Hybrid energy storage device control method, equipment and medium

Abstract

The invention discloses a hybrid energy storage device control method, equipment and a medium, relates to the technical field of hybrid energy storage system control, and provides a hybrid energy storage device control method for solving the problem that a current lithium battery and a super capacitor are difficult to use in a hybrid manner, and the direct current bus voltage of a hybrid energy storage device is stabilized by using the super capacitor. Based on electrical characteristics, it can be known that the direct-current bus voltage is stable and does not have an over-high peak value. Furthermore, under the condition that the current is constant, the output power does not have an over-high peak value, so that the problem that the lithium battery is not suitable for a high-power scene is solved. Furthermore, in the method, the super-capacitor is only responsible for balancing the voltage of the direct-current bus, and the discharging time is short, so that the problem that the super-capacitor is not suitable for a high-capacity scene can be solved. Therefore, according to the method, the application scene problems of the lithium battery and the super capacitor are solved respectively, and preconditions and an effective control scheme are provided for implementation of the lithium battery-super capacitor hybrid energy storage device.

Description

Technical Field

[0001] The present application relates to the field of hybrid energy storage system control, and in particular to a hybrid energy storage device control method, equipment and medium. Background Art

[0002] As a product of the combination of energy storage technology and traditional transformers, energy storage transformers have the functions of converting, storing and releasing electric energy, and can achieve the regulation and balance of electric energy in the power grid. Among energy storage transformers, lithium batteries and supercapacitors are commonly used as energy storage elements. Both have their own unique advantages and applicable scenarios. For example, lithium batteries have the characteristics of high energy density and long cycle life, which are suitable for long-term energy storage; while supercapacitors have the characteristics of high power density and fast charging and discharging, which are suitable for transient power compensation and frequency regulation.

[0003] Currently, common energy storage transformers mainly use lithium batteries or supercapacitors as energy storage elements. Although they perform well in their respective application scenarios, lithium batteries are not suitable for high-power scenarios and supercapacitors are not suitable for large-capacity scenarios, which has become the biggest challenge restricting the realization of lithium battery-supercapacitor hybrid energy storage devices.

[0004] Therefore, technicians in this field now urgently need a hybrid energy storage device control method to overcome the incompatibility problem of applicable scenarios of lithium batteries and supercapacitors, thereby realizing hybrid energy storage of lithium batteries and supercapacitors, taking into account the advantages of both to improve the comprehensive performance of energy storage transformers. Summary of the invention

[0005] The purpose of this application is to provide a hybrid energy storage device control method, equipment and medium, which is used to provide a control method for a lithium battery and supercapacitor hybrid energy storage device, thereby solving the problem that traditional energy storage technology cannot achieve hybrid energy storage of lithium batteries and supercapacitors.

[0006] In order to solve the above technical problems, the present application provides a hybrid energy storage device control method, which is applied to the hybrid energy storage device, wherein the hybrid energy storage device includes a supercapacitor and a lithium battery; the method includes:

[0007] Obtaining the actual voltage value and rated voltage value of the DC bus of the hybrid energy storage device;

[0008] Determine a DC bus voltage deviation value according to an actual voltage value and a rated voltage value of the DC bus;

[0009] Determining a DC bus power compensation value according to the DC bus voltage deviation value;

[0010] The charging and discharging power of the supercapacitor is adjusted based on the DC bus power compensation value to stabilize the DC bus voltage.

[0011] In a possible embodiment, the method further includes:

[0012] Obtaining an actual voltage value and a target voltage value of the supercapacitor;

[0013] Determine a supercapacitor voltage deviation value according to an actual voltage value of the supercapacitor and a target voltage value;

[0014] Determining a supercapacitor power compensation value according to the supercapacitor voltage deviation value;

[0015] The charging and discharging power of the lithium battery is adjusted based on the supercapacitor power compensation value to balance the voltage of the supercapacitor.

[0016] In a possible embodiment, determining the supercapacitor power compensation value according to the supercapacitor voltage deviation value includes:

[0017] Determining a supercapacitor power compensation value according to the supercapacitor voltage deviation value by a rebalancing controller;

[0018] Wherein, the transfer function of the rebalancing controller is a proportional-integral function, and the proportional-integral function is obtained according to the power-voltage model of the supercapacitor and the power model of the lithium battery.

