Model predictive current control method and device, computer device and storage medium

Abstract

The application relates to a model predictive current control method and device, computer equipment and a storage medium. The method comprises the following steps: in a sampling period, a value function is used to determine a target voltage vector group in a substrate voltage vector group, the target voltage vector group comprises three different target voltage vectors, the number of model predictive current control output vectors is three vectors, compared with single vectors or double vectors, the coverage range of the alternative voltage vectors corresponding to the three vectors is large, the current ripple is small, therefore, the action time lengths corresponding to the three target voltage vectors are determined, and the expected voltage vector generated by combining the three target voltage vectors with small current ripples and the corresponding action time lengths can effectively reduce the direct-axis current ripple, and the inverter has good control performance and dynamic characteristics.

Description

Technical Field

[0001] This application relates to the field of power electronics technology, and in particular to a model predictive current control method, device, computer equipment, and storage medium. Background Technology

[0002] Model predictive current control (MPCC) features fast dynamic response and simple control methods. Compared to PWM control, MPCC offers more flexible and accurate control of the inverter's switching transistors within a single sampling period. It predicts the inverter's output current state, inputs the predicted value into a cost function to select the optimal voltage vector, and then uses this optimal voltage vector to synthesize the desired voltage to control the inverter. However, MPCC typically outputs either a single or dual vector within a single sampling period. Regardless of the number of vectors, the coverage of the candidate voltage vectors is relatively small, resulting in significant current ripple and ultimately poor control performance of the synthesized desired voltage for the inverter. Summary of the Invention

[0003] To address the technical problem of poor inverter control performance caused by the expected voltage generated based on existing MPCC, this application provides a model predictive current control method, apparatus, computer device, and storage medium.

[0004] In a first aspect, this application provides a model predictive current control method, including:

[0005] Within the sampling period, a target voltage vector group is determined in the basic voltage vector group based on the value function, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group;

[0006] Determine the duration of action for each of the target voltage vectors;

[0007] Based on each of the target voltage vectors and their corresponding durations, a desired voltage vector for controlling the inverter is formed.

[0008] Secondly, this application provides a model predictive current control device, comprising:

[0009] The first determining module is used to determine a target voltage vector group in the basic voltage vector group based on a value function within a sampling period, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group;

[0010] The second determining module is used to determine the duration of action corresponding to each of the target voltage vectors;

[0011] A voltage generation module is used to combine the target voltage vectors and their corresponding durations to form a desired voltage vector for controlling the inverter.

[0012] Thirdly, this application provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to perform the following steps:

[0013] Within the sampling period, a target voltage vector group is determined in the basic voltage vector group based on the value function, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group;

[0014] Determine the duration of action for each of the target voltage vectors;

[0015] Based on each of the target voltage vectors and their corresponding durations, a desired voltage vector for controlling the inverter is formed.

[0016] Fourthly, this application provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, performs the following steps:

[0017] Within the sampling period, a target voltage vector group is determined in the basic voltage vector group based on the value function, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group;

[0018] Determine the duration of action for each of the target voltage vectors;

[0019] Based on each of the target voltage vectors and their corresponding durations, a desired voltage vector for controlling the inverter is formed.

[0020] Based on the aforementioned model-predictive current control method, in each sampling period, a target voltage vector group is determined from the substrate voltage vector group using a value function. The target voltage vector group includes three different target voltage vectors, meaning the model-predictive current control output vectors are three vectors. Compared to single or dual vectors, the three vectors correspond to a wider coverage range of candidate voltage vectors and smaller current ripple. Therefore, the duration of action of the three target voltage vectors is determined. The desired voltage vector generated by combining the three target voltage vectors with smaller current ripple and their corresponding durations effectively reduces the direct-axis current ripple, resulting in good control performance and dynamic characteristics for the inverter. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] 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, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a diagram illustrating the application environment of the model predictive current control method in one embodiment.

[0024] Figure 2 This is a flowchart illustrating a model predictive current control method in one embodiment;

[0025] Figure 3 This is a schematic diagram illustrating the effect of the basic voltage vector in one embodiment;

[0026] Figure 4 This is a schematic diagram illustrating the coverage area of ​​the desired voltage vector in one embodiment;

[0027] Figure 5 The steady-state current waveform of a dual-vector MPCC in one embodiment is shown.

[0028] Figure 6 The steady-state current waveform of a three-vector MPCC in one embodiment is shown.

