Dynamic commutation control methods, systems, equipment, media, and products for energy storage converters

Abstract

This invention relates to the field of energy storage converter technology, and discloses a dynamic commutation control method, system, device, medium, and product for energy storage converters. The method determines the commutation time window by comprehensively considering the internal potential, grid voltage, output current, and current reference value during the switching process of the energy storage converter. It then calculates the available commutation voltage-time area and the commutation area required to complete the target current change within this time window, respectively. Based on the difference between these two calculations, a commutation margin is formed, and the current commutation state is identified. A joint evaluation is performed on the predicted commutation margin and operating state tracking error corresponding to multiple candidate switching states. The predicted commutation margin constrains the selection of the switching state in the next control cycle, enabling the energy storage converter to prioritize switching states with sufficient commutation drive capability while considering current and voltage tracking performance, thereby improving the reliability of the energy storage converter's commutation control.

Description

Technical Field

[0001] This invention relates to the field of energy storage converter technology, and in particular to a dynamic commutation control method, system, device, medium and product for energy storage converters. Background Technology

[0002] As the core equipment for energy exchange between the energy storage system and the power grid, the control performance of the energy storage converter directly affects the stable operation of the energy storage system under grid disturbances. Based on the method of establishing voltage and frequency, energy storage converters can generally be divided into grid-linked energy storage converters and grid-connected energy storage converters. Grid-linked energy storage converters typically rely on phase-locked loops (PLLs) to track the voltage phase and frequency of the external power grid and output current to the grid according to given current commands. Grid-connected energy storage converters, on the other hand, can autonomously form voltage amplitude and phase references within the converter itself through grid-connected control strategies such as virtual synchronous machines, enabling the converter ports to exhibit external voltage source characteristics, thereby providing voltage and frequency support to the power grid.

[0003] In grid-connected energy storage converters, commutation refers to the process of current transfer from one switch to another when the switching states of power semiconductor devices change. Under conditions of large disturbances such as weak grids, voltage dips, and phase jumps, grid-connected energy storage converters may fail to commutate due to insufficient net drive voltage during commutation, which prevents the available voltage-time area from meeting the current transfer requirements.

[0004] Therefore, how to determine in advance whether the commutation voltage-time area of ​​the grid-type energy storage converter can meet the current transfer requirements under weak grid and large disturbance conditions, and select the switching state that can reduce the risk of commutation failure accordingly, is a technical problem that urgently needs to be solved. Summary of the Invention

[0005] In view of this, in order to solve the above-mentioned technical problems, the present invention provides a dynamic commutation control method, system, device, medium and product for energy storage converters.

[0006] The first aspect of this invention provides a dynamic commutation control method for an energy storage converter, the method comprising:

[0007] When the energy storage converter undergoes a switching state transition, the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value are acquired, and the commutation time window corresponding to the switching state transition is determined.

[0008] Based on the internal potential, the grid voltage, and the output current, determine the available commutation voltage-time area within the commutation time window, and determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0009] The commutation margin is determined based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0010] Based on the relationship between the commutation margin and the preset safety margin threshold, the commutation state of the energy storage converter in the current commutation process is determined;

[0011] The predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states are predicted respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating state tracking error is used to determine the state evaluation result of each candidate switch state. The target switch state of the energy storage converter in the next control cycle is determined based on the state evaluation result.

[0012] The energy storage converter is controlled according to the target switching state.

[0013] In one example, acquiring the internal potential of the energy storage converter, the grid voltage, the output current, and the current reference value, and determining the commutation time window corresponding to the switching state transition, includes:

[0014] The amplitude and phase of the internal potential generated by the network control are obtained, and the internal potential is determined based on the amplitude and phase of the internal potential.

[0015] The three-phase instantaneous voltage at the common coupling point is collected, and the coordinate transformation of the three-phase instantaneous voltage is performed to obtain the grid voltage;

[0016] Obtain the output current of the energy storage converter, the preset current reference value, and the current change to be completed;

[0017] The commutation start time is determined based on the change in the switching sector corresponding to the current reference value, and the minimum current transfer time required to complete the current change to be completed is determined. The minimum current transfer time is compared with the switching cycle of the energy storage converter, and the larger of the two times is determined as the commutation duration.

[0018] The commutation time window is composed of the commutation start time and the commutation duration.

[0019] In one example, determining the available commutation voltage-time area within the commutation time window based on the internal potential, the grid voltage, and the output current, and determining the required commutation area based on the amount of current change required for the output current to change towards the current reference value, includes:

[0020] The virtual impedance voltage drop is determined based on the preset virtual impedance parameters and the output current;

[0021] The net driving voltage acting on the commutation process is determined based on the difference between the internal potential, the grid voltage, and the virtual impedance voltage drop.

[0022] Integrating the net drive voltage within the commutation time window yields the available commutation voltage-time area.

[0023] The amount of current change between the output current and the current reference value is determined, and the required commutation area is determined based on the amount of current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbance.

[0024] In one example, determining the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the current change and the commutation required area includes:

[0025] The commutation reference direction is determined based on the current change vector between the output current and the current reference value;

[0026] The available commutation voltage-time area is projected onto the commutation reference direction to obtain the effective commutation area;

[0027] The commutation margin is determined based on the difference between the effective commutation area and the required commutation area, as well as a preset area base value.

[0028] In one example, the prediction of the predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states includes:

[0029] For each of the candidate switch states, determine the corresponding inverter output voltage;

[0030] Based on the grid voltage at the current sampling time and the historical sampling time, predict the grid voltage within the commutation time window, and predict the virtual impedance voltage drop within the commutation time window based on the current output current;

[0031] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the output current and filter capacitor voltage of the energy storage converter are predicted at the end of the commutation time window.

[0032] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the predicted net drive voltage within the commutation time window is determined, and based on the effective component of the predicted net drive voltage in the direction of the predicted current change, the corresponding predicted available commutation area is determined.

[0033] Based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance, the corresponding predicted commutation demand area is determined, and based on the difference between the predicted available commutation area and the predicted commutation demand area, the predicted commutation margin corresponding to the candidate switch state is determined.

[0034] The operating state tracking error corresponding to the candidate switch state is determined based on the difference between the output current at the end of the commutation time window and the current reference value, and the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value.

[0035] In one example, the predicted commutation margin is used as a constraint, combined with the commutation state, and the state evaluation results of each candidate switching state are determined based on the operating state tracking error. Then, the target switching state of the energy storage converter for the next control cycle is determined based on the state evaluation results, including:

[0036] Determine the corresponding commutation area constraint strategy based on the commutation state;

[0037] For each of the candidate switch states, based on the relationship between the predicted commutation margin corresponding to the candidate switch state and the preset safety margin threshold, the corresponding commutation area penalty value is determined according to the commutation area constraint strategy.

[0038] The operating state tracking error and commutation area penalty value corresponding to each candidate switch state are weighted and evaluated to obtain the corresponding state evaluation result.

[0039] The candidate switch states that meet the preset selection criteria are determined as the target switch states for the next control cycle of the energy storage converter.

[0040] Secondly, the present invention also provides a dynamic commutation control system for an energy storage converter, the system comprising:

[0041] The commutation window determination module is used to acquire the internal potential, grid voltage, output current and current reference value of the energy storage converter when the switching state of the energy storage converter changes, and to determine the commutation time window corresponding to the switching state change.

[0042] The commutation area determination module is used to determine the available commutation voltage-time area within the commutation time window based on the internal potential, the grid voltage, and the output current, and to determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0043] The commutation margin determination module is used to determine the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0044] The commutation state determination module is used to determine the commutation state of the energy storage converter in the current commutation process based on the relationship between the commutation margin and the preset safety margin threshold.

[0045] The switch state determination module is used to predict the predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states respectively, and use the predicted commutation margin as a constraint, combined with the commutation state, to determine the state evaluation result of each candidate switch state according to the operating state tracking error, and determine the target switch state of the energy storage converter in the next control cycle according to the state evaluation result.

[0046] The commutation control module is used to control the energy storage converter according to the target switching state.

[0047] Thirdly, the present invention also provides an electronic device, the electronic device including a memory and a processor, the memory storing a computer program, the computer program being executed by the processor causing the processor to perform the steps of the dynamic commutation control method for energy storage converter as described in the first aspect.

[0048] Fourthly, the present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed, implements the steps of the dynamic commutation control method for energy storage converter as described in the first aspect.

[0049] Fifthly, the present invention also provides a computer program product comprising a computer program stored on a non-transitory computer-readable storage medium, the computer program comprising program instructions, wherein when the program instructions are executed by a computer, the computer performs the steps of the dynamic commutation control method for energy storage converter as described in the first aspect.

