Method and system for calculating inductance value of high-voltage direct-hanging energy storage system

Abstract

The invention relates to a method and a system for calculating an inductance value of a high-voltage direct-hanging energy storage system. The method comprises the following steps of collecting equivalent resistance, system frequency, a control period, fundamental current and angular frequencies of different harmonic waves of the high-voltage direct-hanging energy storage system; expected performance indexes are determined; error influence factors during operation of the high-voltage direct-hanging energy storage system are considered, and an empirical coefficient is introduced to correct deviation; the error influence factors comprise control response speed, control precision, harmonic quality empirical coefficient and reactive power output capability; and according to different operation requirements of the high-voltage direct-hanging energy storage system, a weight coefficient is introduced to balance the performance of the high-voltage direct-hanging energy storage system, and the inductance value of the high-voltage direct-hanging energy storage system is calculated according to the empirical coefficient and the weight coefficient.

Description

Technical Field

[0001] The present application relates to the technical field of inductance calculation of energy storage systems, and more specifically, to a method and system for calculating the inductance value of a high-voltage direct-mounted energy storage system. Background Art

[0002] In high-voltage direct-mounted energy storage systems, inductance is a critical parameter, and its size is closely related to many system performances. When the inductance is large, the control accuracy and harmonic quality of the system can be improved, but the control response speed will be reduced, and the reactive power output capacity will also be limited. If the inductance is small, the control response speed can be accelerated and the reactive output upper limit can be increased, but the control accuracy and harmonic quality will be adversely affected.

[0003] When determining the inductance value of a high-voltage direct-mounted energy storage system, existing technical means often fail to accurately take into account the system's power output capacity, control response speed and accuracy, harmonic quality and other requirements. How to find a suitable reactance value calculation method to achieve balanced optimization of the system's performance has become a technical problem that needs to be solved urgently.

[0004] Prior art, such as a Chinese patent application with publication number "CN116644661A", discloses a method for designing a high energy storage density inductor, the method comprising: obtaining the value ranges corresponding to the size information and calculation information of the inductor coil; wherein the size information at least includes: the number of turns, the number of layers, the inner diameter of the coil, the height of a single turn, the width of a single turn, the distance between turns, and the distance between layers; the calculation information at least includes: the turn voltage, the current density, and the resistance; according to the calculation formulas for the coil current, the coil resistance, the coil inductance, and the energy storage density, an optimization is performed within the value range to determine the specific size information corresponding to the maximum energy storage density that satisfies the value range.

[0005] The problem with the above-mentioned prior art is that this method mainly focuses on determining the specific size information that meets the maximum energy storage density by optimizing within a range of values ​​based on the size information and calculation information of the inductor coil, without fully considering the system operation performance factors and lacking consideration of the dynamic operation of the system. Summary of the invention

[0006] In order to solve the above technical problems, the present invention proposes a method and system for calculating the inductance value of a high-voltage direct-mounted energy storage system.

[0007] The technical solution of the present invention is as follows:

[0008] The present invention proposes a method for calculating the inductance value of a high-voltage direct-mounted energy storage system, comprising the following steps:

[0009] Step S1, collect the equivalent resistance R, system frequency f, and control period T of the high-voltage direct-mounted energy storage system s, fundamental current I1 and angular frequencies ω of different harmonics h ; and determine the expected performance indicators;

[0010] Step S2, considering the error influencing factors during the operation of the high-voltage direct-mounted energy storage system, introducing an empirical coefficient to correct the deviation; the error influencing factors include: control response speed, control accuracy, harmonic quality empirical coefficient and reactive power output capacity;

[0011] Step S3, according to different requirements of the operation of the high-voltage direct-mounted energy storage system, introduce a weight coefficient to balance the performance of the high-voltage direct-mounted energy storage system, and calculate the inductance value of the high-voltage direct-mounted energy storage system according to the empirical coefficient and the weight coefficient.

[0012] As a preferred implementation, the desired performance indicators include: desired control response time T r , the desired control accuracy error range ΔI, the desired total harmonic distortion THD and the desired reactive power output capacity Q and the rated reactive power Q of the converter n .