[0029] Figure 7 Here is a dq-axis current waveform diagram of a dual-vector MPCC in one embodiment;

[0030] Figure 8 Here is a dq-axis current waveform diagram of a three-vector MPCC in one embodiment;

[0031] Figure 9This is a block diagram of the model prediction current control device in one embodiment;

[0032] Figure 10 This is an internal structural diagram of a computer device in one embodiment. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] Figure 1 This is a diagram illustrating the application environment of the model predictive current control method in one embodiment. (Refer to...) Figure 1 This model predictive current control method is applied to a model predictive current control system. The model predictive current control system includes a model predictive current control device, a preprocessor, a pulse generator, an inverter, and a DC power supply. The preprocessor collects the three-phase grid-connected current output from the inverter, which are i... a (k), i b (k), i c (k) is used to perform analog-to-digital conversion on the three-phase grid-connected current, followed by coordinate transformation to obtain the first sampled current i at time k after transformation to the rotating coordinate axis. d (k) and the second acquisition current i q (k), i d (k) and i q (k) is transmitted to the model predictive current control device, which uses the first and second sampled currents received at time k to predict the predicted current at time (k+1), thus obtaining the first predicted current i. d (k+1) and the second predicted current i q (k+1), the model predictive current control device then uses the predicted current to select the optimal voltage vector, obtaining the optimized u. i and u j Calculate the duration of action of each voltage vector, and output the duration of action of each voltage vector, denoted as t. i t j t z Each voltage vector and its corresponding duration are input into the pulse generator to generate the desired voltage vector for controlling the inverter.

[0035] In one embodiment, Figure 2This is a flowchart illustrating a model predictive current control method in one embodiment, with reference to... Figure 2 This paper provides a model predictive current control method. This embodiment primarily applies this method to the aforementioned... Figure 1 Taking the model-predictive current control device as an example, the specific steps of this model-predictive current control method are as follows:

[0036] Step S200: During the sampling period, a target voltage vector group is determined in the basic voltage vector group based on the value function, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group.

[0037] Specifically, the model predictive current control device periodically samples the three-phase grid-connected current output by the inverter according to the sampling period, predicts the current at time (k+1) based on the three-phase grid-connected current at time k, and selects the optimal target voltage vector from the basic voltage vector group based on the predicted current. For example... Figure 3 As shown, the basic voltage vector group includes eight basic voltage vectors, V0 to V7, where V0 and V7 are zero vectors, and V1 to V6 are valid vectors. The target voltage vector group contains any three basic voltage vectors from the basic voltage vector group.

[0038] Step S220: Determine the duration of action for each of the target voltage vectors.

[0039] Specifically, the duration of action of each target voltage vector is calculated based on the sampling duration corresponding to the sampling period. The sum of the durations of action of the three target voltage vectors is equal to the sampling duration of the sampling period, that is, the sampling duration is divided into the time period of action of different target voltage vectors.

[0040] Step S240: Based on each of the target voltage vectors and their corresponding durations, a desired voltage vector for controlling the inverter is formed.

[0041] Specifically, since the desired voltage vector is composed of target voltage vectors, in this embodiment, the model predictive current control output vectors are three vectors. Compared to single or double vectors, the range of desired voltage vectors that can be selected for three vectors is larger. If the model predictive current control output vectors are single vectors, then the range of desired voltage vectors that can be selected for a single vector is only 8 basic voltage vectors. If the model predictive current control output vectors are double vectors, and both double vectors are valid vectors, then the range of desired voltage vectors that can be selected for double vectors is... Figure 3The dashed lines connecting the endpoints of V0 to V7 in the middle, if there is a zero vector in the two vectors, then the range of the desired voltage vector corresponding to the two vectors can be selected as the solid lines corresponding to each basic voltage vector.

[0042] When the model predicts that the current control output vector has three vectors, assuming that the first effective vector is V1(100), the range of the desired voltage vector is as follows: Figure 4 As shown in the shaded area, the first group of voltage vectors consists of (V1, V4) and a zero vector, with the desired voltage u. d The coverage area is the solid line formed by connecting V1 and V4; the second and third vector combinations are (V1,V3) and (V1,V5) respectively. Without the zero vector, u d The coverage area is the dashed line from V1 to V3 and the dashed line from V1 to V5. After adding the zero vector, u d The coverage area is expanded to include the aforementioned dashed lines combined with solid lines, as well as the isosceles triangles formed by V1, V3, and V0, and the isosceles triangles formed by V1, V5, and V0. The fourth and fifth vector combinations are (V1, V2) and (V1, V6) respectively. Without the addition of the zero vector, u d The coverage area is the dashed line from V1 to V2 and the dashed line from V1 to V6. After adding the zero vector, u d The coverage area has been expanded to include not only the equilateral triangles formed by the above-mentioned dotted lines using V1, V2, and V0, but also the equilateral triangles formed by V1, V6, and V0. For example... Figure 4 It can be seen that the expected voltage coverage range corresponding to the three vectors not only includes the solid line range and the dashed line range, but also includes the triangular region formed by the solid line and / or dashed line. Therefore, the expected voltage coverage range corresponding to the three vectors is larger than that corresponding to the single vector or double vectors, which can improve the tracking accuracy of the current and reduce the current ripple.