[0050] As can be seen from the above technical solution, this invention determines the commutation time window by comprehensively considering the internal potential, grid voltage, output current, and current reference value during the switching state transition of the energy storage converter. It then calculates the available commutation voltage-time area that can actually be used for current transfer within this time window, as well as the commutation area required to complete the target current change. Based on the difference between these two, a commutation margin is formed, and the current commutation state is identified. Furthermore, the predicted commutation margin and operating state tracking error corresponding to multiple candidate switching states are jointly evaluated to constrain the selection of the switching state in the next control cycle. This allows the energy storage converter to prioritize the selection of switching states with sufficient commutation drive capability while considering current and voltage tracking performance. Therefore, it can predict whether the commutation area is sufficient before serious current deviations or overcurrents actually occur, avoiding the selection of switching states that may cause insufficient commutation based solely on conventional tracking errors. This reduces the risks of incomplete current transfer, waveform distortion, power oscillation, and protection disconnection under disturbances such as weak grids, voltage dips, and phase jumps, thereby improving the reliability, proactivity, and transient adaptability of the energy storage converter's commutation control. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 This is an application environment diagram of a dynamic commutation control method for an energy storage converter provided in an embodiment of the present invention;

[0053] Figure 2 A flowchart of a dynamic commutation control method for an energy storage converter provided in an embodiment of the present invention;

[0054] Figure 3 This is a schematic diagram of the structure of a dynamic commutation control system for an energy storage converter provided in an embodiment of the present invention;

[0055] Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention. Detailed Implementation

[0056] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0057] The dynamic commutation control method for energy storage converters provided in this application embodiment can be applied to, for example... Figure 1 In the application environment shown, terminal 101 communicates with server 102 via a network. A data storage system can store the data that server 102 needs to process. The data storage system can be integrated onto server 102 or placed on a cloud or other network server. Terminal 101 or server 102 executes a dynamic commutation control method for an energy storage converter. This method includes: when the energy storage converter undergoes a switching state transition, acquiring the internal potential, grid voltage, output current, and current reference value of the energy storage converter, and determining the commutation time window corresponding to the switching state transition; determining the available commutation voltage-time area within the commutation time window based on the internal potential, grid voltage, and output current, and determining the required commutation area based on the current change required for the output current to change towards the current reference value; and determining the commutation demand area based on the available commutation voltage-time area in the direction corresponding to the current change. The difference between the effective component and the required commutation area is used to determine the commutation margin. Based on the relationship between the commutation margin and the preset safety margin threshold, the commutation state of the energy storage converter in the current commutation process is determined. The predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states are predicted respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating state tracking error is used to determine the state evaluation result of each candidate switch state. Based on the state evaluation result, the target switch state of the energy storage converter in the next control cycle is determined. The energy storage converter is controlled according to the target switch state.

[0058] Terminal 101 can be, but is not limited to, various personal computers, laptops, smartphones, and tablets.

[0059] Server 102 can be a standalone physical server, a server cluster or distributed system consisting of multiple physical servers, or a cloud server that provides cloud computing services.

[0060] Here, "commutation" refers to the process by which the output current shifts from the current conductive path to a new conductive path when the switching state of a power semiconductor device changes. Because the energy storage converter side is equipped with a filter inductor, and the grid side may have transformer leakage inductance and line inductance, the output current cannot change instantaneously. Instead, it needs to be gradually driven to the target value by the net drive voltage acting on the equivalent inductance during commutation.

[0061] In this embodiment, "commutation failure" mainly refers to a situation where, within a given commutation time window, the voltage-time area provided by the net drive voltage is insufficient to allow the output current to complete the predetermined change, resulting in the actual current at the end of commutation deviating significantly from the current reference value. Commutation failure may cause current distortion, power oscillation, transient overcurrent, or disconnection of the energy storage converter protection.

[0062] like Figure 2 As shown, this application provides a dynamic commutation control method for an energy storage converter, which is applied to... Figure 1 Taking terminal 101 or server 102 as an example, the explanation includes the following steps S1 to S6. Wherein:

[0063] Step S1: When the energy storage converter switches between states, obtain the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value, and determine the commutation time window corresponding to the switch state switching.

[0064] In this embodiment, when the controller of the energy storage converter detects a change in the switching sector corresponding to the current reference vector or voltage reference vector, it determines that the energy storage converter has entered the switching state switching control process and determines that a switching state to be applied in the next control cycle needs to be selected. At this time, the commutation area prediction and candidate switching state selection are preferably completed before the target switching state is actually applied, so as to achieve feedforward prevention of commutation failure.

[0065] Internal potential is a voltage source reference quantity generated inside the energy storage converter by grid control, used to represent the voltage amplitude and phase that the energy storage converter is expected to establish.

[0066] The grid voltage can be the grid voltage space vector obtained by Clarke transformation of the three-phase instantaneous voltage at the common coupling point.

[0067] The output current can be the filter inductor current on the energy storage converter side, or it can be the grid-side current selected according to the control structure. Preferably, the output current adopts the current space vector consistent with that in the virtual impedance control and current prediction model to avoid mixing current quantities at different locations.

[0068] The current reference value is the current value that the energy storage converter is expected to reach at the end of the commutation time window. It can be generated by the upper-level power control, virtual synchronous machine control, and voltage and current dual-loop control of the grid-type energy storage converter.

[0069] The commutation time window is the total time range allowed from the start to the end of the commutation process. It is determined by the phase start time of the switch state switching and the preset commutation duration. Its length is generally matched with the switching cycle of the energy storage converter to ensure that the commutation process has a complete drive time after the switch state switching is completed.

[0070] Step S2: Based on the internal potential, grid voltage, and output current, determine the available commutation voltage-time area within the commutation time window, and determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0071] The available commutation voltage-time area represents the volt-second action that the energy storage converter can provide in the commutation direction within the commutation time window; the required commutation area represents the volt-second action required for the output current to change from its current value to the current reference value. By comparing the available commutation area and the required commutation area, it can be determined whether the current commutation process has sufficient driving capability.

[0072] Step S3: Determine the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0073] Since the available commutation voltage-time area is a vector while the commutation demand area is a scalar corresponding to the change in target current, the effective component of the available commutation area in the direction of the change in target current needs to be determined before comparing the two.

[0074] Commutation margin is used to indicate the remaining amount of effective commutation area relative to the required commutation area. A positive commutation margin indicates that there is theoretically enough area to complete the current transfer; the larger the commutation margin, the stronger the tolerance of the commutation process to sampling errors, parameter errors, and grid disturbances; a commutation margin of zero or negative indicates that the effective commutation area does not provide sufficient safety margin or is insufficient to meet the commutation requirements.

[0075] Step S4: Determine the commutation state of the energy storage converter in the current commutation process based on the relationship between the commutation margin and the preset safety margin threshold.

[0076] Among them, the safety margin threshold The parameters of the energy storage converter, sampling error, control delay and expected grid disturbance can be preset, such as the value range of 0.1 to 0.2, and for example, 0.15.

[0077] When the commutation margin of multiple consecutive control cycles is greater than or equal to the safety margin threshold, it can be determined that the energy storage converter has recovered to the commutation safety state and has exited the enhanced commutation area constraint adopted for high-risk or failure states.

[0078] Commutation status can be categorized into commutation safety status, commutation high-risk status, and commutation failure status. Specifically, they can be classified according to the following relationships.

[0079] Set commutation start time dimensionless commutation margin ,when At this point, it is determined that the current commutation process is in a safe commutation state. The effective commutation area not only meets the commutation requirements but also has an area margin not less than the safety margin threshold, allowing the selection of the switching state for the next control cycle according to the conventional voltage and current tracking target.

[0080] when At this point, the current commutation process is determined to be in a high-risk commutation state. Theoretically, commutation may still be possible at this stage, but the area margin is small, and sampling errors, parameter perturbations, or continued changes in grid voltage could all lead to actual commutation failure. Therefore, in subsequent candidate switch status evaluations, the priority of commutation area constraints should be increased.

[0081] when If the current commutation process is determined to be in a commutation failure state or a state of severely insufficient commutation area, and the currently available effective commutation area is not greater than the required commutation area, the controller needs to prioritize selecting the switching state that can increase the predicted commutation area, even if the voltage or current tracking error corresponding to that switching state is slightly larger.

[0082] When the commutation margin of multiple consecutive control cycles is greater than or equal to the safety margin threshold, it can be determined that the energy storage converter has recovered to the commutation safety state and has exited the enhanced commutation area constraint adopted for high-risk or failure states.

[0083] Step S5: Predict the predicted commutation margin and operating status tracking error corresponding to multiple preset candidate switch states respectively, and use the predicted commutation margin as a constraint. Combined with the commutation state, determine the status evaluation result of each candidate switch state based on the operating status tracking error, and determine the target switch state of the energy storage converter in the next control cycle based on the status evaluation result.