[0019] In a possible embodiment, adjusting the charging and discharging power of the supercapacitor based on the DC bus power compensation value to stabilize the DC bus voltage includes:

[0020] Adjusting the output power of the supercapacitor based on the DC bus power compensation value through the power electronic converter of the supercapacitor;

[0021] The transfer function of the power electronic converter of the supercapacitor is obtained according to the power-voltage model of the DC bus and the power-voltage model of the supercapacitor.

[0022] In a possible embodiment, the power-voltage model of the DC bus is:

[0023] ;

[0024] Among them, v dc Represents the actual voltage value of the DC bus; G c represents the conductivity value of the hybrid energy storage device; C dc Represents the capacitance value of the DC bus; V dc Represents the voltage unit value of the DC bus; H dc Represents the inertia constant of the DC power system; P uc , P batRespectively represent the power unit value of the supercapacitor and the lithium battery; P dcL Indicates the instantaneous power value of the DC load.

[0025] In a possible embodiment, the power-voltage model of the supercapacitor is:

[0026] ;

[0027] Among them, V uc , P uc Respectively represent the unit value of the supercapacitor voltage and power; G uc , C uc Respectively represent the parallel conductance and capacitance of the supercapacitor; H uc Represents the inertia constant of the AC power system.

[0028] In a possible embodiment, the power model of the lithium battery is:

[0029] ;

[0030] Among them, P uc , P bat Respectively represent the power unit values ​​of the supercapacitor and the lithium battery; Indicates the target power value of the lithium battery; Represents the supercapacitor power compensation value; K puc , K iuc are the proportional gain and integral gain of the rebalancing controller respectively; H uc Represents the inertia constant of the AC power system; G uc , C uc Respectively represent the parallel conductance value and capacitance value of the supercapacitor; V uc Represents the voltage unit value of the supercapacitor; Indicates the target voltage unit value of the supercapacitor.

[0031] In order to solve the above technical problems, the present application also provides a hybrid energy storage device control device, which is applied to a hybrid energy storage device, wherein the hybrid energy storage device includes a supercapacitor and a lithium battery; the device includes:

[0032] An acquisition module, used to acquire an actual voltage value and a rated voltage value of a DC bus of a hybrid energy storage device;

[0033] A determination module, used to determine a DC bus voltage deviation value according to an actual voltage value and a rated voltage value of the DC bus;

[0034] A compensation module, used to determine a DC bus power compensation value according to the DC bus voltage deviation value;

[0035] The adjustment module is used to adjust the charging and discharging power of the supercapacitor based on the DC bus power compensation value to stabilize the DC bus voltage.

[0036] In order to solve the above technical problems, the present application also provides a hybrid energy storage device control device, including:

[0037] Memory for storing computer programs;

[0038] A processor is used to implement the steps of the hybrid energy storage device control method as described above when executing the computer program.

[0039] In order to solve the above technical problems, the present application also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the hybrid energy storage device control method as described above are implemented.

[0040] The present application provides a hybrid energy storage device control method, which uses a supercapacitor to stabilize the DC bus voltage of the hybrid energy storage device. Based on the electrical characteristics of the DC bus voltage of the energy storage device, it can be known that the DC bus voltage is stable, which means that there will be no particularly high peak value. Furthermore, when the current is constant, the output power will not have a particularly high peak value, thereby solving the problem that lithium batteries are not suitable for high-power scenarios. Furthermore, in this method, the supercapacitor is only responsible for balancing the DC bus voltage, so its discharge time is short, which can solve the problem that the supercapacitor is not suitable for large-capacity scenarios. It can be seen that the control method provided by the present method overcomes the applicable scenario problems of lithium batteries and supercapacitors respectively, so that whether it is a high-power scenario or a large-capacity scenario, the availability of supercapacitors and lithium batteries can be guaranteed, which provides a prerequisite for the realization of a lithium battery-supercapacitor hybrid energy storage device. Therefore, based on the control method provided by the present application, the effective control of lithium batteries and supercapacitors and the effective management of electrical energy storage and release can be achieved in large-capacity scenarios or high-power scenarios, taking into account the advantages of both and bringing better energy storage performance.

