions are eliminated at the integral level, providing necessary integral control guarantees for system desaturation. When these steps work in conjunction with outer-layer reference power adjustment and current command feedforward compensation, the deviation between the actual output of the inner loop and the reference command can be gradually reduced, ultimately driving the system from a saturated state to a non-saturated state, thus achieving saturation desaturation.

[0100] The feedforward compensation module is used to convert the corrected reference power into a base current value, and then correct the base current value through feedforward compensation to obtain the corrected current value.

[0101] Based on the power-current conversion model, the corrected reference power is converted into a base current value. and ; The calculation method is as follows: , The calculation method is as follows: .in, This is the base current value for the corrected reference active power conversion. This is the base current value for the corrected reference reactive power conversion.

[0102] The feedforward compensation is incorporated, specifically through the following method: The saturation direction angle φ is the angle of the deviation vector in the dq synchronous rotating coordinate system. In the dq synchronous rotating coordinate system, the d-axis is aligned with the active current direction, and the q-axis is aligned with the reactive current direction. Based on the vector decomposition principle of trigonometric functions, cosφ is used to calculate the proportion of the deviation vector component on the d-axis (active direction), and sinφ is used to calculate the proportion of the deviation vector component on the q-axis (reactive direction). Through the cosφ and sinφ functions, the saturation difference ΔI can be accurately decomposed into compensation components corresponding to the active and reactive directions, ensuring that the compensation amount matches the direction of the saturation deviation. Specifically, ΔI is multiplied by a preset feedforward weight coefficient, and then multiplied by cosφ (active component) and sinφ (reactive component) respectively. The decomposed compensation components are used as negative feedback. The preset feedforward weight coefficient is pre-set according to the system compensation requirements and stability requirements. Its function is to balance the compensation effect and control stability, avoiding excessive compensation that leads to current value fluctuations. In this embodiment, this coefficient can be set to 0.3. Based on the decomposed compensation components, the basic instruction is corrected, and the method for calculating the corrected current value is as follows:

[0103]

[0104] ;

[0105] In the formula, and These are the corrected current values ​​for the d-axis and q-axis, respectively. The preset feedforward weighting coefficients.

[0106] The base current value is a theoretical command calculated based solely on the adjusted reference power, without considering the accumulated deviations from the previous saturation state. If used directly, it may still exceed the actual carrying capacity of the inner loop, leading to re-triggering saturation. By adding feedforward compensation to the base current value, a corrected current value is obtained. The component corresponding to the saturation deviation can be deducted from the base current value in advance, making the corrected current value closer to the current physical constraint capacity of the inner loop. This reduces the deviation between the command and the actual execution capacity, lowers the probability of re-entering the saturation state, and accelerates the system's recovery from the saturation state to a stable operating state.

[0107] The gradual recovery module is used to smoothly recover from the current actual power to the original target reference power.

[0108] The overall logic of progressive recovery trajectory planning is based on the principle of dynamically matching the recovery speed with the remaining capacity of the inner loop. When the system is released from saturation, i.e., S changes from 1 to 0, although the inner loop has the ability to follow the command again, the actual output of the inner loop still differs from the original target reference power. If the reference power is directly restored to its original value, the sudden change in power command may exceed the current remaining capacity of the inner loop, leading to secondary saturation or system oscillation. This principle quantifies the additional power margin that the inner loop can currently carry, i.e., the recovery margin, and dynamically adjusts the recovery speed of the reference power, i.e., the recovery slope, so that the recovery process always stays within the capacity range of the inner loop, balancing recovery efficiency and system stability, as detailed below:

[0109] First, calculate the recovery margin. Specific methods include: based on the power-current conversion model, the active power recovery margin Δ... and reactive power recovery margin Δ The calculation method is as follows:

[0110] ;

[0111] ;

[0112] Calculating the recovery margin is to quantify the upper limit of active and reactive power that the inner loop can currently handle. Among them ( This represents the current remaining current capacity along the d-axis, i.e., the additional current the inner loop can still withstand in the active direction; This represents the current remaining current capacity along the q-axis, i.e., the additional current the inner loop can still withstand in the reactive direction. Converting this remaining current capacity into a recovery margin in power units using a power-current conversion model allows it to be directly used as the upper limit of the power increase during recovery, preventing the power increase from exceeding the inner loop's remaining carrying capacity and thus preventing secondary saturation.

