Light storage and charging integrated control method and system, product and medium

Abstract

The invention discloses a light storage and charging integrated control method and system, a product and a medium. The method comprises the steps that under the condition that a composite disturbance state is detected, the increasing rate of photovoltaic power is analyzed to predict imminent power imbalance, and a basic feed-forward absorption power value is calculated; meanwhile, a feedback regulation power value is calculated according to the real-time deviation of the direct-current bus voltage. And adding the feedforward value and the feedback value to obtain a total absorption power instruction. The total power is used for controlling the super capacitor bank bidirectional converter to perform power absorption to cope with voltage fluctuation. And when the bus voltage falls below the safety threshold and is kept stable for a period of time, the conventional control mode is recovered. By implementing the technical scheme provided by the invention, the stability of the direct-current bus voltage under specific composite disturbance is enhanced.

Description

Technical Field

[0001] This application relates to the field of power distribution, and in particular, to a photovoltaic-storage-charging integrated control method, system, product, and medium. Background Art

[0002] With the gradual popularization of electric vehicles, their charging demand has gradually increased. Industrial parks or urban charging stations utilize idle carports to install photovoltaic systems, which are then combined with energy storage systems and charging pile systems to form a photovoltaic-storage-charging integrated charging station system, which can actively respond to the call for energy conservation and emission reduction and achieve the "dual carbon" goal.

[0003] The photovoltaic-storage-charging integrated charging station combines photovoltaic power generation, energy storage systems, and charging equipment, enabling efficient utilization of clean energy. In existing photovoltaic-storage-charging integrated charging stations, energy storage batteries share a DC bus with a photovoltaic system of a DC / DC bidirectional DC converter and a DC / DC unidirectional conversion module, and a DC / DC high-power vehicle bidirectional charging system. The DC bus is then connected to an external AC grid through a DC / AC power electronic bidirectional conversion device.

[0004] Currently, in related technologies, maintaining the stability of the DC bus voltage mainly relies on feedback control based on voltage deviation. The control system monitors the bus voltage in real time and calculates adjustment commands through controllers such as proportional-integral (PI). This command usually acts on the battery energy storage system to control its power converter (PCS) to absorb or emit power to compensate for power imbalance within the system, thereby maintaining the voltage near the target value. This method is a conventional means for voltage control in current photovoltaic-storage-charging systems.

[0005] However, when the photovoltaic power grows rapidly and the battery energy storage approaches saturation, the battery energy storage cannot effectively absorb excess power due to saturation, resulting in the inability to promptly suppress the rapidly accumulating power surplus, which may cause a rapid and large overshoot of the DC bus voltage, thus seriously threatening system stability. Summary of the Invention

[0006] This application provides a photovoltaic-storage-charging integrated control method, system, product, and medium, which enhances the stability of the DC bus voltage under specific combined disturbances.

[0007] In a first aspect of this application, a photovoltaic-storage-charging integrated control method is provided, and the method includes: Obtain the photovoltaic power generation, the state of charge of the energy storage device, and the DC bus voltage; in the case of detecting a composite disturbance state, calculate the power imbalance growth rate of the DC bus according to the power generation growth rate of the photovoltaic power generation within a preset unit time and a preset conversion function; based on the power imbalance growth rate, apply a preset time accumulation algorithm to calculate the basic feed-forward absorption power value; calculate the absolute value of the voltage deviation to a preset power, and multiply it by the voltage deviation and a preset gain coefficient to obtain the feedback regulation power value; add the basic feed-forward absorption power value and the feedback regulation power value to obtain the total absorption power value, and control the bidirectional converter of the supercapacitor bank to absorb power using the total absorption power value; when the DC bus voltage drops below the first DC bus voltage safety threshold and lasts for a preset unit time, restore the bidirectional converter to the preset conventional control mode.

[0008] In the above embodiment, after detecting a specific composite disturbance state, by calculating the feed-forward absorption power value that can predict the power shock and combining the feedback regulation power value that corrects the current voltage deviation, a total absorption power command is generated for the supercapacitor bank to perform power absorption. The coordination of this feed-forward prediction and feedback correction ensures that even when the energy storage battery is limited, the supercapacitor can absorb excess power in a timely and accurate manner, and its dynamic power response suppresses the severe fluctuation of the DC bus voltage, thereby improving the voltage stability.

[0009] Combined with some embodiments of the first aspect, in some embodiments, based on the power imbalance growth rate, applying a preset time accumulation algorithm to calculate the basic feed-forward absorption power value specifically includes: Based on the power imbalance growth rate, apply a preset time accumulation algorithm to calculate the preliminary feed-forward absorption power value; monitor the real-time charging power of the charging pile connected to the DC bus and having controllability; in the case where the real-time charging power of the charging pile is greater than zero, subtract the reduced charging power value from the preliminary feed-forward absorption power value to obtain the basic feed-forward absorption power value.

[0010] In the above embodiment, after calculating the preliminary feed-forward absorption power, by monitoring the real-time charging power of the charging pile, when it is detected that the charging pile is charging (i.e., has the ability to absorb power), a reduced charging power value planned to be shared by the charging pile is subtracted from the total preliminary absorption demand, so as to calculate the basic feed-forward absorption power value that needs to be borne by the supercapacitor. The system no longer relies solely on the supercapacitor, but allocates part of the power absorption task to the charging pile, making more full use of the adjustable resources existing in the system, and improving the flexibility and efficiency of the overall power balance.

[0011] Combined with some embodiments of the first aspect, in some embodiments, before subtracting the reduced charging power value from the preliminary feed-forward absorption power value to obtain the basic feed-forward absorption power value, it further includes: Send a power reduction intention query command to the charging pile; in the case that a preset confirmation command is not received within a unit time, confirm the preliminary feedforward absorption power value as the basic feedforward absorption power value.

[0012] In the above embodiment, by introducing a necessary communication confirmation link before planning to use the charging pile to cooperate in absorbing power, if the confirmation command is not received within the specified time, the charging pile will no longer be used to share the power, and the preliminary feedforward absorption power value without reduction will be used as the final basic feedforward value. This avoids the wrong reduction of the absorption command of the supercapacitor due to the actual unavailability or non-response of the charging pile, thereby ensuring that sufficient power absorption can be executed under the condition of uncertain cooperative resources, and maintaining the robustness and safety of the control strategy.

[0013] Combined with some embodiments of the first aspect, in some embodiments, add the basic feedforward absorption power value and the feedback regulation power value to obtain the total absorption power value, and control the supercapacitor bank bidirectional converter to use the total absorption power value for power absorption, specifically including: Add the basic feedforward absorption power value and the feedback regulation power value to obtain the initial total absorption power command; obtain the real-time state of charge of the energy storage device; determine whether the real-time state of charge is lower than a preset auxiliary absorption safety state threshold; if so, allocate the total absorption power value to a first absorption power value for the supercapacitor bank bidirectional converter and a second absorption power value for the energy storage device bidirectional converter; if not, allocate the total absorption power value entirely as the first absorption power value and the second absorption power value is zero; respectively control the supercapacitor bank bidirectional converter to perform power absorption according to the first absorption power value, and control the energy storage device bidirectional converter to perform power absorption according to the second absorption power value.

