Direct-current micro-grid isomorphic energy storage adaptive voltage / power droop control method, terminal equipment and storage medium

Abstract

The invention discloses a DC micro-grid isomorphic energy storage adaptive voltage / power droop control method, terminal equipment and a storage medium. The method comprises an isomorphic energy storage unit bus voltage / power droop control strategy and an adaptive power support strategy based on droop bus voltage translation. Wherein the bus voltage / power droop control link is used for parallel output distribution control of isomorphic energy storage units, the two energy storage units are connected in parallel through a port converter according to a voltage / power droop control strategy, a voltage control reference value Uref is obtained through a droop curve, and bus voltage and bearing load power are jointly established through voltage and current double-closed-loop control; in order to cope with the impact of a high-power load, a self-adaptive power support strategy based on droop curve bus voltage translation is added on the basis of voltage / power droop control and is used for dynamic power active support of the isomorphic energy storage unit, the bus voltage fluctuation is reduced, and the voltage quality is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of isomorphic energy storage power supply and control, and particularly to an adaptive voltage / power droop control method, a terminal device and a storage medium for isomorphic energy storage in a DC microgrid. Background Art

[0002] Due to its advantages such as simple structure and high energy conversion efficiency, the DC microgrid has become an important form of distributed energy systems. In a DC microgrid, the energy storage system (ESS), as the core unit for power balance and voltage support, the quality of its control strategy directly affects the system stability and equipment life. Traditional droop control simulates the external characteristics of a synchronous generator, enabling the energy storage unit to autonomously distribute power based on local voltage information. However, the design of fixed droop coefficients in this method faces significant challenges in practical applications. Moreover, the linear voltage / power relationship of traditional droop control is difficult to adapt to complex working conditions. For example, when the load suddenly changes or the output of renewable energy fluctuates violently, the system's dynamic response is slow, which may cause the bus voltage to exceed the limit and even trigger the operation of the protection device. Therefore, an adaptive voltage / power droop control strategy for isomorphic energy storage in a DC microgrid under special large-power load impact scenarios in remote areas is needed, including a bus voltage / power droop control system for isomorphic energy storage units and an adaptive power support strategy based on droop bus voltage translation. On the one hand, it ensures the reasonable distribution of the parallel output of isomorphic energy storage units, and on the other hand, it ensures the active support of the dynamic power of isomorphic energy storage units, reduces the bus voltage fluctuation, and improves the voltage quality. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an adaptive voltage / power droop control method, a terminal device and a storage medium for isomorphic energy storage in a DC microgrid, in view of the deficiencies of the prior art, to ensure the reasonable distribution of the parallel output of isomorphic energy storage units and the active support of the dynamic power of isomorphic energy storage units, reduce the bus voltage fluctuation, and improve the voltage quality.

[0004] To solve the above technical problem, the technical solution adopted by the present invention is: an adaptive voltage / power droop control method for isomorphic energy storage in a DC microgrid, comprising the following steps:

[0005] S1. Calculate the output signal \(i\) of the voltage outer-loop PI controller of the \(j\)-th energy storage DC / DC converter refj : \(i\) ref,j \(=G\) bv \((U\) ref* \(-K\) db \(*P\) o \(+\Delta U)\); where \(U\) ref* is the bus voltage reference value, \(P\) o is the output power of the energy storage DC / DC converter, \(k\) dbis the voltage / power droop coefficient, U ref is the voltage outer-loop control command value, ΔU is the bus voltage translation amount, G bvi are respectively the PI controllers of the voltage outer loop, k pv is the proportional coefficient, k pi is the integral coefficient, s is the complex variable;

[0006] S2. According to the output signal i of the voltage outer-loop PI controller of the j-th energy storage DC / DC converter refj calculate the duty cycle d of the j-th energy storage DC / DC converter j , and through PWM modulation, obtain the drive signal of the switching tube of the j-th energy storage DC / DC converter.