[0041] The hybrid energy storage device control apparatus and computer-readable storage medium provided in the present application correspond to the above method and have the same effects as above. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0043] Figure 1A flow chart of a hybrid energy storage device control method provided by the present invention;

[0044] Figure 2 A closed-loop control structure diagram for stabilizing DC bus voltage provided by the present invention;

[0045] Figure 3 A control structure diagram of supercapacitor voltage rebalancing provided by the present invention;

[0046] Figure 4 A structural diagram of a hybrid energy storage device control device provided by the present invention;

[0047] Figure 5 A structural diagram of another hybrid energy storage device control device provided by the present invention. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] The core of this application is to provide a hybrid energy storage device control method, equipment and medium.

[0050] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0051] At present, in energy storage transformers and other equipment, common energy storage components are mainly lithium batteries and supercapacitors, both of which have their own unique advantages and applicable scenarios. Among them, lithium batteries have the characteristics of high energy density and long cycle life, which are suitable for long-term energy storage and are mainly used in large-capacity scenarios. However, due to the slow charging and discharging speed of lithium batteries, they are not suitable for transient power compensation, that is, they are not suitable for high-power scenarios. Supercapacitors have the characteristics of high power density and fast charging and discharging, which are suitable for transient power compensation and frequency regulation, so they are mainly used in high-power scenarios. However, due to the low energy density of supercapacitors, they cannot meet the needs of long-term energy storage, that is, they are not suitable for large-capacity scenarios.

[0052] It can be seen that the above problems have become the biggest challenge restricting the realization of lithium battery-supercapacitor hybrid energy storage devices. In order to solve the above problems and make the realization of lithium battery-supercapacitor hybrid energy storage devices possible, the present application provides a hybrid energy storage device control method, which is applied to the hybrid energy storage device, and the hybrid energy storage device includes supercapacitors and lithium batteries. Figure 1 As shown, the method includes:

[0053] S11: Acquire the actual voltage value and rated voltage value of the DC bus of the hybrid energy storage device.

[0054] S12: Determine the DC bus voltage deviation value according to the actual voltage value and the rated voltage value of the DC bus.

[0055] S13: Determine the DC bus power compensation value according to the DC bus voltage deviation value.

[0056] S14: Adjust the output power of the supercapacitor based on the DC bus power compensation value to stabilize the output voltage of the DC bus.

[0057] The control flow of this method is as follows Figure 2 As shown, for a lithium battery-supercapacitor hybrid energy storage device, the DC bus voltage is related to the charging and discharging power of the supercapacitor, the charging and discharging power of the lithium battery, and the power value of the DC load. Among them, the DC load is all loads connected to the DC bus to consume and exchange electrical energy. Since the load changes in real time, the DC load power value also changes in real time, which cannot be predicted or controlled. Therefore, in order to stabilize the DC bus voltage, we can only start from the charging and discharging power of the lithium battery or supercapacitor. In this method, according to the respective characteristics of supercapacitors and lithium batteries, supercapacitors have high power density and fast charging and discharging characteristics, and are suitable for transient power compensation and frequency regulation. Therefore, in this method, the DC bus voltage is adjusted to maintain its stability by adjusting the charging and discharging power of the supercapacitor, which can bring better control effects. Specifically, such as Figure 2 As shown, the method collects the actual voltage value (or instantaneous voltage value) of the DC bus as feedback to control the charging and discharging power of the supercapacitor, thereby stabilizing the DC bus voltage.

[0058] In addition, for Figure 2 K uc , which represents the gain of the supercapacitor power controller. In practical applications, when the DC bus voltage deviation exceeds ±10%, a bidirectional power demand (i.e., increasing and decreasing the two adjustment demand directions) will be generated. Since the maximum power demand is equal to the rated power of the energy storage system, it is equivalent to a voltage deviation of ±0.1 for each unit rated power. Therefore, if the unit system is used to represent the power demand and the DC bus voltage deviation, the gain K uc Can be set to 10 to produce a bidirectional power demand of ±1 per unit when the DC bus voltage deviation exceeds ±10%.

