Synchronization modulation phase alignment method and apparatus

Abstract

The application provides a synchronous modulation phase alignment method and device, and belongs to the technical field of motor operation control. The method comprises the following steps: when the phase deviation is greater than a set deviation threshold, a second phase alignment mode is started, and the output frequency of an actual output voltage is equal to the expected frequency of an expected output voltage; a plurality of sampling points are determined according to a preset selection principle; the angle between two adjacent output vectors of the synchronous modulation is denoted as, the angle between the output vectors in the adjustment process is denoted as, and the angle deviation between the adjustment starting vector and the adjustment ending vector is denoted as; the number of intermediate vectors is determined according to the carrier direction of the adjustment ending vector and the jump point; the duration of the vector is obtained through vector decomposition; the carrier direction is determined according to the carrier difference principle, and the embedding mode is determined according to the sector division; and the arrangement sequence of the vector is determined according to the carrier direction and the embedding mode. In this way, there is no deviation between the adjustment process output vector and the expected vector, and the adjustment speed is accelerated.

Description

Technical Field

[0001] This application relates to the field of motor operation control technology, and in particular to a synchronous modulation phase alignment method and apparatus. Background Technology

[0002] In recent years, high-speed motor technology has been widely used in the industrial field, especially driven by advanced bearing technologies such as magnetic levitation and air suspension, resulting in continuous improvements in speed and power density. The operation of high-speed motors relies on high-frequency drive signals provided by frequency converters, which places higher demands on the switching frequency of power semiconductor devices. However, the switching losses of power semiconductor devices increase significantly with increasing frequency, while the computation time of digital controllers also limits the potential for increasing the switching frequency. This leads to a continuous decrease in the ratio of the frequency converter's switching frequency to its output frequency (i.e., the carrier ratio), directly affecting the waveform quality of the output voltage. Under low carrier ratio conditions, traditional pulse width modulation technology generates more harmonic components. These harmonics can cause problems such as motor torque pulsation and increased heat generation, and in severe cases, even affect the stable operation of the system.

[0003] Under low carrier ratio conditions, PWM waveforms exhibiting periodic symmetry, three-phase symmetry, half-wave odd symmetry, and approximately quarter-cycle symmetry demonstrate better output voltage quality and effectively reduce harmonics; this is known as synchronous modulation. Synchronous modulation has two specific implementation methods: one is synchronous optimized PWM, where the switching timing is determined by minimizing output harmonics. This is an optimization problem requiring the solution of numerous nonlinear equations, making online implementation difficult. The other is synchronous space vector modulation (SVPWM), which follows the traditional space vector modulation approach, selecting an output vector on the space vector diagram that satisfies synchronous modulation constraints. However, this method suffers from problems such as long adjustment periods, poor dynamic response, large adjustment deviations, and poor control performance when the phase angle of the desired output voltage vector changes significantly during dynamic processes involving sudden load changes or under harmonic influences. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides a synchronous modulation phase alignment method and apparatus.

[0005] In a first aspect, the present invention provides a synchronous modulation phase alignment method, the method comprising:

[0006] Set the first phase alignment mode and the second phase alignment mode;

[0007] Calculate the phase deviation between the phase angle of the desired output voltage vector and the phase angle of the actual output voltage vector;

[0008] When the phase deviation is greater than the set deviation threshold, the second phase alignment mode is activated. In the second phase alignment mode, the output frequency of the actual output voltage is equal to the expected frequency of the desired output voltage. The desired output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector after the target vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point.

[0009] Multiple sampling points are determined during the adjustment process according to a preset selection principle. The first sampling point is the target vector, and the last sampling point is the second synchronization vector. The first sampling point is named the adjustment start vector, the last sampling point is named the adjustment end vector, and the other sampling points are named intermediate vectors.