[0013] As a preferred implementation, the error influencing factors during the operation of the high-voltage direct-mounted energy storage system are considered, and an empirical coefficient is introduced to correct the deviation; for the control response speed deviation, an empirical coefficient of the control response speed is introduced to correct the deviation. The specific formula is as follows:

[0014]

[0015] Where: T r is the expected control response time; k1 is the empirical coefficient of control response speed; L is the bridge arm inductance; R is the equivalent resistance.

[0016] As a preferred implementation, the error influencing factors during the operation of the high-voltage direct-mounted energy storage system are considered, and an empirical coefficient is introduced to correct the deviation; for the control accuracy deviation, a control accuracy empirical coefficient is introduced to correct the deviation. The specific formula is as follows:

[0017]

[0018] Where: k2 is the control accuracy empirical coefficient; ΔV is the given voltage ripple; ΔI is the expected control accuracy error range; T s To control the cycle.

[0019] As a preferred implementation, the error influencing factors during the operation of the high-voltage direct-mounted energy storage system are considered, and an empirical coefficient is introduced to correct the deviation; for the harmonic quality deviation, a harmonic quality empirical coefficient is introduced to correct the deviation. The specific formula is as follows:

[0020]

[0021] Where: k3 is the harmonic quality empirical coefficient; ω is the fundamental angular frequency; THD is the total harmonic distortion.

[0022] As a preferred implementation, the error influencing factors during the operation of the high-voltage direct-mounted energy storage system are considered, and an empirical coefficient is introduced to correct the deviation; for the reactive power output capacity deviation, an empirical coefficient of reactive power output capacity is introduced to correct the deviation. The specific formula is as follows:

[0023]

[0024] Where: k4 is the empirical coefficient of reactive power output capacity; Q n is the rated reactive power of the converter; Q is the expected reactive power output value; I is the operating current flowing through the converter.

[0025] As a preferred implementation, the inductance value of the high-voltage direct-mounted energy storage system is calculated based on the empirical coefficient and the weight coefficient, and the inductance value calculation formula is:

[0026]

[0027] Wherein: a, b, c, d are the control response speed weight coefficient, control accuracy weight coefficient, harmonic quality weight coefficient and reactive power output capacity weight coefficient respectively, and a+b+c+d=1.

[0028] On the other hand, the present invention also provides a high-voltage direct-mounted energy storage system inductance value calculation system, comprising:

[0029] Data collection and performance index determination module, collects the equivalent resistance R, system frequency f, and control period T of the high-voltage direct-mounted energy storage system s , fundamental current I b And the angular frequencies ω of the different harmonics h ; and determine the expected performance indicators;

[0030] Deviation correction module, considering the error influencing factors during the operation of the high-voltage direct-mounted energy storage system, introduces empirical coefficients to correct the deviation; error influencing factors include: control response speed, control accuracy, harmonic quality empirical coefficient and reactive power output capacity;

[0031] The weight confirmation and inductance calculation module introduces a weight coefficient to balance the performance of the high-voltage direct-mounted energy storage system according to the different requirements of the operation of the high-voltage direct-mounted energy storage system, and calculates the inductance value of the high-voltage direct-mounted energy storage system based on the empirical coefficient and the weight coefficient.

[0032] On the other hand, the present invention further provides an electronic device having a computer program stored thereon, wherein when the computer program is executed by a processor, a method for calculating the inductance value of a high-voltage direct-mounted energy storage system as described in any embodiment of the present invention is implemented.

[0033] On the other hand, the present invention also provides a computer-readable medium for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement a method for calculating the inductance value of a high-voltage direct-mounted energy storage system as described in any embodiment of the present invention.

[0034] The present invention has the following beneficial effects: by collecting parameters such as the equivalent resistance, system frequency, control cycle, fundamental current, and angular frequencies of different harmonics of the high-voltage direct-mounted energy storage system, and determining the desired performance indicators, such as control response time, control accuracy error range, total harmonic distortion rate, and reactive power output capacity, the key factors of system operation are fully considered. The introduction of empirical coefficients to correct error influencing factors such as control response speed, control accuracy, harmonic quality, and reactive power output capacity, and setting weight coefficients according to different system operation requirements can balance the various performances of the high-voltage direct-mounted energy storage system, thereby more accurately calculating the inductance value, and effectively solving the problem that the existing technology is difficult to take into account the various performance requirements of the system; the introduction of empirical coefficients and weight coefficients makes the inductance calculation method of the present invention more flexible and adaptable, and can be applied to a variety of inductance value calculation scenarios of high-voltage direct-mounted energy storage systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a schematic diagram of the process of the present invention;

[0037] Figure 2 This is the topology diagram of the high-voltage direct-mounted energy storage system. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be understood that the step numbers used in this document are only for convenience of description and are not intended to limit the order in which the steps are executed.