[0059] It should also be noted that supercapacitors and lithium batteries, as mature energy storage devices, can be used independently as voltage sources, and both have power electronic converters and power controller structures to control their own working status and output. Among them, the voltage signal generated by the power controller uses a pulse width modulation signal to control the switching state of the electronic devices in its half-bridge power electronic converter to achieve control of the charging and discharging power. That is, this embodiment provides a possible implementation plan for how to implement the above step S14:

[0060] The output power of the supercapacitor is adjusted based on the DC bus power compensation value through the power electronic converter of the supercapacitor.

[0061] Furthermore, in order to ensure reliable and effective supercapacitor charging and discharging power control, the transfer function of the power electronic converter of the supercapacitor is obtained according to the power-voltage model of the DC bus and the power-voltage model of the supercapacitor.

[0062] Since this part is the original control structure of the supercapacitor and the lithium battery, the power-voltage model of the DC bus and the power-voltage model of the supercapacitor can be obtained by modeling the original electrical models of the DC bus and the supercapacitor, and this method mainly proposes an improvement on the control method of the hybrid energy storage device. Therefore, it will not be repeated here, and will be further explained in combination with examples in the subsequent embodiments.

[0063] The purpose of maintaining the DC bus voltage stable is: since power = voltage * current, when the DC bus current is constant, the power is mainly related to the voltage. When the DC bus voltage is kept stable by this method, its power will also be stable, that is, there will be no excessive peak value due to fluctuations.

[0064] Based on this, there will be no excessively high DC bus power peak, which can ensure that the charging and discharging power of the lithium battery in the hybrid energy storage device does not need to be too high, which solves the problem that the lithium battery cannot be used at high power. In other words, even if the hybrid energy storage device works in a high-power scenario, the DC bus voltage can be stabilized by supercapacitors to avoid high-power charging and discharging requirements for the lithium battery, thus overcoming the disadvantage that the lithium battery is not suitable for high-power scenarios.

[0065] Furthermore, since the supercapacitor in this method is only used to balance the DC bus voltage, its discharge time is short, and the power of the hybrid energy storage device is mainly provided by the lithium battery, there is no need for the supercapacitor to have a large capacity, which solves the problem that the supercapacitor is not suitable for large-capacity scenarios.

[0066] In summary, based on the hybrid energy storage device control method provided in this application, the shortcomings of lithium batteries being unsuitable for high-power scenarios and supercapacitors being unsuitable for large-capacity scenarios can be overcome, thereby solving the problem of incompatibility between the applicable scenarios of lithium batteries and supercapacitors, and providing the possibility for the mixed use of lithium batteries and supercapacitors. Therefore, based on this method, a lithium battery-supercapacitor hybrid energy storage device can be realized, which can be applied to energy storage transformers to take into account the advantages of lithium batteries and supercapacitors, bringing better energy storage performance.

[0067] In addition, it should be noted that the above has shown that this method can avoid the occurrence of excessively high power peaks, and that the supercapacitor in the hybrid energy storage device is only responsible for balancing the DC bus voltage, and the lithium battery is responsible for the main power output. Therefore, the DC bus power is mainly provided by the lithium battery. The fact that the DC bus power does not have an excessively high power peak also means that the discharge power of the lithium battery will not have an excessively high power peak. The lithium battery consumes energy more slowly, which means that fewer charging times are required per unit time. And because the number of charge and discharge times directly affects the service life of the lithium battery. It can be seen that this method can extend the service life of the lithium battery and indirectly solve the problem of the high cost of replacing lithium batteries.

[0068] It can be seen from the above embodiment that in this method, the supercapacitor is only used to stabilize the DC bus voltage. When the DC bus voltage deviation is too large, the DC bus voltage will be stabilized by adjusting the charging and discharging power of the supercapacitor. However, this will cause another problem. The voltage of the supercapacitor changes due to the need to stabilize the DC bus voltage, and the supercapacitor voltage needs to be rebalanced to ensure the stable operation of the hybrid energy storage device. In view of this, this embodiment provides a possible implementation scheme, and the above method also includes:

[0069] S21: Obtain the actual voltage value and target voltage value of the supercapacitor.

