Power Allocation Method and System for Hybrid Energy Storage System Based on Active Disturbance Rejection Control

Abstract

The present invention relates to the technical field of a hybrid energy storage system composed of a fuel cell and an electrical energy storage device, and discloses a power distribution method and system for a hybrid energy storage system based on active disturbance rejection control. The present invention adopts active disturbance rejection control, which includes four parts: a nonlinear tracking differentiator, an extended state observer, feedback, and disturbance compensation. The nonlinear tracking differentiator generates a tracking trajectory and a differential trajectory based on the bus voltage and the reference voltage; the extended state observer is used to generate three state estimation outputs corresponding to the tracking trajectory, the differential trajectory, and the disturbance. In the feedback part, the tracking trajectory and the differential trajectory generated by the nonlinear tracking differentiator are respectively subtracted from the corresponding state estimation outputs generated by the extended state observer to obtain two tracking errors, and their weighted sum is calculated. Finally, disturbance compensation is performed through the disturbance observation value to obtain the reference value of the bus current to control the operation of the system. The present invention can effectively reduce the bus voltage fluctuation and ensure the safe operation of the hybrid energy storage system.

Description

Technical Field

[0001] The present invention relates to the technical field of a hybrid energy storage system of a fuel cell and an electrical energy storage device, and particularly relates to a power distribution method and system for a hybrid energy storage system based on active disturbance rejection control. Background Art

[0002] Under the background of carbon neutrality, the global automotive industry urgently needs to explore new energy fuels to reduce dependence on traditional petrochemical fuels. As a new energy source, hydrogen has the advantages of being clean, pollution-free, widely sourced, and having high combustion energy. Fuel cells (FCs) have become the main form of hydrogen energy application and have received much attention due to their high energy conversion efficiency and clean operation. Considering that the power output of fuel cells is slow and it is difficult to recover regenerative braking energy, using a fuel cell in combination with an electrical energy storage device is considered a good choice. For vehicles using a hybrid energy storage system, traditional filtering methods use a low-pass filter (LPF) or a high-pass filter to divide the load power into a high-frequency part and a low-frequency part, and distribute them to the electrical energy storage device and the FC in the hybrid energy storage system respectively. However, traditional PI control is easily affected by external disturbances, resulting in severe fluctuations in the DC bus voltage and affecting the stability of the hybrid energy storage system. Summary of the Invention

[0003] The present invention provides a power distribution method and system for a hybrid energy storage system based on active disturbance rejection control. Traditional PI control is easily affected by external disturbances, resulting in severe fluctuations in the DC bus voltage. When this method is applied to a vehicle, it can reduce the fluctuations in the DC bus voltage and ensure the stability of the hybrid energy storage system.

[0004] An embodiment of the present invention provides a power distribution method for a hybrid energy storage system based on active disturbance rejection control, which is applied to a hybrid energy storage system. The hybrid energy storage system is applied to a carrier vehicle and / or a renewable energy system. The carrier vehicle includes one or more of a passenger car, a truck, a bus, a ship, and an airplane. The renewable energy system includes one or more of a power grid and a microgrid. The hybrid energy storage system includes at least a first type of energy storage device and a second type of energy storage device. The second type of energy storage device includes one or more of a supercapacitor, a lithium-ion battery, a lithium-ion capacitor, a sodium-ion battery, and a solid-state battery. The first type of energy storage device includes one or more of a proton exchange membrane fuel cell, an alkaline fuel cell, a phosphoric acid fuel cell, a solid oxide fuel cell, and a molten carbonate fuel cell. The method includes: receiving the bus voltage at the previous moment and the reference voltage at the current moment, and generating a tracking trajectory and a differential trajectory through a nonlinear tracking differentiator; generating a first state estimation output, a second state estimation output, and a third state estimation output according to the bus voltage at the previous moment through an extended state observer; generating a first tracking error according to the reference voltage at the current moment, the tracking trajectory, and the first state estimation output, generating a second tracking error according to the second state estimation output and the differential trajectory, and adjusting the first tracking error and the second tracking error to determine the weighted sum at the current moment; performing disturbance compensation on the weighted sum based on the third state estimation output to obtain the current reference value of the bus current at the current moment, and determining the bus voltage at the current moment according to the current reference value of the bus current and the device disturbance, and distributing the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment.

[0005] In an embodiment of the present invention, the nonlinear tracking differentiator includes:

[0006] L1 = x1,

[0007]

[0008] where L1 is the tracking trajectory, x1 is the transition curve, x2 is the differential of the transition curve, L2 is the differential trajectory, r is the speed adjustment factor, V ref is the reference voltage at the current moment, and V bus is the bus voltage at the previous moment.

[0009] In an embodiment of the present invention, the extended state observer generates a first state estimation output, a second state estimation output, and a third state estimation output based on the bus voltage at the previous moment, including: removing disturbance compensation from the reference value of the bus current at the previous moment of the previous moment to obtain the weighted sum at the previous moment; generating the first state estimation output, the second state estimation output, and the third state estimation output based on the weighted sum at the previous moment and the bus voltage at the previous moment through the extended state observer.