[0084] This step employs the finite set predictive control concept, enumerating multiple candidate switching states that the energy storage converter can adopt in the next control cycle at the current sampling time, and predicting the commutation result and operation status tracking result for each candidate switching state. The candidate switching states include all possible combinations of switching actions of the energy storage converter; the number is determined by the number of independently controllable switches in the topology. For a common two-level three-phase topology, there are a total of 8 candidate switching states.

[0085] By calculating the predicted commutation margin and operating state tracking error for each candidate switching state, it is possible to identify candidate states that have small voltage and current tracking errors but insufficient commutation area, and avoid using them as target switching states for the next control cycle.

[0086] Step S6: Control the energy storage converter according to the target switch state.

[0087] In the next control cycle, the controller outputs a drive signal corresponding to the target switching state to the power semiconductor device drive circuit of the energy storage converter, so that the energy storage converter outputs the corresponding voltage space vector.

[0088] A rolling optimization process can be formed by re-acquiring operational data, predicting candidate switch states, and updating target switch states in each sampling period. As the grid voltage or internal potential continues to change, the predicted commutation margin will be recalculated in the next sampling period, thereby correcting the switch state selection results in real time.

[0089] It should be noted that this application determines the commutation time window by comprehensively considering the internal potential, grid voltage, output current, and current reference value during the switching state transition of the energy storage converter. It then calculates the available commutation voltage-time area and the commutation area required to complete the target current change within this time window, respectively. Based on the difference between these two, a commutation margin is formed, and the current commutation state is identified. Furthermore, the predicted commutation margin and operating state tracking error corresponding to multiple candidate switching states are jointly evaluated to constrain the selection of the switching state in the next control cycle. This allows the energy storage converter to prioritize switching states with sufficient commutation drive capability while considering current and voltage tracking performance. Therefore, it can predict whether the commutation area is sufficient before serious current deviations or overcurrents occur, avoiding the selection of switching states that may cause insufficient commutation based solely on conventional tracking errors. This reduces the risks of incomplete current transfer, waveform distortion, power oscillation, and protection disconnection under disturbances such as weak grids, voltage dips, and phase jumps, thereby improving the reliability, proactivity, and transient adaptability of the energy storage converter's commutation control.

[0090] In some embodiments, acquiring the internal potential of the energy storage converter, the grid voltage, the output current, and the current reference value, and determining the commutation time window corresponding to the switching state transition, includes: acquiring the amplitude and phase of the internal potential generated by the grid control, and determining the internal potential based on the amplitude and phase of the internal potential; acquiring the three-phase instantaneous voltage at the common coupling point, and performing coordinate transformation on the three-phase instantaneous voltage to obtain the grid voltage; acquiring the output current of the energy storage converter, the preset current reference value, and the current change to be completed; determining the commutation start time based on the switching sector change corresponding to the current reference value, and determining the minimum current transfer time required to complete the current change to be completed, comparing the minimum current transfer time with the switching cycle of the energy storage converter, and determining the larger of the two times as the commutation duration; the commutation start time and the commutation duration constitute the commutation time window.

[0091] Under normal steady-state conditions, the amplitude and phase of the internal potential change relatively little within a single switching cycle. However, under transient conditions such as voltage dips, phase jumps, or sudden load changes, the phase of the internal potential may change with the virtual rotational speed, and the amplitude of the internal potential may also change with the voltage regulation loop. Therefore, this embodiment does not treat the internal potential as a fixed AC voltage, but rather uses it as a dynamic quantity within the commutation time window in the commutation area calculation.

[0092] For example, taking virtual synchronous machine control as an example, the internal potential can be expressed as:

[0093] ;

[0094] in, is the internal electric potential space vector, with units of V; This represents the internal potential amplitude, corresponding to the excitation voltage in virtual synchronous machine control. The internal electromotive force phase, in rad, corresponds to the virtual rotor angle of the virtual synchronous machine.

[0095] The phase of the internal potential can be obtained by integrating over the virtual angular frequency, that is:

[0096] ;

[0097] in, This refers to the virtual angular frequency obtained from the virtual synchronous machine control. Since the virtual angular frequency is affected by the virtual synchronous machine swing equation and the active power regulation process, the amplitude and phase of the internal potential may dynamically change during grid disturbances.

[0098] The point of common coupling (PCC) is the electrical node connecting the energy storage converter, transformer, or grid-connected line to the external power grid. The controller acquires the three-phase instantaneous phase voltages at PCC in real time via voltage sensors and converts the acquired results to a static value. The coordinate system forms the spatial vector of the power grid voltage.

[0099] The grid voltage can be obtained as a grid voltage space vector by performing Clarke transformation on the three-phase instantaneous voltages at the point of common coupling. Specifically, the three-phase instantaneous phase voltages at the point of common coupling are collected. , and The result obtained using the constant amplitude Clarke transform is:

[0100] ;

[0101] Or written as Component form:

[0102] ;

[0103] in, Let be the grid voltage space vector corresponding to time t. and They are at rest Grid voltage components in a coordinate system. By converting the three-phase instantaneous voltage into a space vector, grid voltage, internal potential, output current, and current reference value can be vector-calculated in the same coordinate system.

[0104] The output current can be the filter inductor current on the energy storage converter side, or it can be the grid-side current selected according to the control structure. Preferably, the output current adopts the current space vector consistent with that in the virtual impedance control and current prediction model to avoid mixing current quantities at different locations.

[0105] The current reference value is the current value that the energy storage converter is expected to reach at the end of the commutation time window. It can be generated by the upper-level power control, virtual synchronous machine control, and voltage and current dual-loop control of the grid-type energy storage converter.

[0106] The current change to be completed represents the total change in output current that needs to be completed from the start of commutation to the end of commutation. It can be expressed as:

[0107] ;

[0108] Alternatively, it can be represented in spatial vector form as follows:

[0109] ;

[0110] in, or This is the measured output current at the start of commutation; or This is the current reference value at the end of the commutation time window.

[0111] The larger the current change to be completed, the greater the change in output current needs to be completed within the same time period, and the higher the requirements for net drive voltage and available commutation area.

[0112] Commutation start time It can be determined by the sector judgment logic in the space vector modulation process. When the current reference vector or the corresponding reference voltage vector enters the adjacent sector from the current sector, the moment of sector change is determined as the commutation start moment.

[0113] The minimum current transfer time required to complete the desired current change can be estimated using the following formula:

[0114] ;

[0115] in, This is the filter inductance on the energy storage converter side, measured in watts (H). The current change to be completed is expressed in amperes (A). This is the voltage of the DC bus (dc), in volts (V).

[0116] The commutation duration can be expressed as:

[0117] ;

[0118] in, denoted as the switching cycle of the energy storage converter s.

[0119] when When this occurs, it indicates that theoretically, the corresponding current transfer can be completed within one switching cycle; therefore, one switching cycle is taken as the commutation duration. When This indicates that even if the maximum driving capability corresponding to the DC bus voltage is estimated, it is difficult to complete the current change within a single switching cycle. In this case, the commutation time window is extended to the estimated minimum current transfer time.

[0120] By adopting the aforementioned adaptive commutation duration, we can avoid using a fixed switching cycle as the integration interval under conditions of weak power grids or large current variations, thereby preventing the available commutation area from being underestimated or the analysis process from being terminated before the actual commutation process has ended.

[0121] The commutation time window can be represented as:

[0122] ;

[0123] The controller integrates the net drive voltage over this time interval to obtain the available commutation voltage-time area that can be provided by a single switching state transition.

[0124] The commutation time window is adapted to the amount of current change to be completed. When the commutation duration is longer than one switching cycle, the commutation time window can span multiple consecutive control cycles. The controller can reacquire operating data and update the remaining commutation time window in each control cycle to achieve rolling commutation area evaluation.

[0125] In some embodiments, the available commutation voltage-time area within the commutation time window is determined based on the internal potential, grid voltage, and output current, and the required commutation area is determined based on the current change required for the output current to change towards the current reference value. This includes: determining the virtual impedance voltage drop based on preset virtual impedance parameters and the output current; determining the net drive voltage acting on the commutation process based on the difference between the internal potential, grid voltage, and virtual impedance voltage drop; integrating the net drive voltage within the commutation time window to obtain the available commutation voltage-time area; determining the current change between the output current and the current reference value, and determining the required commutation area based on the current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbances.