[0070] S22: Determine a supercapacitor voltage deviation value according to an actual voltage value of the supercapacitor and a target voltage value.

[0071] S23: Determine the supercapacitor power compensation value according to the supercapacitor voltage deviation value.

[0072] S24: adjusting the charging and discharging power of the lithium battery based on the supercapacitor power compensation value to balance the voltage of the supercapacitor.

[0073] The control flow of the method provided in this embodiment is as follows Figure 3As shown. The above embodiments have shown that the only controlled quantities that can affect the DC bus power are the charge and discharge power of the supercapacitor and the lithium battery, and the charge and discharge power of the supercapacitor needs to be adjusted to stabilize the DC bus voltage. Therefore, the change in the supercapacitor voltage caused by the change in the supercapacitor charge and discharge power requires the lithium battery to balance. Therefore, in order to rebalance the voltage of the supercapacitor, the lithium battery needs to add the power loss caused by the supercapacitor stabilizing the DC bus voltage on the basis of the power required by the average DC load. In this embodiment, the power loss is determined based on the supercapacitor voltage deviation value, that is, the supercapacitor power compensation value mentioned above, and then balanced by adjusting the charge and discharge power of the lithium battery.

[0074] It can be seen that the method provided in this embodiment solves the new control problem caused by using supercapacitors to stabilize the DC bus voltage after the method provided in the above embodiment overcomes the incompatibility problem of supercapacitors and lithium batteries. The lithium battery is used to balance the voltage of the supercapacitor, so that the hybrid energy storage device can be charged and discharged stably and reasonably, ensuring that the operation of the hybrid energy storage device meets the application requirements.

[0075] Furthermore, how to implement the control method of the previous embodiment. It can be seen from the above embodiment that the lithium battery also has control devices such as power electronic converters and power controllers, which can realize the control of the charging and discharging power of the lithium battery. However, in order to ensure that the energy storage error is driven to 0, this embodiment also provides a possible implementation scheme, and the above step S23 is:

[0076] The supercapacitor power compensation value is determined by the rebalancing controller according to the supercapacitor voltage deviation value.

[0077] Among them, the transfer function of the rebalancing controller is a proportional-integral function, and the proportional-integral function is obtained according to the power-voltage model of the supercapacitor and the power model of the lithium battery.

[0078] That is, Figure 3 As shown, in this embodiment, the rebalancing controller determines the supercapacitor power compensation value based on the supercapacitor voltage deviation value. , and then the supercapacitor power compensation value As feedback input to the power electronic converter of the lithium battery, the charging and discharging power of the lithium battery is controlled. Among them, the transfer function of the rebalancing controller is a proportional integral function, which is simple and has an integral memory term, which can ensure that the energy storage error is driven to 0, thereby bringing a better supercapacitor voltage balancing effect.

[0079] On the other hand, it can be seen from the above embodiments that the core of the hybrid energy storage device control method provided by the present application is to stabilize the DC bus voltage through the supercapacitor and balance the supercapacitor voltage through the lithium battery. The controller involved includes the power electronic converter, power controller, and rebalancing controller that the supercapacitor and lithium battery already have. The control process is as follows: Figure 2 and Figure 3 shown.

[0080] In this embodiment, a possible implementation scheme is provided for the subsystem model and controller design involved in the above embodiment:

[0081] 1. DC bus power-voltage model;

[0082] First, the DC bus electrical model can be described by the following differential equation:

[0083] (1);

[0084] In the formula, v dc Indicates the actual voltage value of the DC bus; i cdc Indicates the flow into or out of the DC bus capacitor C dc Current value; G c C dc Represents the conductance G of the hybrid energy storage system c Leakage current. Considering v dc In normal operation, it remains at its rated value v dcn If the DC bus voltage is close to the rated value v, multiply both sides of the above formula by the rated value v of the DC bus voltage. dcn , the power voltage expression is as follows:

[0085] (2);

[0086] In the formula, p uc 、p bat 、p dcL Represent the instantaneous power values ​​of the supercapacitor, lithium battery and DC load respectively. When both sides of the equation are divided by the rated power P of the DC bus dcn When , the equation can be converted into a unit power-voltage model as follows:

[0087] (3);

[0088] Where P uc , P bat Represents the power unit value of supercapacitor and lithium battery respectively (voltage and power variables are represented by capital letters to represent the value per unit power of the corresponding lowercase variable). DC load power P dcL Represents the instantaneous value of the power consumed and exchanged by all loads via the connected DC bus. Hdc represents the inertia constant of the DC power system and is defined as: .