[0010] In an embodiment of the present invention, the determination method of the extended state observer includes:

[0011] e = z1(k) - y(k),

[0012] z1(k + t s ) = z1(k) + t s (z2(k) - t s β 01 e),

[0013] z2(k + t s ) = z2(k) + t s (z3(k) - t s β 02 fal(e, α1, h) + t s bu(k)),

[0014] z3(k + t s ) = z3(k) - t s β 03 fal(e, α2, h),

[0015]

[0016] β 01 = 3ω0,

[0017]

[0018] where e is the discrete system error, z1(k), z2(k), z3(k), y(k), and u(k) are the observed values of the tracking trajectory, the observed value of the differential of the tracking trajectory, the observed value of the system disturbance, the system output, and the discrete expression form of the system input at the k-th moment, respectively. z1(k + t s ), z2(k + t s ), and z3(k + t s ) are the discrete expression forms of the observed values of the tracking trajectory, the differential of the tracking trajectory, and the system disturbance at the k + t s moment, respectively. t s is the preset time interval, β 01 , β 02 , β03 For the calculation gain of the extended state observer, ω0 is the bandwidth of the extended state observer, α1 and α2 are preset parameters, h is the integration step of the discrete system, b is the disturbance compensation, and fal(e, α2, h) can be regarded as the differential of the disturbance.

[0019] In an embodiment of the present invention, after determining the bus voltage at the current moment according to the current bus current reference value and the device disturbance, the method further includes: if the bus voltage at the current moment is greater than a first preset bus voltage threshold, cutting off the load power compensation of the electrical energy storage device; if the bus voltage at the current moment is less than or equal to a second preset bus voltage threshold, turning on the load power compensation of the electrical energy storage device; wherein, the first type of energy storage device is a fuel cell, and the second type of energy storage device is an electrical energy storage device.

[0020] In an embodiment of the present invention, if the bus voltage at the current moment is greater than a first preset bus voltage threshold, the method further includes determining the charging required state of the electrical energy storage device according to the current remaining power of the electrical energy storage device; and / or, if the bus voltage at the current moment is less than or equal to a second preset bus voltage threshold, the method further includes controlling the power generation system of the fuel cell to increase the power output, and the second preset bus voltage threshold is less than or equal to the first preset bus voltage threshold.

[0021] The embodiment of the present invention also provides a power distribution system for a hybrid energy storage system based on active disturbance rejection control, which is applied to the hybrid energy storage system. The hybrid energy storage system is applied to a carrier vehicle and / or a renewable energy system. The carrier vehicle includes one or more of a passenger car, a truck, a bus, a ship, and an airplane. The renewable energy system includes one or more of a power grid and a microgrid. The hybrid energy storage system includes at least a first type of energy storage device and a second type of energy storage device. The second type of energy storage device includes one or more of a supercapacitor, a lithium-ion battery, a lithium-ion capacitor, a sodium-ion battery, and a solid-state battery. The first type of energy storage device includes one or more of a proton exchange membrane fuel cell, an alkaline fuel cell, a phosphoric acid fuel cell, a solid oxide fuel cell, and a molten carbonate fuel cell. The system includes: a nonlinear tracking differentiator for receiving the bus voltage at the previous moment and the reference voltage at the current moment to generate a tracking trajectory and a differential trajectory; an extended state observer for generating a first state estimation output, a second state estimation output, and a third state estimation output according to the bus voltage at the previous moment; a feedback module for generating a first tracking error according to the reference voltage at the current moment, the tracking trajectory, and the first state estimation output, generating a second tracking error according to the second state estimation output and the differential trajectory, and adjusting the first tracking error and the second tracking error to determine the weighted sum at the current moment; and a disturbance compensation module for performing disturbance compensation on the weighted sum based on the third state estimation output to obtain the current bus current reference value at the current moment, determining the bus voltage at the current moment according to the current bus current reference value and the device disturbance, and distributing the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment.

[0022] The embodiment of the present invention also provides a power management system for a hybrid vehicle. The power management system of the hybrid vehicle includes the power distribution system for a hybrid energy storage system based on active disturbance rejection control as described in any one of the above embodiments, a filter, a first PI controller, a second PI controller, a Boost converter, and a bidirectional Buck-Boost converter; the bus voltage V at the previous moment bus and the reference voltage V at the current moment refInput the power distribution system of the hybrid energy storage system based on active disturbance rejection control to obtain the current bus current reference value; input the current bus current reference value into the filter to obtain the reference current of the first type of energy storage device; perform PI control on the theoretical current of the first type of energy storage device determined by the reference current of the first type of energy storage device and the current current of the first type of energy storage device through the first PI controller, and input the first PI control result into the Boost converter; determine the reference current of the second type of energy storage device based on the reference current of the first type of energy storage device and the current bus current reference value, determine the theoretical current of the second type of energy storage device according to the reference current of the second type of energy storage device and the current current of the second type of energy storage device, and input it into the second PI controller for PI control, and input the second PI control result into the bidirectional Buck-Boost converter; determine the bus current at the current moment through the first output result of the Boost converter, the second output result of the bidirectional Buck-Boost converter, and the device disturbance, and obtain the bus voltage at the current moment, and distribute the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment.

[0023] An embodiment of the present invention further provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the method described in any of the above embodiments is implemented.

[0024] An embodiment of the present invention further provides 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 method described in any of the above embodiments is implemented.

[0025] In the solution implemented by the above-provided power distribution method and system of the hybrid energy storage system based on active disturbance rejection control, the power distribution method of the hybrid energy storage system based on active disturbance rejection control considers the influence of load disturbance during the calculation of the bus voltage at the current moment, and introduces nonlinearity into the tracking differentiator to track the given signal faster without overshooting, avoiding the problem of severe fluctuations in the DC bus voltage caused by the influence of disturbances mainly composed of load disturbances, further ensuring the safe operation of the hybrid energy storage system. When this solution is applied to a vehicle, it can further ensure the safe driving of the vehicle. Description of the Drawings

[0026] To more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0027] Figure 1 Schematic structural diagram of a fuel cell hybrid vehicle provided by an embodiment of the present invention;

[0028] Figure 2 Flow schematic diagram of a power distribution method for a hybrid energy storage system based on active disturbance rejection control provided by an embodiment of the present invention;

[0029] Figure 3 Schematic structural diagram of a power distribution system for a hybrid energy storage system based on active disturbance rejection control provided by an embodiment of the present invention;

[0030] Figure 4 Another schematic structural diagram of a power distribution system for a hybrid energy storage system based on active disturbance rejection control provided by an embodiment of the present invention;

[0031] Figure 5 Principle schematic diagram of a power management system for a hybrid vehicle provided by an embodiment of the present invention;

[0032] Figure 6 Schematic structural diagram of an electronic device provided by an embodiment of the present invention. Detailed implementation manners

[0033] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the protection scope of the present invention.