[0014] In the above embodiment, by introducing the judgment of the real-time state of charge of the energy storage device, check whether the SOC of the energy storage device is lower than a preset safety threshold. If it is lower than this threshold, it indicates that the energy storage device still has a safe absorption capacity, and the total absorption power will be split into two parts and respectively commanded to the supercapacitor and the energy storage device to jointly execute the absorption task. On the contrary, if the SOC is equal to or higher than the threshold, it means that the energy storage device is not suitable to continue absorbing power (it may be close to full charge or there are risks), and at this time the system will only allocate all the absorption tasks to the supercapacitor to undertake. This ensures that the energy storage device is only called for auxiliary absorption when its state permits, thereby effectively avoiding potential safety problems such as overcharging that may be caused by the energy storage device absorbing excessive power, and improving the safety of the operation of the entire hybrid energy storage system.

[0015] In combination with some embodiments of the first aspect, in some embodiments, after separately controlling the bidirectional converter of the supercapacitor bank to absorb power at a first absorption power value and controlling the bidirectional converter of the energy storage device to absorb power at a second absorption power value, it further includes: Real-time judge whether the real-time state of charge reaches or exceeds the auxiliary absorption safety state threshold; if so, correct the second absorption power value to zero and allocate the total absorption power value entirely to the first absorption power value.

[0016] In the above embodiments, after the supercapacitor and the energy storage device start to absorb power according to the allocated power values, the state of charge of the energy storage device is continuously and real-time judged. Once it is found that the real-time SOC of the energy storage device reaches or exceeds the preset safety threshold, corrective measures will be immediately taken. The second absorption power value allocated to the energy storage device will be corrected to zero, and the total absorption power value originally planned to be borne by both will be entirely borne by the supercapacitor. This ensures that even if the state of the energy storage device changes during the absorption task and touches the safety boundary, the charging operation of the energy storage device can be immediately stopped, preventing the overcharging risk of the energy storage device and improving the operation safety of the hybrid energy storage system under dynamic working conditions.

[0017] In combination with some embodiments of the first aspect, in some embodiments, after adding the basic feedforward absorption power value and the feedback regulation power value to obtain the total absorption power value and controlling the bidirectional converter of the supercapacitor bank to use the total absorption power value to absorb power, it further includes: Monitor whether the DC bus voltage exceeds the preset second DC bus voltage safety threshold; if so, control the bidirectional converter of the supercapacitor bank to absorb power at its preset peak power value; control the bidirectional converter of the standby load to perform absorption operation at the peak power value.

[0018] In the above embodiments, by continuously monitoring the DC bus voltage, once it is found that the voltage exceeds the preset higher second safety threshold, it is determined that there is a serious overvoltage risk. At this time, control the bidirectional converter of the supercapacitor bank and the bidirectional converter of the standby load to absorb power at their respective preset maximum peak power values. This enables the system to absorb the instantaneous high power that causes the abnormal voltage spike, thereby pulling the bus voltage back to the safe range and effectively preventing damage to system equipment or triggering chain failures due to extreme overvoltage.

[0019] In combination with some embodiments of the first aspect, in some embodiments, after calculating the absolute value of the voltage deviation value to a preset power and multiplying it by the voltage deviation value and a preset gain coefficient to obtain the feedback regulation power value, it further includes: Obtain the internal temperature value of the supercapacitor bank; if the temperature value exceeds the preset temperature warning threshold, reduce the feedback regulation power value.

[0020] In the above embodiments, by obtaining the internal temperature of the supercapacitor bank. If the temperature value exceeds the preset warning threshold, it indicates that the supercapacitor may be at risk of overheating. The system will actively reduce (or limit) the feedback regulation power value, limit its working intensity when the supercapacitor temperature is high, thereby avoiding the risk of performance degradation or damage caused by overheating, and improving the operating safety and service life of the supercapacitor bank.

[0021] In a second aspect, an embodiment of the present application provides an integrated photovoltaic energy storage charging control system, which includes: one or more processors and a memory; the memory is coupled to the one or more processors, and the memory is used to store computer program code, and the computer program code includes computer instructions. The one or more processors call the computer instructions to cause the integrated photovoltaic energy storage charging control system to execute the method described in the first aspect and any possible implementation manner in the first aspect.

[0022] In a third aspect, an embodiment of the present application provides a computer program product containing instructions. When the computer program product runs on the integrated photovoltaic energy storage charging control system, it causes the integrated photovoltaic energy storage charging control system to execute the method described in the first aspect and any possible implementation manner in the first aspect.

[0023] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium including instructions. When the instructions run on the integrated photovoltaic energy storage charging control system, it causes the integrated photovoltaic energy storage charging control system to execute the method described in the first aspect and any possible implementation manner in the first aspect.

[0024] It can be understood that the integrated photovoltaic energy storage charging control system provided in the second aspect, the computer program product provided in the third aspect, and the computer storage medium provided in the fourth aspect are all used to execute the integrated photovoltaic energy storage charging control system provided in the embodiments of the present application. Therefore, the beneficial effects that can be achieved can refer to the beneficial effects in the corresponding method, which will not be elaborated here.

[0025] One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages: 1. In the present application, after detecting a specific composite disturbance state, by calculating the feedforward absorption power value that can predict the power impact, and combining the feedback regulation power value that corrects the current voltage deviation, a total absorption power command is generated to execute power absorption for the supercapacitor bank. The cooperation of this feedforward prediction and feedback correction ensures that even when the energy storage battery is limited, the supercapacitor can absorb excess power in a timely and accurate manner, and its dynamic power response suppresses the severe fluctuation of the DC bus voltage, thereby improving the voltage stability.

[0026] 2. After calculating the preliminary feedforward absorption power, this application monitors the real-time charging power of the charging pile. When it detects that the charging pile is charging (i.e., has the ability to absorb power), a reduced charging power value planned to be shared by the charging pile is subtracted from the total preliminary absorption demand, thereby calculating the basic feedforward absorption power value that needs to be borne by the supercapacitor. This enables the system to no longer rely solely on the supercapacitor, but instead allocates part of the power absorption task to the charging pile, making more full use of the adjustable resources already available in the system and improving the flexibility and efficiency of the overall power balance.

[0027] 3. Before planning to utilize the charging pile to cooperate in absorbing power, this application introduces a necessary communication confirmation link. If the confirmation instruction is not received within the specified time, the charging pile will no longer be used to share the power, and the un-reduced preliminary feedforward absorption power value will be used as the final basic feedforward value. This avoids erroneously reducing the absorption instruction of the supercapacitor due to the actual unavailability or non-response of the charging pile, thereby ensuring that sufficient power absorption can be executed under uncertain cooperative resources and maintaining the robustness and safety of the control strategy. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic flowchart of an integrated photovoltaic energy storage charging control method in an embodiment of this application; Figure 2 is another schematic flowchart of an integrated photovoltaic energy storage charging control method in an embodiment of this application; Figure 3 is an exemplary hardware structure schematic diagram of an integrated photovoltaic energy storage charging control system in an embodiment of this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The terms used in the following embodiments of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. As used in the specification and appended claims of this application, the singular forms "a", "an", "the", "above", "said", "this" are also intended to include the plural forms, unless clearly indicated otherwise in the context. It should also be understood that the term "and / or" used in this application refers to and includes any and all possible combinations of one or more of the listed items.