[0126] Virtual impedance parameters include virtual resistance and virtual inductance. Grid-type energy storage converters typically use virtual impedance to simulate the stator resistance and synchronous reactance characteristics of synchronous generators. The virtual impedance voltage drop can be expressed as:

[0127] ;

[0128] in, This is the virtual impedance voltage drop space vector, with units of V; This is a virtual resistance, with units of . Used to provide damping; This is a virtual inductance, measured in ohms (H), used to simulate synchronous reactance. The rated angular frequency, for example, when the rated frequency is 50Hz, can be taken as... ; This is the space vector of the output current.

[0129] The virtual impedance itself is not a physical component actually connected in series in the power circuit, but its control effect changes the voltage characteristics presented by the energy storage converter. Therefore, when calculating the net drive voltage acting on the physical filter inductor and the grid-side equivalent inductance, it is necessary to deduct the equivalent voltage drop caused by the virtual impedance control.

[0130] The net drive voltage can be expressed as:

[0131] ;

[0132] in, It is the space vector of the net driving voltage acting on the commutation process.

[0133] The internal electromotive force (EMF) represents the voltage actively established by the energy storage converter, the grid voltage represents the voltage applied to the converter port by the external grid, and the virtual impedance voltage drop represents the equivalent voltage drop introduced by grid control. The vector difference between these three can approximate the net EMF acting on the filter inductor on the converter side and the equivalent inductance on the grid side.

[0134] Since all the voltages mentioned above are space vectors, their differences include not only amplitude relationships but also phase relationships. When a phase jump occurs in the grid voltage, even if the amplitude changes of the internal potential and the grid voltage are not significant, the vector difference between them may still change significantly. Therefore, using space vector differences is beneficial for reflecting the impact of phase disturbances on commutation capability.

[0135] The commutation voltage-time area can be expressed as:

[0136] ;

[0137] in, This is the available commutation voltage-time area vector, in V·s.

[0138] The integral result retains the directional information of the net drive voltage, and is therefore a vector. Even if the magnitude of the available commutation area vector is large, if its direction deviates significantly from the desired current change direction, the effective component that can actually drive the target current change may still be small. Subsequent steps extract the effective commutation area corresponding to the commutation requirement through directional projection.

[0139] In digital controllers, integration can be approximated using discrete sampled data. For example, the commutation time window can be divided into multiple sampling intervals, and the product of the net drive voltage and the sampling period within each interval can be accumulated. This discrete calculation is merely a digital implementation of continuous integration and does not change the physical meaning of the commutation area mentioned above.

[0140] By introducing the dynamic amplitude and phase of the internal potential, the available commutation area not only reflects the external power grid conditions, but also directly reflects the internal potential support capability generated by the grid control, thus enabling the commutation area to serve as an active adjustment object for subsequent switch state control.

[0141] The required commutation area can be expressed as:

[0142] ;

[0143] in, The required area for commutation is expressed in V·s; For the filter inductor on the energy storage converter side; The grid-side equivalent inductance can include the leakage inductance of the grid-connected transformer and the inductance of the weak grid lines. It is the equivalent disturbance current vector caused by grid voltage distortion, phase jump or other transient disturbances within the commutation time window.

[0144] The equivalent disturbance current can be estimated by the grid state observer based on the amplitude change, phase change, or harmonic component of the grid voltage within the commutation time window. Specifically, the grid state observer continuously acquires the grid voltage space vector corresponding to each sampling moment within the commutation time window, and determines the amplitude change, phase change, and / or harmonic change of the grid voltage based on the grid voltage space vectors at adjacent sampling moments or before and after the disturbance, thereby determining the voltage vector deviation caused by the grid voltage change; combined with the grid-side equivalent inductance L... g Furthermore, the relationship between the voltage and current changes across the inductor is analyzed, converting the voltage vector deviation into a corresponding additional current change, and using this additional current change as the equivalent disturbance current vector. For example, when the grid voltage undergoes a phase jump within the commutation time window, the grid state observer can estimate the corresponding additional current change based on the voltage vector difference before and after the phase jump and the grid-side equivalent inductance.

[0145] By simultaneously considering the converter-side filter inductance, the grid-side equivalent inductance, and grid disturbances, we can avoid underestimating the actual commutation requirements under weak grid conditions based solely on ideal current changes.

[0146] In some embodiments, determining the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the current change and the commutation requirement area includes: determining the commutation reference direction based on the current change vector between the output current and the current reference value; projecting the available commutation voltage-time area onto the commutation reference direction to obtain the effective commutation area; and determining the commutation margin based on the difference between the effective commutation area and the commutation requirement area and a preset area base value.

[0147] The commutation reference direction angle can be expressed as:

[0148] ;

[0149] in, This represents the phase angle of a spatial vector.

[0150] The commutation reference direction indicates the direction along which the output current should change from its current value to the current reference value. For example, when the current reference vector primarily requires... When the shaft current increases, the commutation reference direction mainly points to Positive axis direction; when the current reference vector is simultaneously required shaft current decrease and When the shaft current increases, the commutation reference direction is determined by the corresponding current change vector.

[0151] By determining the reference direction based on the current change vector, it is possible to avoid mistaking commutation area that is unrelated to or opposite to the target current change as effective commutation capability.

[0152] The effective commutation area can be expressed as:

[0153] ;

[0154] in, This represents taking the real part of a complex space vector. The usable commutated area vector is rotated... Taking the real part after the angle is equivalent to projecting the available commutation area onto the commutation reference direction.

[0155] When the available commutation area vector is in the same direction as the commutation reference direction, the projected effective commutation area is close to its magnitude; when there is an angle between them, the effective commutation area decreases as the angle increases; when the two directions are opposite, the effective commutation area may be negative, indicating that the corresponding net drive voltage will hinder the change of the target current.

[0156] Commutation margin can be expressed as:

[0157] ;

[0158] in, This is a dimensionless commutation margin; The preset area base value can be expressed as:

[0159] ;

[0160] in, This is the peak value of the rated phase current of the energy storage converter.

[0161] By normalizing the difference between the effective commutation area and the required commutation area using the area base value, the difference in absolute area values ​​between energy storage converters of different capacity levels can be eliminated, allowing the safety margin threshold to adopt a relatively uniform dimensionless value.

[0162] In some embodiments, predicting the predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switching states includes: determining the corresponding inverter output voltage for each candidate switching state; predicting the grid voltage within the commutation time window based on the grid voltage at the current sampling time and historical sampling times, and predicting the virtual impedance voltage drop within the commutation time window based on the current output current; predicting the output current of the energy storage converter and the filter capacitor voltage at the end of the commutation time window based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop; and determining the predicted commutation margin and operating state tracking error corresponding to the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop. The predicted net drive voltage within the commutation time window is used to determine the corresponding predicted available commutation area based on the effective component of the predicted net drive voltage in the direction of the predicted current change. The predicted commutation demand area is determined based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance. The predicted commutation margin corresponding to the candidate switch state is determined based on the difference between the predicted available commutation area and the predicted commutation demand area. The operating state tracking error corresponding to the candidate switch state is determined based on the difference between the output current at the end of the commutation time window and the current reference value, as well as the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value.

[0163] In this process, multiple candidate switching states that can be used in the next control cycle of the energy storage converter are enumerated at the current sampling time, and the commutation result and operation status tracking result are predicted for each candidate switching state.

[0164] The controller calculates the inverter output voltage space vector corresponding to each candidate switching state based on the current DC bus voltage and the switching functions of the three-phase bridge arms in each candidate switching state. Taking a two-level three-phase energy storage converter as an example, the upper and lower transistors of each phase bridge arm are complementary in conduction, and the switching function can be defined as:

[0165] ;

[0166] in, The time indicates phase a of the bridge arm. The time indicates phase b of the bridge arm. The time indicates the c-phase bridge arm.

[0167] Therefore, the three-phase bridge arms can form eight possible switching state combinations. The inverter output voltage space vector corresponding to each candidate switching state can be expressed as:

[0168] ;

[0169] in, For the first Candidate switch states, =(S a,j S b,j S c,j ), S a,j S b,j S c,j Let represent the switching functions of phase a, phase b, and phase c bridge arms respectively under the j-th candidate switching state. For a two-level three-phase inverter, It can be 8.

[0170] At the current discrete sampling time Since the actual grid voltage within the next commutation time window has not yet been obtained, a first-order linear extrapolation can be performed based on the grid voltage change trends at the current sampling time and the previous sampling time.

[0171] The predicted grid voltage can be expressed as:

[0172] ;

[0173] in, For the next sampling time k The corresponding predicted grid voltage space vector, superscript Indicates the predicted value; This represents the space vector of the grid voltage at the current sampling time. This is the space vector of the grid voltage at the previous sampling time; This represents the extrapolation step size ratio.

[0174] Take under normal working conditions When the above formula is used, it can be simplified to:

[0175] ;

[0176] This prediction method assumes that the grid voltage continues to change at the rate of change of the most recent sampling interval within a short commutation time window, and is suitable for situations where the commutation time window is one or a few switching cycles.