[0034] It should be known that the "first", "second", etc. mentioned in the present invention are not necessarily used to describe a specific order of sequence, but are used to distinguish similar objects. When distinguishing similar objects with "first", "second", etc., the "first" and "second" they identify can be adjusted and interchanged under appropriate circumstances. The "multiple" described in the present invention refers to two or more without clear indication. In addition, in the embodiments of the present invention, for the description of "determining B according to A", it can be to determine B only according to A, or to determine B in combination with other information according to A.

[0035] Please refer to Figure 1As shown Figure 1 This is a schematic diagram of the structure of a fuel cell hybrid vehicle provided by an embodiment of the present invention. The electrical energy storage device is taken as a super capacitor for example. Figure 1 It is a topology of an FC / SC hybrid energy storage system in the context of the power system of a fuel cell hybrid electric vehicle. As Figure 1 shown, the vehicle is powered by at least a fuel cell and a super capacitor (energy storage battery). Among them, the fuel cell current I fc from one end of the fuel cell passes through the first fuel cell resistor R fc1 , the first fuel cell inductor L fc1 , and is supplied to the load through a Boost converter. The Boost converter (step-up converter) includes the second fuel cell resistor R fc2 , the second fuel cell inductor L fc2 , the fuel cell switch D fc . The output end of the first fuel cell inductor L fc1 is connected to one end of the fuel cell capacitor C fc , and the other end of the fuel cell is connected to the other end of the fuel cell capacitor C fc . The super capacitor current I sc from one end of the super capacitor is supplied to the load through a bidirectional Buck-Boost converter. The bidirectional Buck-Boost converter includes the super capacitor resistor R sc , the super capacitor inductor L sc , the super capacitor switch D sc . One end of the DC bus capacitor C bus is connected to the output ends of the Boost converter and the bidirectional Buck-Boost converter, and the other end of the DC bus capacitor C bus is connected to the other end of the fuel cell and the other end of the super capacitor. The DC bus current I bus is provided by the fuel cell and / or the super capacitor.

[0036] The load can be a device functioned by devices such as a vehicle motor. The disturbance brought by this load can be called device disturbance, which is mainly dominated by the load current I load . The load power is divided into a high-frequency part and a low-frequency part through a low-pass filter, etc. They are respectively allocated to the electrical energy storage device and the FC in the hybrid energy storage system through the bus voltage V bus . As mentioned above, due to the influence of disturbances mainly from the external load disturbance, the DC bus voltage (bus voltage) V bus fluctuates violently, which will lead to unreasonable power distribution.

[0037] To solve the above problems, an embodiment of the present invention provides a power distribution method for a hybrid energy storage system based on active disturbance rejection control. The hybrid energy storage system in this method or other embodiments can be applied to various scenarios, including but not limited to energy storage scenarios such as transportation tools and renewable energy systems. Transportation tools include but are not limited to vehicles, ships, aircraft, etc., such as passenger cars, trucks, buses, ships, airplanes and other transportation tools; renewable energy systems include but are not limited to power grids, microgrids, etc. As an example, this method can be applied to the vehicle hybrid energy storage system of a hybrid vehicle.

[0038] Please refer to Figure 2 as shown in Figure 2 FIG. is a schematic flowchart of a power distribution method for a hybrid energy storage system based on active disturbance rejection control provided by an embodiment of the present invention. The power distribution method for a hybrid energy storage system based on active disturbance rejection control can be applied to a hybrid energy storage system, which at least includes a first type of energy storage device and a second type of energy storage device. For example, the first type of energy storage device is a fuel cell, and the second type of energy storage device is an electrical energy storage device (such as a supercapacitor, etc.). Among them, the electrical energy storage device includes but is not limited to one or more of supercapacitors, lithium-ion batteries, lithium-ion capacitors, sodium-ion batteries, solid-state batteries, etc.; fuel cells include but are not limited to one or more of proton exchange membrane fuel cells, alkaline fuel cells, phosphoric acid fuel cells, solid oxide fuel cells, and molten carbonate fuel cells, etc. As Figure 2 shown, the method includes the following steps:

[0039] Step S210, receiving the bus voltage at the previous moment and the reference voltage at the current moment, and generating a tracking trajectory and a difference trajectory through a nonlinear tracking differentiator.

[0040] The nonlinear tracking differentiator (Nonlinear Tracking Differentiator, NTD), compared with the classical (linear) differential tracker, has quite good differential tracking effect, and the sensitivity to noise is much smaller than that of the classical differential tracker.

[0041] Introduce nonlinearity into the tracking differentiator to track the given signal bus current reference value more quickly

[0042] without overshoot.

[0043] L1 = x1 Equation (1),

[0044]

[0045] Among them, L1 is the tracking trajectory, x1 is the transition curve, x2 is the differential of the transition curve, L2 is the difference trajectory, r is the speed adjustment factor, V ref is the reference voltage at the current moment, and V bus is the bus voltage at the previous moment.

[0046] Step S220: Generate the first state estimation output, the second state estimation output, and the third state estimation output according to the bus voltage at the previous moment through an extended state observer.