[0030] Hereinafter, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as implying or indicating relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of this application, unless otherwise stated, the meaning of "a plurality" is two or more.

[0031] In the related art, the integrated photovoltaic energy storage and charging system generally adopts a feedback control strategy based on the DC bus voltage deviation. The control system monitors the voltage change, calculates and adjusts the power through a controller such as a PI controller, and mainly commands the battery energy storage system to charge and discharge to maintain the stability of the bus voltage. However, when facing a specific combined working condition where the photovoltaic power climbs sharply and the battery energy storage is close to saturation, the battery cannot effectively absorb a large amount of instantaneous excess power due to physical limitations. At this time, the control mechanism relying solely on voltage feedback has insufficient response speed and cannot timely respond to the rapidly accumulating power imbalance, easily leading to a severe overshoot of the DC bus voltage and endangering the system stability and equipment safety.

[0032] In the embodiment of the present application, a composite control method combining feedforward and feedback is proposed. This method can actively identify the combined disturbance state of sharp increase in photovoltaic power, battery saturation, and bus voltage overlimit. Calculate the feedback adjustment power based on the voltage deviation and the basic feedforward absorption power calculated according to the predicted power imbalance growth rate. The total absorption power command obtained by superimposing these two powers is preferentially and mainly executed by the supercapacitor bank with faster response. It not only proposes a method for power absorption under extreme disturbances, but also realizes the accurate control of the power absorbed by the supercapacitor through the cooperation of feedforward prediction and feedback correction. Moreover, when the battery is limited and the supercapacitor is used for power absorption, the dynamic response of its absorbed power more effectively suppresses the fluctuation of the real-time DC bus voltage, thereby improving the stability of the DC bus voltage.

[0033] Figure 1 It is a schematic flowchart of a process using the integrated photovoltaic energy storage and charging control method in the embodiment of the present application, including the following steps: S101. Obtain the photovoltaic power generation, the state of charge of the energy storage device, and the DC bus voltage.

[0034] Specifically, the core of obtaining the photovoltaic power generation lies in synchronously measuring the DC voltage and current on the photovoltaic side. Captured by the corresponding voltage and current sensors, the output signals go through necessary signal conditioning links such as filtering, amplification, and isolation, and then are converted into digital signals by the analog-to-digital converter (ADC). The controller receives these digitized voltage and current sample values, and calculates the instantaneous photovoltaic power generation in real time by performing the multiplication operation of power = voltage × current. If the system includes multiple maximum power point tracking (MPPT) units, the power of each unit needs to be calculated separately and then summed to obtain the total power.

[0035] Since the state of charge (SOC) of an energy storage device cannot be directly measured, indirect estimation methods must be relied upon. Common techniques include: the ampere-hour integration method that tracks the change in charge by precisely measuring the current flowing in and out of the battery and performing time integration; and the model method that establishes an equivalent circuit or an electrochemical model of the battery, combines data such as voltage, current, and temperature measured in real time, and uses state estimation algorithms (such as filter-based techniques) for dynamic prediction. In an actual system, a battery management system (BMS) usually integrates these estimation functions and reports the real-time SOC to the main controller via a communication bus (such as CAN or RS485).

[0036] The DC bus voltage is obtained by connecting a voltage sensor between the positive and negative poles of the bus. The sensor converts the bus voltage into a standard signal, which is processed by a signal conditioning circuit and digitized by an ADC, and then provided to the controller.

[0037] S102. In the case of detecting a combined disturbance state, calculate the power imbalance growth rate of the DC bus according to the power generation growth rate of the photovoltaic power generation within a preset unit time and a preset conversion function.

[0038] Specifically, first, while monitoring the photovoltaic power generation, the state of charge of the energy storage device, and the DC bus voltage, calculate the change rate of the photovoltaic power generation in real time, usually by performing numerical differentiation on consecutive sampled values. Calculating the power growth rate can capture the dynamic characteristics of system disturbances, especially the rapid changes in photovoltaic input, which are common sources of voltage stability problems.

[0039] Next, perform a combined disturbance state determination. The combined disturbance state requires three specific conditions to be met simultaneously: 1) The growth rate of the photovoltaic power exceeds a preset growth rate threshold; 2) The state of charge of the energy storage device reaches or exceeds its upper limit for safe operation; 3) The DC bus voltage has exceeded the set first DC bus voltage safety threshold. The purpose of performing the combined disturbance state determination is to lock in a power source with rapid growth, while the main buffer unit (energy storage battery) of the system is already unable to absorb (high SOC), and the consequence of power imbalance has initially manifested as an increase in the bus voltage. This can effectively avoid mis-triggering subsequent intervention measures in non-emergency situations (such as when the photovoltaic power is increasing but the energy storage has capacity to absorb, or when the voltage is high but the power change is stable), reducing unnecessary system disturbances.

[0040] After confirming entry into the combined disturbance state, calculate the power imbalance growth rate of the DC bus according to the currently confirmed excessive growth rate of the photovoltaic power and a preset conversion function.

[0041] The preset conversion function is used to convert the measured photovoltaic power growth rate into a mathematical relationship or model that more accurately reflects the actual power imbalance growth rate on the DC bus. It is obtained in advance based on the analysis of the energy transmission link, taking into account factors such as the energy conversion efficiency (such as MPPT or DC / DC converter efficiency) and line losses from the output of the photovoltaic module to the DC bus. It can be obtained through theoretical modeling, simulation analysis or actual system test calibration. The use of a preset conversion function (which may be a simple efficiency coefficient, or a more complex model considering multiple factors) is precisely to compensate for the influence of factors such as losses in the process of energy transmission from the photovoltaic array to the bus (such as converter efficiency), and aims to provide an estimate that is closer to the actual net power surplus growth rate on the bus.

[0042] S103: Based on the power imbalance growth rate, a preset time accumulation algorithm is applied to calculate a basic feedforward absorption power value.

[0043] The preset time accumulation algorithm is to perform time integration or discrete accumulation on the power imbalance growth rate within a unit time.

[0044] Specifically, after entering the compound disturbance state and calculating the aggravation speed of the power imbalance phenomenon on the DC bus (i.e., the power imbalance growth rate), the specific power value, i.e., the basic feedforward absorption power, is calculated using the power imbalance growth rate. The basic feedforward absorption power is to cope with the energy surplus caused by the continuous growth of power imbalance, and the amount of power absorbed by the relevant equipment needs to be prepared and controlled in advance.

