A capacitor energy storage system adaptive charge and discharge control system

Abstract

A capacitor energy storage system adaptive charging and discharging control system, specifically in the technical field of power grid charging and discharging control, the scheme comprises a state sensing module that acquires state acquisition data of the capacitor in real time through a current sensor, a temperature sensor and a voltage sensor, a dynamic calculation module that integrates the state acquisition data acquired by the state sensing module and calculates the polarization capacitance, equivalent series resistance and state of charge of the capacitor through a dynamic quantization algorithm, an adaptive control module that adjusts the size and direction of the charging and discharging current through a closed-loop feedback algorithm according to the polarization capacitance, equivalent series resistance and state of charge output by the dynamic calculation module, and a safety protection module that triggers a hardware protection mechanism to cut off the charging and discharging circuit based on the overcurrent, overtemperature and overvoltage data acquired by the state sensing module. The application realizes adaptive charging and discharging of the capacitor energy storage system through dynamic quantization of the polarization state, real-time compensation of internal resistance loss, high-precision updating of the state of charge and closed-loop feedback control.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of power grid charging and discharging control, and particularly relates to a capacitor energy storage system adaptive charging and discharging control system. BACKGROUND

[0002] The capacitor energy storage system is widely applied to urban rail transit regenerative braking, power grid frequency modulation, new energy vehicle energy recovery and the like due to the characteristics of high power density and fast charging and discharging speed. The core requirement is to realize efficient and safe charging and discharging control under complex working conditions (large current and wide temperature range) - to maximize energy recovery efficiency and minimize polarization loss and thermal damage and prolong system life.

[0003] The control logic of the traditional capacitor energy storage system is based on a static strategy of "rated current + fixed temperature threshold", that is, the charging and discharging current is set according to the rated parameters (such as rated current 100A and temperature upper limit 60 DEG C) of the capacitor, and thus the influence of dynamic changes of working conditions on the system state is not considered. With the increasing requirement of the new energy industry on the adaptive capability of the energy storage system, the static control strategy has been difficult to meet the actual demand, and adaptive control technology based on dynamic state sensing is urgently needed.

[0004] Therefore, the technical personnel in the art provide a capacitor energy storage system adaptive charging and discharging control system to solve the problems in the background. SUMMARY

[0005] The technical problem solved by the application is to provide a capacitor energy storage system adaptive charging and discharging control system to realize accurate quantification of polarization intensity, dynamic quantification of internal resistance loss and accurate update and closed-loop feedback of the state of charge.

[0006] To solve the above problems, the application provides the following technical scheme:

[0007] A capacitor energy storage system adaptive charging and discharging control system comprises:

[0008] A state sensing module is configured to collect state collection data of the capacitor including charging and discharging current, core temperature and terminal voltage data in real time through a current sensor, a temperature sensor and a voltage sensor;

[0009] A dynamic calculation module is configured to integrate the state collection data collected by the state sensing module and calculate the polarization capacitance, equivalent series resistance and state of charge of the capacitor through a dynamic quantification algorithm;

[0010] An adaptive control module is configured to adjust the size and direction of the charging and discharging current through a closed-loop feedback algorithm according to the polarization capacitance, the equivalent series resistance and the state of charge output by the dynamic calculation module;

[0011] A safety protection module is configured to trigger a hardware protection mechanism to cut off the charging and discharging circuit based on the overcurrent, overtemperature, and overvoltage data collected by the state perception module.

[0012] The dynamic calculation module of the capacitor energy storage system adaptive charging and discharging control system comprises:

[0013] The polarization intensity calculation submodule is configured to combine real-time current and temperature data, and quantize the polarization state of the capacitor and output the polarization capacity by coupling calculation of current relative intensity and temperature deviation.

[0014] The equivalent internal resistance calculation submodule is configured to quantize the internal resistance loss of the capacitor and output the equivalent series resistance by nonlinear fitting of polarization relative value and temperature interval based on the polarization capacity and in combination with temperature deviation.

[0015] The state of charge update submodule is configured to integrate ideal charging and discharging capacity and internal resistance loss, and predict the state of charge of the capacitor remaining at the next moment by a dynamic compensation algorithm.

[0016] Further, the calculation logic of the polarization intensity calculation submodule is:

[0017] The real-time charging and discharging current is collected by the current sensor, the first ratio of the charging and discharging current to the rated current is calculated, and the current correction term of the current to the polarization impact strength is affected by the product of the experimentally calibrated current influence coefficient.

[0018] The real-time capacitor temperature is collected by the temperature sensor, the temperature deviation of the capacitor temperature from the preset reference temperature is calculated, and the first temperature correction term of the temperature to the polarization dissipation capacity is affected by the product of the experimentally calibrated first temperature influence coefficient.

[0019] The current correction term and the first temperature correction term are weighted and coupled, and multiplied by the initial polarization capacity, and the real-time polarization capacity is output.