[0177] The predicted virtual impedance voltage drop can be expressed as:

[0178] ;

[0179] in, For the next sampling time k The corresponding predicted virtual impedance voltage drop space vector. Using the output current at the current sampling moment. This approximates the average current within the commutation time window. This approach avoids the problem of being unable to calculate the virtual impedance voltage drop before obtaining the future current trajectory, and the controller will re-predict in the next sampling period to reduce the accumulation of approximation errors.

[0180] Regarding the first Given a candidate switching state, the output current at the end of the commutation time window can be expressed as:

[0181] ;

[0182] in, To apply the first Predicted output current at the end of the commutation time window after each candidate switch state.

[0183] The above formula is based on the relationship between the voltage and current change rate across the inductor. It discretizes the result of the net drive voltage corresponding to the candidate switching state acting on the filter inductor to predict the output current that can be reached at the end of the commutation time window.

[0184] The predicted value of the filter capacitor voltage can be discretely predicted based on the state equation of the filter used in the energy storage converter, as well as the current filter capacitor voltage, output current, and grid-side current. The predicted value of the filter capacitor voltage is used to evaluate the impact of candidate switch states on the output voltage tracking performance of the energy storage converter.

[0185] Among them, the The predicted net driving voltage corresponding to each candidate switch state can be expressed as:

[0186] ;

[0187] The direction of current change can be predicted based on the difference between the current reference value in the next control cycle and the current output current:

[0188] ;

[0189] The angle between the predicted net drive voltage and the predicted current change direction It can be represented as:

[0190] ;

[0191] in, This indicates the calculation of the phase angle of the corresponding space vector.

[0192] In this embodiment, the grid voltage, internal potential, output current, and predicted net drive voltage can all be represented by two-dimensional space vectors in a stationary αβ coordinate system. For space vectors... Its Euclidean norm can be expressed as:

[0193] ;

[0194] in, , These are the components of the space vector along the α-axis and β-axis, respectively. The Euclidean norm is used to characterize the magnitude of the space vector. Therefore, by multiplying the Euclidean norm of the predicted net drive voltage by the cosine of the included angle, the effective component of the predicted net drive voltage in the direction of the target current change can be obtained. The square of the Euclidean norm is used in the calculation of current tracking error and filter capacitor voltage tracking error. On the one hand, this converts the vector difference into a non-negative scalar; on the other hand, the squaring operation maintains the monotonic relationship of the error magnitude and can increase the impact of large tracking deviations on the state evaluation results. Simultaneously, it avoids additional square root operations, facilitating the comparison between candidate switch states by the controller.

[0195] Therefore, the first The predicted available commutation area corresponding to each candidate switch state can be expressed as:

[0196] ;

[0197] in, This represents the Euclidean norm. (Through...) By projecting the magnitude of the predicted net drive voltage onto the direction of the predicted current change, we can obtain the predicted volt-second area that the candidate switching state can actually be used to complete the target current change.

[0198] The predicted commutation area requirement can be expressed as:

[0199] ;

[0200] in, To predict the additional commutation area corresponding to power grid disturbances.

[0201] in, ,in, This is the predicted internal potential space vector corresponding to the next commutation time window. The predicted internal potential is determined according to the aforementioned internal potential generation method, that is, obtaining the internal potential amplitude and phase corresponding to the next commutation time window under grid control, and constructing the predicted internal potential space vector based on the internal potential amplitude and phase. The internal potential amplitude is determined by the excitation or voltage regulation loop in the grid control, and the internal potential phase is determined by the virtual angular frequency integral obtained from the virtual synchronous machine control. The above expression can be understood as follows: first, the equivalent disturbance current is estimated based on the difference between the predicted grid voltage and the predicted internal potential, as well as the grid-side equivalent inductance; then, the equivalent disturbance current is multiplied by the grid-side equivalent inductance to obtain the corresponding disturbance volt-second area.

[0202] No. The predicted commutation margin corresponding to each candidate switch state can be expressed as:

[0203] ;

[0204] The predicted commutation margin represents the remaining amount of the predicted effective commutation area relative to the predicted commutation demand area when the corresponding candidate switching state is applied in the next control cycle. This predicted commutation margin is used to subsequently determine the commutation area penalty value.

[0205] The operating status tracking error can include current tracking error and filter capacitor voltage tracking error.

[0206] No. The current tracking error corresponding to each candidate switch state can be determined based on the difference between the current reference value and the predicted output current, for example:

[0207] ;

[0208] in, The current reference value, corresponding to the end of the commutation time window or the next control cycle, is generated by the upper-level power control, virtual synchronous machine control, and / or voltage and current control loop of the grid-type energy storage converter. The controller obtains this value from the current reference value generation stage before predicting candidate switch states. .

[0209] The filter capacitor voltage tracking error can be determined based on the difference between the reference value and the predicted filter capacitor voltage. For example:

[0210] ;

[0211] in, The reference value of the filter capacitor voltage for the next control cycle of the network control is output by the voltage reference generation circuit or voltage control loop in the network control, and is obtained by the controller before the evaluation of the candidate switch status. For the first Predicted values ​​of the filter capacitor voltage corresponding to each candidate switch state.

[0212] Current tracking error is used to evaluate whether the candidate switching state can bring the output current close to the current reference value; filter capacitor voltage tracking error is used to evaluate whether the candidate switching state can maintain the voltage source external characteristics of the grid-type energy storage converter. These errors, along with the predicted commutation margin, participate in the state evaluation of the candidate switching state.

[0213] In some embodiments, the predicted commutation margin is used as a constraint, and the commutation state is combined with the operating state tracking error to determine the state evaluation result of each candidate switch state. The target switch state for the next control cycle of the energy storage converter is then determined based on the state evaluation result. This includes: determining the corresponding commutation area constraint strategy based on the commutation state; for each candidate switch state, determining the corresponding commutation area penalty value according to the relationship between the predicted commutation margin and the preset safety margin threshold, based on the commutation area constraint strategy; performing a weighted evaluation on the operating state tracking error and the commutation area penalty value corresponding to each candidate switch state to obtain the corresponding state evaluation result; and determining the candidate switch state whose state evaluation result meets the preset selection criteria as the target switch state for the next control cycle of the energy storage converter.

[0214] Specifically, the predicted commutation margin is transformed from a simple detection indicator into a constraint in the candidate switch state selection process. The controller adjusts the relative priority between the commutation area constraint and the operating state tracking target based on the current commutation state, and establishes a state evaluation result for each candidate switch state, including current tracking error, voltage tracking error, and commutation area penalty value.

[0215] When the current commutation process is in a safe commutation state, the main function of the conventional voltage and current tracking target can be maintained, and no commutation area penalty is imposed on candidate switch states whose predicted commutation margin is not less than the safety margin threshold. When the current commutation process is in a high-risk commutation state or a commutation failure state, the weight of the commutation area penalty term is increased, so that the controller prioritizes candidate switch states that can provide a larger predicted commutation area.

[0216] For example, the first candidate switching state has the smallest current tracking error, but its predicted commutation margin is less than zero; the second candidate switching state has a slightly larger current tracking error, but its predicted commutation margin is greater than the safety margin threshold. Through commutation area constraints, the first candidate switching state will generate a larger commutation area penalty value, and the controller will ultimately select the second candidate switching state, thereby trading a smaller instantaneous tracking performance loss for the reliable completion of the commutation process.

[0217] The commutation area penalty value can be determined using a piecewise commutation area penalty function:

[0218] ;

[0219] in, For the first The commutation area penalty value corresponding to each candidate switch state; For a preset large number, for example, we can take... .

[0220] When the predicted commutation margin is not less than the safety margin threshold, it means that the candidate switch state has sufficient commutation area margin, so the commutation area penalty value can be zero.

[0221] When the predicted commutation margin is between zero and the safety margin threshold, as the predicted commutation margin decreases, the commutation area penalty value increases according to a quadratic relationship, guiding the controller to prioritize the candidate state with a larger commutation margin among multiple candidate switch states that can complete commutation.

[0222] When the predicted commutation margin is less than or equal to zero, a large number exponent penalty is applied to significantly increase the state evaluation result of the corresponding candidate switch state, thereby eliminating it when other feasible candidate switch states exist.

[0223] No. The state evaluation result corresponding to each candidate switch state can be represented by the following cost function:

[0224] ;

[0225] in, For the first The state evaluation value of each candidate switch state; This is the weighting coefficient for the voltage tracking error of the filter capacitor. Based on the typical amplitudes of current tracking error and filter capacitor voltage tracking error, and their relative importance in the evaluation of energy storage converter operation status, the weighted filter capacitor voltage tracking error and current tracking error are determined to be of comparable magnitude under normal operating conditions, where 0 < 0. ≤1; For the commutation area penalty weight, Determined based on the current commutation status and the control priority of commutation reliability relative to conventional current and voltage tracking performance, 0 < ≤1; This is the penalty value for the commutation area.