[0113] Next, the recovery slope is determined. The specific method includes: the recovery slope is determined according to the principle that the larger the recovery margin, the steeper the slope, that is, the recovery speed is dynamically allocated based on the remaining capacity of the inner loop. When the recovery margin is large, it indicates that the inner loop has sufficient additional carrying capacity. In this case, using a steeper recovery slope can accelerate the approximation of the reference power to the original value, reduce the system's operating time in suboptimal power states, and improve energy conversion efficiency. When the recovery margin is small, it indicates that the inner loop has limited additional carrying capacity. In this case, using a gentler recovery slope can prevent the power increment from exceeding the remaining capacity, ensuring a smooth recovery process. Specifically, the active power recovery slope... and reactive power recovery slope The calculation method is as follows:

[0114] =min(YSXS1×Δ YSCK1× );

[0115] =min(YSXS2×Δ YSCK2× );

[0116] In the formula, min(˙) represents taking the minimum value. and YSXS1 and YSXS2 are the preset original target reference power for the d-axis and q-axis, respectively. YSXS1 is the preset margin ratio coefficient for the d-axis, and YSXS2 is the preset margin ratio coefficient for the q-axis. Their preset values ​​need to be determined in conjunction with the system's dynamic recovery requirements and equipment safety constraints. In this embodiment, if the inverter current change rate limit is 2A / ms and the battery charging / discharging current change rate constraint is 1.5A / ms, YSXS1 can be set to 0.1 based on the active power recovery margin calculation logic. Similarly, YSXS2 can be set to 0.1 based on the reactive power recovery margin calculation logic. YSCK1 is the preset reference ratio coefficient for the d-axis, and YSCK2 is the preset reference ratio coefficient for the q-axis. Their preset values ​​need to be determined in conjunction with the original target reference power scale and the operating characteristics of the power grid and load. In this embodiment, if the power grid requires that the power fluctuation within a single control cycle not exceed 20% of the original target reference power, and the load's allowed power fluctuation limit is 25%, then YSXS1 and YSCK2 are set to 0.1 based on the original target reference power for the d-axis. To meet control requirements, YSCK1 can be set to 0.2. Similarly, this can be combined with the original target reference power on the q-axis. To meet control requirements, set YSCK2 to 0.2.

[0117] Finally, the recovery trajectory is generated. The specific method includes: within each control cycle, the reference power gradually approximates the original target reference power according to the recovery slope determined above, to obtain the gradually recovered reference power. and The specific formula is as follows:

[0118]

[0119] ;

[0120] If the reference power is directly changed from the current actual power to the original target reference power, the corresponding d-axis and q-axis current values ​​will increase instantaneously. This increase will far exceed the current remaining capacity of the inner loop, causing the inner loop to re-enter saturation, or potentially triggering DC bus voltage fluctuations and grid-side power surges. However, by adjusting the reference power slightly within each control cycle according to the recovery slope, the current value increases gradually, synchronizing with the gradual release of the inner loop's remaining capacity, ensuring that the current value after each adjustment remains within the acceptable range. Within the specified range, while avoiding power surges that could impact the power grid or load, a smooth transition from actual power to the original target reference power is ultimately achieved.

[0121] Example 2:

[0122] Please see Figure 2 As shown, this embodiment provides an adaptive charge-discharge coordinated control method for energy storage batteries, including:

[0123] The maximum allowable current is corrected based on the real-time collected SOC and preset low battery charge threshold, high battery charge threshold, reference coefficient, first attenuation coefficient and second attenuation coefficient to obtain the inner loop current limit.