[0047] In one embodiment, generating the first state estimation output, the second state estimation output, and the third state estimation output according to the bus voltage at the previous moment through an extended state observer includes: removing the disturbance compensation from the reference value of the bus current at the previous moment of the previous moment to obtain the weighted sum at the previous moment; generating the first state estimation output, the second state estimation output, and the third state estimation output according to the weighted sum at the previous moment and the bus voltage at the previous moment through an extended state observer.

[0048] Compared with the feedforward compensator, ADRC (Active Disturbance Rejection Control Algorithm) has less dependence on the model accuracy. Regarding the system as a second-order system, a design example of an Extended State Observer (ESO) is as follows:

[0049] e = z1(k) - y(k) Equation (4),

[0050] z1(k + t s ) = z1(k) + t s (z2(k) - t s β 01 e) Equation (5),

[0051] z2(k + t s ) = z2(k) + t s (z3(k) - t s β 02 fal(e, α1, h) + t s bu(k)) Equation (6),

[0052] z3(k + t s ) = z3(k) - t s β 03 fal(e, α2, h) Equation (7),

[0053]

[0054] β 01 = 3ω0 Equation (9),

[0055]

[0056] Among them, e is the discrete system error, z1(k), z2(k), z3(k), y(k), and u(k) are respectively the observed value of the tracking trajectory, the observed value of the differential of the tracking trajectory, the observed value of the disturbance, the system output, and the expression form of the system input at time k. z1(k + t s ), z2(k + t s ), and z3(k + t s ) are respectively the discrete expression forms of the observed values of the tracking trajectory, the differential of the tracking trajectory, and the system disturbance at time k + t s . t s is the preset time interval, β 01 , β 01 , and β 03 are the calculation gains of the extended state observer. ω0 is the bandwidth of the extended state observer, α1 and α2 are preset parameters, h is the integration step of the discrete system, b is the disturbance compensation, and fal(e, α2, h) can be regarded as the differential of the disturbance.

[0057] fal can be regarded as the differential of the disturbance. Therefore, z3 is the estimated disturbance, which is subsequently subtracted from the weighted sum u0 to achieve disturbance compensation. In an exemplary embodiment, α1 and α2 are set to 0.5 and 0.25.

[0058] Step S230: Generate a first tracking error based on the reference voltage, tracking trajectory, and first state estimation output at the current moment, generate a second tracking error based on the second state estimation output and the differential trajectory, and adjust the first tracking error and the second tracking error to determine the weighted sum at the current moment.

[0059] For the determination of the weighted sum at the current moment, it can be implemented in a manner known to those skilled in the art and will not be limited herein. This adjustment method can be achieved by weighted summing the first tracking error and the second tracking error. That is, the above adjustment includes weighted summing. The specific weight values can be set by those skilled in the art according to needs.

[0060] Step S240: Perform disturbance compensation on the weighted sum based on the third state estimation output to obtain the reference value of the current bus current at the current moment, determine the bus voltage at the current moment according to the reference value of the current bus current and the device disturbance, and allocate the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment.

[0061] In one embodiment, after determining the bus voltage at the current moment according to the current bus current reference value and the device disturbance, the method further includes: if the bus voltage at the current moment is greater than a first preset bus voltage threshold, cutting off the load power compensation of the electrical energy storage device; if the bus voltage at the current moment is less than or equal to a second preset bus voltage threshold, turning on the load power compensation of the electrical energy storage device; wherein, the first type of energy storage device is a fuel cell, and the second type of energy storage device is an electrical energy storage device.

[0062] Continuing with the above embodiment, if the bus voltage at the current moment is greater than the first preset bus voltage threshold, the method further includes determining the charging required state of the electrical energy storage device according to the current remaining power of the electrical energy storage device; and / or, if the bus voltage at the current moment is less than or equal to the second preset bus voltage threshold, the method further includes controlling the power generation system of the fuel cell to increase the power output. Wherein, the first preset bus voltage threshold is greater than or equal to the second preset bus voltage threshold.

[0063] For example, if the output power P of the fuel cell fc is greater than the load demand power P load , that is, the bus voltage U at the current moment o〉 is greater than the first preset bus voltage threshold U TH , then the battery power supply is cut off, and it is determined whether to start charging the battery according to the current SOC of the battery; if the load suddenly increases or the output power P of the fuel cell fc is less than the load demand power P load , that is, the bus voltage U at the current moment o〈 is less than the second preset bus voltage threshold U TL , then the battery is turned on, and the battery and the fuel cell jointly provide power for the load, so that when the output power of the fuel cell is insufficient, the battery performs dynamic power compensation to ensure the stable and reliable operation of the load device. Since the calculation of the bus voltage U at the current moment provided by the embodiment of the present invention o is reliable, the subsequent distribution of the load demand power is also reasonable.

[0064] The power distribution method of the hybrid energy storage system based on active disturbance rejection control provided by the above embodiment obtains a tracking trajectory and a differential trajectory by using a nonlinear tracking differentiator based on the bus voltage at the previous moment and the reference voltage at the current moment; through an extended state observer, three estimated outputs are generated according to the bus voltage at the previous moment, and two tracking errors are determined. The above tracking errors are weighted and summed to obtain the weighted sum at the current moment, and a disturbance compensation is performed on the weighted sum through an estimated output to obtain the reference value of the current bus current at the current moment. In this way, the reference value of the current bus current can be tracked faster without overshoot. During the calculation process, the influence of load disturbance is considered, and the problem of severe voltage fluctuation of the DC bus caused by the disturbance mainly composed of load disturbance is avoided, further ensuring the safe operation of the hybrid energy storage system (also known as the hybrid energy storage system).