[0226] Under commutation safety conditions, when the predicted commutation margins of multiple candidate switch states are not less than the safety margin threshold, the corresponding commutation area penalty values ​​are all zero. The state evaluation process is mainly based on the current tracking error and the filter capacitor voltage tracking error, and the control effect is close to that of conventional finite set predictive control.

[0227] In high-risk or failed commutation states, predicting candidate switch states with smaller commutation margins will result in a significantly increased commutation area penalty. Even if the current tracking error corresponding to this candidate switch state is small, its overall state evaluation value may still be greater than other candidate switch states with sufficient commutation margin, thus achieving priority protection for commutation reliability.

[0228] The preset selection criterion can be the minimum state evaluation value. The controller can calculate the state evaluation values ​​corresponding to all candidate switch states and determine the target switch state according to the following formula:

[0229] ;

[0230] in, The target switch state.

[0231] In the next control cycle, the controller outputs a drive signal corresponding to the target switching state to the power semiconductor device drive circuit of the energy storage converter, so that the energy storage converter outputs the corresponding voltage space vector.

[0232] A rolling optimization process can be formed by re-acquiring operational data, predicting candidate switch states, and updating target switch states in each sampling period. As the grid voltage or internal potential continues to change, the predicted commutation margin will be recalculated in the next sampling period, thereby correcting the switch state selection results in real time.

[0233] Based on the same inventive concept, this application also provides a dynamic commutation control system for energy storage converters to implement the dynamic commutation control method for energy storage converters mentioned above.

[0234] The solution provided by this system is similar to the solution described in the above method. Therefore, the specific limitations of one or more embodiments of the dynamic commutation control system for energy storage converters provided below can be found in the limitations of the dynamic commutation control method for energy storage converters described above, and will not be repeated here.

[0235] like Figure 3 As shown in the figure, this application provides a dynamic commutation control system for an energy storage converter, the system comprising:

[0236] The commutation window determination module 100 is used to obtain the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value when the energy storage converter switches between different states, and to determine the commutation time window corresponding to the switch state switching.

[0237] The commutation area determination module 200 is used to determine the available commutation voltage-time area within the commutation time window based on the internal potential, grid voltage and output current, and to determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0238] The commutation margin determination module 300 is used to determine the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0239] The commutation state determination module 400 is used to determine the commutation state of the energy storage converter in the current commutation process based on the relationship between the commutation margin and the preset safety margin threshold.

[0240] The switch state determination module 500 is used to predict the predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating state tracking error is used to determine the state evaluation result of each candidate switch state. The target switch state of the energy storage converter in the next control cycle is determined based on the state evaluation result.

[0241] The commutation control module 600 is used to control the energy storage converter according to the target switching state.

[0242] In some embodiments, the commutation window determination module 100 is configured to:

[0243] The amplitude and phase of the internal potential generated by the grid control are obtained, and the internal potential is determined based on the amplitude and phase of the internal potential.

[0244] The three-phase instantaneous voltage at the common coupling point is collected, and the coordinate transformation of the three-phase instantaneous voltage is performed to obtain the grid voltage;

[0245] Obtain the output current of the energy storage converter, the preset current reference value, and the current change to be completed;

[0246] The commutation start time is determined based on the change in the switching sector corresponding to the current reference value, and the minimum current transfer time required to complete the current change is determined. The minimum current transfer time is compared with the switching cycle of the energy storage converter, and the larger of the two times is determined as the commutation duration.

[0247] The commutation time window is composed of the commutation start time and the commutation duration.

[0248] In some embodiments, the commutation area determination module 200 is configured to:

[0249] The virtual impedance voltage drop is determined based on the preset virtual impedance parameters and output current.

[0250] The net driving voltage acting on the commutation process is determined based on the difference between the internal potential, the grid voltage, and the virtual impedance voltage drop.

[0251] Integrate the net drive voltage within the commutation time window to obtain the available commutation voltage-time area;

[0252] Determine the current change between the output current and the current reference value, and based on the current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbances, determine the required commutation area.

[0253] In some embodiments, the commutation margin determination module 300 is configured to:

[0254] The commutation reference direction is determined based on the current change vector between the output current and the current reference value;

[0255] The effective commutation area is obtained by projecting the available commutation voltage-time area onto the commutation reference direction;

[0256] The commutation margin is determined based on the difference between the effective commutation area and the required commutation area, as well as the preset area base value.

[0257] In some embodiments, the switch state determination module 500 is configured to:

[0258] For each candidate switch state, determine the corresponding inverter output voltage;

[0259] Based on the grid voltage at the current sampling time and the historical sampling time, predict the grid voltage within the commutation time window, and predict the virtual impedance voltage drop within the commutation time window based on the current output current.

[0260] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, predict the output current and filter capacitor voltage of the energy storage converter at the end of the commutation time window.

[0261] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the predicted net drive voltage within the commutation time window is determined, and the corresponding predicted available commutation area is determined based on the effective component of the predicted net drive voltage in the direction of the predicted current change.

[0262] Based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance, the corresponding predicted commutation demand area is determined. Based on the difference between the predicted available commutation area and the predicted commutation demand area, the predicted commutation margin corresponding to the candidate switch state is determined.

[0263] Based on the difference between the output current and the current reference value at the end of the commutation time window, and the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value, the operating state tracking error corresponding to the candidate switch state is determined.

[0264] In some embodiments, the switch state determination module 500 is configured to:

[0265] Determine the corresponding commutation area constraint strategy based on the commutation state;

[0266] For each candidate switch state, based on the relationship between the predicted commutation margin corresponding to the candidate switch state and the preset safety margin threshold, the corresponding commutation area penalty value is determined according to the commutation area constraint strategy.

[0267] The operating status tracking error and commutation area penalty value corresponding to each candidate switch state are weighted and evaluated to obtain the corresponding state evaluation results.

[0268] Candidate switch states whose status evaluation results meet the preset selection criteria are determined as the target switch states for the next control cycle of the energy storage converter.

[0269] like Figure 4 As shown, this application provides an electronic device 10, which includes a memory 20 and a processor 30. The memory 20 stores a computer program, and when the computer program is executed by the processor 30, the processor 30 performs the following:

[0270] When the energy storage converter undergoes a switching state transition, the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value are obtained, and the commutation time window corresponding to the switching state transition is determined.

[0271] Based on the internal potential, grid voltage, and output current, determine the available commutation voltage-time area within the commutation time window, and determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0272] The commutation margin is determined based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0273] Based on the relationship between the commutation margin and the preset safety margin threshold, the commutation state of the energy storage converter in the current commutation process is determined.

[0274] The predicted commutation margin and operating status tracking error corresponding to multiple preset candidate switch states are predicted respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating status tracking error is used to determine the status evaluation result of each candidate switch state. The target switch state of the energy storage converter in the next control cycle is determined based on the status evaluation result.

[0275] Control the energy storage converter according to the target switching state.

[0276] In some embodiments, when the computer program is executed by the processor 30, the processor 30 also performs the following:

[0277] The amplitude and phase of the internal potential generated by the grid control are obtained, and the internal potential is determined based on the amplitude and phase of the internal potential.

[0278] The three-phase instantaneous voltage at the common coupling point is collected, and the coordinate transformation of the three-phase instantaneous voltage is performed to obtain the grid voltage;

[0279] Obtain the output current of the energy storage converter, the preset current reference value, and the current change to be completed;

[0280] The commutation start time is determined based on the change in the switching sector corresponding to the current reference value, and the minimum current transfer time required to complete the current change is determined. The minimum current transfer time is compared with the switching cycle of the energy storage converter, and the larger of the two times is determined as the commutation duration.

[0281] The commutation time window is composed of the commutation start time and the commutation duration.

[0282] In some embodiments, when the computer program is executed by the processor 30, the processor 30 also performs the following:

[0283] The virtual impedance voltage drop is determined based on the preset virtual impedance parameters and output current.

[0284] The net driving voltage acting on the commutation process is determined based on the difference between the internal potential, the grid voltage, and the virtual impedance voltage drop.

[0285] Integrate the net drive voltage within the commutation time window to obtain the available commutation voltage-time area;

[0286] Determine the current change between the output current and the current reference value, and based on the current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbances, determine the required commutation area.

[0287] In some embodiments, when the computer program is executed by the processor 30, the processor 30 also performs the following:

[0288] The commutation reference direction is determined based on the current change vector between the output current and the current reference value;

[0289] The effective commutation area is obtained by projecting the available commutation voltage-time area onto the commutation reference direction;

[0290] The commutation margin is determined based on the difference between the effective commutation area and the required commutation area, as well as the preset area base value.