[0007] In the case of a DC microgrid, the present invention designs a homogeneous energy storage unit bus voltage / power droop control system for the parallel output power distribution control of homogeneous energy storage units. Two energy storage units are connected in parallel through an energy storage DC / DC converter by a voltage / power droop control strategy, and the voltage control reference value U ref is obtained from the droop curve, and the bus voltage is jointly established and the load power is borne through voltage-current double closed-loop control, so as to realize the efficient utilization of energy and the stability of power supply.

[0008] The duty cycle d of the j-th energy storage DC / DC converter j has the following calculation formula: d j =G bi (I ref,j -i b,j ); where G bi is the transfer function of the current inner-loop PI controller, k pi is the proportional coefficient, k ii is the integral coefficient, i b,j is the input current of the j-th energy storage DC / DC converter.

[0009] The voltage / power droop coefficient k db has the following calculation formula: where, U max , U min are respectively the upper and lower limits of the output voltage control command value U ref of the energy storage DC / DC converter, P omax , P omin are respectively the maximum output power and the maximum absorption power of the energy storage DC / DC converter.

[0010] The calculation formula for the bus voltage translation amount ΔU is:

[0011]

[0012] where m is the translation coefficient, and P o is the current output power of the energy storage DC / DC converter, and P omax and P imax are the maximum output power and the maximum absorption power of the energy storage DC / DC converter respectively, and u bus is the bus voltage.

[0013] As an inventive concept, the present invention further provides a terminal device, including:

[0014] one or more processors;

[0015] a memory, on which one or more programs are stored, and when the one or more programs are executed by the one or more processors, the one or more processors are caused to implement the steps of the above method.

[0016] As an inventive concept, the present invention further provides a computer-readable storage medium, which stores a computer program, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0018] 1) In the case of a DC microgrid, the present invention designs a bus voltage / power droop control system for isomorphic energy storage units for parallel output power distribution control of isomorphic energy storage units. Two energy storage units are connected in parallel through a port converter by a voltage / power droop control strategy, and the voltage control reference value Uref is obtained from the droop curve. The bus voltage is jointly established and the load power is borne through a voltage-current double closed-loop control, so as to realize the efficient utilization of energy and the stability of power supply;

[0019] 2) Aiming at the problem that the inherent support ability of the bus capacitor in the DC microgrid system is weak, the present invention invents an adaptive power support strategy based on the translation of the bus voltage of the droop curve. When the bus voltage changes due to a load impact, the droop curve is dynamically translated according to the rate of change of the bus voltage. The energy storage unit provides instantaneous power support for the DC bus, improves the system support ability, reduces the bus voltage fluctuation, and at the same time, to ensure the full utilization of the support ability of the energy storage DC / DC converter and avoid overcompensation, the arctangent function is introduced to calculate the bus voltage translation amount to achieve the adaptive function.

[0020] 3) In the adaptive power support strategy based on the translation of the bus voltage of the droop curve in the present invention, the arctangent function is used to calculate the bus voltage translation amount of the droop curve, which has a large slope when the independent variable m*du bus / dt is small, indicating that the translation speed of the droop curve is fast in the initial stage of a large-power load impact, and as the independent variable m*du bus / dt increases continuously, which can smoothly approach the output limit and is beneficial to the stability of the system bus voltage. Description of the Drawings

[0021] Figure 1 It is the overall control block diagram of the adaptive voltage / power droop control strategy for the homogeneous energy storage in the DC microgrid of the embodiment of the present invention;

[0022] Figure 2 It is the power support diagram realized by the droop curve translation in the embodiment of the present invention;

[0023] Figure 3 It is the compensator control detection timing and calculation method selection unit in the embodiment of the present invention;

[0024] Figure 4 It is the calculation block diagram of the bus voltage translation amount in the embodiment of the present invention;

[0025] Figure 5 It is the main simulation waveform diagram of the adaptive voltage / power droop control strategy for the homogeneous energy storage in the DC microgrid of the embodiment of the present invention; (a) Output current and bus voltage waveforms when using the conventional voltage / power droop control strategy, (b) Output current and bus voltage waveforms when using the adaptive voltage / power droop control strategy for the homogeneous energy storage in the DC microgrid, (c) Bus voltage translation amount and maximum translation amount waveforms. Detailed Embodiment

[0026] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying 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 shall fall within the protection scope of the present invention.