[0010] Let the angle between two adjacent output vectors of synchronous modulation be . Let the angle between the output vectors during the adjustment process be denoted as . Let the angular deviation between the adjustment start vector and the adjustment end vector be denoted as . ,in, ;

[0011] The number of intermediate vectors is determined based on the adjustment end vector and the carrier direction of the jump point;

[0012] The durations of the adjustment start vector, the intermediate vector, and the adjustment end vector are obtained through vector decomposition.

[0013] The carrier direction is determined based on the carrier phase difference principle, the embedding mode is determined based on the sector division, and the arrangement sequence of the adjustment start vector, the intermediate vector, and the adjustment end vector is determined based on the carrier direction and the embedding mode.

[0014] In an optional implementation, the preset selection principle includes:

[0015] The deviation between the actual output voltage vector and the desired output voltage vector during the adjustment process is less than or equal to a preset deviation threshold.

[0016] The duration of the adjustment process is less than or equal to a preset time threshold;

[0017] The carrier direction corresponding to each sampling point during the adjustment process is different from the carrier direction corresponding to the sampling points before and after it;

[0018] During the adjustment process, the PWM period is greater than or equal to 0.5 times the normal interval, and during the adjustment process, the PWM period is less than or equal to 1.5 times the normal interval.

[0019] In an optional implementation, determining the number of intermediate vectors based on the adjustment end vector and the carrier direction of the transition point includes:

[0020] When the adjustment end vector and the carrier direction of the jump point are different, an odd number of intermediate vectors are determined.

[0021] In an optional implementation, determining an odd number of intermediate vectors when the adjustment end vector and the carrier direction of the jump point are different includes:

[0022] An intermediate vector is set at the midpoint between the adjustment start vector and the adjustment end vector, wherein, , .

[0023] In an optional implementation, determining the number of intermediate vectors based on the adjustment end vector and the carrier direction of the transition point includes:

[0024] When the adjustment end vector and the carrier direction of the jump point are the same, an even number of intermediate vectors are determined.

[0025] In an optional implementation, determining an even number of intermediate vectors when the adjustment end vector and the carrier direction of the jump point are the same includes:

[0026] when When, the intermediate vector is not specified, where, , ;

[0027] when At that time, two intermediate vectors are set, and the two intermediate vectors are evenly distributed between the adjustment start vector and the adjustment end vector. , .

[0028] In an optional implementation, determining the carrier direction of each of the sampling points includes:

[0029] Based on the principle that adjacent sampling points should have different carrier directions during the adjustment process, the carrier direction of each sampling point during the adjustment process is determined according to the carrier direction of the jump point or the carrier direction of the adjustment end vector.

[0030] Determining the embedding mode includes:

[0031] The adjustment of the initial vector is not embedded;

[0032] The adjustment end vector is a synchronization vector, which is embedded according to the corresponding synchronization space vector strategy execution method;

[0033] The embedding method of the intermediate vector is determined based on its position on the spatial vector map.

[0034] In an optional implementation, determining the embedding method of the intermediate vector based on its position on the spatial vector map includes:

[0035] Each sector is divided into two symmetrical sub-sectors, and the embedding method of the intermediate vector is kept consistent with the embedding method of the synchronization vector in the same sub-sector.

[0036] In an optional implementation, the method further includes:

[0037] When the phase deviation is less than the set deviation threshold, the first phase alignment mode is activated; in the first phase alignment mode, a proportional-integral regulator is used to align the phase angle of the desired output voltage with the phase angle of the actual output voltage.

[0038] In a second aspect, the present invention provides a synchronous modulation phase alignment device, the device comprising:

[0039] The settings module is used to set the first phase alignment mode and the second phase alignment mode;

[0040] The calculation module is used to calculate the phase deviation between the phase angle of the desired output voltage vector and the phase angle of the actual output voltage vector;

[0041] The startup module is used to activate the second phase alignment mode when the phase deviation is greater than a set deviation threshold. In the second phase alignment mode, the output frequency of the actual output voltage is equal to the expected frequency of the expected output voltage. The expected output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector after the target vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point.