[0020] Further, the calculation logic of the equivalent internal resistance calculation submodule is:

[0021] Based on the polarization capacity output by the polarization intensity calculation submodule, the second ratio of the polarization capacity to the initial polarization capacity is calculated, and the polarization correction term of the polarization to the internal resistance blocking effect is affected by the product of the experimentally calibrated polarization capacity influence coefficient.

[0022] Based on the temperature deviation calculated by the polarization intensity calculation submodule, the second temperature correction term of the temperature to the ohmic loss is calculated under the influence of the product of the experimentally calibrated second temperature influence coefficient.

[0023] The fitting results of the polarization correction term and the second temperature correction term are coupled and multiplied by a reference equivalent series resistance to output a real-time equivalent series resistance.

[0024] Further, the calculation logic of the state of charge updating submodule is:

[0025] Based on the charging and discharging current collected by the current sensor, the proportion of the charging and discharging current multiplied by a pre-set control period to the total capacitance is calculated, and the ideal charging and discharging amount at no loss is obtained.

[0026] Based on the product of the equivalent series resistance, the charging and discharging current and the control period, the internal resistance loss energy is obtained, and the internal resistance loss is obtained by dividing the product of the rated voltage and the total capacitance.

[0027] The state of charge at the previous moment, the ideal charging and discharging amount and the internal resistance loss are dynamically coupled to output the state of charge at the next moment after updating.

[0028] Further, the adaptive control module comprises:

[0029] A current adjusting unit adjusts the duty cycle of the charging and discharging current through a PWM signal.

[0030] A closed-loop feedback unit adjusts the current influence coefficient based on the state of charge output by the state of charge updating submodule, and feeds back to the polarization intensity calculation submodule to update the polarization capacitance at the next moment, and dynamically adjusts the current sampling strategy at the next moment based on the polarization capacitance at the next moment.

[0031] Further, the adjustment of the current influence coefficient is based on the polarization characteristics of the pre-set state of charge interval, and the specific mode is:

[0032] When the state of charge is in the low state of charge interval (state of charge < 30%), the electrode surface charge density is low, and the polarization effect is weak, and the current influence coefficient is 0.001.

[0033] When the state of charge is in the medium state of charge interval (30%≤state of charge≤80%), the electrode surface charge density is moderate, and the polarization effect is linearly enhanced with the state of charge, and the current influence coefficient is 0.005.

[0034] When the state of charge is in the high state of charge interval (state of charge > 80%), the electrode surface charge density is close to saturation, and the polarization effect is sharply enhanced, and the current influence coefficient is 0.01.

[0035] Further, the current sampling strategy is specifically:

[0036] When the polarization capacitance at the next moment > the initial polarization capacitance x 1.2 (strong polarization), it is reflected that the polarization loss is too large, and the charging and discharging current needs to be reduced to avoid overheating and capacity attenuation;

[0037] When the polarization capacitance at the next moment < the initial polarization capacitance x 0.8 (weak polarization), it is reflected that the polarization loss is small, and the charging and discharging current needs to be increased to improve the charging and discharging efficiency;

[0038] When the initial polarization capacitance x 0.8 ≤ the polarization capacitance at the next moment ≤ the initial polarization capacitance x 1.2 (moderate polarization), the current charging and discharging current is maintained to balance the efficiency and loss.

[0039] Further, the safety protection module comprises:

[0040] An overcurrent protection unit, when the current collected by the current sensing unit exceeds 1.5 times the rated current, a relay is triggered to cut off the circuit;

[0041] An over-temperature protection unit, when the core temperature collected by the temperature sensing unit exceeds 60℃, a cooling fan is started and the charging and discharging current is reduced;

[0042] An over-voltage protection unit, when the voltage collected by the voltage sensing unit exceeds 1.1 times the rated voltage, the charging is stopped and the discharging circuit is started.

[0043] The effects of the above scheme are as follows:

[0044] 1、The polarization intensity calculation sub-module in the application realizes accurate quantization of the polarization intensity through coupling calculation of the current relative intensity and the temperature deviation. Among them, the polarization capacitance is adjusted according to the current relative intensity, that is, the greater the current, the greater the polarization capacitance increment, so that it automatically reduces the current in the high state of charge (avoid overcharging polarization), reduces the polarization loss, and achieves dynamic compensation of current polarization impact; and the polarization capacitance is adjusted according to the temperature deviation, that is, the higher the temperature, the greater the polarization capacitance decrement, and in the medium temperature interval (25-60℃), the polarization dissipation space of temperature rise is utilized to automatically increase the current and improve the charging efficiency, so as to adaptively utilize the temperature polarization dissipation.