[0124] Determine whether the current system has reached current saturation or voltage saturation, and mark the corresponding saturation flag; calculate the saturation difference and saturation direction angle based on the current value output by the inner loop control and the actual current value output by the inner loop.

[0125] Based on the saturation flag, the preset outer reference power is corrected using the saturation difference and inner loop current limiting to obtain the corrected reference power, and the integral gain in the preset integrator is corrected to remove the saturation state.

[0126] The corrected reference power is converted into a base current value, and feedforward compensation is added to correct the base current value to obtain the corrected current value.

[0127] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

[0128] In conclusion, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An adaptive charging and discharging coordination control method for an energy storage battery, characterized in that, The method comprises the following steps: The maximum allowable current is corrected based on the real-time collected SOC and the preset battery low charge threshold, battery high charge threshold, reference coefficient, first attenuation coefficient and second attenuation coefficient, to obtain an inner loop current limit; It is judged whether the current system reaches current saturation or voltage saturation, and the corresponding saturation flag is marked; based on the current value output by the inner loop control and the actual current value output by the inner loop, the saturation difference value and the saturation direction angle are calculated; According to the saturation flag, the saturation difference value and the inner loop current limit are used to correct the preset outer layer reference power to obtain the corrected reference power, and the integral gain in the preset integral link is corrected to remove the saturation state; The corrected reference power is converted into a basic current value, and the basic current value is corrected by adding a feedforward compensation to obtain a corrected current value.

2. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 1, characterized in that, The method for obtaining the inner loop current limit comprises: When the SOC is less than or equal to the battery low charge threshold, the maximum allowable current = the current maximum allowable current × (the first attenuation coefficient + the second attenuation coefficient × the SOC); When the SOC is greater than or equal to the battery high charge threshold, the maximum allowable current = the current maximum allowable current × (the reference coefficient - the second attenuation coefficient × the SOC); When the SOC is greater than the battery low charge threshold and less than the battery high charge threshold, the maximum allowable current remains unchanged; The maximum allowable current is used as the inner loop current limit.

3. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 1, characterized in that, The method for judging whether the current system reaches current saturation or voltage saturation and marking the corresponding saturation flag comprises: If the absolute value of the collected active current value continuously exceeds the inner loop current limit, or the absolute value of the collected reactive current value continuously exceeds the inner loop current limit, and the continuous time reaches the preset first continuous control cycle number, it is determined that the current saturation is reached, and the saturation flag is marked as 1a; If the modulation ratio derived based on the voltage value continuously exceeds the preset modulation ratio safety coefficient, and the continuous time reaches the preset second continuous control cycle number, it is determined that the voltage saturation is reached, and the saturation flag is marked as 1b; If the current saturation or the voltage saturation is not reached, the saturation flag is marked as 0; The saturation flag can be marked as 1a and 1b at the same time.

4. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 3, characterized in that, The calculation method of the modulation ratio comprises: Based on the collected AC power grid voltage phase, the maximum output phase voltage peak value of the inverter and the preset modulation ratio safety coefficient, the voltage limit of the maximum active current and the voltage limit of the maximum reactive current are calculated; The voltage limit of the maximum active current and the voltage limit of the maximum reactive current are added and then divided by 2 to obtain a first voltage value; The modulation ratio is obtained by squaring the sum of the collected d-axis voltage value and q-axis voltage value, and then calculating the ratio of the first voltage value.

5. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 1, characterized in that, The method for calculating the saturation difference value and the saturation direction angle comprises: The difference between the d-axis inner loop control output current value and the d-axis inner loop actual output current value is calculated to obtain a first difference value; The difference between the q-axis inner loop control output current value and the q-axis inner loop actual output current value is calculated to obtain a second difference value; The square root of the sum of the squares of the first difference value and the second difference value is calculated to obtain the saturation difference value; The saturation direction angle is the inverse tangent value of the ratio of the first difference value to the second difference value.

6. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 5, characterized in that, The method for correcting the preset outer layer reference power comprises: calculating a product of the preset voltage correction amount and the saturation difference value to obtain a first product; if the saturation flag is 0, keeping the current outer loop reference power unchanged; if the saturation flag contains 1a and the direction of the saturation direction angle is to reduce active output, reducing the reference active power in the current outer loop reference power by the first product to obtain an adjusted reference active power, and keeping the reference reactive power in the current outer loop reference power unchanged; if the direction of the saturation direction angle is to reduce reactive output, reducing the reference reactive power in the current outer loop reference power by the first product to obtain an adjusted reference reactive power, and keeping the reference active power in the current outer loop reference power unchanged; if the saturation flag contains 1b, freezing the reference active power in the current outer loop reference power as the actual active power, and calculating a ratio of the saturation difference value to the inner loop current limit to obtain a first ratio, multiplying the reference reactive power in the current outer loop reference power by a difference between 1 and the first ratio to obtain an adjusted reference reactive power.

7. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 6, characterized in that, The method for determining the direction of the saturation direction angle comprises: if the absolute value of the saturation direction angle is less than a preset threshold angle, the direction of the saturation direction angle is to reduce active output; if the absolute value of the saturation direction angle is greater than or equal to a difference between 90° and the threshold angle, the direction of the saturation direction angle is to reduce reactive output.

8. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 6, characterized in that, The method for correcting the integral gain in the preset integral link comprises: if the saturation flag is 0, keeping the integral gain in the integral link unchanged; if the saturation flag contains 1a or 1b, multiplying the integral gain in the integral link by a difference between 1 and the first ratio to obtain a corrected integral gain; if the direction of the saturation direction angle is the same as that of the integral error, stopping the integration; if the direction of the saturation direction angle is opposite to that of the integral error, continuing the integration according to the corrected integral gain.

9. The adaptive charge and discharge coordination control method of an energy storage battery according to claim 7, characterized in that, The method for determining the direction of the integral error comprises: the active integral error is a difference between the reference active power and the actual active power, if the reference active power is greater than the actual active power, the active integral error is positive, and the direction of the integral error is to increase active output; if the reference active power is less than the actual active power, the active integral error is negative, and the direction of the integral error is to reduce active output; the reactive integral error is a difference between the reference reactive power and the actual reactive power, if the reference reactive power is greater than the actual reactive power, the reactive integral error is positive, and the direction of the integral error is to increase reactive output; if the reference reactive power is less than the actual reactive power, the reactive integral error is negative, and the direction of the integral error is to reduce reactive output.

10. The adaptive charge-discharge coordination control method of an energy storage battery according to claim 1, characterized in that, The method for obtaining the corrected current value comprises: based on a preset power-current conversion model, converting the corrected reference power into a basic current value; based on a vector decomposition principle of a trigonometric function, decomposing the saturation difference value into compensation components corresponding to active and reactive directions, and multiplying the decomposed compensation components by preset feedforward weight coefficients to obtain a negative feedback amount; subtracting the negative feedback amount from the basic current value to obtain the corrected current value.

11. An adaptive charging and discharging coordination control system for energy storage batteries, for implementing the adaptive charging and discharging coordination control method for energy storage batteries according to any one of claims 1-10, characterized in that, The method comprises: The amplitude limiting calculation module corrects the maximum allowable current based on the real-time collected SOC and the preset battery low charge threshold, battery high charge threshold, reference coefficient, first attenuation coefficient and second attenuation coefficient, to obtain an inner loop current amplitude limit; The saturation judgment module is configured to judge whether the current system reaches current saturation or voltage saturation, and mark the corresponding saturation flag; The saturation calculation module is configured to calculate a saturation difference value and a saturation direction angle based on the current value output by the inner loop control and the actual current value output by the inner loop; The saturation correction module is configured to correct the preset outer layer reference power by using the saturation difference value and the inner loop current amplitude limit according to the saturation flag, to obtain a corrected reference power, and correct the integral gain in the preset integral link to remove the saturation state; The feedforward compensation module is configured to convert the corrected reference power into a basic current value, and correct the basic current value through feedforward compensation to obtain a corrected current value.

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