[0040] It should be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0041] The terms “include” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0042] The term "and / or" means and includes any and all possible combinations of one or more of the associated listed items.

[0043] Embodiment 1:

[0044] In order to make the purpose, technical solutions and advantages of the present invention more clear, the following will be combined with the specific embodiments of the present application and refer to the attached Figure 1 , clearly and completely describe the technical solution of the present invention.

[0045] In order to solve the problems in the prior art, the present invention provides a method for calculating the inductance value of a high-voltage direct-mounted energy storage system, comprising the following steps:

[0046] Step S1, collect the equivalent resistance R, system frequency f, and control period T of the high-voltage direct-mounted energy storage system s , fundamental current I1 and angular frequencies ω of different harmonics h ; and determine the expected performance indicators; including: expected control response time T r , the desired control accuracy error range ΔI, the desired total harmonic distortion THD and the desired reactive power output capacity Q and the rated reactive power Q of the converter n .

[0047] Step S2, considering the error influencing factors during the operation of the high-voltage direct-mounted energy storage system, introducing the empirical coefficient to correct the deviation; the error influencing factors include: control response speed, control accuracy, harmonic quality empirical coefficient and reactive power output capacity; wherein:

[0048] Consider controlling the response speed:

[0049] The control response speed is related to the time constant of the system. For a circuit containing inductance, the time constant τ = L / R. To meet the desired control response time T r , the formula for correcting the deviation by introducing the empirical coefficient of control response speed can be obtained:

[0050]

[0051] Where: k1 is the control response speed empirical coefficient, the value range is [0.5,1.5], determined according to the specific characteristics of the system, and used to correct the deviation between the actual and ideal models; L is the bridge arm inductance; R is the equivalent resistance. Transformation can be obtained:

[0052]

[0053] Consider control accuracy:

[0054] According to Kirchhoff's laws and the law of electromagnetic induction, in an inductive circuit, the rate of change of current is related to the inductance value, that is, For the desired control accuracy error range ΔI and a given voltage ripple ΔV, the calculation formula for correcting the deviation by introducing the control accuracy empirical coefficient can be derived, as follows:

[0055]

[0056] Where: T s is the control period, k2 is the empirical coefficient of control accuracy, and its value range is [0.1, 0.2], which is determined according to the system characteristics and control strategy.

[0057] Consider the harmonic quality:

[0058] In AC circuits, inductance has a suppressive effect on harmonic current. According to harmonic analysis theory, the harmonic current I h The relationship with inductance is:

[0059]

[0060] Where: I1 is the fundamental current, ω h is the harmonic angular frequency. In order to make the total harmonic distortion THD meet the expectations, it can be calculated by the following formula:

[0061]

[0062] Where: THD is the total harmonic distortion; It is the sum of the squares of the effective values ​​of the harmonic current (or voltage) from the second harmonic to the infinite harmonic;

[0063] The relationship between THD and inductance L is relatively complex. This method generally introduces the coefficient k3 to obtain an approximate relationship between the two:

[0064]

[0065] Where: k3 is a coefficient related to the harmonic order and system characteristics, and is determined based on the harmonic spectrum characteristics of the system.

[0066] Consider reactive power output capability

[0067] High voltage direct-connection system reactive power Q = Q n -I 2 X=Q n -I 2 ωL, X is the reactance; to achieve the desired reactive power output capacity, we can get:

[0068]

[0069] Where: k4 is a coefficient related to the reactive power regulation characteristics of the system, and its value range is [0.8,1.2].