[0065] The power distribution method of the hybrid energy storage system based on active disturbance rejection control provided by the above embodiment considers the influence of load disturbance during the calculation process, and introduces nonlinearity into the tracking differentiator to track the given signal faster without overshoot, avoiding the problem of severe voltage fluctuation of the DC bus caused by the disturbance mainly composed of load disturbance, and further ensuring the safe driving of the vehicle.

[0066] By using a nonlinear tracking differentiator to obtain a tracking trajectory and a differential trajectory based on the bus voltage at the previous moment and the reference voltage at the current moment, and generating a first state estimated output, a second state estimated output, and a third state estimated output according to the bus voltage at the previous moment through an extended state observer, then generating a first tracking error based on the reference voltage at the current moment, the tracking trajectory, and the first state estimated output, generating a second tracking error according to the second state estimated output and the differential trajectory, adjusting the above tracking errors to obtain the weighted sum at the current moment, and performing disturbance compensation on the weighted sum through the third state estimated output to obtain the reference value of the current bus current at the current moment, the reference value of the current bus current can be tracked faster without overshoot. During the calculation of the bus voltage at the current moment, the influence of load disturbance is considered, avoiding the problem of severe voltage fluctuation of the DC bus caused by the disturbance mainly composed of load disturbance, and further ensuring the safe driving of the vehicle.

[0067] Adopting active disturbance rejection control, it includes four parts: a nonlinear tracking differentiator, an extended state observer, feedback, and disturbance compensation. The nonlinear tracking differentiator generates a tracking trajectory and a differential trajectory based on the bus voltage and the reference voltage; the extended state observer is used to generate three state estimation outputs corresponding to the tracking trajectory, the differential trajectory, and the disturbance. In the feedback part, the tracking trajectory and the differential trajectory generated by the nonlinear tracking differentiator are respectively subtracted from the corresponding state estimation outputs generated by the extended state observer to obtain two tracking errors, and their weighted sum is calculated. Finally, disturbance compensation is performed through the disturbance observation value to obtain the reference value of the bus current to control the operation of the system. The present invention can effectively reduce the bus voltage fluctuation and ensure the safe operation of the hybrid energy storage system.

[0068] In one embodiment, a power distribution system of a hybrid energy storage system based on active disturbance rejection control is provided. The power distribution system of the hybrid energy storage system based on active disturbance rejection control corresponds one-to-one with the power distribution method of the hybrid energy storage system based on active disturbance rejection control in the above embodiment. Please refer to Figure 3 , Figure 3 FIG. is a schematic structural diagram of a power distribution system of a hybrid energy storage system based on active disturbance rejection control provided by an embodiment of the present invention. This system is applied to the hybrid energy storage system. The hybrid energy storage system in this embodiment or other embodiments can be applied to various scenarios, including but not limited to energy storage scenarios such as transportation tools, renewable energy systems, etc. Transportation tools include but are not limited to: vehicles, ships, aircraft, etc., such as passenger cars, trucks, buses, ships, airplanes and other transportation tools; renewable energy systems include but are not limited to: power grids, microgrids, etc. The hybrid energy storage system at least includes a first type of energy storage device and a second type of energy storage device. As an example, the first type of energy storage device can be a fuel cell, and the second type of energy storage device can be an electrical energy storage device. Among them, the electrical energy storage device includes one or more of supercapacitors, lithium-ion batteries, lithium-ion capacitors, sodium-ion batteries, and solid-state batteries; the fuel cell includes one or more of proton exchange membrane fuel cells, alkaline fuel cells, phosphoric acid fuel cells, solid oxide fuel cells, and molten carbonate fuel cells. As Figure 3As shown in the figure, the power distribution 300 of the hybrid energy storage system based on active disturbance rejection control includes a nonlinear tracking differentiator 310, an extended state observer 320, a feedback module 330, and a disturbance compensation module 340. The detailed description of each functional module is as follows: The nonlinear tracking differentiator 310 is used to receive the bus voltage at the previous moment and the reference voltage at the current moment, and generate a tracking trajectory and a differential trajectory; The extended state observer 320 is used to generate a first state estimation output, a second state estimation output, and a third state estimation output according to the bus voltage at the previous moment; The feedback module 330 is used to generate a first tracking error according to the reference voltage, the tracking trajectory, and the first state estimation output at the current moment, generate a second tracking error according to the second state estimation output and the differential trajectory, and adjust the first tracking error and the second tracking error to determine the weighted sum at the current moment; The disturbance compensation module 340 is used to perform disturbance compensation on the weighted sum based on the third state estimation output to obtain the current reference value of the bus current at the current moment, and determine the bus voltage at the current moment according to the current reference value of the bus current and the device disturbance, and distribute the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment.

[0069] Among them, the state equation of the nonlinear tracking differentiator includes those shown in the above formulas (1)-(3), which will not be elaborated here. The determination method of the extended state observer includes those shown in the above formulas (4)-(11), which will not be elaborated here.

[0070] In an embodiment, the power distribution system of the hybrid energy storage system based on active disturbance rejection control further includes a distribution module, which is used to cut off the load power compensation of the electrical energy storage device if the bus voltage at the current moment is greater than the first threshold of the preset bus voltage; and cut in the load power compensation of the electrical energy storage device if the bus voltage at the current moment is less than or equal to the second threshold of the preset bus voltage; where the first type of energy storage device is a fuel cell and the second type of energy storage device is an electrical energy storage device.

[0071] Continuing with the above embodiment, the distribution module is further used to determine the charging state required by the electrical energy storage device according to the current remaining power of the electrical energy storage device if the bus voltage at the current moment is greater than the first threshold of the preset bus voltage; and / or control the power output of the power generation system of the fuel cell to increase if the bus voltage at the current moment is less than or equal to the second threshold of the preset bus voltage, and the second threshold of the preset bus voltage is less than or equal to the first threshold of the preset bus voltage.