[0089] 2. Supercapacitor power-voltage model;

[0090] As a short-term energy storage element, supercapacitors are mainly designed to provide high power. Therefore, the equivalent series resistance of supercapacitors is usually very small and can generally be ignored. However, in order to consider the self-discharge loss of the supercapacitor, a conductance in parallel can be added. Based on this consideration, the dynamic model of the supercapacitor can be simplified to the following first-order differential equation:

[0091] (4);

[0092] In the formula, v uc 、i cuc , C uc , G uc are the voltage, output current, capacitance and parallel conductance of the supercapacitor respectively. Considering that the supercapacitor is at its rated voltage v ucn Working near the supercapacitor, multiply both sides of equation (4) by the rated voltage value v of the supercapacitor. ucn , we can get the following power-voltage expression:

[0093] (5);

[0094] In the formula, p uc is the instantaneous value of the supercapacitor output power. Divide both sides of the equation by the rated power p of the supercapacitor ucn By moving the terms together, we can get the unit power-voltage model of the supercapacitor as:

[0095] (6);

[0096] Where V uc , P uc are the unit values ​​of supercapacitor voltage and power respectively. uc represents the inertia constant of the AC power system and is defined as: .

[0097] It should be noted that due to the power p of the supercapacitor uc Much greater than the power of lithium batteries bat , so the power p of the supercapacitor uc It is approximately equivalent to the power of a supercapacitor energy storage-lithium battery hybrid energy storage system.

[0098] 3. DC bus power-voltage model;

[0099] The rebalancing controller of the lithium battery-supercapacitor hybrid energy storage system is selected to be as simple as possible and have an integral memory term to ensure that the energy storage error is driven to zero. Therefore, the proportional integral function is suitable for the hybrid energy storage system rebalancing controller. Figure 3 The block diagram and its input and output variables in , and considering the proportional integral function form of the hybrid energy storage system rebalancing controller, the following expression can be obtained:

[0100] (7);

[0101] In the formula, Represents the supercapacitor power compensation value, that is, the power demand generated by the supercapacitor rebalancing controller; Indicates the unit value of the supercapacitor power to be determined; the variable with an asterisk "*" indicates the demand in the control process of this method (i.e., the unknown quantity to be calculated and required in the control). K puc , K iuc are the proportional gain and integral gain of the rebalancing controller respectively.

[0102] Furthermore, the voltage derivative in equation (6) is Substituting into formula (7), we can get:

[0103] (8);

[0104] The power requirement of the lithium battery is:

[0105] (9);

[0106] In the formula, and Represent the p to be determined bat and p uc The unit value of .

[0107] For the purpose of system analysis and design, the power bandwidth of the lithium battery power electronic converter can be considered to be high enough so that its response delay can be ignored. bat can be approximately equal to its power requirement , and so on for its power derivative. Therefore, according to formula (9), the lithium battery power can be modeled as follows:

[0108] (10);

[0109] In the formula, Indicates the target voltage unit value of the supercapacitor.