[0042] The first determining module is used to determine multiple sampling points in the adjustment process according to a preset selection principle, wherein the first sampling point is the target vector, the last sampling point is the second synchronization vector; the first sampling point is named the adjustment start vector, the last sampling point is named the adjustment end vector, and the other sampling points are named intermediate vectors;

[0043] The recording module is used to record the angle between two adjacent output vectors of synchronous modulation. Let the angle between the output vectors during the adjustment process be denoted as . Let the angular deviation between the adjustment start vector and the adjustment end vector be denoted as . ,in, ;

[0044] The second determining module is used to determine the number of intermediate vectors based on the adjustment end vector and the carrier direction of the jump point;

[0045] The acquisition module is used to acquire the durations of the adjustment start vector, the intermediate vector, and the adjustment end vector through vector decomposition;

[0046] The third determining module is used to determine the carrier direction based on the carrier phase difference principle, determine the embedding mode based on the sector division, and determine the arrangement sequence of the adjustment start vector, the intermediate vector, and the adjustment end vector based on the carrier direction and the embedding mode.

[0047] The synchronous modulation phase alignment method provided in this application ensures that the output vector and the desired vector do not deviate during the adjustment process, resulting in accurate voltage output and improved dynamic performance. It accelerates the adjustment speed, improves dynamic response, and the maximum adjustment time does not exceed two synchronization intervals. By limiting the angle of the adjustment vector interval, it avoids the PWM period being too long, which reduces output voltage quality, or too short, which shortens program calculation time and increases the number of switching operations. Through reasonable settings of the carrier direction and clamping mode, it avoids the simultaneous switching of two or more transistors, maintains clamping consistency, and prevents an increase in the number of switching operations. Attached Figure Description

[0048] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this application and should not be considered as a limitation on the scope of protection of this application. In the various drawings, similar components are numbered similarly.

[0049] Figure 1 This application illustrates the spatial vector definition and sector division diagram provided in this application;

[0050] Figure 2a This paper shows a schematic diagram of the vector arrangement of the sampling points of CSVS in the first sector provided in this application;

[0051] Figure 2b This application provides a schematic diagram of the vector arrangement of BBCSII sampling points in the first sector.

[0052] Figure 3 The phase angle adjuster for synchronous modulation provided in this application is shown;

[0053] Figure 4 This application provides a schematic diagram illustrating the synchronous SVPWM response process during a phase abrupt change.

[0054] Figure 5A schematic flowchart of the synchronous modulation phase alignment method provided in this application is shown;

[0055] Figure 6a A schematic diagram of Case 1 of the synchronous modulation phase alignment method provided in this application is shown;

[0056] Figure 6b A schematic diagram of Case 2 of the synchronous modulation phase alignment method provided in this application is shown;

[0057] Figure 6c A schematic diagram of scenario 3 of the synchronous modulation phase alignment method provided in this application is shown;

[0058] Figure 7 This paper shows a schematic diagram of the response of the phase adjuster provided in this application when there is a large phase jump;

[0059] Figure 8 A schematic diagram of the response using the synchronous modulation phase alignment method provided in Embodiment 1 is shown in this application;

[0060] Figure 9 A schematic diagram of the synchronous modulation phase alignment device provided in this application is shown. Detailed Implementation

[0061] The technical solutions 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, and not all embodiments.

[0062] The components of this application, typically described and illustrated in the accompanying drawings, can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0063] In the following, the terms “comprising,” “having,” and their cognates, which may be used in various embodiments of this application, are intended only to indicate a particular feature, number, step, operation, element, component, or combination thereof, and should not be construed as excluding, firstly, the presence of one or more other features, numbers, steps, operations, elements, components, or combinations thereof, or adding the possibility of one or more features, numbers, steps, operations, elements, components, or combinations thereof.