[0045] 2、The equivalent internal resistance calculation submodule in the application realizes dynamic quantification of internal resistance loss through the coupling calculation of the polarization capacitance relative value and the temperature deviation. Among them, according to the polarization capacitance relative value, the internal resistance is adjusted (the stronger the polarization is, the greater the internal resistance increment is), the current is automatically reduced in the large current working condition (to avoid excessive heat loss), the error of internal resistance loss estimation is reduced, the real-time compensation of the polarization internal resistance block is realized; and according to the temperature deviation, the medium temperature and high temperature intervals are distinguished (the internal resistance decreases in the medium temperature interval, and the internal resistance increases in the high temperature interval), so that the current is automatically increased in the medium temperature interval (the low loss space of the internal resistance reduction is utilized), and the current is automatically reduced in the high temperature interval (to avoid overheating and burning), the system life is prolonged, and the interval adaptation of the temperature internal resistance change is achieved.

[0046] 3、The equivalent internal resistance calculation submodule in the application realizes accurate updating and closed-loop feedback of the state of charge through the coupling calculation of the ideal charge and discharge amount and the internal resistance loss. Among them, the internal resistance loss is converted into the decrement of the state of charge (the greater the current is, the greater the internal resistance is, and the greater the decrement is), the error of the state of charge estimation is reduced, and the energy compensation of the internal resistance loss is achieved; then the updated state of charge is fed back, and the current is automatically reduced in the high state of charge (to avoid overcharging), and the current is automatically increased in the low state of charge (to avoid undercharging), forming a closed loop of "current-polarization-internal resistance-state of charge-current", so as to greatly improve the charging and discharging efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 The system flow framework diagram for realizing the adaptive charging and discharging control of the capacitor energy storage system of the application. DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the application will be clearly and completely introduced below with reference to the drawings in the embodiments of the application.

[0049] Embodiment one, please refer to Figure 1 A capacitor energy storage system adaptive charging and discharging control system, comprising:

[0050] A state sensing module configured to collect state acquisition data of the capacitor including charging and discharging current, core temperature and terminal voltage data in real time through a current sensor, a temperature sensor and a voltage sensor;

[0051] A dynamic calculation module configured to integrate the state acquisition data collected by the state sensing module, and calculate the polarization capacitance, the equivalent series resistance and the state of charge of the capacitor through a dynamic quantification algorithm;

[0052] An adaptive control module configured to adjust the size and direction of the charging and discharging current through a closed-loop feedback algorithm according to the polarization capacitance, the equivalent series resistance and the state of charge output by the dynamic calculation module;

[0053] The safety protection module is configured to trigger a hardware protection mechanism to cut off a charging and discharging circuit based on overcurrent, overtemperature and overvoltage data collected by the state sensing module.

[0054] The dynamic calculation module of the capacitor energy storage system adaptive charging and discharging control system comprises:

[0055] The polarization intensity calculation submodule is configured to combine real-time current and temperature data, and quantize the polarization state of the capacitor and output the polarization capacitance through coupling calculation of the relative intensity of the current and the temperature deviation.

[0056] The equivalent internal resistance calculation submodule is configured to quantize the internal resistance loss of the capacitor and output the equivalent series resistance through nonlinear fitting of the polarization relative value and the temperature interval based on the polarization capacitance and in combination with the temperature deviation.

[0057] The state of charge update submodule is configured to integrate ideal charging and discharging capacity and internal resistance loss, and predict the state of charge of the capacitor at the next moment through a dynamic compensation algorithm.

[0058] In the above embodiment, the state sensing module realizes all-round real-time acquisition of key state parameters of the capacitor through multi-sensor fusion technology, providing a data basis for subsequent dynamic calculation and control. The dynamic calculation module realizes dynamic modeling and real-time estimation of the internal state of the capacitor through the cooperation of the polarization intensity calculation, equivalent internal resistance calculation and state of charge update submodules. The adaptive control module realizes precise regulation and control of the charging and discharging current through a closed-loop feedback mechanism based on the state parameters output by the dynamic calculation module, improving the energy efficiency and safety of the system. The safety protection module, as the last line of defense at the hardware level, ensures that the system can quickly cut off the circuit under abnormal working conditions to prevent equipment damage.

[0059] The state sensing module adopts high-precision current sensors (such as Hall sensors), temperature sensors (such as PT100) and voltage sensors, with a sampling frequency not less than 1 kHz to ensure data real-time and accuracy. The dynamic calculation module runs on an embedded processor (such as ARM Cortex-M4) with a control period of 10 ms to meet real-time control requirements. The adaptive control module adjusts the charging and discharging current through PWM modulation technology, supporting bidirectional energy flow. The safety protection module adopts a combination of hardware comparators and relays with a response time of less than 10 ms to ensure quick and reliable protection action.

[0060] In summary, the embodiment builds a complete capacitor energy storage system adaptive charging and discharging control system through modular design and multi-sensor information fusion, realizes intelligent management of the whole process from state sensing, dynamic modeling, closed-loop control to safety protection, and provides technical support for efficient and safe operation of the capacitor under complex working conditions.