[0027] Embodiment 1

[0028] As Figure 1 shown, for the adaptive voltage / power droop control strategy of the homogeneous energy storage in the DC microgrid of the embodiment of the present invention, two energy storage units are connected in parallel through a port converter by the voltage / power droop control strategy, and the voltage control reference value U ref is obtained from the droop curve. Through the voltage-current double closed-loop control, the bus voltage is jointly established and the load power is borne. To cope with the impact of large-power loads, an adaptive power support strategy based on the bus voltage translation of the droop curve is added on the basis of the voltage / power droop control to reduce the bus voltage fluctuation and improve the voltage quality.

[0029] Figure 1Adaptive voltage / power droop control strategy for the isomeric energy storage in the DC microgrid of the embodiment. The specific operation steps are as follows:

[0030] S1. Calculate the output signal i of the voltage outer-loop PI controller of the j-th energy storage DC / DC converter ref,j ;

[0031] i ref,j =G bv (U ref* -K db *P o +ΔU);

[0032] Where where U ref* is the bus voltage reference value, P o is the output power of the energy storage DC / DC converter, k db is the voltage / power droop coefficient, U ref is the voltage outer-loop control command value, G bv is the PI controller of the voltage outer-loop, k pv is the proportional coefficient, k pi is the integral coefficient, ΔU is the bus voltage translation amount, and s is the complex variable;

[0033] S2. Calculate the duty cycle d of the j-th energy storage DC / DC converter j , and through PWM modulation, obtain the drive signal of the switching tube of the j-th energy storage DC / DC converter;

[0034] The calculation formula for the duty cycle d of the j-th energy storage DC / DC converter is: d j =G j (I bi -i ref,j );Where b,j G bi is the transfer function of the current inner-loop PI controller, k pi is the proportional coefficient, k ii is the integral coefficient, and i b,j is the input current of the converter.

[0035] In the isomeric energy storage unit bus voltage / power droop control system, according to the output powers P o1 and P o2 of the two energy storage port converters and the rated values U ref* of the output voltages of the energy storage unit port converters and the output voltage control command values U ref1 and U ref2 、U max draw the U-P droop curve of the energy storage unit, where U min 、U ref are the output voltage control command values Uref The upper and lower limits of P omax and P omin are the maximum output power and the maximum absorption power of the port converter respectively, and the droop coefficient K is obtained db The calculation formula of which is

[0036] The adaptive power support strategy based on the droop bus voltage translation includes the following steps:

[0037] S1. To avoid excessive amplification of differential control when dealing with high-frequency noise, the bus voltage u bus enters the differential control after passing through a low-pass filter to extract the change rate u m of the bus voltage under the impact of high-power loads. The expression of the low-pass filter is RC is the time constant of the low-pass filter;

[0038] S2. The compensator control is divided into two parts. The first part includes a detection timing unit and a calculation method selection unit, which are used to detect the bus voltage volatility and judge whether the bus voltage reaches the steady state. The extracted change rate of the bus voltage is substituted into the detection timing unit, and the initial values of the flag bits C, T, and S w are 0, 1, and 0 respectively. When the change rate of the bus voltage exceeds the set upper or lower limit, the flag bit C is set to 1, and at the same time the flag bit T is set to 0. At this time, the values of the three flag bits C, T, and S w in the calculation method selection unit are 1, 0, and 0 respectively. According to the relationship between the change rate u m of the bus voltage and the upper and lower limits U up and U lim , the flag bit S w is set to the corresponding value, and the value of S w is substituted into the bus voltage translation amount calculation block diagram shown in the bus voltage translation amount calculation block diagram to generate the bus voltage translation amount ΔU.

[0039] S3. The second unit is the droop curve bus voltage translation amount calculation block diagram. To ensure the full utilization of the bus voltage support ability of the energy storage unit when it operates at different steady-state working points of the droop curve to achieve the adaptive function, and at the same time meet the limit of the translation amount of the droop curve, the arctangent function is used to calculate the translation amount of the droop curve bus voltage, and the expression is Substitute the value of S w obtained in step S2 into the bus voltage translation amount calculation block diagram to generate the bus voltage translation amount ΔU.

