Black-start voltage balance control method, device, equipment, medium and program product

Abstract

The invention relates to a black-start voltage balance control method, device and equipment, a medium and a program product. The method comprises the following steps: acquiring a capacitor voltage at a current moment, a common connection point current at the current moment and a voltage outer ring reference value at the current moment; determining a reference current controlled by a current inner loop according to the voltage outer loop reference value at the current moment; according to the reference current controlled by the current inner loop, the capacitor voltage at the current moment and the predicted current at the current moment, determining the predicted current at the next moment; according to a preset cost function, the predicted current at the current moment and the predicted current at the next moment, determining the on-off state of each control switch and a corresponding voltage vector; therefore, the energy storage system is indicated to execute self-starting. Therefore, the future state of the system can be predicted in real time, a traditional sequence component separation link is abandoned, computing resource consumption and system delay are reduced, parameters do not need to be independently set for each sequence component, and the robustness and engineering practicability of the control system are remarkably enhanced.

Description

Technical Field

[0001] This application relates to the field of power system technology, and in particular to a black-start voltage equalization control method, device, computer equipment, computer-readable storage medium, and computer program product. Background Technology

[0002] With the development of new energy technologies, the penetration rate of renewable energy sources such as wind power and photovoltaics has increased significantly, but their strong volatility and weak fault-bearing capacity have also increased the risk of power grid outages.

[0003] To address the voltage imbalance problem caused by unbalanced loads during the black start process of distribution networks, traditional sequence control strategies require the extraction of negative sequence voltage components to construct a positive / negative sequence dual closed-loop control structure to achieve sequence regulation.

[0004] However, the positive / negative sequence dual closed-loop control structure constructed in the traditional scheme has insufficient engineering applicability. Summary of the Invention

[0005] Therefore, it is necessary to provide a black-start voltage equalization control method, device, computer equipment, computer-readable storage medium, and computer program product that can overcome bandwidth limitations, simplify parameter tuning process, and improve engineering applicability in response to the above-mentioned technical problems.

[0006] In a first aspect, this application provides a black-start voltage equalization control method, the method comprising:

[0007] Obtain the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value;

[0008] The reference current for the inner current loop control is determined based on the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value.

[0009] The predicted current for the next moment is determined based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0010] Based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment, the switching state of each control switch and the corresponding voltage vector are determined; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

[0011] In one embodiment, obtaining the current voltage outer loop reference value includes: obtaining the current voltage outer loop reference value through a zero-voltage start-up V / f control method.

[0012] In one embodiment, before acquiring the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value, the method further includes:

[0013] A control architecture for the self-starting phase of an energy storage system is constructed, comprising: an LC filter, a zero-start boost V / f control module, an abc / dq coordinate transformation module, a voltage-current dual closed-loop control module, and an SPWM module; wherein:

[0014] The LC filter is connected to the energy storage system to filter out switching frequency interference signals;

[0015] The zero-start boost V / f control module is used to obtain the current voltage outer loop reference value;

[0016] The abc / dq coordinate transformation module is used to convert the three-phase current components into d-axis and q-axis components;

[0017] The voltage and current dual closed-loop control module includes a voltage outer loop control module and a current inner loop control module. The voltage outer loop control module is used to acquire the capacitor voltage at the current moment, the current of the point of common coupling at the current moment, and the voltage outer loop reference value at the current moment. The current inner loop control module is used to determine the predicted current at the next moment based on the reference current controlled by the current inner loop, the capacitor voltage at the current moment, and the predicted current at the current moment, and to determine the switching state of each control switch and the corresponding voltage vector based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment.

[0018] The SPWM module is used to convert the switching states of each control switch and the corresponding voltage vector into modulation signals and transmit them to the energy storage system so that the energy storage system can perform self-starting.

[0019] In one embodiment, the formula for determining the reference current for the inner current loop control based on the current capacitor voltage, the current common coupling point current, and the current voltage outer loop reference value is as follows:

[0020]

[0021] In the formula: i ref C represents the reference current for the inner current loop control. f T represents the capacitance value. s Indicates the sampling frequency, v cref This represents the outer loop reference value of the voltage, v. c (k) represents the capacitor voltage at time k, i p (k) represents the current at the point of common connection at time k.

[0022] In one embodiment, the formula for calculating the predicted current at the next moment is as follows, based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment:

[0023]

[0024] In the formula: i(k+1) represents the predicted current at time k+1, L f Indicates the inductance value, v c (k) represents the capacitor voltage at time k, R represents the resistance value, and T s The sampling frequency i(k) represents the predicted current at time k.

[0025] In one embodiment, the calculation formula for the preset cost function is as follows:

[0026] g = (i αref -i α (k+1)) 2 +(i βref -i β (k+1)) 2

[0027] In the formula: g represents the cost function, i αref The α-axis component of the reference current for the inner current loop control, i α (k+1) represents the predicted value of the α-axis current at time k+1, i βref i represents the β-axis component of the reference current for the inner current loop control. β (k+1) represents the predicted value of the β-axis current at time k+1.

[0028] Secondly, this application also provides a black-start voltage equalization control device, the device comprising:

[0029] The acquisition module is used to acquire the capacitor voltage, the point of common coupling current, and the voltage outer loop reference value at the current moment.

[0030] The first determining module is used to determine the reference current for the current inner loop control based on the capacitor voltage at the current moment, the common coupling point current at the current moment, and the voltage outer loop reference value at the current moment.