[0043] like Figure 5 As shown, the three-phase current waveform under the dual-vector MPCC control scheme exhibits large current fluctuations and numerous glitches, resulting in lower control accuracy for the inverter. In contrast, the three-phase current waveform under the three-vector MPCC control scheme is as follows: Figure 6 As shown, the current ripple is significantly reduced, the curve is smoother, and the current control accuracy is improved. The three-vector MPCC control scheme can effectively track the current reference value and significantly reduce current ripple.

[0044] By utilizing three target voltage vectors with low current ripple and their corresponding durations to generate a desired voltage vector, the direct-axis and quadrature-axis current ripple is effectively reduced, resulting in good control performance and dynamic characteristics for the inverter. To verify the dynamic performance of the three-vector output MPCC control scheme, simulations were performed to verify that the reference value of the three-phase grid-connected current abruptly changes from 5A to 10A at 0.05s. The simulation experiment is as follows. Figure 7 As shown, the MPCC control with dual vector outputs requires 5 control cycles to reach the temperature state, i.e., t d =0.0005, the duration of one control cycle is 0.0001. However, MPCC control using three-vector outputs only requires two control cycles to reach a stable state, such as... Figure 8 As shown, t d =0.0002, which has better dynamic characteristics compared with the dual vector output control scheme.

[0045] In one embodiment, the step S200 of determining the target voltage vector group in the basic voltage vector group based on the value function includes:

[0046] Step S2001: Based on the value function, determine the first target voltage vector among the multiple effective voltage vectors in the basic voltage vector group, wherein the basic voltage vector is an effective voltage vector or a zero vector;

[0047] Step S2002: Determine a second target voltage vector in the candidate voltage vector group based on the value function, wherein the candidate voltage vector group includes all effective voltage vectors in the basic voltage vector group except for the first target voltage vector;

[0048] Step S2003: The first target voltage vector, the second target voltage vector, and the zero vector in the basic voltage vector group are taken as the three target voltage vectors in the target voltage vector group.

[0049] Specifically, the first target voltage vector is selected from the basic voltage vector group based on the value function. Since the basic voltage vector group includes two zero vectors, the first target voltage vector is selected only from the remaining six valid basic vectors, which is a six-to-one selection operation in the basic voltage vector group. Then, the second target voltage vector is selected again from the remaining basic voltage vectors other than the first target voltage vector according to the value function, which is a five-to-one selection operation in the remaining basic voltage vectors. That is, two valid target voltage vectors are determined twice using the value function. In other words, a total of 30 optimization steps are required to select and determine two valid target voltage vectors. In contrast, the optimization process for dual vectors requires selection from 7 basic voltage vectors, where the two zero vectors are used as one basic voltage vector, and then selection is made from the remaining 6 basic voltage vectors. Therefore, the optimization steps for dual vectors are 42. Thus, this embodiment reduces the number of optimization steps and speeds up the efficiency of determining the target voltage vector by following the above optimization process.

[0050] Desired voltage vector u d =u i +u j +u z , where u i Let u be the first target voltage vector. j For the second target voltage vector, u z As a zero vector, the magnitude and direction of the voltage vector can be adjusted.

[0051] In one embodiment, determining the first target voltage vector among multiple effective voltage vectors within the basic voltage vector group based on the value function, i.e., step S2001, includes:

[0052] Step S20011: Based on the current acquisition current obtained from the inverter, determine the predicted current corresponding to each effective voltage vector in the basic voltage vector group;

[0053] Step S20012: Determine the function value corresponding to each of the predicted currents based on the value function;

[0054] Step S20013: The effective voltage vector corresponding to the function value with the smallest value is taken as the first target voltage vector.