[0045] This calculation process is completed by applying a preset time accumulation algorithm, which mainly converts the current instantaneous power imbalance growth rate into a power amount that is expected to be accumulated in a short, preset unit time in the future (also called the prediction time domain).

[0046] The power imbalance growth rate describes the speed at which the current imbalance is increasing, and it cannot be used directly as a power instruction. By multiplying it by a prediction time window, this speed information is converted into a predicted value of the accumulated power imbalance after a short period of time in the future. This predicted power value, namely the basic feedforward absorption power, is a specific and executable power instruction that can mobilize resources (such as supercapacitors) in advance to respond. Secondly, the intensity of the intervention is quantified, and the abstract growth rate is converted into a clear power target that needs to be absorbed or compensated, so that the size of the feedforward control effect has a basis. Compared with relying solely on feedback control (that is, waiting until the voltage shows a significant deviation before responding), it can intervene earlier and thus more effectively offset the impact of disturbances.

[0047] In some embodiments, the power measurement contains noise, or there are frequent small power fluctuations, and the directly calculated growth rate may have more fluctuations, resulting in frequent and small fluctuations in the feedforward instructions, increasing the number of unnecessary charge and discharge times of the supercapacitor.

[0048] Before calculating the growth rate, the original power imbalance signal can be low-pass filtered to remove high-frequency noise. Alternatively, after calculating the preliminary feedforward value, a deadband (only effective when the calculated value exceeds a certain threshold) or a rate limit (limiting the rate of change of the feedforward command) can be set to improve the smoothness of the feedforward control and avoid overreacting to small fluctuations. For example, the feedforward power value is only actually enabled or adjusted when the calculated growth rate exceeds a certain threshold for a period of time.

[0049] S104: Calculate the preset power of the absolute value of the voltage deviation value, and multiply it by the voltage deviation value and a preset gain coefficient to obtain a feedback regulation power value.

[0050] Specifically, first, the voltage deviation value is calculated. Voltage deviation value = current DC bus voltage - stable target voltage. This difference quantifies the specific degree and direction of the current voltage deviation from the target: a positive result indicates that the voltage is higher than the target, a negative result indicates that it is lower than the target, and zero indicates that the voltage just meets the requirements.

[0051] Secondly, the preset power of the absolute value of the voltage deviation is calculated. After the voltage deviation value is obtained, the absolute size of the deviation value is taken, and then a preset power operation is performed on the absolute value. The preset power here (we call it exponent n) is a parameter that can be preset according to the control requirements. The operation process is: calculate the nth power of the absolute value of the voltage deviation. This step is the key to introducing nonlinear feedback control. By adjusting the value of the exponent n (usually a number greater than or equal to 0 is selected), the response characteristics of the controller to voltage deviations of different sizes can be flexibly changed. For example: if the exponent n is equal to 0, as long as the deviation is not zero, the result of this calculation is constant to 1, and finally the feedback power and the voltage deviation are simply proportional (i.e. linear proportional control). If the exponent n is greater than 0 (for example, equal to 1, 1.5 or 2), then when the voltage deviation is large, the calculation result of this item will increase significantly; and when the deviation is small, the result is relatively small. In particular, when n is greater than 1, this amplification effect is more intense. It can achieve an intelligent response mode of "large deviation, strong adjustment; small deviation, fine tuning". When the voltage deviates seriously from the target, the control action is swift and powerful, striving to pull it back quickly; when the voltage approaches the target area, the adjustment force naturally weakens, which helps to stabilize smoothly and accurately near the target value, avoiding unnecessary oscillations around the target point or too frequent small adjustments, thereby improving the dynamic response speed and steady-state control accuracy.

[0052] Finally, combine the deviation direction and the gain coefficient to complete the calculation. Multiply the result of the nth power of the absolute value of the voltage deviation obtained in the previous step by the original voltage deviation value with a positive or negative sign calculated in the first step, and finally multiply by an adjustment factor called the preset gain coefficient to obtain the final feedback regulation power value.

[0053] In some embodiments of the present application, after calculating the basic feedback regulation power value based on the voltage deviation, it is also possible to further integrate the monitoring and protection of the operating state of key energy storage components (such as supercapacitor banks), especially considering their temperature limits. By dynamically adjusting the feedback power command, the aim is to ensure the safe operation of the supercapacitors and extend their effective working life.

[0054] Monitor the temperature inside the supercapacitor bank. This is usually accomplished by means of temperature sensors installed at key locations inside the supercapacitor. The sensors feed the real-time temperature data back to the controller. After receiving the temperature data, the controller compares it with a pre-set temperature warning threshold. This threshold is determined based on the safe operating range of the supercapacitor itself, the manufacturer's recommendations, and the overall safety requirements of the system, representing a critical temperature point. Once the monitored internal temperature exceeds this warning threshold, it is determined that the supercapacitor has an overheating risk and protection measures must be taken. At this time, the control system will actively reduce the previously calculated feedback regulation power value.

[0055] The operation of reducing the feedback regulation power value can be achieved in various specific ways. For example, set a safety power upper limit related to the temperature. When it is detected that the temperature threshold is exceeded, no matter how large the original calculated feedback power demand is, the actual command issued to the supercapacitor cannot exceed this safety upper limit. A smoother method can also be adopted to gradually reduce the power command to avoid impacting the system until the temperature drops back to the safe area.

[0056] Implementing this temperature protection step is crucial to ensure the safe operation of the supercapacitors themselves. When supercapacitors operate in a high-temperature environment, it will accelerate the aging of internal materials, which may lead to performance degradation (such as increased internal resistance and reduced capacitance). In severe cases, it may even trigger safety accidents such as thermal runaway. By actively limiting the working power when the temperature is detected to be too high, the heat generation of the supercapacitor can be directly reduced, preventing the temperature from rising further, thereby avoiding potential safety risks.

[0057] S105. Add the basic feedforward absorption power value and the feedback regulation power value to obtain the total absorption power value, and control the supercapacitor bank bidirectional converter to use the total absorption power value for power absorption.

[0058] Specifically, the basic feedforward absorbed power value and the feedback regulated power value are arithmetically added to obtain the total absorbed power value. This total absorbed power value represents the net power exchange amount executed by the supercapacitor at the current moment, comprehensively considering predictive compensation and closed-loop correction based on actual errors.

[0059] The last step is to execute control. The total absorbed power value will be used as the final power command and sent to the bidirectional converter (i.e., the power control system) of the supercapacitor bank. The converter will control the power flow according to the total absorbed power value, controlling the supercapacitor to absorb the corresponding power (charge) from the DC bus. The fast control loop inside the converter ensures that the actually executed power can closely follow the command.