[0110] 4. DC bus power-voltage model;

[0111] The above mathematical expressions can be used to form the basis Figure 1 The signal flow shown in the block diagram leads to a system dynamic model that shows all subsystems involved in the closed-loop control process. Combining all subsystem models results in a single state-space model that can be used for system analysis and design of the DC voltage and rebalancing controllers. Considering that the power electronic converter for supercapacitors has an ideal step response, according to Figure 2 The following equation can be implemented:

[0112] (11);

[0113] Substituting the above formula (11) into the subsystem models of formulas (3), (6), and (10) respectively, the state space model of the entire system can be obtained. Among them, formula (11) is substituted into formula (3) to obtain:

[0114] (12);

[0115] Substituting formula (11) into formula (6) yields:

[0116] (13);

[0117] Substituting formula (11) into formula (10) yields:

[0118] (14);

[0119] Using common state-space notation, the model can be represented as:

[0120] (15);

[0121] (16);

[0122] in:

[0123] ;

[0124] ;

[0125] ;

[0126] ;

[0127] In the above formula, y(𝑡) is the output vector of the model, C is the unit matrix, and 𝑇 is the matrix transpose. Based on the closed-loop model of the system, the general transfer function G(𝑠) of the entire system in the S domain can be obtained:

[0128] (17);

[0129] Where ∆ is the change in the relevant variable.

[0130] Based on the system transfer function obtained from equation (17), we can design Figure 2 , Figure 3 The controllers involved in the closed-loop control system include the stable control of the DC bus voltage and the rebalancing control of the supercapacitor voltage. In other words, the design of the electronic current converter and rebalancing controller for supercapacitors and lithium batteries can be realized.

[0131] In the above embodiment, a hybrid energy storage device control method is described in detail, and the present application also provides a corresponding embodiment of a hybrid energy storage device control device. It should be noted that the present application describes the embodiment of the device part from two perspectives, one is based on the functional module perspective, and the other is based on the hardware perspective.

[0132] Based on the functional module perspective, such as Figure 4 As shown, this embodiment provides a hybrid energy storage device control device, including:

[0133] An acquisition module 11 is used to acquire an actual voltage value and a rated voltage value of a DC bus of a hybrid energy storage device;

[0134] A determination module 12 is used to determine a DC bus voltage deviation value according to an actual voltage value and a rated voltage value of the DC bus;

[0135] The compensation module 13 is used to determine the DC bus power compensation value according to the DC bus voltage deviation value;

[0136] The adjustment module 14 is used to adjust the charging and discharging power of the supercapacitor based on the DC bus power compensation value to stabilize the DC bus voltage.

[0137] Since the embodiments of the device part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the device part, which will not be repeated here.

[0138] Figure 5 A structural diagram of a hybrid energy storage device control device provided in another embodiment of the present application, such as Figure 5 As shown, a hybrid energy storage device control device includes: a memory 20 for storing a computer program;

[0139] The processor 21 is used to implement the steps of a hybrid energy storage device control method as described in the above embodiment when executing a computer program.

[0140] The hybrid energy storage device control device provided in this embodiment may include but is not limited to a mobile terminal, a personal computer, a workstation, etc.

[0141] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 can be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), and a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the awake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), which is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may also include an artificial intelligence (AI) processor, which is used to process computing operations related to machine learning.

[0142] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include a high-speed random access memory, and a non-volatile memory, such as one or more disk storage devices, flash memory storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201, wherein, after the computer program is loaded and executed by the processor 21, it can implement the relevant steps of a hybrid energy storage device control method disclosed in any of the aforementioned embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, etc., and the storage method may be temporary storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc. Data 203 may include, but is not limited to, a hybrid energy storage device control method, etc.

[0143] In some embodiments, a hybrid energy storage device control apparatus may further include a display screen 22 , an input / output interface 23 , a communication interface 24 , a power supply 25 , and a communication bus 26 .

[0144] Those skilled in the art will understand that Figure 5 The structure shown in the figure does not constitute a limitation on a hybrid energy storage device control device, and may include more or fewer components than those shown in the figure.

[0145] A hybrid energy storage device control device provided in an embodiment of the present application includes a memory and a processor. When the processor executes a program stored in the memory, it can implement the following method: a hybrid energy storage device control method.

[0146] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps recorded in the above method embodiment are implemented.

[0147] It is understandable that if the method in the above embodiment is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application is essentially or the part that contributes to the prior art or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a storage medium to execute all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), disk or optical disk and other media that can store program code.