[0055] Specifically, the current being acquired is the current acquired at time k. The current being acquired includes the currents acquired along the d-axis and q-axis. The current at time (k+1) is predicted using the current acquired at time k. The formula for calculating the predicted current is as follows:

[0056]

[0057] Among them, i d (k), i q (k) is t k The current collected at any given time along the d and q axes (rotating coordinate axes); i d (k+1),i q (k+1) is t k+1 Predicted current on the d and q axes at any given time; t s The sampling period; u d u q This is the effective voltage vector conversion to the effective voltage on the d and q axes; i d i q This is the three-phase grid-connected current converted to the current sampled on the d and q axes; e d e q ω represents the grid voltage on the d and q axes; ω is the grid angular frequency, r s For the filter resistor, L s For filtering inductance.

[0058] By successively transforming each effective voltage vector to the d-axis and q-axis and substituting the resulting effective voltages into the above formula, the predicted currents corresponding to each effective voltage vector are obtained. These predicted currents include the first predicted current corresponding to the d-axis and the second predicted current corresponding to the q-axis. Then, the predicted currents corresponding to each effective voltage vector are substituted into the value function to calculate the corresponding function values. The value function calculation formula is as follows:

[0059]

[0060] in, These are the reference currents corresponding to the d and q axes, respectively.

[0061] From this, we can obtain the function values ​​corresponding to each effective voltage vector. The effective voltage vector corresponding to the function value with the smallest value is taken as the first target voltage vector u. i Then, following the same procedure described above, the second target voltage vector u is selected from the remaining 5 effective voltage vectors excluding the first target voltage vector. j .

[0062] In one embodiment, determining the duration of action corresponding to each of the target voltage vectors, i.e., step S220, includes:

[0063] Step S2201: Determine the current slope of each target voltage vector under the rotating coordinate axis;

[0064] Step S2202: Determine the duration of action of each target voltage vector based on the current slope corresponding to each target voltage vector and the sampling duration corresponding to the sampling period, wherein the sum of the durations of action of each target voltage vector is the sampling duration.

[0065] Specifically, based on the deadbeat principle of the dq axis, the calculation formula for the predicted current of the three-vector MPCC is as follows:

[0066]

[0067] Among them, S di S qi u i The first current slope corresponding to the d-axis and the second current slope corresponding to the q-axis, S dj S qj u j The first current slope corresponding to the d-axis and the second current slope corresponding to the q-axis, S do S qo u z The first current slope corresponding to the d-axis and the second current slope corresponding to the q-axis.

[0068] Based on the above formula, the formula for calculating the slope of the dq-axis current under zero vector action is:

[0069]

[0070] Among them, i d and i q These refer to the predicted current along the d-axis and the predicted current along the q-axis at time (k+1), respectively.

[0071] First target voltage vector u i The formula for calculating the slope of the dq-axis current during operation is as follows:

[0072]

[0073] Second target voltage vector u j The formula for calculating the slope of the dq-axis current during operation is as follows:

[0074]

[0075] The duration coefficient is calculated by combining the current slope corresponding to each target voltage vector. The calculation formula is as follows:

[0076] D = s q0 ·s dj +s qi ·s d0 +s qj ·s di -s qi ·s dj -s qj ·s d0 -s q0 ·s dj

[0077] Therefore, the duration of action for each target voltage vector can be obtained as follows:

[0078]

[0079] Among them, t i For u i The corresponding duration of action, t j For u j The corresponding duration of action, t z For u z The corresponding duration of action, t s t represents the sampling duration corresponding to the sampling period. Under normal circumstances, t i t j t z All are greater than 0, and t i +t j <t s , and t z <t s .

[0080] In one embodiment, before combining the target voltage vectors and their corresponding durations to form the desired voltage vector for controlling the inverter, i.e., before step S240, the method further includes:

[0081] Step S230: Determine the matching status between the duration of action of each target voltage vector and the preset duration condition;

[0082] Step S240 further includes step S2401, in which, if the matching status between the action duration corresponding to each of the target voltage vectors and the preset duration conditions is successful, the step of combining the target voltage vectors and their corresponding action durations to form the desired voltage vector for controlling the inverter is executed.

[0083] Specifically, it involves determining whether the duration of action corresponding to each target voltage vector is greater than zero and less than the sampling duration, and whether the sum of the durations of action corresponding to any two target voltage vectors is less than the sampling duration. If the duration of action corresponding to each target voltage vector is greater than zero and less than the sampling duration, and the sum of the durations of action corresponding to any two target voltage vectors is less than the sampling duration, then the matching status between the duration of action corresponding to each target voltage vector and the preset duration condition is determined to be successful, indicating that the allocation of the durations of action corresponding to the three target voltage vectors is normal, and then step S240 is executed.