[0064] Furthermore, the terms "first," "second," and "third" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0065] Unless otherwise specified, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which the various embodiments of this application pertain. Terms (such as those defined in commonly used dictionaries) shall be interpreted as having the same meaning as in their contextual meaning in the relevant technical field and shall not be construed as having an idealized or overly formal meaning, unless clearly defined in the various embodiments of this application.

[0066] In existing technologies, synchronous modulation techniques include synchronous optimized PWM and synchronous SVPWM. These two synchronous modulation techniques are explained below. Existing synchronous optimized PWM determines the switching timing with the goal of minimizing output harmonics. This is an optimization problem requiring the solution of numerous nonlinear equations, making online implementation difficult. The common approach is to calculate the optimal switching angle offline for different carrier ratios and modulation ratios, store the results in a table, and then use the program to look up the table and fit the desired switching angle—a cumbersome process.

[0067] Existing synchronous SVPWM, following the traditional space vector modulation approach, selects an output vector on the space vector map that satisfies synchronous modulation constraints. The basic principles, sector division, and vector definition of space vector modulation are as follows: Figure 1 As shown. Currently, five synchronous space vector modulation strategies have been developed: Traditional Space Vector (CSVS), Basic Bus Clamping (BBCS), Basic Bus Clamping II (BBCSII), Boundary Sampling (BSS), and Boundary Sampling II (BSSII). The common features of these five vector modulation strategies include: (1) determining the position of the output sampling point on the space vector diagram, or in other words, determining the phase angle of the output vector. (2) determining the vector arrangement. The vector arrangement determines the carrier counting direction and PWM clamping method when using the counting comparison method. For example, the carrier corresponding to the vector arrangement 7→2→1→0 is increasing. Since there is both 0 vector (000) and 7 vector (111), there is no clamped phase. The carrier corresponding to the vector arrangement 0→1→2 is decreasing. There is no 7 vector (111), so one phase of the PWM will be clamped to 0.

[0068] Please see Figure 2a , Figure 2a The figure shows the distribution and vector arrangement of CSVC sampling points in the first sector when the number of sector samples N=3.

[0069] Please see Figure 2b , Figure 2b The figure shows the distribution of BBCSII sampling points in the first sector when the number of sector samples N=4.

[0070] Combination Figure 2a and Figure 2bIt is known that in the sampling synchronous space vector modulation strategy, the output voltage vector must be output according to the specified sampling points, meaning its phase is discrete and cannot be freely selected. However, in actual control, the output voltage is obtained through current loop regulation, and its phase is arbitrary. This contradiction is generally resolved by... Figure 3 The phase angle adjuster shown solves this problem, where It is the rotational angular frequency of the desired output voltage. It is the phase angle of the desired output voltage vector. It is the rotational angular frequency of the actual output voltage vector of synchronous modulation. It is the phase angle of the actual output voltage that is synchronously modulated, obviously It can only be a discrete value specified by the synchronous modulation strategy. and deviation To adjust ,when Lag hour, For positive, Increase, thus Spin faster, until it catches up ,vice versa.

[0071] When the motor is operating in a steady state, or under relatively stable operating conditions, the voltage vector required by the motor rotates at approximately a constant speed. Without significant jumps, the above method can achieve good alignment. However, during dynamic processes with sudden load changes, or when affected by harmonics, The phase can change significantly. See also Figure 4 In the previous cycle, the desired vector and the output vector were phase-aligned, both being synchronous vectors V1. In the next cycle, the desired vector abruptly changes phase to position V4. Synchronous modulation must also output V2, V3, ... sequentially according to a predetermined output order, gradually catching up with the target vector by increasing the rotation frequency. This presents several shortcomings. First, the adjustment process is relatively long, resulting in poor dynamic response. Second, the output vector consistently deviates from the desired vector during the adjustment process, worsening control performance. Third... Deviation from normal operating angular frequency The scope is large. When An excessively large value will shorten the PWM cycle, increasing the switching frequency and reducing the time available for processor computation. When the PWM period is too small, the carrier ratio decreases further, and the control delay increases, resulting in degraded control performance. These drawbacks prevent its application in high-performance control applications.