[0291] In some embodiments, when the computer program is executed by the processor 30, the processor 30 also performs the following:

[0292] For each candidate switch state, determine the corresponding inverter output voltage;

[0293] Based on the grid voltage at the current sampling time and the historical sampling time, predict the grid voltage within the commutation time window, and predict the virtual impedance voltage drop within the commutation time window based on the current output current.

[0294] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, predict the output current and filter capacitor voltage of the energy storage converter at the end of the commutation time window.

[0295] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the predicted net drive voltage within the commutation time window is determined, and the corresponding predicted available commutation area is determined based on the effective component of the predicted net drive voltage in the direction of the predicted current change.

[0296] Based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance, the corresponding predicted commutation demand area is determined. Based on the difference between the predicted available commutation area and the predicted commutation demand area, the predicted commutation margin corresponding to the candidate switch state is determined.

[0297] Based on the difference between the output current and the current reference value at the end of the commutation time window, and the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value, the operating state tracking error corresponding to the candidate switch state is determined.

[0298] In some embodiments, when the computer program is executed by the processor 30, the processor 30 also performs the following:

[0299] Determine the corresponding commutation area constraint strategy based on the commutation state;

[0300] For each candidate switch state, based on the relationship between the predicted commutation margin corresponding to the candidate switch state and the preset safety margin threshold, the corresponding commutation area penalty value is determined according to the commutation area constraint strategy.

[0301] The operating status tracking error and commutation area penalty value corresponding to each candidate switch state are weighted and evaluated to obtain the corresponding state evaluation results.

[0302] Candidate switch states whose status evaluation results meet the preset selection criteria are determined as the target switch states for the next control cycle of the energy storage converter.

[0303] This application provides a computer-readable storage medium having a computer program stored thereon, which, when executed, implements:

[0304] When the energy storage converter undergoes a switching state transition, the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value are obtained, and the commutation time window corresponding to the switching state transition is determined.

[0305] Based on the internal potential, grid voltage, and output current, determine the available commutation voltage-time area within the commutation time window, and determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0306] The commutation margin is determined based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0307] Based on the relationship between the commutation margin and the preset safety margin threshold, the commutation state of the energy storage converter in the current commutation process is determined.

[0308] The predicted commutation margin and operating status tracking error corresponding to multiple preset candidate switch states are predicted respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating status tracking error is used to determine the status evaluation result of each candidate switch state. The target switch state of the energy storage converter in the next control cycle is determined based on the status evaluation result.

[0309] Control the energy storage converter according to the target switching state.

[0310] In some embodiments, the computer program, when executed, also implements:

[0311] The amplitude and phase of the internal potential generated by the grid control are obtained, and the internal potential is determined based on the amplitude and phase of the internal potential.

[0312] The three-phase instantaneous voltage at the common coupling point is collected, and the coordinate transformation of the three-phase instantaneous voltage is performed to obtain the grid voltage;

[0313] Obtain the output current of the energy storage converter, the preset current reference value, and the current change to be completed;

[0314] The commutation start time is determined based on the change in the switching sector corresponding to the current reference value, and the minimum current transfer time required to complete the current change is determined. The minimum current transfer time is compared with the switching cycle of the energy storage converter, and the larger of the two times is determined as the commutation duration.

[0315] The commutation time window is composed of the commutation start time and the commutation duration.

[0316] In some embodiments, the computer program, when executed, also implements:

[0317] The virtual impedance voltage drop is determined based on the preset virtual impedance parameters and output current.

[0318] The net driving voltage acting on the commutation process is determined based on the difference between the internal potential, the grid voltage, and the virtual impedance voltage drop.

[0319] Integrate the net drive voltage within the commutation time window to obtain the available commutation voltage-time area;

[0320] Determine the current change between the output current and the current reference value, and based on the current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbances, determine the required commutation area.

[0321] In some embodiments, the computer program, when executed, also implements:

[0322] The commutation reference direction is determined based on the current change vector between the output current and the current reference value;

[0323] The effective commutation area is obtained by projecting the available commutation voltage-time area onto the commutation reference direction;

[0324] The commutation margin is determined based on the difference between the effective commutation area and the required commutation area, as well as the preset area base value.

[0325] In some embodiments, the computer program, when executed, also implements:

[0326] For each candidate switch state, determine the corresponding inverter output voltage;

[0327] Based on the grid voltage at the current sampling time and the historical sampling time, predict the grid voltage within the commutation time window, and predict the virtual impedance voltage drop within the commutation time window based on the current output current.

[0328] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, predict the output current and filter capacitor voltage of the energy storage converter at the end of the commutation time window.

[0329] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the predicted net drive voltage within the commutation time window is determined, and the corresponding predicted available commutation area is determined based on the effective component of the predicted net drive voltage in the direction of the predicted current change.

[0330] Based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance, the corresponding predicted commutation demand area is determined. Based on the difference between the predicted available commutation area and the predicted commutation demand area, the predicted commutation margin corresponding to the candidate switch state is determined.

[0331] Based on the difference between the output current and the current reference value at the end of the commutation time window, and the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value, the operating state tracking error corresponding to the candidate switch state is determined.

[0332] In some embodiments, the computer program, when executed, also implements:

[0333] Determine the corresponding commutation area constraint strategy based on the commutation state;

[0334] For each candidate switch state, based on the relationship between the predicted commutation margin corresponding to the candidate switch state and the preset safety margin threshold, the corresponding commutation area penalty value is determined according to the commutation area constraint strategy.

[0335] The operating status tracking error and commutation area penalty value corresponding to each candidate switch state are weighted and evaluated to obtain the corresponding state evaluation results.

[0336] Candidate switch states whose status evaluation results meet the preset selection criteria are determined as the target switch states for the next control cycle of the energy storage converter.

[0337] This application provides a computer program product, which includes a computer program stored on a non-transitory computer-readable storage medium. The computer program includes program instructions, wherein when the program instructions are executed by a computer, the computer performs the following:

[0338] When the energy storage converter undergoes a switching state transition, the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value are obtained, and the commutation time window corresponding to the switching state transition is determined.

[0339] Based on the internal potential, grid voltage, and output current, determine the available commutation voltage-time area within the commutation time window, and determine the required commutation area based on the amount of current change required for the output current to change to the current reference value.

[0340] The commutation margin is determined based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area.

[0341] Based on the relationship between the commutation margin and the preset safety margin threshold, the commutation state of the energy storage converter in the current commutation process is determined.

[0342] The predicted commutation margin and operating status tracking error corresponding to multiple preset candidate switch states are predicted respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating status tracking error is used to determine the status evaluation result of each candidate switch state. The target switch state of the energy storage converter in the next control cycle is determined based on the status evaluation result.

[0343] Control the energy storage converter according to the target switching state.

[0344] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0345] The amplitude and phase of the internal potential generated by the grid control are obtained, and the internal potential is determined based on the amplitude and phase of the internal potential.

[0346] The three-phase instantaneous voltage at the common coupling point is collected, and the coordinate transformation of the three-phase instantaneous voltage is performed to obtain the grid voltage;

[0347] Obtain the output current of the energy storage converter, the preset current reference value, and the current change to be completed;

[0348] The commutation start time is determined based on the change in the switching sector corresponding to the current reference value, and the minimum current transfer time required to complete the current change is determined. The minimum current transfer time is compared with the switching cycle of the energy storage converter, and the larger of the two times is determined as the commutation duration.

[0349] The commutation time window is composed of the commutation start time and the commutation duration.

[0350] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0351] The virtual impedance voltage drop is determined based on the preset virtual impedance parameters and output current.

[0352] The net driving voltage acting on the commutation process is determined based on the difference between the internal potential, the grid voltage, and the virtual impedance voltage drop.

[0353] Integrate the net drive voltage within the commutation time window to obtain the available commutation voltage-time area;

[0354] Determine the current change between the output current and the current reference value, and based on the current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbances, determine the required commutation area.

[0355] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0356] The commutation reference direction is determined based on the current change vector between the output current and the current reference value;

[0357] The effective commutation area is obtained by projecting the available commutation voltage-time area onto the commutation reference direction;

[0358] The commutation margin is determined based on the difference between the effective commutation area and the required commutation area, as well as the preset area base value.

[0359] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0360] For each candidate switch state, determine the corresponding inverter output voltage;

[0361] Based on the grid voltage at the current sampling time and the historical sampling time, predict the grid voltage within the commutation time window, and predict the virtual impedance voltage drop within the commutation time window based on the current output current.

[0362] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, predict the output current and filter capacitor voltage of the energy storage converter at the end of the commutation time window.