[0084] In one embodiment, after determining the matching state between the duration of action corresponding to each of the target voltage vectors and the preset duration condition, i.e. after step S230, the method further includes:

[0085] Step S231: If the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a failure, determine the redistribution action duration corresponding to each of the target voltage vectors based on the sampling duration corresponding to the sampling period;

[0086] Step S240 further includes step S2402, which involves using the redistribution duration as the duration to perform the step of combining the target voltage vectors and their corresponding durations to form the desired voltage vector for controlling the inverter.

[0087] Specifically, when at least one target voltage vector's corresponding action duration does not meet the preset duration condition, it is determined that an overmodulation phenomenon has occurred. It is necessary to redistribute the corresponding action duration of each target voltage vector to redetermine the redistributed action duration of each target voltage vector. A vector insertion control method is used to change the order of vector action. The redistributed action durations of each target voltage vector after redistribution are used to form the desired voltage vector, so as to avoid controlling the inverter according to the action duration under abnormal conditions.

[0088] In one embodiment, the three target voltage vectors are a first target voltage vector, a second target voltage vector, and a third target voltage vector, respectively. When the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a failure, determining the redistribution action duration corresponding to each of the target voltage vectors based on the sampling duration corresponding to the sampling period includes at least one of the following:

[0089] If the duration of action of the first target voltage vector fails to match the preset duration condition, the redistribution duration of the first target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the second target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the second target voltage vector is equal to the duration of action of the second target voltage vector;

[0090] If the duration of action of the second target voltage vector fails to match the preset duration condition, the redistribution duration of the second target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the first target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the first target voltage vector is equal to the duration of action of the first target voltage vector.

[0091] If the duration of action of the third target voltage vector fails to match the preset duration condition, the redistribution duration corresponding to the third target voltage vector is allocated to zero, and the sampling duration is divided into the redistribution duration corresponding to the first target voltage vector and the redistribution duration corresponding to the second target voltage vector according to the ratio between the duration of action of the first target voltage vector and the duration of action of the second target voltage vector.

[0092] If the duration of action of the first target voltage vector and the duration of action of the second target voltage vector both fail to match the preset duration conditions, the redistribution duration of action of the first target voltage vector and the redistribution duration of action of the second target voltage vector are both assigned to zero, and the sampling duration is used as the redistribution duration of action of the third target voltage duration.

[0093] Specifically, the first target voltage vector is denoted as u. i The second target voltage vector is denoted as u. j The third target voltage vector is denoted as u. z The duration of action of the first target voltage vector is denoted as t. i The duration of action of the second target voltage vector is denoted as t. j The duration of action of the third target voltage vector is denoted as t. z The following four situations exist where the duration of action of each target voltage vector does not meet the preset duration condition:

[0094] In the first case, at t i <0, and t j >0, and t z >0, and t i +t j <t s , t i The corresponding u i No effect, u j and u z The redistribution process applies throughout the entire sampling period, which is equivalent to the duty cycle dual-vector model prediction. The redistribution durations for each target voltage vector after redistribution are as follows:

[0095]

[0096] in, The redistribution duration corresponds to the redistribution of the first target voltage vector. t0 represents the redistribution duration of the second target voltage vector after redistribution, and t0 represents the redistribution duration of the third target voltage vector after redistribution.

[0097] In the second case, at t j <0, and t i >0, and t z >0, and t i +t j <t s , t j The corresponding u j No effect, u i and u z The redistribution process applies throughout the entire sampling period, which is equivalent to the duty cycle dual-vector model prediction. The redistribution durations for each target voltage vector after redistribution are as follows:

[0098]

[0099] In the third case, at t z <0, and t i >0, and t j >0, and t i +t j <t s , t z The corresponding u z No effect, u i and u j The redistribution process applies throughout the entire sampling period, which is equivalent to the duty cycle dual-vector model prediction. The redistribution durations for each target voltage vector after redistribution are as follows:

[0100]

[0101] The fourth case is when t i and t j If both are less than zero, neither of the two effective voltage vectors has any effect, and the zero vector acts for the entire cycle. That is, the redistribution duration corresponding to the third target voltage vector is made equal to the sampling duration.

[0102] Using the redistribution duration corresponding to each target voltage vector, the desired voltage vector is calculated. The desired voltage vector includes the effective voltage on the d-axis and the effective voltage on the q-axis. The formula for calculating the desired voltage vector is as follows:

[0103]

[0104] Among them, u di For u i Converted to the effective voltage of the d-axis, u dj For u j Converted to the effective voltage of the d-axis, u qi For u i Effective voltage converted to the q-axis, u qj For u j Effective voltage converted to the q-axis, ti and t j These correspond to the redistribution durations of the first and second target voltage vectors, respectively.