[0031] The second determining module is used to determine the predicted current at the next moment based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0032] The third determining module is used to determine the switching state of each control switch and the corresponding voltage vector based on a preset cost function, the predicted current at the current moment and the predicted current at the next moment; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

[0033] Thirdly, this application also provides a computer device, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to perform the following steps:

[0034] Obtain the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value;

[0035] The reference current for the inner current loop control is determined based on the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value.

[0036] The predicted current for the next moment is determined based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0037] Based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment, the switching state of each control switch and the corresponding voltage vector are determined; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

[0038] Fourthly, this application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0039] Obtain the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value;

[0040] The reference current for the inner current loop control is determined based on the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value.

[0041] The predicted current for the next moment is determined based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0042] Based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment, the switching state of each control switch and the corresponding voltage vector are determined; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

[0043] Fifthly, this application also provides a computer program product, including a computer program that, when executed by a processor, performs the following steps:

[0044] Obtain the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value;

[0045] The reference current for the inner current loop control is determined based on the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value.

[0046] The predicted current for the next moment is determined based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0047] Based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment, the switching state of each control switch and the corresponding voltage vector are determined; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

[0048] The aforementioned black-start voltage equalization control method, device, computer equipment, computer-readable storage medium, and computer program product acquire the current capacitor voltage, the current point of common coupling current, and the current voltage outer loop reference value. Based on the current capacitor voltage, the current point of common coupling current, and the current voltage outer loop reference value, a reference current for the current inner loop control is determined. Therefore, based on a model predictive control strategy, the reference current for the current inner loop control is determined using the voltage outer loop control, achieving dual closed-loop control of voltage and current. Based on the reference current for the current inner loop control, the current capacitor voltage, and the current predicted current, the predicted current for the next moment is determined. Therefore, based on a model predictive control strategy, the predicted current for the next moment can be directly predicted, avoiding the passive "biased first, compensated later" mode of PI control and overcoming the bandwidth limitations of traditional PI control. Based on a preset cost function, the current predicted current, and the predicted current for the next moment, the switching states of each control switch and the corresponding voltage vectors are determined. The switching states of each control switch and the corresponding voltage vectors are used to instruct the energy storage system to perform self-start. This allows for real-time prediction of the system's future state, eliminates the need for traditional sequential component separation, reduces computational resource consumption and system latency, eliminates the need to set separate parameters for each sequential component, and significantly enhances the robustness and engineering practicality of the control system. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0050] Figure 1(a) is a schematic diagram of the structure of the first type of unbalanced load;

[0051] Figure 1(b) is a schematic diagram of the structure of the second type of unbalanced load;

[0052] Figure 2 This is a flowchart illustrating a black-start voltage equalization control method in one embodiment;

[0053] Figure 3 A schematic diagram of the equivalent architecture of the energy storage system self-starting process of a three-phase three-wire inverter;

[0054] Figure 4 This is a block diagram of the voltage and current dual closed-loop control of the MPC in one embodiment;

[0055] Figure 5 This is a flowchart of the MPC voltage and current dual closed-loop control in one embodiment;

[0056] Figure 6(a) is a schematic diagram of the three-phase voltage waveforms during the black start phase of an energy storage system under traditional PI control;

[0057] Figure 6(b) is a schematic diagram of the negative sequence voltage waveform during the black start stage of an energy storage system under traditional PI control.

[0058] Figure 6(c) is a schematic diagram of the voltage imbalance waveform during the black start stage of an energy storage system under traditional PI control.

[0059] Figure 7(a) is a schematic diagram of the three-phase voltage waveforms during the black start phase of the energy storage system under MPC control;

[0060] Figure 7(b) is a schematic diagram of the negative sequence voltage waveform during the black start phase of the energy storage system under MPC control;

[0061] Figure 7(c) is a schematic diagram of the voltage imbalance waveform during the black start phase of the energy storage system under MPC control.

[0062] Figure 8 This is a structural block diagram of a black-start voltage equalization control device in one embodiment;

[0063] Figure 9 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0065] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0066] To facilitate understanding of the technical solutions in the various embodiments of this application, a brief explanation of the technical terms that may appear in each embodiment is provided first.

[0067] 1) Black start refers to the process by which, after the entire system has been shut down due to a fault and cannot be restored by relying on power from other power grids, the system starts units with self-starting capabilities, thereby driving units without self-starting capabilities, gradually expanding the scope of system restoration, and ultimately restoring the entire system.

[0068] 2) Model Predictive Control (MPC) does not require parameter tuning. It mainly includes: an internal (predictive) model, a reference trajectory, and a control algorithm. It is now more clearly described as an internal (predictive) model, rolling optimization, and feedback control.

[0069] Predictive Model: To achieve effective prediction, MPC requires the construction of a mathematical model that describes the dynamic characteristics of the system. This model is typically a discrete-time state-space equation or difference equation. The model can be a mechanistic model or a data-based model.

[0070] Rolling optimization: MPC treats the control process as a series of continuous optimization problems to be solved. At each sampling time k, the controller uses the currently measured state variables and known disturbance information to calculate the optimal control sequence for a future period of time. This period of time is called the "prediction time domain" or "rolling window".

[0071] Feedback control: Although all future control actions are planned, only the first control increment or value is implemented in actual operation. Then, the new state is re-evaluated in the next sampling period and the above process is repeated, thus forming a closed-loop feedback mechanism that can effectively deal with uncertainty, nonlinearity and constraints, and shows good control effect and robustness.