[0061] In the embodiment two, on the basis of the embodiment one, the calculation logic of the polarization intensity calculation submodule provided by the embodiment of the application is:

[0062] The real-time charging and discharging current is collected by the current sensor, a first ratio of the charging and discharging current to the rated current is calculated, and the current correction term of the current to the polarization impact intensity is affected by the product of the current influence coefficient calibrated in the experiment;

[0063] The real-time capacitor temperature is collected by the temperature sensor, a temperature deviation of the capacitor temperature from the preset reference temperature is calculated, and the first temperature correction term of the temperature to the polarization dissipation capacity is affected by the product of the first temperature influence coefficient calibrated in the experiment;

[0064] The current correction term and the first temperature correction term are coupled by weighting, and are multiplied by the initial polarization capacitance to output the real-time polarization capacitance.

[0065] The calculation formula of the polarization capacitance is as follows:

[0066] ;

[0067] In the formula,

[0068] C p(t) is the polarization capacitance at time t, reflecting the dynamic capacitance value of the internal polarization effect of the capacitor, C p0 is the initial polarization capacitance, that is, the polarization capacitance reference value of the capacitor when it is shipped, which can be measured by a factory test, a is the current influence coefficient, I (t) is the charging and discharging current at time t, which can be measured in real time by a current sensor (positive for charging and negative for discharging), I rated is the rated current, that is, the maximum design working current of the capacitor, which is determined by a product specification book, b is the first temperature influence coefficient, T (t) is the capacitor temperature at time t, which can be measured in real time by a temperature sensor, T ref is the reference temperature, specifically a standard temperature of capacitor performance test, wherein, time t represents the current time.

[0069] In the above embodiment, the polarization intensity calculation submodule realizes dynamic correction of the polarization capacitance through real-time correction of the double factors of the current and the temperature and the introduction of the current influence coefficient a and the first temperature influence coefficient b, specifically:

[0070] On the one hand, the current correction term reflects the enhancement effect of large current on polarization intensity. When the capacitor is charging and discharging, the current passing through the electrode-electrolyte interface will produce double-layer polarization (charge accumulation at the interface) and Faraday polarization (charge transfer caused by electrochemical reaction). The larger the current, the more charges passing through the interface per unit time, and the faster the accumulation speed of the polarization charge. Therefore, the polarization capacitance C p(t) at time t will increase with the increase of current. Within the rated current I rated range (I (t) ≤I rated ), the accumulation amount of polarization charge is approximately linearly related to the current, and after exceeding the rated current I rated , the polarization effect enters the nonlinear saturation region, but through normalization, it can be ensured that the correction term is within a reasonable range;

[0071] On the other hand, the first temperature correction term reflects the promotion effect of temperature rise on polarization dissipation. Temperature rise will accelerate the dissipation of polarization charge (enhanced thermal motion, charge is more likely to escape from the interface binding), so the polarization capacitance C p(t) at time t decreases with the increase of temperature, and vice versa. Temperature reduction will inhibit the dissipation of polarization charge, and the polarization capacitance C p(t) at time t increases. Within the working temperature range, the dissipation rate of polarization charge is approximately linearly related to temperature, and after exceeding the working temperature range, the performance of the capacitor will decrease sharply, but the present application corrects the difference to ensure that the correction term reflects the actual temperature deviation effect on polarization;

[0072] Therefore, the model combines physical mechanism and experimental calibration to realize high-precision quantification of the polarization state.

[0073] Among them, the current influence coefficient a and the first temperature influence coefficient b are empirical coefficients calibrated by experiments, and need to be determined in combination with the specific type of capacitor (such as super capacitor, electrolytic capacitor) and application scenario, the steps are as follows:

[0074] For the current influence coefficient a: set the fixed temperature to (25℃), and set different charging and discharging currents I (t) (such as 0.1I rated , 0.5I rated , I rated ), and measure the polarization capacitance after stabilization under each current using an LCR tester. Draw the relationship curve of polarization capacitance and , and obtain the current influence coefficient a (slope) through linear fitting. Example: if the current increases from 0 to I rated , C p increases from C p0 to 1.1C p0 ​If current I = 0.1 A, then current influence coefficient a = 0.1.

[0075] For the first temperature influence coefficient b: the fixed current is 0 (to avoid current interference), different capacitor temperatures T are set (t) (such as -10℃, 0℃, 25℃, 40℃, 60℃), at each temperature, the C p value after stabilization is measured by an LCR tester, a C p vs. curve is drawn, and the first temperature influence coefficient b (the absolute value of the slope) is obtained by linear fitting. Example: if the temperature rises from 25℃ to 60℃, C p drops from C p0 to 0.93 C p0 , then the first temperature influence coefficient b = 0.07 / 35 = 0.002 (for every 1℃ rise, C p drops by 0.2%).

[0076] In summary, the polarization strength calculation submodule in this embodiment realizes dynamic estimation of the polarization capacitance by coupling the effects of current and temperature, provides accurate polarization state input for subsequent internal resistance calculation, state of charge update and current control, and improves the adaptability of the system to changes in working conditions.