[0105] In summary, the three-vector MPCC control strategy selects the optimal vector combination twice within a single sampling period using the value function. Specifically, it iterates through six effective voltage vectors in each sampling period to select the first target voltage vector. When selecting the second target voltage vector, it iterates through the remaining five effective voltage vectors. Compared to the two-vector MPCC control scheme, this reduces the number of optimization steps in generating the optimal vector combination. The optimal vector combination includes two effective voltage vectors and one zero vector. Then, deadbeat control is applied to calculate the duration of each target voltage vector, and the corresponding action time for each target voltage vector is determined. When overmodulation occurs, the duration of action is redistributed, and a vector insertion control method is used to change the action sequence of each target voltage vector. Any two effective voltage vectors and one zero vector can be combined to form any desired voltage vector. Compared with the dual-vector MPCC control strategy, the coverage of the desired voltage vector is expanded. While tracking the right-angle axis current, deadbeat control is performed, and when overmodulation occurs, the action time of the voltage vector is redistributed. The desired voltage vector is determined by using the redistributed action time. The three-vector MPCC control strategy has better dynamic characteristics than the dual-vector MPCC control strategy.

[0106] Figure 2 This is a flowchart illustrating a model predictive current control method in one embodiment. It should be understood that, although... Figure 2 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 2 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0107] In one embodiment, such as Figure 9 As shown, a model predictive current control device is provided, comprising:

[0108] The first determining module 300 is used to determine a target voltage vector group in a basic voltage vector group based on a value function within a sampling period, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group;

[0109] The second determining module 320 is used to determine the duration of action corresponding to each of the target voltage vectors;

[0110] The voltage generation module 340 is used to combine the target voltage vectors and their corresponding durations to form a desired voltage vector for controlling the inverter.

[0111] In one embodiment, the first determining module 300 is specifically used for:

[0112] Based on the value function, a first target voltage vector is determined from multiple effective voltage vectors within the basic voltage vector group, wherein the basic voltage vector is an effective voltage vector or a zero vector;

[0113] A second target voltage vector is determined from the candidate voltage vector group based on the value function, wherein the candidate voltage vector group includes all valid voltage vectors in the basic voltage vector group except for the first target voltage vector;

[0114] The first target voltage vector, the second target voltage vector, and the zero vector in the basic voltage vector group are taken as the three target voltage vectors in the target voltage vector group.

[0115] In one embodiment, the first determining module 300 is specifically used for:

[0116] Based on the current acquisition current obtained from the inverter, determine the predicted current corresponding to each effective voltage vector in the basic voltage vector group;

[0117] The function value corresponding to each of the predicted currents is determined based on the value function.

[0118] The effective voltage vector corresponding to the function value with the smallest value is taken as the first target voltage vector.

[0119] In one embodiment, the second determining module 320 is specifically used for:

[0120] Determine the current slope of each target voltage vector along the rotating coordinate axis;

[0121] The duration of action of each target voltage vector is determined based on the current slope corresponding to each target voltage vector and the sampling duration corresponding to the sampling period, wherein the sum of the durations of action of each target voltage vector is the sampling duration.

[0122] In one embodiment, the voltage generation module 340 is specifically used for:

[0123] Determine the matching status between the duration of action of each target voltage vector and the preset duration condition;

[0124] If the matching status between the duration of each target voltage vector and the preset duration condition is successful, the step of combining each target voltage vector and its corresponding duration to form the desired voltage vector for controlling the inverter is executed.

[0125] In one embodiment, the voltage generation module 340 is specifically used for:

[0126] If the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a matching failure, the redistribution action duration corresponding to each of the target voltage vectors is determined based on the sampling duration corresponding to the sampling period;

[0127] The step of combining the redistribution duration as the duration of action to form the desired voltage vector for controlling the inverter is performed based on each of the target voltage vectors and the corresponding duration of action.

[0128] In one embodiment, the voltage generation module 340 is specifically configured to perform at least one of the following:

[0129] If the duration of action of the first target voltage vector fails to match the preset duration condition, the redistribution duration of the first target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the second target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the second target voltage vector is equal to the duration of action of the second target voltage vector;

[0130] If the duration of action of the second target voltage vector fails to match the preset duration condition, the redistribution duration of the second target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the first target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the first target voltage vector is equal to the duration of action of the first target voltage vector.