[0060] The total absorbed power value combines feedforward control and feedback control. Feedforward control is fast and forward-looking, and can intervene at the initial stage of the disturbance to suppress the peak value of voltage fluctuation, but there may be calculation errors or it may not be able to cope with unforeseen disturbances. Although feedback control has hysteresis (it needs to wait for the error to appear), it is based on actual measurement, has robustness and accuracy, and can eliminate errors. Adding the two together enables the system to utilize the feedforward component to quickly respond to known or predictable disturbances, and at the same time utilize the feedback component to correct residual errors and cope with unknown disturbances, enhancing the accuracy of the supercapacitor's absorbed power under various complex working conditions, improving the precision of DC bus voltage control, and better enhancing the stability of the DC bus voltage.

[0061] In some embodiments of the present application, in addition to the power control strategy combining feedforward and feedback, an emergency protection mechanism for extreme overvoltage situations can be set up. By monitoring a higher voltage threshold and simultaneously enabling the maximum absorption capabilities of the supercapacitor and the standby load, the effect of providing ultimate safety protection for the DC bus can be achieved.

[0062] While continuously monitoring the DC bus voltage, the control system will compare the DC bus voltage with a preset second DC bus voltage safety threshold. The second DC bus voltage safety threshold is set significantly higher than the first DC bus voltage safety threshold, representing a voltage upper limit that may cause system damage. Once the monitored DC bus voltage exceeds the second DC bus voltage safety threshold, the system determines that an overvoltage event has occurred. At this time, the conventional combined feedforward and feedback control may not be sufficient to cope with it, and the highest-level protection action will be triggered, overriding the previously calculated total absorbed power command: The bidirectional converter of the supercapacitor bank is required to absorb power at a preset peak situation power value. This peak situation power is the maximum short-time absorbed power preset according to the device capabilities. The standby load connected to the bus is also required to perform absorption operations at the preset peak situation power value. The standby load (such as a braking resistor) is activated and works in cooperation with the supercapacitor to jointly consume the excess energy on the bus.

[0063] The above steps are used to provide a higher level of security and prevent critical devices (such as bus capacitors, inverters, etc.) from being damaged due to overvoltage. In the face of extreme disturbances (such as severe load drops or power supply failures), a single adjustment method may not be sufficient. By simultaneously mobilizing two resources, the supercapacitor and the backup load, and having them both operate at their maximum absorption power states, the total emergency power absorption capacity of the system can be increased to the maximum, thereby enhancing the ability of the entire DC system to resist severe disturbances.

[0064] S106. When the DC bus voltage drops below the first DC bus voltage safety threshold and persists for a preset unit time, restore the bidirectional converter to the preset normal control mode.

[0065] Specifically, continuously monitor the photovoltaic power generation, the state of charge of the energy storage device, and the DC bus voltage. When the currently monitored DC bus voltage drops below the first DC bus voltage safety threshold and persists for a preset unit time, confirm that the current state is stable. Restore the bidirectional converter of the supercapacitor bank to the normal control logic for power absorption. If the backup load is turned on, the backup load is disconnected or its control unit returns to the standby state and stops energy absorption.

[0066] In some embodiments, when the SOC of the energy storage device (such as a supercapacitor bank or a lithium battery bank) approaches the lowest threshold, the energy absorption capacity may be limited, resulting in a slowdown in the rate of decline of the DC bus voltage. In this case, to ensure the accuracy of mode switching and the stability of subsequent operation, the time determination window is dynamically adjusted, that is, the duration required for the bus voltage to drop below the first DC bus voltage safety threshold is extended for determination. This is achieved by real-time detecting the SOC state of the energy storage device and the change trend of the bus voltage, ensuring that there is sufficient time to confirm the stability of the bus voltage when the energy reserve of the energy storage device is insufficient, thereby avoiding the situation where the energy storage device cannot meet the subsequent power regulation requirements due to premature switching to the normal control mode. In this way, the operating state of the energy storage device and the dynamic characteristics of the voltage drop can be fully considered, improving the reliability of mode switching and ensuring the safe operation and efficiency improvement of the photovoltaic energy storage charging system under low SOC conditions.

[0067] In the above embodiments, after detecting a specific combined disturbance state, by calculating the feedforward absorption power value that can predict the power impact and combining it with the feedback regulation power value that corrects the current voltage deviation, a total absorption power command is generated to execute power absorption for the supercapacitor bank. The coordination of this feedforward prediction and feedback correction ensures that even when the energy storage battery is limited, the supercapacitor can absorb excess power in a timely and accurate manner, and its dynamic power response suppresses the severe fluctuations of the DC bus voltage, thereby improving the voltage stability.

[0068] In some other embodiments of the present application, when it is detected that power surplus needs to be absorbed and there are controllable charging piles running and attempts are made to use them for power regulation, it may not be possible to confirm the power reduction instruction in a timely manner due to unstable charging pile communication or user-side reasons, resulting in the system being unable to accurately know whether this part of the potential regulation ability takes effect. By adopting the integrated photovoltaic energy storage and charging control method provided in the present application, it is possible to clearly distinguish between the confirmed and unconfirmed situations, thereby ensuring that sufficient power absorption can be performed under the condition of uncertain collaborative resources, and maintaining the robustness and safety of the control strategy.

[0069] As Figure 2 shown, it is another schematic flowchart of the integrated photovoltaic energy storage and charging control method provided by the embodiments of the present application, including the following steps: S201. Obtain the photovoltaic power generation, the state of charge of the energy storage device, and the DC bus voltage.

[0070] S202. In the case of detecting a composite disturbance state, calculate the power imbalance growth rate of the DC bus according to the power generation growth rate of the photovoltaic power generation within a preset unit time and a preset conversion function.

[0071] S203. Based on the power imbalance growth rate, apply a preset time accumulation algorithm to calculate a preliminary feed-forward absorption power value.

[0072] S204. Monitor the real-time charging power of the charging piles that are connected to the DC bus and have controllability.

[0073] Specifically, first, establish a reliable communication connection with each charging pile. This is usually achieved through standard industrial communication protocols, such as the Open Charge Protocol (OCPP), Modbus TCP / IP, CAN bus, or private protocols provided by specific charging pile manufacturers. The communication network can be based on Ethernet, RS485, wireless networks (such as Wi-Fi or cellular networks), etc.

[0074] The charging pile is usually equipped with a metering unit inside, which can measure its own input voltage and current (for the pile directly connected to the DC bus, it is the DC side; for the pile with an AC / DC converter inside, it may be the AC side power, but ultimately it will be reflected as the power demand for the DC bus). The charging pile packs the measured real-time power data (or other basic data that can calculate power, such as voltage and current) according to the agreed protocol format.

[0075] Actively send a data request command to each charging pile at a preset time interval (for example, every 1 second or 5 seconds). After receiving the request, the charging pile replies with the current real-time power value. Automatically send the real-time power data according to preset rules (for example, when the power change exceeds a certain threshold, or at a fixed time interval). After receiving the power data from each charging pile, perform parsing, verification, and storage.

[0076] S205. When the charging power of the real-time charging pile is greater than zero, calculate the reduced charging power value.

[0077] Specifically, when it is predicted that power needs to be absorbed in the future (manifested as a positive preliminary feedforward absorption power value), the current ongoing charging process can be utilized to contribute a part of the required absorption capacity by actively reducing its power.