[0077] In the embodiment two, based on the embodiment two, the calculation logic of the equivalent internal resistance calculation submodule provided by the embodiment of the application is:

[0078] Based on the polarization capacitance output by the polarization strength calculation submodule, a second ratio of the polarization capacitance to the initial polarization capacitance is calculated, and under the influence of the product of the polarization capacitance influence coefficient calibrated in the experiment, a polarization correction term of the polarization effect on the internal resistance blocking effect is calculated.

[0079] Based on the temperature deviation calculated by the polarization strength calculation submodule, a second temperature correction term of the temperature effect on the ohmic loss under the influence of the product of the second temperature influence coefficient calibrated in the experiment is calculated.

[0080] The fitting results of the polarization correction term and the second temperature correction term are coupled, multiplied by the reference equivalent series resistance, and the real-time equivalent series resistance is output.

[0081] The calculation formula of the real-time equivalent series resistance is as follows:

[0082] ;

[0083] In the formula:

[0084] ESR (t) is the equivalent series resistance at time t, reflecting the dynamic change of the capacitor internal resistance, ESR0 is the reference equivalent series resistance at the reference temperature, indicating the capacitor internal resistance at the reference temperature Tref The internal resistance at a temperature below 25°C can be measured through factory testing. c is the second temperature influence coefficient, determined experimentally (e.g., 0.005, meaning that for every 1°C increase in temperature, the ESR increases). (t) Increase by 0.5%), the specific calculation formula is as follows: And in the formula, Reflects the direction of ESR change. The sign of c reflects the direction of temperature change, and the correlation between the ESR change direction and the temperature change direction (positive / negative correlation) is also represented by c. d is the polarization capacitance influence coefficient, which is also an empirical coefficient calibrated experimentally. The specific calibration process involves fixing the temperature (25℃) and setting different charging and discharging currents I. (t) (e.g., 0.1I) rated 0.5I rated I rated ), for each current, first use Calculate the polarization capacitance C at time t. p(t) Then, use an LCR meter to measure the stabilized ESR value and plot the ESR versus... The relationship curve is used to obtain the polarization capacitance influence coefficient d (slope) through linear fitting. Example: If C p(t) From C p0 Increase to 1.1C p0 When ESR increases from ESR0 to 1.02ESR0, the polarization capacitance influence coefficient d = 0.02 (for every 1% increase in C). p ESR increased by 0.02%.

[0085] In the above embodiments, the equivalent internal resistance calculation submodule introduces the relative value of the polarization capacitance. and temperature deviation term This enables real-time dynamic estimation of internal resistance; among which, the polarization correction term... The increase in internal resistance caused by enhanced polarization was captured, and the second temperature correction term was used. The model distinguishes between the decreasing internal resistance in the mid-temperature region and the increasing internal resistance in the high-temperature region, making the model more closely reflect actual physical changes.

[0086] The calibration method for the second temperature influence coefficient c is as follows: Under zero current conditions, the ESR values ​​at different temperatures are measured, and c is obtained through linear fitting; the calibration method for the polarization capacitance influence coefficient d is as follows:

[0087] At a constant temperature, different polarization capacitances are obtained by changing the current, and the corresponding ESR is measured. The coefficient d is obtained through fitting; the sign and magnitude of the coefficient reflect the sensitivity and direction of the internal resistance to temperature and polarization changes, and need to be determined through experimental data. Furthermore, the sign of the second temperature influence coefficient c is a quantitative result of the physical characteristics of the capacitor's internal resistance, and its relationship with the effect of temperature on ESR can be summarized as follows:

[0088] Capacitor temperature T at time t (t) Reference temperature T ref When: the second temperature influence coefficient c is negative, the temperature decreases → the ESR increases, the second temperature correction term is positive;

[0089] Reference temperature T ref Capacitor temperature T at time t (t) When: the second temperature influence coefficient c is negative, the temperature decreases → the ESR increases, the second temperature correction term is negative;

[0090] Capacitor temperature T at time t (t) When: the second temperature influence coefficient c is positive, the temperature increases → the ESR increases, the second temperature correction term is positive.

[0091] Based on the above, it can be understood that the sign of the second temperature influence coefficient c is not fixed, but changes with the temperature interval, and its essence is to convert the temperature sensitivity of ESR into a calculable mathematical coefficient, to ensure that the internal resistance loss change at different temperatures can be accurately reflected.

[0092] Further, the first temperature influence coefficient b and the second temperature influence coefficient c are both temperature influence coefficients, but the action object of the first temperature influence coefficient b is the storage capacity of the polarization charge (the polarization capacitance C p(t) at time t), which reflects the logic of “temperature → polarization dissipation → capacitance change”; the action object of the second temperature influence coefficient c is the inherent resistance value of ohmic resistance (such as the metal resistance of the electrode and the ion resistance of the electrolyte), which reflects the logic of “temperature → material resistance characteristic → internal resistance change”. The two belong to different physical processes, so different coefficients must be used for quantification.

[0093] In summary, the equivalent internal resistance calculation sub-module of the embodiment realizes high-precision dynamic estimation of the internal resistance of the capacitor through a two-factor coupling model, provides a key parameter for loss compensation in state of charge updating, and also provides a basis for current limiting and thermal management in adaptive control.