[0072] The penetration rate of renewable energy sources such as wind and solar power has increased significantly, but their strong volatility and weak fault-bearing capacity have increased the risk of grid outages. When operating in islanded mode, renewable energy power plants lack the inertia support of the main power grid, making them susceptible to voltage instability due to sudden disturbances. Therefore, there is an urgent need to improve their black-start recovery capabilities to shorten outage time. Unlike traditional synchronous generators, renewable energy power plants mostly use grid-forming (GFM) converters to establish initial voltage, but the randomness of renewable energy limits its reliability as a black-start energy source. Energy storage systems (ESS) have emerged as a reliable solution due to their flexible charging and discharging characteristics, and combined solar / storage / wind / storage power plants have demonstrated their black-start potential.

[0073] Grid-based energy storage converters need to address load characteristic differences and voltage surges during black start. Existing research proposes zero-start boost strategies and improved V / f control to address load surges, but the problem of unbalanced three-phase output voltage caused by load asymmetry remains unresolved. Traditional dual-loop control has limitations due to its lack of negative-sequence voltage regulation capability. It mainly improves the imbalance problem through positive and negative sequence superposition control, unified voltage-current droop strategies, and vector proportional-integral control, but these methods rely on sequence component decomposition and require multiple proportional-integral controller (PI) units to work together, leading to complex parameter design and increased computational burden.

[0074] Existing sequence control methods require separating the negative sequence voltage component generated by unbalanced loads and constructing dual closed-loop control loops for positive and negative sequences to control the positive and negative sequence voltages separately. In practical applications, this method suffers from bandwidth limitations and increases the complexity of control architecture and parameter design, thus lacking widespread applicability.

[0075] Traditional sequence control strategies require the extraction of negative-sequence voltage components to construct a dual-closed-loop control structure for both positive and negative sequences to achieve sequence regulation. However, this method suffers from limitations such as bandwidth constraints, complex control architecture, and difficulties in parameter tuning, resulting in insufficient engineering applicability.

[0076] In summary, while existing control methods can address the black-start voltage imbalance problem under unbalanced loads, they require complex control architectures and have limited performance, hindering their widespread application in practical engineering. Therefore, this paper proposes measures to address the black-start voltage imbalance problem in distribution networks under unbalanced loads.

[0077] To address the problems existing in the prior art, this application aims to provide a black-start voltage balancing control method. It analyzes the generation mechanism of unbalanced voltage, identifies eliminating negative-sequence voltage as the mitigation objective, and proposes a black-start voltage balancing strategy based on model predictive control. Leveraging the rolling optimization and feedback correction characteristics of model predictive control, the method in this application eliminates the need for positive and negative sequence separation, thereby significantly reducing computational resource consumption and system latency. Furthermore, multi-step predictive optimization can improve dynamic response speed. Specifically, model predictive control, with its unified control framework, effectively suppresses negative-sequence voltage generated by asymmetrical loads, reducing voltage imbalance.

[0078] During black start, distribution networks face complex and variable load characteristics. Especially under unbalanced load conditions, when energy storage systems perform on-load voltage boosting operations, the Point of Common Coupling (PCC) is prone to significant unbalanced voltage due to three-phase asymmetrical current. Under traditional voltage-current dual closed-loop control architecture, this phenomenon will trigger power oscillations at twice the base frequency, leading to the following systemic risks: First, periodic fluctuations in active / reactive power are coupled to the DC side through the converter, exacerbating DC bus voltage fluctuations in energy storage, photovoltaic, and other systems, triggering overvoltage or undervoltage protection. Second, the continuous distortion of the PCC voltage amplitude and phase weakens grid stability, forcing grid-connected converters into non-ideal operating ranges, significantly increasing their dynamic regulation burden. These chain reactions may lead to serious consequences such as critical equipment disconnection and system reconfiguration failure during black start, thereby amplifying the economic losses from distribution network outages. Therefore, it is urgent to analyze the generation mechanism of unbalanced voltage, clarify its dynamic coupling relationship with load characteristics and converter control, and design targeted governance strategies accordingly to break the vicious cycle caused by voltage imbalance and ensure the reliable progress of the black start process.

[0079] This application primarily considers the output voltage imbalance characteristics of a three-phase three-wire system under the following two types of unbalanced loads. The first type is an asymmetrical single-phase load, as shown in Figure 1(a), where Z... La Z Lb Z Lc The first category is unbalanced; the second category includes symmetrical single-phase loads and asymmetrical phase-to-phase loads, as shown in Figure 1(b), where Z La Z Lb Z LcBalanced, but there is a load Z between phases AC. Lac It is worth noting that when Z in Figure 1(b) La Z Lb Z Lc When unbalanced, its voltage imbalance characteristics are similar to those of the first type of unbalanced load, so it will not be analyzed separately here.

[0080] For a type I unbalanced load, the voltage at the point of common coupling is in, Let A, B, and C be the phase voltages at point PCC, respectively. The current flowing from point PCC to the distribution network load and the single-phase load current of the distribution network are respectively... and in, These are the phase currents flowing out at point PCC in phases A, B, and C, respectively. These represent the currents flowing to the load from phases A, B, and C, respectively. The equivalent line impedance of the three phases flowing to the load at point PCC is Z. Line The single-phase load is Z. L =[Z La Z Lb Z Lc ], where Z La Z Lb Z Lc Let U be the single-phase load impedances of phases A, B, and C, respectively. Therefore, the voltage at PCC can be calculated as U. P =I P Z Line +I L Z L .