[0072] Please refer to Figure 4 , Figure 4 which is another structural schematic diagram of the power distribution system of the hybrid energy storage system based on active disturbance rejection control provided by the embodiment of the present invention. As shown in Figure 4 the figure, a design for maintaining the stability of the DC bus voltage is proposed by presenting a power distribution scheme based on active disturbance rejection control. The specific design is as follows:

[0073] The power distribution system (ADRC block) is divided into four parts: the Nonlinear Tracking Differentiator (NTD, shown as NTD in Figure 4 ), the feedback module (shown as feedback in Figure 4 ), the disturbance compensation module (shown as disturbance compensation in Figure 4 ), and the Extended State Observer (ESO, shown as ESO in Figure 4 ). The bus voltage V bus (the bus voltage at the previous moment) and its reference value V ref (the reference voltage at the current moment) are fed into the NTD, and the NTD generates the tracking trajectory L1 and its difference L2 (the difference trajectory). Based on V bus , the ESO generates three state estimation outputs z1, z2, and z3 (i.e., the first state estimation output, the second state estimation output, and the third state estimation output). V ref , L1, and z1 together generate the tracking error e1 (the first tracking error). Similarly, L2 and z2 generate the differential error e2 (the second tracking error). The two errors e1 and e2 pass through two gain modules K r and K d in the feedback loop (adjust the two errors) to generate the weighted sum u0. In the disturbance compensation part, z3 from the ESO passes through the 1 / b0 block, where b0 is a compensation coefficient related to the controlled object model. According to u0 and z3, the plant input u is obtained, which is actually the reference value of the bus current The device disturbance is represented as It is dominated by the load current I load . z3 is the estimated disturbance, which is subtracted from the weighted sum u0 to achieve disturbance compensation. The reference DC bus voltage and the DC bus voltage input to the system output the reference DC bus current according to formulas (1) - (11) to achieve control.

[0074] For the specific limitations of the power distribution system of the hybrid energy storage system based on active disturbance rejection control, reference can be made to the limitations of the power distribution method of the hybrid energy storage system based on active disturbance rejection control in the above text, which will not be elaborated here. Each module in the above-mentioned power distribution system of the hybrid energy storage system based on active disturbance rejection control can be implemented in whole or in part through software, hardware, and their combination. The above-mentioned modules can be embedded in the processor of the electronic device in hardware form or be independent of it, or can be stored in the memory of the electronic device in software form, so as to facilitate the processor to call and execute the operations corresponding to the above-mentioned modules.

[0075] In this embodiment, the power distribution system of the hybrid energy storage system based on active disturbance rejection control essentially sets up multiple modules to execute the methods in any of the above embodiments. For the specific functions and technical effects, please refer to the above embodiments and will not be elaborated here.

[0076] In one embodiment, a power management system for a hybrid vehicle is provided. The power management system of the hybrid vehicle includes the power distribution system of the hybrid energy storage system based on active disturbance rejection control provided in any of the above embodiments, and the power distribution system of the hybrid energy storage system based on active disturbance rejection control corresponds one-to-one with the power distribution method of the hybrid energy storage system based on active disturbance rejection control in the above embodiments. Please refer to Figure 5 , Figure 5 which is a schematic diagram of the principle of the power management system for a hybrid vehicle provided by an embodiment of the present invention. As Figure 3 shown, the power management system of the hybrid vehicle includes a power distribution system ADRC (labeled as ADRC here for easy identification), a filter LPF, a first PI controller ( Figure 5 the PI located above in Figure 5 ), a second PI controller ( Figure 5 the Boost converter ( Figure 5 shown as Boost in bus ), a bidirectional Buck-Boost converter ( ref shown as Buck-Boost in bus ), where the input end of the ADRC is used to input the bus voltage V at the previous moment ref and the reference voltage V at the current moment. The output end of the ADRC is connected to the input end of the filter LPF, and the output end of the ADRC is also connected to the output end of the filter LPF and the input end of the second PI controller. The output end of the filter LPF is also connected to the input end of the first PI controller. The output end of the first PI controller is connected to the input end of the Boost converter, and the output end of the second PI controller is connected to the input end of the bidirectional Buck-Boost converter. The output ends of the Boost converter and the bidirectional Buck-Boost converter are connected to the bus DC bus. Among them: the bus voltage V at the previous moment and the reference voltage V at the current moment are input into the power distribution system ADRC of the hybrid energy storage system based on active disturbance rejection control to obtain the current bus current reference value The current bus current reference value is input into the filter LPF to obtain the reference current of the first type of energy storage device fcThe current of the determined theoretical first - type energy storage device is PI - controlled by a first PI controller, and the first PI control result is input into a Boost converter;

[0077] Based on the reference current of the first - type energy storage device and the current reference value of the current bus determine the reference current of the second - type energy storage device According to the reference current of the second - type energy storage device and the current I of the current second - type energy storage device sc the determined theoretical current of the second - type energy storage device is input into a second PI controller for PI control, and the second PI control result is input into a bidirectional Buck - Boost converter;

[0078] Determine the current I of the current bus at the current moment through the first output result of the Boost converter, the second output result of the bidirectional Buck - Boost converter, and the device disturbance bus and obtain the bus voltage V at the current moment bus Through the bus voltage V at the current moment bus allocate the load power of the first - type energy storage device and the second - type energy storage device.

[0079] Compared with the scheme in the related art, the system provided in this embodiment first calculates the line - current reference value through the power distribution system of the hybrid energy storage system based on active disturbance rejection control, excludes the influence of device disturbances caused by load disturbances, etc., avoids the severe fluctuation of the DC bus voltage, improves the accuracy and reliability of load power distribution, and improves the vehicle performance.