[0040] In the adaptive power support strategy based on the droop bus voltage translation, the expression of the voltage / power droop curve of the energy storage unit is U ref = U ref* - K db * Po becomes i ref,j = G bv (U ref* - K db * P o + ΔU), where ΔU is the droop curve bus voltage translation amount, m is the translation coefficient, P o is the current output power of the energy storage DC / DC converter, P omax and P imax are the maximum output power and the maximum absorption power of the energy storage DC / DC converter respectively.

[0041] In the adaptive power support strategy based on droop bus voltage translation, when a large-power impact load is removed, the instantaneous power deficit ΔP of the energy storage unit > 0, and the droop curve translates downward. At this time, the maximum support power of the system is the output power minus the maximum absorption power, that is, P o - P imax . When a large-power impact load is connected, the instantaneous power deficit ΔP of the energy storage unit < 0, and the droop curve translates upward. At this time, the maximum support power of the system is the maximum output power minus the output power, that is, P omax - P o . At the same time, due to different operating points Po, so P o - P imax and P omax - P o have different values, and finally the droop curve bus voltage translation amount ΔU obtained is also different, satisfying the function of realizing system adaptability.

[0042] As Figure 1 shown, in the adaptive voltage / power droop control strategy of the homogeneous energy storage in the DC microgrid of the embodiment of the present invention, an adaptive power support strategy based on droop curve bus voltage translation is added on the basis of voltage / power droop control. The bus voltage u bus passes through a low-pass filter and then enters differential control to extract the bus voltage change rate u m under a large-power load impact, so as to avoid excessive amplification in differential control when dealing with high-frequency noise. The compensator control is divided into two parts. The first part includes a detection timing unit and a calculation method selection unit, which are used to detect the bus voltage volatility and judge whether the bus voltage reaches a steady state. The second unit is a calculation block diagram of the droop curve bus voltage translation amount, which ensures the full utilization of the bus voltage support ability of the energy storage unit when operating at different steady-state operating points of the droop curve to realize the adaptive function, and at the same time satisfies the amplitude limit of the droop curve translation amount.

[0043] As Figure 2As shown in the figure, the adaptive voltage / power droop control strategy for the isomorphic energy storage in the DC microgrid of the embodiment of the present invention takes the input of a large-power impact load as an example, and realizes the power support of the energy storage unit for the DC bus through the translation of the voltage / power droop curve: when the energy storage unit operates at point A, P A , U A are respectively the output power and output voltage of the port converter of the energy storage unit. At this time, when a large-power impact load is input, the instantaneous power deficit will cause the output capacitor to release a large amount of energy, and the bus voltage will drop rapidly. Under normal voltage / power droop control, the energy storage unit moves from the operating point A to the operating point B along the droop curve, and the output power increases from P A to P B . In order to realize the instantaneous power support of the energy storage unit for the DC bus, when a large-power impact load is input, it is required that the droop curve can be quickly translated from point A to point C, and the output power of the port converter can be quickly increased from P A to P B , so as to reduce the energy released by the bus capacitor and thus reduce the bus voltage change rate. In the power support strategy based on the translation of the droop bus voltage, the expression of the voltage / power droop curve of the energy storage unit changes from U ref = U ref* - K db * P o to where ΔU is the translation amount of the bus voltage of the droop curve, m is the translation coefficient, P o is the current output power of the energy storage DC / DC converter, P omax and P imax are respectively the maximum output power and maximum absorption power of the energy storage DC / DC converter. When the large-power impact load is removed, the instantaneous power deficit ΔP of the energy storage unit > 0, and the droop curve moves downward. At this time, the maximum support power of the system is the output power minus the maximum absorption power, that is, P o - P imax . When a large-power impact load is input, the instantaneous power deficit ΔP of the energy storage unit < 0, and the droop curve moves upward. At this time, the maximum support power of the system is the maximum output power minus the output power, that is, P omax - P o . At the same time, since the different operating points Po are different, the values of P o - P imax and P omax - P o are different, and finally the translation amount ΔU of the bus voltage of the droop curve obtained is also different, which satisfies the function of realizing system adaptability.