[0081] When a new energy power station has only a single-phase load, there is no phase-to-phase path, therefore I P with I L Consistent. Based on the symmetrical component method, the voltage at point PCC can be decomposed into U. P =U P(1) +U P(2) +U P(0) , among which, U P(1) U P(2) U P(0) These are the positive-sequence, negative-sequence, and zero-sequence components, respectively. The zero-sequence voltage component is: These are the zero-sequence components of the phase voltages A, B, and C. Based on the rules for solving zero-sequence components, the following zero-sequence components can be derived:

[0082]

[0083] Assuming a three-phase three-wire GSDC system can achieve three-phase voltage balance at the PCC point under unbalanced load, then there is no zero-sequence voltage, meaning the above equation is 0. Since Z La Z Lb Z Lc Imbalance leads to in, It is the zero-sequence current.

[0084] The above equation shows that zero-sequence current exists under this assumption. However, for a three-phase three-wire inverter, its inherent topology determines that there is no path for zero-sequence current to flow, therefore zero-sequence current cannot be actually generated. This contradiction indicates that in the scenario of unbalanced three-phase loads in new energy power plants, if a three-phase three-wire inverter architecture is used, the phase voltage at the PCC point cannot achieve complete symmetry of the three-phase phase voltages by eliminating zero-sequence voltage. It is particularly important to note that although there is asymmetry in the three-phase phase voltages, when calculating the line voltage, the zero-sequence voltage component is naturally canceled out by the difference operation of the phase voltages, and the balance of the line voltage is only affected by the negative-sequence voltage. Therefore, by accurately suppressing the negative-sequence voltage component, complete balance of the three-phase line voltages can be achieved under unbalanced load conditions.

[0085] For the second type of unbalanced load, the following current relationship exists:

[0086]

[0087] In the formula: This represents the current of the AC phase-to-phase load. The zero-sequence voltage at point PCC is as follows:

[0088]

[0089] The above equation shows that under the second type of unbalanced load, the phase voltage at the PCC point established by the three-phase three-wire inverter does not contain a zero-sequence component, and its negative-sequence component can be eliminated to balance it.

[0090] In summary, for the PCC voltage established by a three-phase three-wire inverter, under the first type of unbalanced load, eliminating the negative sequence voltage component can alleviate phase voltage imbalance and achieve line voltage balance; while under the second type of unbalanced load, eliminating the negative sequence voltage component can simultaneously achieve phase voltage and line voltage balance. This reveals the capability of a three-phase three-wire inverter to manage voltage imbalance and establishes that the goal of black-start voltage imbalance management under unbalanced loads is the elimination of negative sequence voltage.

[0091] In one exemplary embodiment, such as Figure 2 As shown, a black-start voltage equalization control method is provided, which may include the following steps 201 to 204. Wherein:

[0092] Step 201: Obtain the capacitor voltage at the current moment, the current common coupling point current at the current moment, and the voltage outer loop reference value at the current moment.

[0093] In this embodiment, the current time can be considered as time k, where k is a natural number greater than 0. Similarly, k+1 represents the next time. It should be understood that the current time and the next time are not restrictions on the sampling timing, but rather to facilitate the explanation of the sequential relationship between two consecutive time points.

[0094] In this embodiment, capacitor voltage generally refers to the voltage across the capacitor in the energy storage system of a three-phase three-wire inverter, and point of common coupling current refers to the three-phase current transmitted from the energy storage system of the three-phase three-wire inverter to the point of common coupling. The outer loop voltage reference value refers to the input outer loop voltage reference value when applying the dual-loop voltage and current control strategy (MPC) for energy storage spike self-start control.

[0095] Optionally, the current voltage outer loop reference value can be obtained through zero-voltage start-up V / f control.

[0096] Step 202: Determine the reference current for the inner current loop control based on the current capacitor voltage, the current common coupling point current, and the current voltage outer loop reference value.

[0097] In this embodiment, the reference current for the inner current loop control can be determined based on the reference value for the outer voltage loop.

[0098] Optionally, the formula for calculating the reference current of the current inner loop control is as follows:

[0099]

[0100] In the formula: i ref C represents the reference current for the inner current loop control. f T represents the capacitance value. s Indicates the sampling frequency, v cref This represents the outer loop reference value of the voltage, v. c (k) represents the capacitor voltage at time k, i p (k) represents the current at the point of common connection at time k.

[0101] Step 203: Determine the predicted current for the next moment based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0102] In this embodiment, the current inner loop control is equivalent to a prediction model, which can directly predict the predicted current at the next moment based on the reference current of the current inner loop control.

[0103] Optionally, the formula for calculating the predicted current at the next moment is as follows:

[0104]

[0105] In the formula: i(k+1) represents the predicted current at time k+1, L f Indicates the inductance value, v c (k) represents the capacitor voltage at time k, R represents the resistance value, and T s The sampling frequency i(k) represents the predicted current at time k.

[0106] Step 204: Determine the switching state of each control switch and the corresponding voltage vector based on the preset cost function, the predicted current at the current moment, and the predicted current at the next moment.

[0107] The switching states of each control switch and the corresponding voltage vector are used to indicate the energy storage system to perform self-starting.

[0108] In this embodiment, by using the optimization strategy of MPC, the negative sequence component of the voltage at PCC can be suppressed without performing positive and negative sequence decomposition, thereby achieving three-phase voltage balance during the black start process of unbalanced loads connected to the distribution network.

[0109] Optionally, the preset cost function is calculated using the following formula:

[0110] g = (i αref -i α (k+1)) 2 +(i βref -i β (k+1)) 2

[0111] In the formula: g represents the cost function, i αref The α-axis component of the reference current for the inner current loop control, i α (k+1) represents the predicted value of the α-axis current at time k+1, i βref i represents the β-axis component of the reference current for the inner current loop control. β (k+1) represents the predicted value of the β-axis current at time k+1.