[0131] If the duration of action of the third target voltage vector fails to match the preset duration condition, the redistribution duration corresponding to the third target voltage vector is allocated to zero, and the sampling duration is divided into the redistribution duration corresponding to the first target voltage vector and the redistribution duration corresponding to the second target voltage vector according to the ratio between the duration of action of the first target voltage vector and the duration of action of the second target voltage vector.

[0132] If the duration of action of the first target voltage vector and the duration of action of the second target voltage vector both fail to match the preset duration conditions, the redistribution duration of action of the first target voltage vector and the redistribution duration of action of the second target voltage vector are both assigned to zero, and the sampling duration is used as the redistribution duration of action of the third target voltage duration.

[0133] Figure 10 An internal structural diagram of a computer device in one embodiment is shown. Specifically, this computer device may be... Figure 1 Model-based predictive current control devices. For example... Figure 10 As shown, the computer device includes a processor, memory, network interface, input device, and display screen connected via a system bus. The memory includes non-volatile storage media and internal memory. The non-volatile storage media stores an operating system and may also store a computer program. When executed by the processor, this computer program enables the processor to implement a model predictive current control method. The internal memory may also store a computer program, which, when executed by the processor, enables the processor to implement the model predictive current control method. The display screen can be an LCD screen or an e-ink screen. The input device can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device's casing, or an external keyboard, touchpad, or mouse.

[0134] Those skilled in the art will understand that Figure 10 The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0135] In one embodiment, the model predictive current control device provided in this application can be implemented as a computer program, which can be implemented in, for example... Figure 10 The computer device shown runs on this device. The computer device's memory can store the various program modules that make up the model's predictive current control device, for example, Figure 9The first determining module 300, the second determining module 320, and the voltage generation module 340 are shown. The computer program comprised of these modules causes the processor to execute the steps in the model prediction current control method of the various embodiments of this application described in this specification.

[0136] Figure 10 The computer device shown can be used as follows Figure 9 The first determining module 300 in the model predictive current control device, within the sampling period, determines a target voltage vector group based on a value function from a set of basic voltage vectors. The basic voltage vector group includes the target voltage vector group, which comprises three different target voltage vectors, each of which is any one of the basic voltage vectors in the set. A computer device can determine the duration of action corresponding to each target voltage vector through a second determining module 320. The computer device can then use a voltage generation module 340 to combine the target voltage vectors and their corresponding durations to form a desired voltage vector for controlling the inverter.

[0137] In one embodiment, a computer device is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in any of the above embodiments.

[0138] In one embodiment, a computer-readable storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the method described in any of the above embodiments.

[0139] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double-rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), RAMbus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and RAMbus dynamic RAM (RDRAM), etc.

[0140] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0141] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A model predictive current control method, characterized in that, The method includes: Within the sampling period, a target voltage vector group is determined in the basic voltage vector group based on the value function, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group; Determine the duration of action for each of the target voltage vectors; Based on each of the target voltage vectors and their corresponding durations, a desired voltage vector for controlling the inverter is formed. Before combining the target voltage vectors and their corresponding durations to form the desired voltage vector for controlling the inverter, the method further includes: Determine the matching status between the duration of action of each target voltage vector and the preset duration condition; If the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a matching failure, the redistribution action duration corresponding to each of the target voltage vectors is determined based on the sampling duration corresponding to the sampling period; the redistribution action duration is used as the action duration to execute the step of combining each of the target voltage vectors and the corresponding action duration to form the desired voltage vector for controlling the inverter. The three target voltage vectors are a first target voltage vector, a second target voltage vector, and a third target voltage vector. When the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a failure, the redistribution action duration corresponding to each of the target voltage vectors is determined based on the sampling duration corresponding to the sampling period, including at least one of the following: If the duration of action of the first target voltage vector fails to match the preset duration condition, the redistribution duration of the first target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the second target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the second target voltage vector is equal to the duration of action of the second target voltage vector; If the duration of action of the second target voltage vector fails to match the preset duration condition, the redistribution duration of the second target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the first target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the first target voltage vector is equal to the duration of action of the first target voltage vector. If the duration of action of the third target voltage vector fails to match the preset duration condition, the redistribution duration corresponding to the third target voltage vector is allocated to zero, and the sampling duration is divided into the redistribution duration corresponding to the first target voltage vector and the redistribution duration corresponding to the second target voltage vector according to the ratio between the duration of action of the first target voltage vector and the duration of action of the second target voltage vector. If the duration of action of the first target voltage vector and the duration of action of the second target voltage vector both fail to match the preset duration conditions, the redistribution duration of action of the first target voltage vector and the redistribution duration of action of the second target voltage vector are both assigned to zero, and the sampling duration is used as the redistribution duration of action of the third target voltage vector.