[0070] Step S3, according to different requirements of the operation of the high-voltage direct-mounted energy storage system, introduce a weight coefficient to balance the performance of the high-voltage direct-mounted energy storage system, and calculate the inductance value of the high-voltage direct-mounted energy storage system according to the empirical coefficient and the weight coefficient.

[0071] Combining the above four aspects, introducing weight coefficients a, b, c and d (satisfying a+b+c+d=1), the final calculation formula of the bridge arm inductance value L is:

[0072]

[0073] Wherein: a, b, c, d are the control response speed weight coefficient, control accuracy weight coefficient, harmonic quality weight coefficient and reactive power output capacity weight coefficient respectively, and a+b+c+d=1.

[0074] like Figure 2 As shown below: The following is a specific calculation case, assuming that a high-voltage direct-mounted energy storage system has the following parameters:

[0075] If the system frequency f=50Hz, then ω=2π×50=100πrad / s.

[0076] Equivalent resistance R = 1Ω.

[0077] Control cycle T s =0.01s.

[0078] Expected control response time T r =0.02s.

[0079] The expected control accuracy error range is ΔI=0.05A.

[0080] The expected total harmonic distortion THD = 5% = 0.05.

[0081] Converter rated reactive power Q n =200kvar, reactive power demand Q=120kvar, assuming fundamental current I1=100A, ΔV=10V.

[0082] According to the system characteristics, the empirical coefficients k1=1, k2=0.15, k3=0.01, k4=1 are taken, and it is assumed that in order to balance the system performance, the weight coefficients a=0.3, b=0.2, c=0.3, d=0.2 are taken.

[0083] Substitute the above data into the formula to calculate the bridge arm inductance value L:

[0084]

[0085] Embodiment 2:

[0086] This embodiment provides a high-voltage direct-mounted energy storage system inductance value calculation system, including:

[0087] Data collection and performance index determination module, collects the equivalent resistance R, system frequency f, and control period T of the high-voltage direct-mounted energy storage system s , fundamental current I b And the angular frequencies ω of the different harmonics h ; and determine the expected performance indicators;

[0088] Deviation correction module, considering the error influencing factors during the operation of the high-voltage direct-mounted energy storage system, introduces empirical coefficients to correct the deviation; error influencing factors include: control response speed, control accuracy, harmonic quality empirical coefficient and reactive power output capacity;

[0089] The weight confirmation and inductance calculation module introduces a weight coefficient to balance the performance of the high-voltage direct-mounted energy storage system according to the different requirements of the operation of the high-voltage direct-mounted energy storage system, and calculates the inductance value of the high-voltage direct-mounted energy storage system based on the empirical coefficient and the weight coefficient.

[0090] Embodiment three:

[0091] This embodiment provides an electronic device having a computer program stored thereon, and when the computer program is executed by a processor, a method for calculating the inductance value of a high-voltage direct-mounted energy storage system as described in any embodiment of the present invention is implemented.

[0092] Embodiment 4:

[0093] This embodiment provides a computer-readable medium for storing one or more programs. When the one or more programs are executed by the one or more processors, the one or more processors implement a method for calculating the inductance value of a high-voltage direct-mounted energy storage system as described in any embodiment of the present invention.

[0094] In the embodiments of the present application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, c can be single or multiple.

[0095] Those of ordinary skill in the art will appreciate that the various units and algorithm steps described in the embodiments disclosed herein can be implemented in a combination of electronic hardware, computer software, and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0096] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0097] In several embodiments provided in the present application, if any function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory; hereinafter referred to as: ROM), random access memory (Random Access Memory; hereinafter referred to as: RAM), disk or optical disk, and other media that can store program codes.

[0098] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for calculating the inductance value of a high-voltage direct-mounted energy storage system, characterized in that: The following steps are involved: Step S1, collect the equivalent resistance R, system frequency f, and control period T of the high-voltage direct-mounted energy storage system s , fundamental current I1 and angular frequencies ω of different harmonics h ; and determine the expected performance indicators; Step S2, considering the error influencing factors during the operation of the high-voltage direct-mounted energy storage system, and introducing an empirical coefficient to correct the deviation; Error influencing factors include: control response speed, control accuracy, harmonic quality empirical coefficient and reactive power output capacity; Step S3, according to different requirements of the operation of the high-voltage direct-mounted energy storage system, introduce a weight coefficient to balance the performance of the high-voltage direct-mounted energy storage system, and calculate the inductance value of the high-voltage direct-mounted energy storage system according to the empirical coefficient and the weight coefficient.