[0112] Optionally, before performing step 201, a control architecture for the self-starting phase of the energy storage system is constructed. This control architecture includes: an LC filter, a zero-start boost V / f control module, an abc / dq coordinate transformation module, a voltage-current dual closed-loop control module, and a sinusoidal pulse width modulation (SPWM) module. The module includes: an LC filter connected to the energy storage system to filter out switching frequency interference signals; a zero-start boost V / f control module to obtain the current voltage outer loop reference value; an abc / dq coordinate transformation module to convert the three-phase current components into d-axis and q-axis components; a voltage and current dual closed-loop control module including a voltage outer loop control module and a current inner loop control module. The voltage outer loop control module obtains the current capacitor voltage, the current common coupling point current, and the current voltage outer loop reference value. The current inner loop control module determines the predicted current for the next moment based on the reference current of the current inner loop control, the current capacitor voltage, and the current predicted current, and determines the switching state of each control switch and the corresponding voltage vector based on a preset cost function, the current predicted current, and the next predicted current; and an SPWM module converts the switching state of each control switch and the corresponding voltage vector into a modulation signal and transmits it to the energy storage system to enable the energy storage system to perform self-start.

[0113] For example, Figure 3 This is a schematic diagram of the equivalent architecture of the self-starting process of an energy storage system for a three-phase three-wire inverter, such as... Figure 3 As shown, the energy storage system uses an LC filter to filter out switching frequency interference before connecting to the PCC point. It is worth noting that the step-up transformer primarily affects the zero-voltage start-up time setting, so its connection is omitted here. For the control architecture, a dual-loop control strategy of voltage and current is adopted, where the reference value of the outer voltage loop is obtained through an improved V / f control based on zero-voltage start-up.

[0114] Model Predictive Control (MPC) comprises a predictive model, rolling optimization, and feedback control. To address model uncertainties such as nonlinearity and disturbances, MPC uses feedback to eliminate prediction errors. It compares the output measurements with the model's predictions and uses the discrepancies to adjust future predictions.

[0115] like Figure 3 As shown, the prediction model in continuous time is as follows:

[0116]

[0117] In the formula: x=[i L ,v c ] Ti L =i Lα +ji Lβ v c =v cα +jv cβ , u = u α +ju β i p =i α +ji β , where C f L represents the filter capacitor. f Indicates the filter inductance, v c Indicates the capacitor voltage, i Lα i represents the α-axis component of the inductor current. Lβ Let β represent the β-axis component of the inductor current, j represent the rotation factor, and v represent the β-axis component of the inductor current. cα The α-axis component of the capacitor voltage, v cβ The β-axis component of the capacitor voltage, u α u represents the α-axis component of the inverter output voltage. β The β-axis component of the inverter output voltage is represented by u, and the output voltage is represented by i. p This indicates the grid-side current.

[0118] According to the zero-order hold principle, the above equation can be written as the following prediction equation:

[0119] x(k+1)=A d ·x(k)+B d ·u(k)+B pd ·i p (k)

[0120] Where k is the transient time at a certain moment, and the sampling frequency is T. s A d Represents the system parameter matrix B d Represents the system parameter matrix x(k) represents the predicted value at time k, u(k) represents the inverter's output voltage at time k, and B pd Represents the system parameter matrix i p (k) represents the predicted value of the grid-side current at time k.

[0121] Following the above method, the goal of the outer loop MPC circuit is to achieve voltage reference tracking and generate the reference current for the inner loop control. Applying the forward differential separation method to the above equation, the discrete model is as follows:

[0122]

[0123] To achieve voltage reference value tracking, vc (k+1) can be v cref =v crefα +jv crefβ Instead, v cref The reference value for capacitor voltage, v crefα The α-axis component representing the reference value of the capacitor voltage, v crefβ The β-axis component represents the reference value of the capacitor voltage. Then, i(k) can be used as the inner-loop current reference value input to the inner-loop current control. The final equation for calculating the current reference value is shown below:

[0124]

[0125] Based on the continuous-time model, the discrete expression for current prediction is as follows:

[0126]

[0127] In order for the predicted current i(k+1) to track the reference current i predicted by the outer loop of the MPC voltage ref The cost function is as follows:

[0128] g = (i αref -i α (k+1)) 2 +(i βref -i β (k+1)) 2

[0129] In the formula: g represents the cost function, i αref The α-axis component of the reference current for the inner current loop control, i α (k+1) represents the predicted value of the α-axis current at time k+1, i βref i represents the β-axis component of the reference current for the inner current loop control. β (k+1) represents the predicted value of the β-axis current at time k+1.

[0130] The MPC uses eight switching states to minimize the cost function to determine the optimal switching state for each sampling period. The switching states and their corresponding voltage vectors are shown in Table 1.

[0131] Table 1

[0132]

[0133] Among them, V dc This indicates the voltage on the DC side.

[0134] Based on the above formula, the voltage and current dual closed-loop control block diagram of MPC is simplified as follows: Figure 4 As shown.

[0135] In the MPC control strategy, the input is a real-time voltage and current signal, and the output is a switching signal. Let's consider the capacitor voltage v at time k. c (k) and the current i at the PCC terminal p (k) is used as input, and the inverter-side reference current i is obtained through MPC voltage outer loop control. ref The reference current, v c The inputs (k) and i(k) are fed into the MPC current inner loop control to obtain the optimal voltage vector u(k+1), which in turn controls the on / off state of the device. Figure 5 This is a flowchart of the MPC voltage and current dual closed-loop control in one embodiment.