[0148] The above is a detailed introduction to a hybrid energy storage device control method, equipment and medium provided by the present application. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can refer to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can refer to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

[0149] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A hybrid energy storage device control method, characterized in that: Applied to a hybrid energy storage device, the hybrid energy storage device includes a supercapacitor and a lithium battery; the method includes: Obtaining the actual voltage value and rated voltage value of the DC bus of the hybrid energy storage device; Determine a DC bus voltage deviation value according to an actual voltage value and a rated voltage value of the DC bus; Determining a DC bus power compensation value according to the DC bus voltage deviation value; The charging and discharging power of the supercapacitor is adjusted based on the DC bus power compensation value to stabilize the DC bus voltage.

2. The hybrid energy storage device control method according to claim 1, characterized in that: The method further comprises: Obtaining an actual voltage value and a target voltage value of the supercapacitor; Determine a supercapacitor voltage deviation value according to an actual voltage value of the supercapacitor and a target voltage value; Determining a supercapacitor power compensation value according to the supercapacitor voltage deviation value; The charging and discharging power of the lithium battery is adjusted based on the supercapacitor power compensation value to balance the voltage of the supercapacitor.

3. The hybrid energy storage device control method according to claim 2, characterized in that: Determining the supercapacitor power compensation value according to the supercapacitor voltage deviation value comprises: Determining a supercapacitor power compensation value according to the supercapacitor voltage deviation value by a rebalancing controller; Wherein, the transfer function of the rebalancing controller is a proportional-integral function, and the proportional-integral function is obtained according to the power-voltage model of the supercapacitor and the power model of the lithium battery.

4. The hybrid energy storage device control method according to any one of claims 1 to 3, characterized in that: The adjusting the charging and discharging power of the supercapacitor based on the DC bus power compensation value to stabilize the DC bus voltage includes: Adjusting the output power of the supercapacitor based on the DC bus power compensation value through the power electronic converter of the supercapacitor; The transfer function of the power electronic converter of the supercapacitor is obtained according to the power-voltage model of the DC bus and the power-voltage model of the supercapacitor.

5. The hybrid energy storage device control method according to claim 4, characterized in that: The power-voltage model of the DC bus is: ； Among them, v dc Represents the actual voltage value of the DC bus; G c represents the conductivity value of the hybrid energy storage device; C dc Represents the capacitance value of the DC bus; V dc Represents the voltage unit value of the DC bus; H dc Represents the inertia constant of the DC power system; P uc , P bat Respectively represent the power unit value of the supercapacitor and the lithium battery; P dcL Indicates the instantaneous power value of the DC load.

6. The hybrid energy storage device control method according to claim 4, characterized in that: The power-voltage model of the supercapacitor is: ； Among them, V uc , P uc Respectively represent the unit value of the supercapacitor voltage and power; G uc , C uc Respectively represent the parallel conductance and capacitance of the supercapacitor; H uc Represents the inertia constant of the AC power system.

7. The hybrid energy storage device control method according to claim 3, characterized in that: The power model of the lithium battery is: ； Among them, P uc , P bat Respectively represent the power unit values ​​of the supercapacitor and the lithium battery; Indicates the target power value of the lithium battery; Represents the supercapacitor power compensation value; K puc , K iuc are the proportional gain and integral gain of the rebalancing controller respectively; H uc Represents the inertia constant of the AC power system; G uc , C uc Respectively represent the parallel conductance value and capacitance value of the supercapacitor; V uc Represents the voltage unit value of the supercapacitor; Indicates the target voltage unit value of the supercapacitor.

8. A hybrid energy storage device control device, characterized in that: Applicable to a hybrid energy storage device, the hybrid energy storage device includes a supercapacitor and a lithium battery; the device includes: An acquisition module, used to acquire an actual voltage value and a rated voltage value of a DC bus of a hybrid energy storage device; A determination module, used to determine a DC bus voltage deviation value according to an actual voltage value and a rated voltage value of the DC bus; A compensation module, used to determine a DC bus power compensation value according to the DC bus voltage deviation value; The adjustment module is used to adjust the charging and discharging power of the supercapacitor based on the DC bus power compensation value to stabilize the DC bus voltage.

9. A hybrid energy storage device control device, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the hybrid energy storage device control method as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the hybrid energy storage device control method according to any one of claims 1 to 7 are implemented.

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