[0080] Figure 6 See Figure 6 , Figure 6 is a schematic structural diagram of an electronic device provided by an embodiment of the present invention. As Figure 6 shown, an embodiment of the present invention also provides an electronic device 600, including a processor 601, a memory 602, and a communication bus 603; the communication bus 603 is used to connect the processor 601 and the memory 602; the processor 601 is used to execute a computer program stored in the memory 602 to implement the method provided in any of the above - mentioned embodiments.

[0081] An embodiment of the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the foregoing memory and executable on the foregoing processor. When the foregoing processor executes the foregoing computer program, it implements the method provided in any of the above - mentioned embodiments.

[0082] An embodiment of the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the method according to any one of the above embodiments is implemented.

[0083] An embodiment of the present invention also provides a non-volatile readable storage medium, in which one or more modules (programs) are stored. When the one or more modules are applied to a device, the device can be caused to execute the instructions included in the first embodiment of the embodiments of the present invention.

[0084] It should be noted that the computer-readable medium described above in the present disclosure may be a computer-readable signal medium, a computer-readable storage medium, or any combination of the two. A computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples of the computer-readable storage medium may include, but are not limited to: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In the present disclosure, a computer-readable storage medium may be any tangible medium that contains or stores a program, which can be used by or in conjunction with an instruction execution system, apparatus, or device. In the present disclosure, a computer-readable signal medium may include a data signal propagated in a baseband or as part of a carrier wave, in which computer-readable program code is carried. Such a propagated data signal may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination of the above. A computer-readable signal medium may also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in conjunction with an instruction execution system, apparatus, or device. The program code contained on the computer-readable medium may be transmitted by any appropriate medium, including but not limited to: wires, optical cables, RF (radio frequency), etc., or any suitable combination of the above.

[0085] The above computer-readable medium may be included in the above electronic device; or it may exist separately and not be assembled into the electronic device.

[0086] Computer program code for performing the operations of this disclosure may be written in one or more programming languages or combinations thereof. The programming languages include object-oriented programming languages such as Java, Smalltalk, C++, and also include conventional procedural programming languages such as “package languages or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, executed as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the case of a remote computer, the remote computer may be connected to the user's computer through any kind of network, including a local area network (LAN) or a wide area network (WAN), or may be connected to an external computer (e.g., by connecting through the Internet using an Internet service provider).

[0087] The flowcharts and block diagrams in the accompanying drawings illustrate the possible architectures, functions, and operations of methods and computer program products according to various embodiments of this disclosure. In this regard, each block in the flowchart or block diagram may represent a module, a segment of a program, or a part of code, which contains one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than marked in the accompanying drawings. For example, two consecutive blocks shown may actually be executed substantially in parallel, and they may sometimes be executed in the reverse order, depending on the functions involved. It should also be noted that each block in the block diagram and / or flowchart, and combinations of blocks in the block diagram and / or flowchart, may be implemented by a dedicated hardware-based system that performs the specified functions or operations, or may be implemented by a combination of dedicated hardware and computer instructions.

[0088] The above embodiments are only used to exemplarily illustrate the principles and effects of the present invention, rather than to limit the present invention. Any person familiar with this technology may modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those of ordinary skill in the art without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A power distribution method for a hybrid energy storage system based on active disturbance rejection control, characterized in that Applied to a hybrid energy storage system, the hybrid energy storage system is applied to a vehicle and / or a renewable energy system. The hybrid energy storage system includes at least a first type of energy storage device and a second type of energy storage device. The second type of energy storage device is an electrical energy storage device, and the first type of energy storage device is a fuel cell. The power distribution method for the hybrid energy storage system based on active disturbance rejection control includes: Receive the bus voltage at the previous moment and the reference voltage at the current moment, and generate a tracking trajectory and a difference trajectory through a nonlinear tracking differentiator; the nonlinear tracking differentiator includes: L1 = x1, where L1 is the tracking trajectory, x1 is the transition curve, x2 is the differential of the transition curve, L2 is the difference trajectory, r is the speed adjustment factor, V ref is the reference voltage at the current moment, and V bus is the bus voltage at the previous moment; Generating a first state estimation output, a second state estimation output, and a third state estimation output by an extended state observer according to the bus voltage at the previous moment; Generating a first tracking error according to the reference voltage at the current moment, the tracking trajectory, and the first state estimation output, generating a second tracking error according to the second state estimation output and the differential trajectory, and adjusting the first tracking error and the second tracking error to determine the weighted sum at the current moment; Performing disturbance compensation on the weighted sum based on the third state estimation output to obtain the current reference value of the bus current at the current moment, determining the bus voltage at the current moment according to the current reference value of the bus current and the device disturbance, and distributing the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment.

2. The power distribution method of the hybrid energy storage system based on active disturbance rejection control according to claim 1, wherein Generating a first state estimation output, a second state estimation output, and a third state estimation output by an extended state observer according to the bus voltage at the previous moment, including: Removing disturbance compensation from the reference value of the bus current at the previous moment of the previous moment to obtain the weighted sum at the previous moment; Generating the first state estimation output, the second state estimation output, and the third state estimation output by the extended state observer according to the weighted sum at the previous moment and the bus voltage at the previous moment.