2. According to claim 1, a method for calculating the inductance value of a high-voltage direct-mounted energy storage system is characterized in that: The desired performance indicators include: the desired control response time T r , the desired control accuracy error range ΔI, the desired total harmonic distortion THD and the desired reactive power output capacity Q and the rated reactive power Q of the converter n .

3. The method for calculating the inductance value of a high-voltage direct-mounted energy storage system according to claim 1 is characterized in that: The error influencing factors of the high-voltage direct-mounted energy storage system during operation are considered, and the empirical coefficient is introduced to correct the deviation; for the control response speed deviation, the control response speed empirical coefficient is introduced to correct the deviation. The specific formula is as follows: Where: T r is the expected control response time; k1 is the control response speed empirical coefficient; L is the bridge arm inductance; R is the equivalent resistance.

4. The method for calculating the inductance value of a high-voltage direct-mounted energy storage system according to claim 1 is characterized in that: The error influencing factors of the high-voltage direct-mounted energy storage system during operation are considered, and the empirical coefficient is introduced to correct the deviation; for the control accuracy deviation, the control accuracy empirical coefficient is introduced to correct the deviation. The specific formula is as follows: Where: k2 is the empirical coefficient of control accuracy; ΔV is the given voltage ripple; ΔI is the expected control accuracy error range; T s To control the cycle.

5. The method for calculating the inductance value of a high-voltage direct-mounted energy storage system according to claim 1 is characterized in that: The error influencing factors during the operation of the high-voltage direct-mounted energy storage system are considered, and the empirical coefficient is introduced to correct the deviation; for the harmonic quality deviation, the harmonic quality empirical coefficient is introduced to correct the deviation. The specific formula is as follows: Where: k3 is the harmonic quality empirical coefficient; ω is the fundamental angular frequency; THD is the total harmonic distortion.

6. The method for calculating the inductance value of a high-voltage direct-mounted energy storage system according to claim 1 is characterized in that: The error influencing factors during the operation of the high-voltage direct-mounted energy storage system are considered, and the empirical coefficient is introduced to correct the deviation; for the reactive power output capacity deviation, the reactive power output capacity empirical coefficient is introduced to correct the deviation. The specific formula is as follows: Where: k4 is the empirical coefficient of reactive power output capacity; Q n is the rated reactive power of the converter; Q is the expected reactive power output value; I is the operating current flowing through the converter.

7. The method for calculating the inductance value of a high-voltage direct-mounted energy storage system according to claim 1 is characterized in that: The inductance value of the high-voltage direct-mounted energy storage system is calculated based on the empirical coefficient and the weight coefficient. The inductance value calculation formula is: Wherein: a, b, c, d are the control response speed weight coefficient, control accuracy weight coefficient, harmonic quality weight coefficient and reactive power output capacity weight coefficient respectively, and a+b+c+d=1.

8. A high-voltage direct-mounted energy storage system inductance value calculation system, characterized in that: include: Data collection and performance index determination module, collects the equivalent resistance R, system frequency f, and control period T of the high-voltage direct-mounted energy storage system s , fundamental current I b And the angular frequencies ω of the different harmonics h ; and determine the expected performance indicators; Deviation correction module, which takes into account the error influencing factors during the operation of the high-voltage direct-mounted energy storage system and introduces empirical coefficients to correct the deviation; Error influencing factors include: control response speed, control accuracy, harmonic quality empirical coefficient and reactive power output capacity; The weight confirmation and inductance calculation module introduces a weight coefficient to balance the performance of the high-voltage direct-mounted energy storage system according to the different requirements of the operation of the high-voltage direct-mounted energy storage system, and calculates the inductance value of the high-voltage direct-mounted energy storage system based on the empirical coefficient and the weight coefficient.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the program, the method for calculating the inductance value of a high-voltage direct-mounted energy storage system as described in any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, a method for calculating the inductance value of a high-voltage direct-mounted energy storage system as described in any one of claims 1 to 7 is implemented.

Images