[0094] In the embodiment three, the calculation logic of the state of charge updating sub-module provided by the embodiment of the application is:

[0095] Based on the charging and discharging current collected by the current sensor, the proportion relationship of the charging and discharging current multiplied by the pre-set control period relative to the total capacitance is calculated, and the ideal charging and discharging amount at no loss is obtained;

[0096] The internal resistance loss energy is obtained based on the product of the equivalent series resistance, the charging and discharging current and the control period, and the internal resistance loss energy is divided by the product of the rated voltage and the total capacitance to obtain the internal resistance loss.

[0097] The state of charge at the last time, the ideal charging and discharging capacity and the internal resistance loss are dynamically coupled to output the state of charge at the next time after updating.

[0098] The calculation formula of the real-time state of charge after updating is as follows:

[0099] C total(t) =C0+C p(t) ;

[0100] ;

[0101] In the formula:

[0102] SOC (t+1) is the state of charge at t+1, reflecting the proportion of the remaining capacity of the capacitor to the rated capacity, SOC (t) is the state of charge at t, specifically representing the SOC value at the last time, obtained from historical data or initial measurement, and Δt is the control period, such as the sampling interval set by the system, which is 10 ms, i.e. one period, which can be set according to the specific control needs, C total(t) is the total capacitance, the sum of the static capacitance and the polarization capacitance, reflecting the actual energy storage capacity of the capacitor, C0 is the static capacitance, V rated is the rated voltage, representing the maximum voltage of the capacitor, determined by the product specification.

[0103] In the above embodiment, the calculation of the state of charge updating submodule is a real-time calculation model of the battery / capacitor state of charge, which essentially couples the "ideal charging and discharging capacity" with the "actual internal resistance loss" to dynamically correct the state of charge; this model not only considers the ideal charging and discharging capacity, but also compensates for the energy loss caused by internal resistance heating, significantly improving the accuracy of state of charge estimation, especially in high temperature and large current conditions, and providing a core state signal for closed-loop feedback of charging and discharging strategy:

[0104] Ideal charging and discharging capacity provides "energy change without loss", so that SOC (t) increases when charging (I (t+1) >0), and SOC (t) decreases when discharging (I (t+1) <0), providing a benchmark for actual SOC (t+1) updating;

[0105] Internal resistance loss correction term : compensate the deviation of "ideal model ignoring loss" - when the current or internal resistance increases, the loss correction term increases, and the SOC (t+1) decreases significantly (such as when the large current is 150A, the loss correction term increases from 0.05 to 0.13), avoiding the risk of "theoretical SOC (t+1) high but actual energy low" over-discharge.

[0106] Wherein, the static capacitance C0 is a capacitor inherent parameter, which can be obtained from the factory specification book or offline measurement; the total capacitance C total(t) changes dynamically with the polarization state, reflecting the time-varying nature of the actual energy storage capacity of the capacitor; the internal resistance loss term converts the Joule heat loss into an equivalent reduction of the state of charge, realizing the closed-loop correction in the energy level; the control period Δt needs to be set according to the system response speed and the calculation load.

[0107] In summary, the state of charge updating sub-module of the embodiment realizes real-time high-precision estimation of the state of charge through dynamic total capacitance and internal resistance loss compensation, provides accurate state feedback for the adaptive control module, and is the core link of the "perception-computation-control" closed loop.

[0108] In the fourth embodiment, the adaptive control module provided by the embodiment of the application comprises:

[0109] a current adjusting unit for adjusting the duty cycle of the charging and discharging current through a PWM signal;

[0110] a closed-loop feedback unit for adjusting the current influence coefficient based on the state of charge output by the state of charge updating sub-module:

[0111] When the state of charge is in the low state of charge interval, the electrode surface charge density is low, the polarization effect is weak, and the current influence coefficient is 0.001;

[0112] When the state of charge is in the medium state of charge interval, the electrode surface charge density is moderate, the polarization effect increases linearly with the state of charge, and the current influence coefficient is 0.005;

[0113] When the state of charge is in the high state of charge interval, the electrode surface charge density is close to saturation, the polarization effect is sharply enhanced, and the current influence coefficient is 0.01;

[0114] Then, the adjusted current influence coefficient a is fed back to the polarization intensity calculation sub-module to update the polarization capacitance at the next time, and the current sampling strategy at the next time is dynamically adjusted based on the polarization capacitance at the next time, and the current sampling strategy is specifically:

[0115] If the polarization capacitance at the next moment is greater than the initial polarization capacitance × 1.2 (strong polarization), it indicates that the polarization loss is too large, and the charging and discharging current needs to be reduced (e.g., from 10A to 5A) to avoid overheating and capacity decay.

[0116] If the polarization capacitance at the next moment is less than the initial polarization capacitance × 0.8 (weak polarization), it indicates that the polarization loss is small, and the charging and discharging current needs to be increased (e.g., from 5A to 10A) to improve the charging and discharging efficiency.