[0044] As Figure 3As shown, the compensator control detection timing and calculation method selection unit of the embodiment of the present invention has the following specific implementation steps: Substitute the extracted bus voltage change rate into the detection timing unit, and the initial values of the flag bits C, T, and S w are 0, 1, and 0 respectively. When the bus voltage change rate exceeds the set upper or lower limit, the flag bit C is set to 1, and at the same time, the flag bit T is set to 0. At this time, the values of the three flag bits C, T, and S w in the calculation method selection unit are 1, 0, and 0 respectively. According to the relationship between the bus voltage change rate u m and the upper and lower limits U up , U lim , set the flag bit S w to the corresponding value, and substitute the S w value into the bus voltage translation amount calculation block diagram shown in the bus voltage translation amount calculation block diagram to generate the bus voltage translation amount ΔU. When the flag bits C and T in the calculation method selection unit are 1 and 0 respectively, and S w is not equal to 0, it means that the compensator is working, so the output of the calculation method selection unit remains the S w value of the previous moment. When the flag bits C and T are 0 and 0 respectively, and S w is not equal to 0, at this time, the bus voltage volatility u m does not exceed the upper and lower limits, but the time when u m is between the upper and lower limits does not meet the requirement for triggering T to be set to 1 in the timing module of the detection timing unit, and the system has not returned to the steady state. Therefore, the output of the calculation method selection unit remains the S w value of the previous moment. When the flag bits C and T are 0 and 1 respectively, at this time, the bus voltage volatility u m does not exceed the upper and lower limits and the time between the upper and lower limits meets the requirement for triggering T to be set to 1 in the timing module of the detection timing unit, indicating that the bus voltage re-enters the steady state. At this time, set S w to 0, ΔU is 0, and the compensator ends its operation to cope with the impact of the next large-power load.

[0045] As Figure 5 shown, the main simulation waveform diagram of the adaptive voltage / power droop control strategy for the isomorphic energy storage in the DC microgrid of the embodiment of the present invention. The energy storage unit parallel subsystem operates with a 2 kW conventional load, and a 14 kW large-power impact load is connected at 0.5 s. Figure 5 In (a) of Figure 5 and (b) of o1 , the output currents i o2 and the bus voltage u busWaveforms. By comparing the two waveforms, it can be concluded that the bus voltage was 698V and in a steady state before 0.5s. After applying a 14kW high-power impact load, the lowest point of the bus voltage drop of the former was 661V, and the lowest point of the bus voltage drop of the latter was 674V. It can be seen that compared with the conventional voltage / power droop control strategy, the adaptive voltage / power droop control strategy using isomorphic energy storage reduces the bus voltage drop by 35%, indicating that the system inertia is improved by using the adaptive voltage / power droop control strategy with isomorphic energy storage. Figure 5 In (c) of it, it is the relationship between the bus voltage translation amount and the maximum translation amount after applying a 14kW high-power impact load at 0.5s. It can be seen that the bus voltage translation amount never exceeds the maximum translation amount, indicating that there is no over-compensation phenomenon in the system.

[0046] Embodiment 2

[0047] Embodiment 2 of the present invention provides a terminal device corresponding to Embodiment 1 above. The terminal device can be a processing device for a client, such as a mobile phone, a laptop computer, a tablet computer, a desktop computer, etc., to execute the method of the above embodiment.

[0048] The terminal device of this embodiment includes a memory, a processor, and a computer program stored on the memory; the processor executes the computer program on the memory to implement the steps of the method in Embodiment 1 above.

[0049] In some implementations, the memory can be a high-speed random access memory (RAM: Random Access Memory), and may also include a non-volatile memory, such as at least one disk memory.

[0050] In other implementations, the processor can be a general-purpose processor of various types such as a central processing unit (CPU), a digital signal processor (DSP), etc., which are not limited here.

[0051] Embodiment 3

[0052] Embodiment 3 of the present invention provides a computer-readable storage medium corresponding to Embodiment 1 above, on which a computer program / instructions are stored. When the computer program / instructions are executed by a processor, the steps of the method in Embodiment 1 above are implemented.