[0363] Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the predicted net drive voltage within the commutation time window is determined, and the corresponding predicted available commutation area is determined based on the effective component of the predicted net drive voltage in the direction of the predicted current change.

[0364] Based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance, the corresponding predicted commutation demand area is determined. Based on the difference between the predicted available commutation area and the predicted commutation demand area, the predicted commutation margin corresponding to the candidate switch state is determined.

[0365] Based on the difference between the output current and the current reference value at the end of the commutation time window, and the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value, the operating state tracking error corresponding to the candidate switch state is determined.

[0366] In some embodiments, when program instructions are executed by a computer, the computer performs the following:

[0367] Determine the corresponding commutation area constraint strategy based on the commutation state;

[0368] For each candidate switch state, based on the relationship between the predicted commutation margin corresponding to the candidate switch state and the preset safety margin threshold, the corresponding commutation area penalty value is determined according to the commutation area constraint strategy.

[0369] The operating status tracking error and commutation area penalty value corresponding to each candidate switch state are weighted and evaluated to obtain the corresponding state evaluation results.

[0370] Candidate switch states whose status evaluation results meet the preset selection criteria are determined as the target switch states for the next control cycle of the energy storage converter.

[0371] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, electronic devices, computer storage media, and computer program products described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0372] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0373] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0374] It should be understood that although the steps in the flowcharts of the embodiments described above 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 embodiments described above 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 of other steps.

[0375] In the several embodiments provided by this invention, it should be understood that the disclosed systems, electronic devices, computer storage media, computer program products, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces, indirect coupling or communication connection between devices or units, and may be electrical, mechanical, or other forms.

[0376] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0377] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0378] If the integrated unit is implemented as 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 invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for executing all or part of the steps of the methods described in the various embodiments of the present invention through a computer device (which may be a personal computer, a server, or a network device, etc.). The aforementioned storage medium includes: USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, optical disks, and other media capable of storing program code.

[0379] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dynamic commutation control method for an energy storage converter, characterized in that, The method includes: When the energy storage converter undergoes a switching state transition, the internal potential of the energy storage converter, the grid voltage, the output current and the current reference value are acquired, and the commutation time window corresponding to the switching state transition is determined. Based on the internal potential, the grid voltage, and the output current, determine the available commutation voltage-time area within the commutation time window, and determine the required commutation area based on the amount of current change required for the output current to change to the current reference value. The commutation margin is determined based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area. Based on the relationship between the commutation margin and the preset safety margin threshold, the commutation state of the energy storage converter in the current commutation process is determined; The predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states are predicted respectively. The predicted commutation margin is used as a constraint. Combined with the commutation state, the operating state tracking error is used to determine the state evaluation result of each candidate switch state. The target switch state of the energy storage converter in the next control cycle is determined based on the state evaluation result. The energy storage converter is controlled according to the target switching state.

2. The dynamic commutation control method for energy storage converter according to claim 1, characterized in that, The steps of acquiring the internal potential, grid voltage, output current, and current reference value of the energy storage converter, and determining the commutation time window corresponding to the switching state transition, include: The amplitude and phase of the internal potential generated by the network control are obtained, and the internal potential is determined based on the amplitude and phase of the internal potential. The three-phase instantaneous voltage at the common coupling point is collected, and the coordinate transformation of the three-phase instantaneous voltage is performed to obtain the grid voltage; Obtain the output current of the energy storage converter, the preset current reference value, and the current change to be completed; The commutation start time is determined based on the change in the switching sector corresponding to the current reference value, and the minimum current transfer time required to complete the current change to be completed is determined. The minimum current transfer time is compared with the switching cycle of the energy storage converter, and the larger of the two times is determined as the commutation duration. The commutation time window is composed of the commutation start time and the commutation duration.

3. The dynamic commutation control method for energy storage converter according to claim 1, characterized in that, The step of determining the available commutation voltage-time area within the commutation time window based on the internal potential, the grid voltage, and the output current, and determining the required commutation area based on the current change required for the output current to change towards the current reference value, includes: The virtual impedance voltage drop is determined based on the preset virtual impedance parameters and the output current; The net driving voltage acting on the commutation process is determined based on the difference between the internal potential, the grid voltage, and the virtual impedance voltage drop. Integrating the net drive voltage within the commutation time window yields the available commutation voltage-time area. The amount of current change between the output current and the current reference value is determined, and the required commutation area is determined based on the amount of current change, the filter inductance on the energy storage converter side, the equivalent inductance on the grid side, and the equivalent disturbance current caused by grid disturbance.

4. The dynamic commutation control method for energy storage converter according to claim 1, characterized in that, The step of determining the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the current change and the commutation required area includes: The commutation reference direction is determined based on the current change vector between the output current and the current reference value; The available commutation voltage-time area is projected onto the commutation reference direction to obtain the effective commutation area; The commutation margin is determined based on the difference between the effective commutation area and the required commutation area, as well as a preset area base value.

5. The dynamic commutation control method for energy storage converter according to claim 4, characterized in that, The prediction of the commutation margin and operating state tracking error corresponding to multiple preset candidate switch states includes: For each of the candidate switch states, determine the corresponding inverter output voltage; Based on the grid voltage at the current sampling time and the historical sampling time, predict the grid voltage within the commutation time window, and predict the virtual impedance voltage drop within the commutation time window based on the current output current; Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the output current and filter capacitor voltage of the energy storage converter at the end of the commutation time window are predicted. Based on the inverter output voltage corresponding to the candidate switching state, the predicted grid voltage, and the virtual impedance voltage drop, the predicted net drive voltage within the commutation time window is determined, and based on the effective component of the predicted net drive voltage in the direction of the predicted current change, the corresponding predicted available commutation area is determined. Based on the predicted current change between the output current at the end of the commutation time window and the corresponding current reference value, as well as the predicted grid disturbance, the corresponding predicted commutation demand area is determined, and based on the difference between the predicted available commutation area and the predicted commutation demand area, the predicted commutation margin corresponding to the candidate switch state is determined. The operating state tracking error corresponding to the candidate switch state is determined based on the difference between the output current at the end of the commutation time window and the current reference value, and the difference between the filter capacitor voltage and the corresponding preset filter capacitor voltage reference value.

6. The dynamic commutation control method for energy storage converter according to claim 5, characterized in that, Using the predicted commutation margin as a constraint, combined with the commutation state, and based on the operating state tracking error, the state evaluation results of each candidate switching state are determined, and the target switching state of the energy storage converter for the next control cycle is determined based on the state evaluation results, including: Determine the corresponding commutation area constraint strategy based on the commutation state; For each of the candidate switch states, based on the relationship between the predicted commutation margin corresponding to the candidate switch state and the preset safety margin threshold, the corresponding commutation area penalty value is determined according to the commutation area constraint strategy. The operating state tracking error and commutation area penalty value corresponding to each candidate switch state are weighted and evaluated to obtain the corresponding state evaluation result. The candidate switch states that meet the preset selection criteria are determined as the target switch states for the next control cycle of the energy storage converter.

7. A dynamic commutation control system for an energy storage converter, characterized in that, The system includes: The commutation window determination module is used to acquire the internal potential, grid voltage, output current and current reference value of the energy storage converter when the switching state of the energy storage converter changes, and to determine the commutation time window corresponding to the switching state change. The commutation area determination module is used to determine the available commutation voltage-time area within the commutation time window based on the internal potential, the grid voltage, and the output current, and to determine the required commutation area based on the amount of current change required for the output current to change to the current reference value. The commutation margin determination module is used to determine the commutation margin based on the difference between the effective component of the available commutation voltage-time area in the direction corresponding to the change in current and the required commutation area. The commutation state determination module is used to determine the commutation state of the energy storage converter in the current commutation process based on the relationship between the commutation margin and the preset safety margin threshold. The switch state determination module is used to predict the predicted commutation margin and operating state tracking error corresponding to multiple preset candidate switch states respectively, and use the predicted commutation margin as a constraint, combined with the commutation state, to determine the state evaluation result of each candidate switch state according to the operating state tracking error, and determine the target switch state of the energy storage converter in the next control cycle according to the state evaluation result. The commutation control module is used to control the energy storage converter according to the target switching state.

8. An electronic device, characterized in that, The electronic device includes a memory and a processor. The memory stores a computer program. When the computer program is executed by the processor, the processor performs the steps of the dynamic commutation control method for energy storage converter as described in any one of claims 1-6.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed, it implements the steps of the dynamic commutation control method for energy storage converters as described in any one of claims 1-6.

10. A computer program product, characterized in that, The computer program product includes a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, wherein when the program instructions are executed by a computer, the computer performs the steps of the dynamic commutation control method for an energy storage converter as described in any one of claims 1-6.

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