[0136] In summary, by using the optimization strategy of MPC, the negative sequence component of the voltage at PCC can be suppressed without performing positive and negative sequence decomposition, thereby achieving three-phase voltage balance during the black start process.

[0137] This embodiment proposes a model predictive control (MPC) method, with negative-sequence voltage suppression as the core governance path, based on voltage imbalance mechanism analysis. By combining the discrete model of the converter with a finite control set, a specific cost function is constructed to directly predict and adjust the converter output state, achieving dynamic three-phase voltage balance without relying on positive / negative sequence decomposition. MPC directly processes the original signal through a rolling optimization framework, constructing a comprehensive dynamic model containing positive and negative sequence components in the prediction time domain. This allows for real-time prediction of the system's future state, eliminating the traditional sequence component separation stage and reducing computational resource consumption and system latency. By pre-simulating the system's future behavior in the prediction time domain and applying the optimal control sequence in advance, it avoids the passive "biased first, compensate later" mode of PI control and overcomes the bandwidth limitations of traditional PI control. The predictive model includes positive / negative sequence interaction terms (such as coupling terms caused by grid impedance asymmetry), automatically balancing the weights of different sequence components during optimization. Furthermore, only the weight matrix of state error and control quantity in the objective function needs adjustment, without setting separate parameters for each sequence component, significantly enhancing the robustness and engineering practicality of the control system.

[0138] It should be understood that MPC, through rolling optimization to eliminate signal decomposition, multi-step prediction to overcome bandwidth limitations, and a unified framework to simplify collaborative control, forms a three-in-one technical advantage of "prediction-optimization-integration". In addressing black-start voltage imbalance under unbalanced loads in distribution networks, MPC will gradually replace traditional cascaded control architectures and become a benchmark solution for the control of complex power electronic systems.

[0139] In the aforementioned black-start voltage equalization control method, the current capacitor voltage, the current point of common coupling (PCC) current, and the current voltage outer loop reference value are obtained. Based on these parameters, the reference current for the current inner loop control is determined. This allows for the determination of the reference current for the current inner loop control using the voltage outer loop control, achieving dual closed-loop control of voltage and current. The predicted current for the next moment is determined based on the reference current for the current inner loop control, the current capacitor voltage, and the predicted current. This enables direct prediction of the predicted current for the next moment using the model predictive control strategy, avoiding the passive "biased first, compensated later" mode of PI control and overcoming the bandwidth limitations of traditional PI control. Based on a preset cost function, the predicted current for the current moment, and the predicted current for the next moment, the switching states of each control switch and the corresponding voltage vectors are determined. These switching states and voltage vectors are used to instruct the energy storage system to perform self-start. This allows for real-time prediction of the system's future state, eliminates the need for traditional sequential component separation, reduces computational resource consumption and system latency, eliminates the need to set separate parameters for each sequential component, and significantly enhances the robustness and engineering practicality of the control system.

[0140] Existing sequence control methods require consuming control resources to separate the positive and negative sequence voltages of the power grid to achieve independent control of positive and negative sequence voltages. This application, based on model prediction principles, effectively suppresses negative sequence voltages caused by unbalanced loads and reduces voltage imbalance by embedding it into an existing control architecture, thereby achieving balanced voltage control during the black start process of renewable energy power plants.

[0141] For example, the operating characteristics of a distribution network energy storage system during the zero-voltage start-up phase are evaluated. In the initial stage of black start, the voltage is very low (less than 0.5 pu), and some loads cannot operate normally. Therefore, to simulate actual load operation scenarios, when the system voltage rises to 0.5 pu during black start, unbalanced loads begin to operate.

[0142] Among them, the black start test results of the energy storage system under traditional PI control are as follows: Figures 6(a) to 6(c)As shown in Figure 6(a), the three-phase voltage waveforms of the energy storage system during the black start phase under traditional PI control are schematic diagrams. Although the voltage amplitude is close to 311V, the three-phase system still exhibits imbalance. Figure 6(b) shows the negative sequence voltage waveforms of the energy storage system during the black start phase under traditional PI control. During the initial voltage ramp-up phase of black start, the negative sequence voltage amplitude gradually increases. After the system enters steady state, the negative sequence voltage is approximately 1V. Figure 6(c) shows the voltage imbalance waveforms of the energy storage system during the black start phase under traditional PI control. The voltage imbalance is measured using the IEEE PES (Power Quality Engineering Society) standard document, "IEEE Standard Test Procedures for Multiphase Induction Motors and Generators," which defines voltage imbalance as the percentage of the maximum voltage difference between the effective voltage value and the average three-phase voltage value relative to the average three-phase voltage value. The standard strictly defines that the voltage imbalance cannot exceed 0.5%.

[0143] After the system reaches steady state, Ku = 0.3%. The black-start test results of the MPC-controlled energy storage system are as follows: Figures 7(a) to 7(c) As shown in Figure 7(a), this is a schematic diagram of the three-phase voltage waveform during the black start phase of the energy storage system under MPC control. After the black start voltage enters steady state, the voltage amplitude is close to 311V. Figure 7(b) is a schematic diagram of the negative sequence voltage waveform during the black start phase of the energy storage system under MPC control. During the zero-start boost phase of black start, the negative sequence voltage amplitude gradually increases. After the system enters steady state, the negative sequence voltage is approximately 0.4V, which is significantly lower than the negative sequence voltage amplitude under traditional PI control. Figure 7(c) is a schematic diagram of the voltage imbalance waveform during the black start phase of the energy storage system under MPC control. After the system enters steady state, Ku = 0.13%, which is significantly lower than the value under traditional PI control.