[0117] If the initial polarization capacitance × 0.8 ≤ the polarization capacitance at the next moment ≤ the initial polarization capacitance × 1.2 (medium polarization), then the current charging and discharging current is maintained to balance efficiency and loss.

[0118] In the above embodiments, the adaptive control module realizes the adaptive adjustment of charging and discharging current through a closed-loop feedback mechanism of "state estimation → coefficient adjustment → strategy decision"; the current influence coefficient α is dynamically adjusted according to the SOC partition, reflecting the difference in polarization sensitivity in different SOC intervals; the current sampling strategy, based on the predicted polarization state, realizes the forward-looking adjustment of the current magnitude, achieving a dynamic balance between efficiency and loss.

[0119] The current influence coefficient 'a' is set according to the SOC range as follows:

[0120] SOC (t+1) <30% (lower range): a=0.001;

[0121] 30%≤SOC (t+1) ≤80% (middle interval): a=0.005;

[0122] SOC (t+1) >80% (high interval) a=0.01.

[0123] This setting depends on different SOCs (t+1) The physical relationship between the surface charge density and polarization intensity of the lower electrode was obtained through experimental calibration and optimization. The current adjustment unit achieves smooth current regulation through a PWM controller, and the response time should be less than the control period Δt.

[0124] In summary, the adaptive control module of this embodiment utilizes SOC (t+1) Feedback and polarization state prediction enable intelligent dynamic control of charging and discharging current, which not only improves energy transmission efficiency but also effectively suppresses polarization loss and heat accumulation, extending the service life of the capacitor.

[0125] Example 6: Based on Example 5, the security protection module provided in this embodiment of the invention includes:

[0126] Overcurrent protection unit, when the current collected by the current sensing unit exceeds 1.5 times of the rated current, triggering the relay to cut off the circuit;

[0127] Over-temperature protection unit, when the core temperature collected by the temperature sensing unit exceeds 60℃, starting the cooling fan and reducing the charge and discharge current;

[0128] Over-voltage protection unit, when the voltage collected by the voltage sensing unit exceeds 1.1 times of the rated voltage, stopping charging and starting the discharge circuit.

[0129] In the above embodiment, the safety protection module serves as the hardware protection layer of the system, providing multiple abnormal state protection; the overcurrent protection prevents device damage caused by short circuit or overload; the over-temperature protection prevents thermal runaway through forced air cooling and load reduction operation; the over-voltage protection avoids breakdown risk caused by over-limit charging voltage; each protection unit works independently, responds quickly, and forms a "soft and hard combined" safety system with the software control layer.

[0130] Among them, the overcurrent protection threshold is set to 1.5 times of the rated current, taking into account fault recognition and misoperation avoidance; the over-temperature protection threshold is set to 60℃, based on the thermal tolerance characteristics of capacitor materials; the over-voltage protection threshold is set to 1.1 times of the rated voltage, taking into account a certain voltage fluctuation margin; the protection action execution device (such as relay, contactor, cooling fan) needs to meet the response speed and load capacity requirements, and usually industrial-grade components are selected.

[0131] In summary, the safety protection module of the embodiment provides a reliable safety barrier for the capacitor energy storage system through multiple hardware protection mechanisms, ensuring that the system can still operate safely under extreme or fault conditions, and improving the robustness and usability of the overall system.

[0132] Although the present application is disclosed as above, the present application is not limited to this. Any person skilled in the art, without departing from the spirit and scope of the present application, can make various changes and modifications, therefore the protection scope of the present application should be limited by the scope defined by the claims.

Claims

1. An adaptive charge and discharge control system for a capacitor energy storage system, characterized in that, Include: The status sensing module is configured to collect status data of the capacitor in real time, including charging and discharging current, core temperature and terminal voltage data, through current sensor, temperature sensor and voltage sensor. The dynamic calculation module is configured to integrate the state acquisition data collected by the state perception module and calculate the polarization capacitance, equivalent series resistance and state of charge of the capacitor through a dynamic quantization algorithm. The adaptive control module is configured to adjust the magnitude and direction of the charging and discharging current through a closed-loop feedback algorithm based on the polarization capacitance, the equivalent series resistance, and the state of charge output by the dynamic calculation module. The safety protection module is configured to trigger a hardware protection mechanism to cut off the charging and discharging circuit based on the overcurrent, overtemperature, and overvoltage data collected by the state sensing module. The dynamic calculation module of the adaptive charge-discharge control system for capacitor energy storage systems includes: The polarization intensity calculation submodule is configured to combine real-time current and temperature data, and through coupled calculation of relative current intensity and temperature deviation, quantify the polarization state of the capacitor and output the polarization capacitance. The equivalent internal resistance calculation submodule is configured to quantify the internal resistance loss of the capacitor and output the equivalent series resistance based on the polarization capacitance and combined with the temperature deviation, through nonlinear fitting of the polarization relative value and temperature range. The state of charge update submodule is configured to integrate ideal charge and discharge quantities and internal resistance losses, and predict the remaining state of charge of the capacitor at the next moment through a dynamic compensation algorithm.