[0072] Example 1

[0073] This application provides a synchronous modulation phase alignment method, which speeds up the phase alignment process, eliminates output voltage deviation during the alignment process, improves dynamic performance, and enables synchronous modulation to achieve the same high dynamic performance as asynchronous modulation.

[0074] For details, see Figure 5 The synchronous modulation phase alignment method includes steps S110-S180, and each step is explained below.

[0075] Step S110: Set the first phase alignment mode and the second phase alignment mode.

[0076] In this embodiment, a first phase alignment mode and a second phase alignment mode are set and switched based on the phase deviation magnitude. The following settings can be made: when the phase deviation is less than or equal to a set deviation threshold... When the phase deviation exceeds a set deviation threshold, the first phase alignment mode is adopted. At this time, the second phase alignment mode is used. This sets the deviation threshold. The value should be determined based on the actual application scenario. Under relatively stable load conditions, a smaller value can be set; under conditions of drastic load changes, a larger value can be set, along with a deviation threshold. It can be used to synchronously modulate the angle between two adjacent output vectors 0.1-0.5 times.

[0077] Step S120: Calculate the phase deviation between the phase angle of the desired output voltage vector and the phase angle of the actual output voltage vector.

[0078] In this embodiment, the actual output voltage vector is the current synchronous modulation actual output voltage vector, and the desired output voltage vector is the voltage vector that is to be output.

[0079] In this embodiment, the synchronous modulation phase alignment method further includes:

[0080] When the phase deviation is less than the set deviation threshold, the first phase alignment mode is activated; in the first phase alignment mode, a proportional-integral regulator is used to align the phase angle of the desired output voltage with the phase angle of the actual output voltage.

[0081] As an example, the proportional-integral (PI) regulator can be a phase-locked loop (PLL) in the form of a PLL. By using a PLL in the form of a PLL to track the phase, the phase angle of the desired output voltage is aligned with the phase angle of the actual output voltage. The phase formula is shown in Equation (1) below:

[0082] (1)

[0083] in, It is the rotational angular frequency of the desired output voltage. It is the phase angle of the desired output voltage vector. It is the rotational angular frequency of the actual output voltage vector. It is the phase angle of the actual output voltage. The proportional gain is the coefficient of variation, and the integral step size is the time interval between synchronous sampling. A proportional-integral (PI) controller is used here, which improves dynamic performance and steady-state accuracy compared to traditional phase angle controllers. For example, Figure 2a In this context, the time interval from 10° to 30° is the synchronous sampling time interval. In this embodiment, the first phase alignment mode uses a PI-type phase-locked loop to track the input phase, improving dynamic performance and steady-state accuracy.

[0084] Step S130: When the phase deviation is greater than the set deviation threshold, the second phase alignment mode is activated. In the second phase alignment mode, the output frequency of the actual output voltage is equal to the expected frequency of the expected output voltage. The expected output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector after the target vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point.

[0085] In this embodiment, the second phase alignment mode, also known as the phase adjustment process, relies on selecting a suitable output vector to achieve phase synchronization. During this process, the output frequency (i.e., the output frequency of the actual output voltage) is... The frequency is equal to the desired frequency (i.e., the desired frequency of the desired output voltage). That is, no more frequency modulation is needed. The phase formula is as follows (2).

[0086] (2)

[0087] In the formula, the integration step size is the output sampling interval during the phase adjustment process. It is the rotational angular frequency of the desired output voltage. It is the phase angle of the desired output voltage vector. It is the rotational angular frequency of the actual output voltage vector. It is the phase angle of the actual output voltage. The desired frequency of the desired output voltage Or the actual output voltage and output frequency During phase adjustment, the sampling interval is no longer determined according to the sampling points of the synchronous PWM. Instead, it is determined according to the sampling points determined in this embodiment. The phase adjustment process involves outputting several vectors and determining the sampling position and arrangement sequence of each vector to ultimately achieve phase synchronization between the actual output vector and the desired output vector.