[0078] First, confirm that the real-time charging power of the charging pile and the preliminary feedforward absorption power value are greater than zero. If the charging pile is not currently charging (the power is zero or negative, such as V2G discharging), it is impossible to achieve the absorption effect by reducing its charging power. A positive feedforward value means that it is predicted that there will be a power surplus in the DC bus in the short term in the future, and absorption measures need to be taken. If the feedforward value is zero or negative (predicting no surplus or a gap), there is no need to reduce the charging power based on this prediction.

[0079] Reduced charging power value = min(preliminary feedforward absorption power value, real-time charging power of the charging pile).

[0080] The reduction amount of the charging power cannot exceed the power actually consumed by the charging pile currently. It is impossible to make a charging pile with a power consumption of only 20 kW reduce its power by 30 kW. Therefore, the real-time charging power of the charging pile is the physical upper limit of the reduction amount. The purpose of reducing the charging power is to meet the absorption demand predicted by the preliminary feedforward absorption power value. Therefore, the preliminary feedforward absorption power value is the demand upper limit of the reduction amount.

[0081] The calculated reduced charging power value represents how much power the charging pile can and needs to contribute at most to help absorb the predicted power surplus under the current prediction and actual charging conditions.

[0082] S206. Send a power reduction intention query instruction to the charging pile.

[0083] Specifically, generate a control message of a specific type based on the reduced charging power value calculated previously. This message is formatted according to the agreed communication protocol (such as OCPP's Transaction Event Request combined with a specific message type, or a custom Mod bus function code, etc.). The data payload part of the message must clearly contain the reduced charging power value, clearly informing the charging pile system how much power it is considering reducing.

[0084] Send the encapsulated query instruction to the target charging pile (or multiple target charging piles if simultaneous query is required) through the established communication network (such as wired Ethernet, wireless network, etc.).

[0085] After receiving the query instruction, the controller inside the charging pile will perform a series of checks. First, it parses the received message to identify that this is an intention query instruction and extracts the reduced charging power value contained therein. The charging pile will check its own real-time status, including but not limited to: the current actual charging power, the communication status with the electric vehicle battery management system (BMS) and the allowable charging range, its own hardware limitations (such as temperature, component health), and possible user-side settings (for example, whether the user has set preferences such as "not allowing interruption" or "minimum charging power"). Based on the internal status verification, the charging pile determines whether it can meet the required power reduction amount in the instruction. The charging pile generates a response message according to the evaluation result. This response message will clearly contain its response status to this query (for example, "Accepted", "Rejected").

[0086] The system receives and parses the response message of the charging pile, so as to know the actual acceptance ability and willingness of the charging pile for the proposed power reduction.

[0087] In practical applications, when the charging pile suddenly goes offline due to power failure, hardware failure, software problem or maintenance; the communication network between the connection controller and the charging pile is interrupted, the signal interference is serious or the network latency is too high, resulting in the instruction or response not being transmitted in time; or although the charging pile is online and the communication is normal, but its internal operating state (such as being in a specific charging protection stage, performing a priority task or the user has set not to allow remote adjustment), it will be unable to perform the task of absorbing the reduced charging power value, then this query step needs to be used.

[0088] S207. When the preset confirmation instruction is not received within the unit time, confirm the preliminary feedforward absorption power value as the basic feedforward absorption power value.

[0089] Specifically, when sending the power reduction intention query instruction, start a timer. The duration of this timer is set to a predefined unit time. During the operation of the timer, continuously monitor the communication port of the corresponding target charging pile and wait for the preset confirmation instruction. This confirmation instruction indicates that the charging pile agrees and undertakes to perform the power reduction proposed in the previous query (either full or partial acceptance may belong to the preset confirmation category, depending on the protocol definition). For example, in the OCPP protocol, this may be a transaction event response (Transaction Event Response) with a specific status code (such as "Accepted").

[0090] The timer keeps timing. If, at the moment when the timer reaches the end of the unit time, the preset confirmation instruction from the charging pile has not been successfully received and effectively parsed, it is determined that the timeout condition is established.

[0091] Once the timeout condition is met, the preliminary feedforward absorption power value calculated based on the power imbalance growth rate before will be directly assigned to the basic feedforward absorption power value, that is, the assignment operation is executed: basic feedforward absorption power value = preliminary feedforward absorption power value.

[0092] Since the information that the charging pile will share the absorption task cannot be obtained within the specified time, the super capacitor will undertake all the predictive absorption requirements calculated by the preliminary feedforward.

[0093] S208. When it is monitored within the unit time that the preset confirmation instruction is received, subtract the charging power reduction value from the preliminary feedforward absorption power value to obtain the basic feedforward absorption power value.

[0094] Specifically, after sending the power reduction intention query instruction, within the unit time, it is monitored and verified that the preset confirmation instruction from the target charging pile is received. This confirmation instruction clearly indicates that the charging pile has received the query, evaluated its own status, and agreed to execute the power reduction action represented by the charging power reduction value included in the instruction.

[0095] Subtract the charging power reduction value (representing the absorption share committed by the charging pile) sent to the charging pile in the query instruction from the preliminary feedforward absorption power value (representing the total predicted absorption demand) calculated previously based on the system power imbalance prediction.

[0096] Basic feedforward absorption power value = preliminary feedforward absorption power value - charging power reduction value. The calculated basic feedforward absorption power value represents the amount of predicted absorption power that still needs to be processed by the super capacitor through feedforward control after the charging pile confirms that it will contribute a part of the absorption capacity by reducing its own power.

[0097] In some embodiments, when the photovoltaic power fluctuates greatly, for example, due to weather changes, the photovoltaic power generation power changes frequently, and the DC bus voltage may rise or fall instantaneously. To ensure that the energy storage device is protected from the impact of frequent power fluctuations, the calculation formula for dynamically adjusting the reduced charging power value is combined with the voltage change rate and the photovoltaic power fluctuation rate, thereby optimizing the power distribution strategy. In this process, the reduced charging power value will increase appropriately with the increase of the photovoltaic power fluctuation amplitude to reduce the charging pressure of the energy storage device. At the same time, by adjusting the basic feedforward absorption power value, the standby device (such as a supercapacitor bank or a standby load) is guided to respond quickly and undertake more power regulation tasks. Through this dynamic adjustment mechanism, the excess energy caused by photovoltaic power fluctuations can be effectively absorbed, the DC bus voltage can be stabilized, and the energy storage device can be prevented from being damaged due to overcharging or frequent power changes, thereby ensuring the safe operation and efficient energy conversion of the photovoltaic energy storage charging system.

[0098] S209. Calculate the preset power of the absolute value of the voltage deviation value, and multiply it by the voltage deviation value and the preset gain coefficient to obtain the feedback regulation power value.

[0099] S210. Add the basic feedforward absorption power value and the feedback regulation power value to obtain the initial total absorption power command.

[0100] S211. Obtain the real-time state of charge of the energy storage device.