[0144] In summary, while existing methods can address voltage imbalance, they require consuming control resources to separate the negative-sequence voltage component generated by the unbalanced load, suffer from bandwidth limitations, and increase the complexity of control architecture and parameter design, thus lacking widespread applicability. The examples above demonstrate that this application's MPC control strategy can effectively solve the voltage balancing problem caused by load asymmetry, avoid active and reactive power oscillations caused by voltage imbalance, enhance the stability of the black start process of renewable energy power plants, and improve the grid-connected power generation efficiency of renewable energy.

[0145] This embodiment analyzes the mechanism of voltage imbalance problems in three-phase three-wire inverters under various unbalanced loads, revealing that the goal of addressing voltage imbalance is to eliminate negative sequence voltage. MPC (Multi-Process Control) achieves a three-in-one technical advantage of "prediction-optimization-integration" by eliminating signal decomposition stages through rolling optimization, overcoming bandwidth limitations through multi-step prediction, and simplifying collaborative control with a unified framework. In addressing black-start voltage imbalance under unbalanced loads in distribution networks, MPC is gradually replacing traditional cascaded control architectures, becoming a benchmark solution for complex power electronic system control. Its core value lies in: simplifying hardware through algorithmic innovation, and replacing manual parameter tuning with intelligent models, meeting the industry's urgent need for efficient, reliable, and easily deployable control systems.

[0146] It should be understood that although the steps in the flowcharts of the above embodiments are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the above embodiments may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0147] Based on the same inventive concept, this application also provides a black-start voltage equalization control device for implementing the black-start voltage equalization control method described above. The solution provided by this device is similar to the solution described in the above method; therefore, the specific limitations in one or more embodiments of the black-start voltage equalization control device provided below can be found in the limitations of the black-start voltage equalization control method described above, and will not be repeated here.

[0148] In one exemplary embodiment, such as Figure 8 As shown, a black-start voltage equalization control device is provided, comprising: an acquisition module 801, a first determination module 802, a second determination module 803, and a third determination module 804, wherein:

[0149] The acquisition module 801 is used to acquire the capacitor voltage at the current moment, the current common coupling point current at the current moment, and the voltage outer loop reference value at the current moment;

[0150] The first determining module 802 is used to determine the reference current for the current inner loop control based on the current capacitor voltage, the current common coupling point current, and the current voltage outer loop reference value.

[0151] The second determining module 803 is used to determine the predicted current at the next moment based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment.

[0152] The third determining module 804 is used to determine the switching state of each control switch and the corresponding voltage vector based on the preset cost function, the predicted current at the current moment and the predicted current at the next moment; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

[0153] For example, the acquisition module 801 is specifically used to: acquire the current voltage outer loop reference value through zero-voltage start-up V / f control.

[0154] For example, the above-mentioned device may further include: a control architecture construction module 805, the control architecture 805 including: an LC filter 8051, a zero-start boost V / f control module 8052, an abc / dq coordinate transformation module 8053, a voltage and current dual closed-loop control module 8054, and an SPWM module 8055; wherein:

[0155] The LC filter 8051 is connected to the energy storage system to filter out switching frequency interference signals;

[0156] The zero-start boost V / f control module 8052 is used to obtain the current voltage outer loop reference value;

[0157] The abc / dq coordinate transformation module 8053 is used to convert three-phase current components into d-axis and q-axis components.

[0158] The voltage and current dual closed-loop control module 8054 includes a voltage outer loop control module and a current inner loop control module. The voltage outer loop control module is used to acquire the current capacitor voltage, the current common coupling point current, and the current voltage outer loop reference value. The current inner loop control module is used to determine the predicted current at the next moment based on the reference current controlled by the current inner loop, the current capacitor voltage, and the current predicted current, and to determine the switching state of each control switch and the corresponding voltage vector based on a preset cost function, the current predicted current, and the next predicted current.

[0159] The SPWM module 8055 is used to convert the switching states of each control switch and the corresponding voltage vector into modulation signals and transmit them to the energy storage system so that the energy storage system can perform self-starting.

[0160] For example, based on the current capacitor voltage, the current at the point of common coupling, and the current outer voltage reference value, the formula for calculating the reference current for the inner current loop control is as follows:

[0161]

[0162] In the formula: i ref C represents the reference current for the inner current loop control. f T represents the capacitance value. s Indicates the sampling frequency, v cref This represents the outer loop reference value of the voltage, v. c (k) represents the capacitor voltage at time k, i p (k) represents the current at the point of common connection at time k.

[0163] For example, based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment, the calculation formula for the predicted current at the next moment is as follows:

[0164]

[0165] In the formula: i(k+1) represents the predicted current at time k+1, L f Indicates the inductance value, v c (k) represents the capacitor voltage at time k, R represents the resistance value, and T s The sampling frequency i(k) represents the predicted current at time k.

[0166] For example, the formula for calculating the preset cost function is as follows:

[0167] g = (i αref -i α (k+1)) 2 +(i βref -i β (k+1)) 2

[0168] In the formula: g represents the cost function, i αref The α-axis component of the reference current for the inner current loop control, i α (k+1) represents the predicted value of the α-axis current at time k+1, i βref i represents the β-axis component of the reference current for the inner current loop control. β (k+1) represents the predicted value of the β-axis current at time k+1.

[0169] Each module in the aforementioned black-start voltage balancing control device can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in the processor of a computer device in hardware form or independent of it, or stored in the memory of a computer device in software form, so that the processor can call and execute the corresponding operations of each module.