[0053] A computer-readable storage medium can be a tangible device that holds and stores instructions used by an instruction execution device. A computer-readable storage medium can be, for example, but not limited to, an electrical storage device, a magnetic storage device, an optical storage device, an electromagnetic storage device, a semiconductor storage device, or any combination of the above.

[0054] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system, or a computer program product. Therefore, the present application can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code. The solutions in the embodiments of the present application can be implemented in various computer languages. For example, object-oriented programming languages such as Java and interpreted scripting languages such as JavaScript, etc.

[0055] The present application is described with reference to the flowcharts and / or block diagrams of methods, apparatuses (systems), and computer program products according to the embodiments of the present application. It should be understood that each flow and / or block in the flowchart and / or block diagram, as well as the combination of flows and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing devices to generate a machine, such that the instructions executed by the processor of the computer or other programmable data processing devices generate means for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0056] These computer program instructions can also be loaded onto a computer or other programmable data processing devices, such that a series of operation steps are executed on the computer or other programmable devices to generate a computer-implemented process. Thus, the instructions executed on the computer or other programmable devices provide steps for implementing the functions specified in Figure 1 one flow or multiple flows and / or blocks Figure 1 one block or multiple blocks.

[0057] Although the preferred embodiments of the present application have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concepts. Therefore, the appended claims are intended to be interpreted to include the preferred embodiments as well as all changes and modifications falling within the scope of the present application.

[0058] Obviously, those skilled in the art can make various changes and variations to the present application without departing from the spirit and scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these modifications and variations.

Claims

1. A method for isomorphic energy storage adaptive voltage / power droop control in a DC microgrid. The isomorphic energy storage system of the DC microgrid includes two energy storage DC / DC converters, and each energy storage DC / DC converter is connected to an energy storage battery; characterized in that, Including the following steps: S1. Calculate the output signal \(i\) of the voltage outer loop PI controller of the \(j\)-th energy storage DC / DC converter refj : i ref,j = G bv (U ref* - K db * P o + ΔU); where U ref* is the bus voltage reference value, P o is the output power of the energy storage DC / DC converter, k db is the voltage / power droop coefficient, U ref is the voltage outer loop control command value, ΔU is the bus voltage translation amount, G bvi are the PI controllers of the voltage outer loop respectively, k pv is the proportional coefficient, k pi is the integral coefficient, s is the complex variable; S2. Calculate the duty cycle d of the j-th energy storage DC / DC converter according to the output signal i of the voltage outer loop PI controller of the j-th energy storage DC / DC converter refj and obtain the driving signal of the switching tube of the j-th energy storage DC / DC converter through PWM modulation. j ​ 2. The method for isomorphic energy storage adaptive voltage / power droop control of a DC microgrid according to claim 1, wherein The duty cycle d of the j-th energy storage DC / DC converter j The calculation formula is as follows: d j = G bi (I ref,j - i b,j ); where G bi is the transfer function of the current inner-loop PI controller, k pi is the proportional coefficient, k ii is the integral coefficient, and i b,j is the input current of the j-th energy storage DC / DC converter.

3. The isomorphic energy storage adaptive voltage / power droop control method for a DC microgrid according to claim 1, wherein Voltage / power droop coefficient k db The calculation formula is as follows: Where, U max , U min are the upper and lower limits of the output voltage control command value U ref of the energy storage DC / DC converter respectively, and P omax , P omin are the maximum output power and the maximum absorption power of the energy storage DC / DC converter respectively.

4. The DC microgrid isomorphic energy storage adaptive voltage / power droop control method according to claim 1, wherein The calculation formula for the bus voltage translation amount ΔU is: Among them, m is the translation coefficient, P o is the current output power of the energy storage DC / DC converter, P omax and P imax are the maximum output power and the maximum absorption power of the energy storage DC / DC converter respectively, and u bus is the bus voltage.

5. A terminal device, characterized in that, Including: One or more processors; A memory storing one or more programs, which when executed by the one or more processors, cause the one or more processors to implement the steps of the method according to any one of claims 1 to 4.

6. A computer-readable storage medium storing a computer program, which when executed by a processor, implements the steps of the method according to any one of claims 1 to 4.

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