2. The adaptive charging and discharging control system for a capacitor energy storage system according to claim 1, characterized in that, The calculation logic of the polarization intensity calculation submodule is as follows: The current sensor collects real-time charging and discharging current, calculates the first ratio of charging and discharging current to rated current, and calculates the current correction term for polarization impact intensity under the influence of the product of the experimentally calibrated current influence coefficient. The capacitor temperature is collected in real time by a temperature sensor, and the temperature deviation between the capacitor temperature and the preset reference temperature is calculated. Under the influence of the first temperature influence coefficient calibrated in the experiment, the first temperature correction term for the polarization dissipation capability is calculated. The current correction term and the first temperature correction term are weighted and coupled together, and multiplied by the initial polarization capacitance to output the real-time polarization capacitance.

3. The adaptive charge and discharge control system for a capacitor energy storage system according to claim 2, characterized in that, The calculation logic of the equivalent internal resistance calculation submodule is as follows: Based on the polarization capacitance output by the polarization intensity calculation submodule, the second ratio of the polarization capacitance to the initial polarization capacitance is calculated, and the polarization correction term for the internal resistance blocking effect is calculated under the influence of the product of the polarization capacitance influence coefficient calibrated in the experiment. The temperature deviation is calculated based on the polarization intensity calculation submodule, and the second temperature correction term for the effect of temperature on ohmic loss is calculated under the influence of the temperature deviation multiplied by the experimentally calibrated second temperature influence coefficient. The fitting results of the polarization correction term and the second temperature correction term are coupled and multiplied with the reference equivalent series resistance to output the real-time equivalent series resistance.

4. The adaptive charge and discharge control system for a capacitor energy storage system according to claim 3, characterized in that, The calculation logic of the state of charge update submodule is as follows: Based on the charging and discharging current collected by the current sensor, the ratio of the charging and discharging current multiplied by the preset control cycle to the total capacitance is calculated, and the ideal charging and discharging amount without loss is obtained. The internal resistance loss energy is obtained by multiplying the equivalent series resistance, the charging and discharging current, and the control period. The internal resistance loss energy is then divided by the product of the rated voltage and the total capacitance to obtain the internal resistance loss. The state of charge at the previous moment, the ideal charge / discharge quantity, and the internal resistance loss are dynamically coupled to output the updated state of charge at the next moment.

5. The adaptive charge and discharge control system for a capacitor energy storage system according to claim 4, characterized in that, The adaptive control module includes: The current adjustment unit adjusts the duty cycle of the charging and discharging current via a PWM signal; The closed-loop feedback unit adjusts the current influence coefficient based on the state of charge output by the state of charge update submodule, and feeds it back to the polarization intensity calculation submodule to update and calculate the polarization capacitance at the next moment. Based on the polarization capacitance at the next moment, the unit dynamically adjusts the current sampling strategy at the next moment.

6. The adaptive charge and discharge control system for a capacitor energy storage system according to claim 5, characterized in that, The adjustment of the current influence coefficient is based on the polarization characteristics of a pre-set state-of-charge range, specifically as follows: When the state of charge is in the low state of charge range, it reflects that the charge density on the electrode surface is low and the polarization effect is weak, and the current influence coefficient is taken as 0.

001. When the state of charge is in the medium state of charge range, it reflects that the charge density on the electrode surface is moderate, and the polarization effect increases linearly with the state of charge. The current influence coefficient is taken as 0.

005. When the state of charge is in the high state of charge range, it reflects that the charge density on the electrode surface is close to saturation, and the polarization effect is sharply enhanced. The current influence coefficient is taken as 0.

01.

7. The adaptive charge and discharge control system for a capacitor energy storage system according to claim 5, characterized in that, The current sampling strategy is specifically as follows: If the polarization capacitance at the next moment is greater than the initial polarization capacitance × 1.2, it indicates that the polarization loss is too large, and the charging and discharging current needs to be reduced to avoid overheating and capacity decay. If the polarization capacitance at the next moment is less than the initial polarization capacitance × 0.8, it indicates that the polarization loss is small, and the charging and discharging current needs to be increased to improve the charging and discharging efficiency. If the initial polarization capacitance × 0.8 ≤ the polarization capacitance at the next moment ≤ the initial polarization capacitance × 1.2, then the current charging and discharging current is maintained to balance efficiency and loss.

8. The adaptive charge and discharge control system for a capacitor energy storage system according to claim 1, characterized in that, The security protection module includes: The overcurrent protection unit triggers a relay to cut off the circuit when the current collected by the current sensing unit exceeds 1.5 times the rated current. The over-temperature protection unit activates the cooling fan and reduces the charging and discharging current when the core temperature collected by the temperature sensing unit exceeds 60°C. The overvoltage protection unit stops charging and starts the discharge circuit when the voltage collected by the voltage sensing unit exceeds 1.1 times the rated voltage.

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