[0101] S212. Determine whether the real-time state of charge is lower than the preset auxiliary absorption safety state threshold; If so, execute the following step S214; If not, execute the following step S213.

[0102] Specifically, the real-time state of charge is the latest value obtained in the previous step, which reflects the percentage of the current remaining energy of the energy storage device.

[0103] The preset auxiliary absorption safety state threshold is a state of charge percentage value pre-configured by the system designer or operator according to specific goals and stored in the control system. Below this threshold, it is considered that the buffering ability of the energy storage device for absorbing power is insufficient or there is a risk.

[0104] If so, it indicates that the real-time state of charge of the current energy storage device has fallen below the safety bottom line set to ensure its auxiliary absorption function.

[0105] If not, it indicates that the real-time state of charge of the current energy storage device is not lower than this safety threshold and has the basic conditions to participate in (including absorbing power) power regulation tasks.

[0106] S213. Allocate the total absorption power value to a first absorption power value for the bidirectional converter of the supercapacitor bank and a second absorption power value for the bidirectional converter of the energy storage device.

[0107] Specifically, the total absorption power value is a power command that requires the joint response of the supercapacitor and the energy storage device.

[0108] Multiple strategies can be adopted to allocate the first absorption power value and the second absorption power value: Fixed ratio allocation: Set a fixed allocation ratio according to the rated power or capacity of the supercapacitor and the energy storage device. For example, allocate according to the rated power ratio.

[0109] State-based dynamic ratio allocation: Dynamically adjust the allocation ratio according to the real-time SOC (or the voltage of the supercapacitor), temperature and other states of the two. For example, when the SOC of the energy storage device is high, reduce its absorption power share; when the voltage of the supercapacitor is low, give priority to charging it.

[0110] Frequency division allocation based on response characteristics: Utilize the characteristics that the supercapacitor has a fast response speed and high power density, while the energy storage device has high energy density. Decompose the total power command into high-frequency and low-frequency components through filters (such as low-pass and high-pass filters). The high-frequency components (representing fast fluctuations and instantaneous shocks) are mainly allocated to the supercapacitor, and the low-frequency components (representing continuous and slowly changing power demands) are mainly allocated to the energy storage device.

[0111] Allocation based on efficiency optimization: Select the allocation scheme that maximizes the total energy conversion efficiency according to the operating efficiency curves of the two at different power levels.

[0112] Priority allocation: Set priority rules to preferentially use the supercapacitor to meet instantaneous power demands, and when it exceeds its capacity or the duration is long, the energy storage device will supplement or take over.

[0113] In some embodiments of the present application, the first absorption power value or the second absorption power value calculated by the allocation strategy may exceed the current actual maximum allowable power of the corresponding device (for example, the energy storage device may trigger its own protection mechanism due to excessive internal temperature or its state of charge being very close to the allowable upper or lower limit, resulting in a temporary reduction in the acceptable charge and discharge power).

[0114] Compare the power value calculated by the strategy with the current actual maximum allowable power value of the device. When finally determining the actual power command issued to the device, the smaller value of the two should be taken. In this way, the power actually allocated to the energy storage device will be limited, generating a part of the redundant power that was originally planned to be borne by the energy storage device but now cannot be allocated.

[0115] Reducing the total power: If the supercapacitor cannot handle this excess power either, then the finally dispatched total power will be less than the original total absorbed power value. There needs to be a mechanism to handle this situation where the power cannot be fully satisfied, temporarily allowing the bus voltage to deviate more from the target value, or the dispatcher enabling other backup power sources, adjusting controllable loads, and other auxiliary resources to make up for the power gap.

[0116] S214. Allocate the total absorbed power value entirely as the first absorbed power value and set the second absorbed power value to zero.

[0117] Specifically, directly assign the total absorbed power value to the first absorbed power value corresponding to the bidirectional converter of the supercapacitor bank. Clearly instruct the bidirectional converter of the energy storage device not to output or absorb power during this cycle, and the second absorbed power value is zero.

[0118] S215. Control the bidirectional converter of the supercapacitor bank to absorb power according to the first absorbed power value respectively, and control the bidirectional converter of the energy storage device to absorb power according to the second absorbed power value, and then return to execute the above step S211.

[0119] Specifically, send the calculated first absorbed power value and second absorbed power value to the corresponding converters respectively.

[0120] Each bidirectional converter has an independent low-level controller inside. After receiving the power command, its internal control loop (usually including a current inner loop and a power / voltage outer loop) will work, and by controlling the on / off of the internal power electronic switches (such as IGBTs, MOSFETs) (usually using PWM modulation technology), the magnitude and direction of the power flowing through the converter are adjusted.

[0121] Return to execute S211. After the power command in the current control cycle is executed, restart to execute step S211. By continuously returning to S211, collect the latest state of charge information of the energy storage device and continuously adjust the distribution strategy.

[0122] S216. When the DC bus voltage drops below the first DC bus voltage safety threshold and lasts for a preset unit time, restore the bidirectional converter to the preset normal control mode.

[0123] Steps S201 - S203, S209 - S211, S216 are similar to Figure 1 Steps S101 - S103, S104 - S106 in the illustrated embodiment. Refer to the descriptions in steps S101 - S102, S104, S106, and details will not be elaborated here.

[0124] In the above embodiments, the impending power imbalance is predicted by analyzing the growth rate of photovoltaic power (S202 - S203), and the preliminary feed-forward absorption power is calculated. Then, an attempt is made to coordinate with the controllable charging pile to query whether it can cut some power (S204 - S206), and the final basic feed-forward value is adjusted according to the response of the charging pile (S207 - S208), aiming to give priority to using the regulation ability on the load side and relieve the pressure on the energy storage system. Then, combined with the feedback regulation based on the real-time voltage deviation (S209), the total absorption power demand is obtained (S210). When performing absorption, a judgment is made based on the real-time state of charge (SOC) of the energy storage device (S211 - S214). Only when the SOC is lower than the safety threshold is the energy storage device allowed to participate in absorption, otherwise it is completely borne by the super capacitor, and this allocation is continuously and dynamically adjusted by circularly monitoring the SOC (S215 -> S211). This enables the system to quickly respond to disturbances and ensures that the energy storage device is not overcharged due to absorbing too much power, thus significantly improving the stability and operation safety of the system under complex disturbances and enhancing the stability of the DC bus voltage under specific complex disturbances.

[0125] The following introduces the exemplary integrated photovoltaic energy storage charging control system 300 provided by the embodiments of the present application. Figure 3 It is an exemplary hardware structure diagram of the integrated photovoltaic energy storage charging control system 300 provided by the embodiments of the present application.

[0126] In some embodiments, the integrated photovoltaic energy storage charging control system 300 is a computer device or the integrated photovoltaic energy storage charging control system 300 includes a computer device. The computer device includes a processor, a memory, and a network interface connected through a system bus. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store data. The network interface of the computer device is used to communicate with other external terminals or servers through a network connection. In some embodiments, the network interface can be a wired network interface, and in some embodiments, the network interface can also be a wireless network interface. The computer program, when executed by the processor, implements the method in the embodiments of the present application.