3. The power distribution method of the hybrid energy storage system based on active disturbance rejection control according to claim 1, wherein The determination method of the extended state observer includes: e = z1(k) - y(k), z1(k + t s ) = z1(k) + t s (z2(k) - t s β 01 e), z2(k + t s ) = z2(k) + t s (z3(k) - t s β 02 fal(e, α1, j) + t s bu(k)), z3(k+t s ) = z3(k) - t s β 03 fal(e, α2, h), β 01 = 3ω0, Among them, e is the discrete system error, z1(k), z2(k), z3(k), y(k), and u(k) are the observed values of the tracking trajectory, the observed value of the differential of the tracking trajectory, the observed value of the system disturbance, the system output, and the discrete expression form of the system input at time k, respectively. z1(k + t s ), z2(k + t s ), and z3(k + t s ) are the discrete expression forms of the observed values of the tracking trajectory, the differential of the tracking trajectory, and the system disturbance at time k + t s , respectively. t s is the preset time interval, β 01 , β 02 , and β 03 are the calculation gains of the extended state observer, ω0 is the bandwidth of the extended state observer, α1 and α2 are preset parameters, h is the integration step of the discrete system, b is the disturbance compensation, and fal(e, α2, h) can be regarded as the differential of the disturbance.

4. The power distribution method of the hybrid energy storage system based on active disturbance rejection control according to any one of claims 1-3, characterized in that, After determining the bus voltage at the current moment according to the current reference value of the bus current and the device disturbance, the method further includes: If the bus voltage at the current moment is greater than the first preset bus voltage threshold, cutting off the load power compensation of the electrical energy storage device; If the bus voltage at the current moment is less than or equal to the second preset bus voltage threshold, turning on the load power compensation of the electrical energy storage device.

5. The power distribution method for the hybrid energy storage system based on active disturbance rejection control according to claim 4, wherein If the bus voltage at the current moment is greater than the first preset bus voltage threshold, the method further includes determining the required charging state of the electrical energy storage device according to the current remaining power of the electrical energy storage device; And / or If the bus voltage at the current moment is less than or equal to the second preset bus voltage threshold, the method further includes controlling the power generation system of the fuel cell to increase the power output, and the second preset bus voltage threshold is less than or equal to the first preset bus voltage threshold.

6. A power distribution system for a hybrid energy storage system based on active disturbance rejection control, characterized in that, Applied to a hybrid energy storage system, the hybrid energy storage system is applied to a vehicle and / or a renewable energy system. The hybrid energy storage system includes at least a first type of energy storage device and a second type of energy storage device. The second type of energy storage device is an electrical energy storage device, and the first type of energy storage device is a fuel cell. The power distribution system includes: A non-linear tracking differentiator, which is used to receive the bus voltage at the previous moment and the reference voltage at the current moment, and generate a tracking trajectory and a differential trajectory; the non-linear tracking differentiator includes: L1 = x1, wherein, L1 is the tracking trajectory, x1 is the transition curve, x2 is the differential of the transition curve, L2 is the differential trajectory, r is the speed adjustment factor, V ref is the reference voltage at the current moment, V bus is the bus voltage at the previous moment; An extended state observer for generating a first state estimation output, a second state estimation output, and a third state estimation output based on the bus voltage at the previous moment; A feedback module for generating a first tracking error based on the reference voltage at the current moment, the tracking trajectory, and the first state estimation output, generating a second tracking error based on the second state estimation output and the differential trajectory, and adjusting the first tracking error and the second tracking error to determine the weighted sum at the current moment; A disturbance compensation module for performing disturbance compensation on the weighted sum based on the third state estimation output to obtain the current bus current reference value at the current moment, determining the bus voltage at the current moment based on the current bus current reference value and the device disturbance, and allocating the load power of the first type of energy storage device and the second type of energy storage device through the bus voltage at the current moment; 7. The power distribution system of the hybrid energy storage system based on active disturbance rejection control according to claim 6, wherein The extended state observer is configured to: Remove disturbance compensation from the bus current reference value at the previous moment of the previous moment to obtain the weighted sum at the previous moment; Generate the first state estimation output, the second state estimation output, and the third state estimation output through the extended state observer based on the weighted sum at the previous moment and the bus voltage at the previous moment; 8. The power distribution system of the hybrid energy storage system based on active disturbance rejection control according to claim 6, wherein The power distribution system of the hybrid energy storage system based on active disturbance rejection control further includes a distribution module, and the distribution module is used to cut off the load power compensation of the electrical energy storage device if the bus voltage at the current moment is greater than the first preset bus voltage threshold; if the bus voltage at the current moment is less than or equal to the second preset bus voltage threshold, cut in the load power compensation of the electrical energy storage device; wherein, the first type of energy storage device is a fuel cell, and the second type of energy storage device is an electrical energy storage device.

9. A power management system for a hybrid vehicle, characterized in that, The power management system of the hybrid vehicle includes the power distribution system of the hybrid energy storage system based on active disturbance rejection control as claimed in claim 7, a filter, a first PI controller, a second PI controller, a Boost converter, and a bidirectional Buck-Boost converter; The bus voltage V at the previous moment bus and the reference voltage V at the current moment ref are input into the power distribution system of the hybrid energy storage system based on active disturbance rejection control to obtain the current reference value of the bus current; Input the current bus current reference value into the filter to obtain the reference current of the first type of energy storage device; Perform PI control on the theoretical current of the first type of energy storage device determined by the reference current of the first type of energy storage device and the current current of the first type of energy storage device through the first PI controller, and input the result of the first PI control into the Boost converter; Determine the reference current of the second type of energy storage device based on the reference current of the first type of energy storage device and the current bus current reference value, determine the theoretical current of the second type of energy storage device based on the reference current of the second type of energy storage device and the current current of the second type of energy storage device, and input it into the second PI controller for PI control, and input the result of the second PI control into the bidirectional Buck-Boost converter; Determine the bus current at the current moment based on the first output result of the Boost converter, the second output result of the bidirectional Buck-Boost converter, and the device disturbance, and obtain the bus voltage at the current moment. Allocate the load power of the first type of energy storage device and the second type of energy storage device based on the bus voltage at the current moment.

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