2. The method according to claim 1, characterized in that, The determination of the target voltage vector set in the basic voltage vector set based on the value function includes: Based on the value function, a first target voltage vector is determined from multiple effective voltage vectors within the basic voltage vector group, wherein the basic voltage vector is an effective voltage vector or a zero vector; A second target voltage vector is determined from the candidate voltage vector group based on the value function, wherein the candidate voltage vector group includes all valid voltage vectors in the basic voltage vector group except for the first target voltage vector; The first target voltage vector, the second target voltage vector, and the zero vector in the basic voltage vector group are taken as the three target voltage vectors in the target voltage vector group.

3. The method according to claim 2, characterized in that, The step of determining the first target voltage vector from among the multiple effective voltage vectors in the basic voltage vector group based on the value function includes: Based on the current acquisition current obtained from the inverter, determine the predicted current corresponding to each effective voltage vector in the basic voltage vector group; The function value corresponding to each of the predicted currents is determined based on the value function. The effective voltage vector corresponding to the function value with the smallest value is taken as the first target voltage vector.

4. The method according to claim 1, characterized in that, Determining the duration of action corresponding to each of the target voltage vectors includes: Determine the current slope of each target voltage vector along the rotating coordinate axis; The duration of action of each target voltage vector is determined based on the current slope corresponding to each target voltage vector and the sampling duration corresponding to the sampling period, wherein the sum of the durations of action of each target voltage vector is the sampling duration.

5. The method according to claim 1, characterized in that, Before combining the target voltage vectors and their corresponding durations to form the desired voltage vector for controlling the inverter, the method further includes: Determine the matching status between the duration of action of each target voltage vector and the preset duration condition; If the matching status between the duration of each target voltage vector and the preset duration condition is successful, the step of combining each target voltage vector and its corresponding duration to form the desired voltage vector for controlling the inverter is executed.

6. A model predictive current control device, characterized in that, The device includes: The first determining module is used to determine a target voltage vector group in the basic voltage vector group based on a value function within a sampling period, wherein the basic voltage vector group includes the target voltage vector group, the target voltage vector group includes three different target voltage vectors, and the target voltage vector is any one of the basic voltage vectors in the basic voltage vector group; The second determining module is used to determine the duration of action corresponding to each of the target voltage vectors; A voltage generation module is used to combine the target voltage vectors and their corresponding durations to form a desired voltage vector for controlling the inverter. Before combining the target voltage vectors and their corresponding durations to form the desired voltage vector for controlling the inverter, the process further includes: Determine the matching status between the duration of action of each target voltage vector and the preset duration condition; If the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a matching failure, the redistribution action duration corresponding to each of the target voltage vectors is determined based on the sampling duration corresponding to the sampling period; the redistribution action duration is used as the action duration to execute the step of combining each of the target voltage vectors and the corresponding action duration to form the desired voltage vector for controlling the inverter. The three target voltage vectors are a first target voltage vector, a second target voltage vector, and a third target voltage vector. When the matching status between the action duration corresponding to at least one of the target voltage vectors and the preset duration condition is a failure, the redistribution action duration corresponding to each of the target voltage vectors is determined based on the sampling duration corresponding to the sampling period, including at least one of the following: If the duration of action of the first target voltage vector fails to match the preset duration condition, the redistribution duration of the first target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the second target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the second target voltage vector is equal to the duration of action of the second target voltage vector; If the duration of action of the second target voltage vector fails to match the preset duration condition, the redistribution duration of the second target voltage vector is assigned to zero, and the difference between the sampling duration and the duration of action of the first target voltage vector is used as the redistribution duration of the third target voltage vector, wherein the redistribution duration of the first target voltage vector is equal to the duration of action of the first target voltage vector. If the duration of action of the third target voltage vector fails to match the preset duration condition, the redistribution duration corresponding to the third target voltage vector is allocated to zero, and the sampling duration is divided into the redistribution duration corresponding to the first target voltage vector and the redistribution duration corresponding to the second target voltage vector according to the ratio between the duration of action of the first target voltage vector and the duration of action of the second target voltage vector. If the duration of action of the first target voltage vector and the duration of action of the second target voltage vector both fail to match the preset duration conditions, the redistribution duration of action of the first target voltage vector and the redistribution duration of action of the second target voltage vector are both assigned to zero, and the sampling duration is used as the redistribution duration of action of the third target voltage vector.

7. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 5.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 5.

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