[0127] Those skilled in the art can understand that Figure 3 the structure shown in merely represents a block diagram of some structures related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0128] As described above, the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the various embodiments of the present application.

[0129] In the above embodiments, depending on the context, the term "when..." can be interpreted as "if...", or "after...", or "in response to determining...", or "in response to detecting...". Similarly, depending on the context, the phrase "when determining..." or "if detecting (the stated condition or event)" can be interpreted as "if determining...", or "in response to determining...", or "when detecting (the stated condition or event)", or "in response to detecting (the stated condition or event)".

[0130] In the above embodiments, it can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented using software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by wire (such as coaxial cable, optical fiber, digital subscriber line) or wirelessly (such as infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that the computer can access, or a data storage device such as a server or data center that includes one or more integrated available media. The available medium can be a magnetic medium (for example, a floppy disk, a hard disk, a magnetic tape), an optical medium (for example, a DVD), or a semiconductor medium (for example, a solid-state drive), etc.

[0131] Those of ordinary skill in the art can understand all or part of the processes in the above embodiments of the method. This process can be completed by relevant hardware instructed by a computer program. The program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The foregoing storage media include: ROM or random access memory RAM, magnetic disks, or optical disks and other media that can store program codes.

Claims

1. A method for integrated control of photovoltaic energy storage and charging, characterized in that, Including: Obtain the photovoltaic power generation, the state of charge of the energy storage device, and the DC bus voltage; In the case of detecting a combined disturbance state, according to the power generation growth rate of the photovoltaic power generation within a preset unit time and a preset conversion function, calculate the power imbalance growth rate of the DC bus; the combined disturbance state is that the growth rate of the photovoltaic power generation exceeds a preset growth rate threshold, the state of charge of the energy storage device reaches the upper limit of operation of the state of charge of the energy storage device, and the DC bus voltage exceeds a preset first DC bus voltage safety threshold; Based on the power imbalance growth rate, apply a preset time accumulation algorithm to calculate a basic feed-forward absorption power value; the preset time accumulation algorithm is to perform time integration or discrete accumulation on the power imbalance growth rate within the unit time; Calculate the absolute value of the voltage deviation value to a preset power, and multiply it by the voltage deviation value and a preset gain coefficient to obtain a feedback regulation power value; the voltage deviation value is the difference between the DC bus voltage and a preset stable target voltage; Add the basic feed-forward absorption power value and the feedback regulation power value to obtain a total absorption power value, and control the bidirectional converter of the supercapacitor bank to absorb power using the total absorption power value; When the DC bus voltage drops below the first DC bus voltage safety threshold and lasts for a preset unit time, restore the bidirectional converter to a preset conventional control mode.

2. The method according to claim 1, characterized in that, The calculating the basic feed-forward absorption power value based on the power imbalance growth rate by applying a preset time accumulation algorithm specifically includes: Based on the power imbalance growth rate, apply a preset time accumulation algorithm to calculate a preliminary feed-forward absorption power value; Monitor the real-time charging power of a charging pile that is connected to the DC bus and has controllability; In the case where the real-time charging power of the charging pile is greater than zero, subtract the reduced charging power value from the preliminary feed-forward absorption power value to obtain the basic feed-forward absorption power value; the reduced charging power value is the smaller value between the preliminary feed-forward absorption power value and the real-time charging power of the charging pile.

3. The method according to claim 2, wherein Before subtracting the reduced charging power value from the preliminary feed-forward absorption power value to obtain the basic feed-forward absorption power value, it further includes: Send a power reduction intention query instruction to the charging pile; the power reduction intention query instruction includes the reduced charging power value; In the case where a preset confirmation instruction is not received within the unit time, confirm the preliminary feed-forward absorption power value as the basic feed-forward absorption power value.

4. The method according to claim 1, characterized in that, The adding the basic feed-forward absorption power value and the feedback regulation power value to obtain a total absorption power value, and controlling the bidirectional converter of the supercapacitor bank to absorb power using the total absorption power value specifically includes: Add the basic feed-forward absorption power value and the feedback regulation power value to obtain an initial total absorption power instruction; Obtain the real-time state of charge of the energy storage device; Judge whether the real-time state of charge is lower than a preset auxiliary absorption safety state threshold; If so, allocate the total absorption power value as a first absorption power value for the bidirectional converter of the supercapacitor bank and a second absorption power value for the bidirectional converter of the energy storage device; the total absorption power value is the sum of the first absorption power value and the second absorption power value; If not, allocate the total absorption power value entirely as the first absorption power value and the second absorption power value is zero; Respectively control the bidirectional converter of the supercapacitor bank to absorb power according to the first absorption power value, and control the bidirectional converter of the energy storage device to absorb power according to the second absorption power value.

5. The method according to claim 4, characterized in that, After respectively controlling the bidirectional converter of the supercapacitor bank to absorb power according to the first absorption power value and controlling the bidirectional converter of the energy storage device to absorb power according to the second absorption power value, it further includes: Real-time judge whether the real-time state of charge reaches or exceeds the auxiliary absorption safety state threshold; If so, correct the second absorption power value to zero, and allocate the total absorption power value entirely as the first absorption power value.

6. The method according to claim 1, wherein After adding the basic feedforward absorption power value and the feedback adjustment power value to obtain the total absorption power value, and controlling the bidirectional converter of the supercapacitor bank to use the total absorption power value to absorb power, it further includes: Monitor whether the DC bus voltage exceeds a preset second DC bus voltage safety threshold; the second DC bus voltage safety threshold is greater than the first DC bus voltage safety threshold; If so, control the bidirectional converter of the supercapacitor bank to absorb power with its preset peak situation power value; Control the standby load bidirectional converter to perform an absorption operation with the peak situation power value.

7. The method according to claim 1, wherein After calculating the absolute value of the voltage deviation value to the preset power, multiplying the voltage deviation value and the preset gain coefficient to obtain the feedback adjustment power value, it further includes: Obtain the internal temperature value of the supercapacitor bank; If the temperature value exceeds the preset temperature warning threshold, reduce the feedback adjustment power value.

8. An integrated control system for photovoltaic energy storage and charging, characterized in that, The integrated photovoltaic energy storage and charging control system includes: one or more processors and a memory; the memory is coupled to the one or more processors, the memory is used to store computer program code, the computer program code includes computer instructions, and the one or more processors call the computer instructions to enable the integrated photovoltaic energy storage and charging control system to execute the method according to any one of claims 1-7.

9. A computer program product comprising instructions, characterized in that, When the computer program product runs on the integrated photovoltaic energy storage and charging control system, enable the integrated photovoltaic energy storage and charging control system to execute the method according to any one of claims 1-7.

10. A computer-readable storage medium, comprising instructions, characterized in that, When the instruction runs on the integrated photovoltaic energy storage and charging control system, enable the integrated photovoltaic energy storage and charging control system to execute the method according to any one of claims 1-7.

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