[0170] In one exemplary embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 9 As shown, the computer device includes a processor, memory, input / output interfaces, a communication interface, a display unit, and an input device. The processor, memory, and input / output interfaces are connected via a system bus, and the communication interface, display unit, and input device are also connected to the system bus via the input / output interfaces. The processor provides computing and control capabilities. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores the operating system and computer programs. The internal memory provides an environment for the operation of the operating system and computer programs stored in the non-volatile storage media. The input / output interfaces are used for exchanging information between the processor and external devices. The communication interface is used for wired or wireless communication with external terminals; wireless communication can be achieved through Wi-Fi, mobile cellular networks, Near Field Communication (NFC), or other technologies. When the computer program is executed by the processor, it implements a black-start voltage equalization control method. The display unit is used to form a visually visible image and can be a display screen, a projection device, or a virtual reality imaging device. The display screen can be an LCD screen or an e-ink screen. The input device of the computer device can be a touch layer covering the display screen, or buttons, trackballs, or touchpads set on the casing of the computer device, or external keyboards, touchpads, or mice, etc.

[0171] Those skilled in the art will understand that Figure 9 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0172] In one exemplary embodiment, a computer device is provided, including a memory and a processor, wherein the memory stores a computer program, and the processor executes the computer program to implement the method steps described in the various embodiments above.

[0173] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method steps of the various embodiments described above.

[0174] In one embodiment, a computer program product is provided, including a computer program that, when executed by a processor, implements the method steps of the various embodiments described above.

[0175] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium. When executed, the computer program can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0176] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0177] The above embodiments are merely illustrative of several implementation methods of this application, and their descriptions are relatively specific and detailed. However, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A black-start voltage equalization control method, characterized in that, The method includes: Obtain the current capacitor voltage, the current common coupling point current, and the current voltage outer loop reference value; The reference current for the inner current loop control is determined based on the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value. The predicted current for the next moment is determined based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment. Based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment, the switching state of each control switch and the corresponding voltage vector are determined; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

2. The method according to claim 1, characterized in that, The process of obtaining the current voltage outer loop reference value includes: The current voltage outer loop reference value is obtained through zero-voltage start-up V / f control.

3. The method according to claim 1, characterized in that, Before obtaining the current capacitor voltage, the current at the point of common coupling, and the current voltage outer loop reference value, the method further includes: A control architecture for the self-starting phase of an energy storage system is constructed, comprising: an LC filter, a zero-start boost V / f control module, an abc / dq coordinate transformation module, a voltage-current dual closed-loop control module, and an SPWM module; wherein: The LC filter is connected to the energy storage system to filter out switching frequency interference signals; The zero-start boost V / f control module is used to obtain the current voltage outer loop reference value; The abc / dq coordinate transformation module is used to convert the three-phase current components into d-axis and q-axis components; The voltage and current dual closed-loop control module includes a voltage outer loop control module and a current inner loop control module. The voltage outer loop control module is used to acquire the capacitor voltage at the current moment, the current of the point of common coupling at the current moment, and the voltage outer loop reference value at the current moment. The current inner loop control module is used to determine the predicted current at the next moment based on the reference current controlled by the current inner loop, the capacitor voltage at the current moment, and the predicted current at the current moment, and to determine the switching state of each control switch and the corresponding voltage vector based on a preset cost function, the predicted current at the current moment, and the predicted current at the next moment. The SPWM module is used to convert the switching states of each control switch and the corresponding voltage vector into modulation signals and transmit them to the energy storage system so that the energy storage system can perform self-starting.

4. The method according to claim 1, characterized in that, The formula for determining the reference current for the inner current loop control based on the current capacitor voltage, the current common coupling point current, and the current outer voltage loop reference value is as follows: In the formula: i ref C represents the reference current for the inner current loop control. f T represents the capacitance value. s Indicates the sampling frequency, v cref This represents the outer loop reference value of the voltage, v. c (k) represents the capacitor voltage at time k, i p (k) represents the current at the point of common connection at time k.

5. The method according to any one of claims 1 to 4, characterized in that, Based on the reference current of the inner current loop control, the capacitor voltage at the current moment, and the predicted current at the current moment, the calculation formula for the predicted current at the next moment is as follows: In the formula: i(k+1) represents the predicted current at time k+1, L f Indicates the inductance value, v c (k) represents the capacitor voltage at time k, R represents the resistance value, and T s The sampling frequency i(k) represents the predicted current at time k.

6. The method according to any one of claims 1 to 4, characterized in that, The formula for calculating the preset cost function is as follows: g=(i αref -i α (k+1)) 2 +(i βref -i β (k+1)) 2 In the formula: g represents the cost function, i αref The α-axis component of the reference current for the inner current loop control, i α (k+1) represents the predicted value of the α-axis current at time k+1, i βref i represents the β-axis component of the reference current for the inner current loop control. β (k+1) represents the predicted value of the β-axis current at time k+1.

7. A black-start voltage equalization control device, characterized in that, The device includes: The acquisition module is used to acquire the capacitor voltage, the point of common coupling current, and the voltage outer loop reference value at the current moment. The first determining module is used to determine the reference current for the current inner loop control based on the capacitor voltage at the current moment, the common coupling point current at the current moment, and the voltage outer loop reference value at the current moment. The second determining module is used to determine the predicted current at the next moment based on the reference current of the current inner loop control, the capacitor voltage at the current moment, and the predicted current at the current moment. The third determining module is used to determine the switching state of each control switch and the corresponding voltage vector based on a preset cost function, the predicted current at the current moment and the predicted current at the next moment; the switching state of each control switch and the corresponding voltage vector are used to instruct the energy storage system to perform self-starting.

8. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 6.

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