[0088] For ease of subsequent description, this embodiment specifies the relevant naming conventions. The desired output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point. The adjustment process outputs voltage vectors at multiple sampling points. The first sampling point is named the adjustment start point (i.e., the adjustment start vector), the last sampling point is named the adjustment end point (i.e., the adjustment end vector), and the other sampling points are named adjustment intermediate points (i.e., intermediate vectors). Obviously, to achieve phase alignment, the adjustment end point should be the sampling point specified by the synchronization modulation.

[0089] In the second phase alignment mode, through sampling point design and vector arrangement design (carrier direction and embedding mode), the output phase can be brought back to the synchronization mode in a very short time.

[0090] Step S140: Determine multiple sampling points in the adjustment process according to preset selection principles, wherein the first sampling point is the target vector, the last sampling point is the second synchronization vector; name the first sampling point as the adjustment start vector, name the last sampling point as the adjustment end vector, and name the other sampling points as intermediate vectors.

[0091] In this embodiment, the preset selection principle includes:

[0092] The deviation between the actual output voltage vector and the desired output voltage vector during the adjustment process is less than or equal to a preset deviation threshold.

[0093] The duration of the adjustment process is less than or equal to a preset time threshold;

[0094] The carrier direction corresponding to each sampling point during the adjustment process is different from the carrier direction corresponding to the sampling points before and after it;

[0095] During the adjustment process, the PWM period is greater than or equal to 0.5 times the normal interval, and during the adjustment process, the PWM period is less than or equal to 1.5 times the normal interval.

[0096] In this embodiment, the preset deviation threshold and the preset time threshold can be determined according to the actual situation in order to minimize the error between the output voltage vector and the desired voltage vector during the adjustment process and to shorten the adjustment process as much as possible (i.e., the duration of the entire adjustment process should be short).

[0097] It is understood that in this embodiment, the deviation between the actual output voltage vector and the desired output voltage vector during the adjustment process is a dynamically changing value. The ideal adjustment result is to make the deviation between the actual output voltage vector and the desired output voltage vector zero. During the adjustment process, the deviation between the actual output voltage vector and the desired output voltage vector gradually tends to zero.

[0098] In this embodiment, the carrier direction corresponding to each sampling point is different from the carrier direction corresponding to the sampling points before and after it. This is to ensure that two-phase switches do not operate simultaneously. The PWM carrier period cannot change too much. If the period is too long, the output PWM carrier ratio will decrease, increasing output harmonics and deteriorating the output voltage quality. If the PWM period is too short, the switching frequency will increase, causing device heating, and the control interval will be shortened, failing to meet the processor's processing time requirements. In this embodiment, during the forced constraint adjustment process, the PWM period cannot exceed 1.5 times the normal interval and cannot be less than 0.5 times the normal interval.

[0099] In this embodiment, multiple suitable sampling points are selected according to the above-mentioned preset selection principles. The target vector is selected as the adjustment starting point, which directly eliminates the output vector deviation. The second synchronization vector is selected as the adjustment ending vector, ensuring that the synchronization process does not exceed two synchronization intervals. The selection of intermediate vectors needs to be discussed on a case-by-case basis.

[0100] Step S150, record the angle between two adjacent output vectors of synchronous modulation as . Let the angle between the output vectors during the adjustment process be denoted as . Let the angular deviation between the adjustment start vector and the adjustment end vector be denoted as . ,in, .

[0101] Step S160: Determine the number of intermediate vectors based on the adjustment end vector and the carrier direction of the jump point.

[0102] In one embodiment, determining the number of intermediate vectors based on the adjustment end vector and the carrier direction of the transition point includes:

[0103] When the adjustment end vector and the carrier direction of the jump point are different, an odd number of intermediate vectors are determined.

[0104] It is understandable that when the carrier direction of the adjustment end point and the transition point are different, an odd number of intermediate sampling points are needed to ensure the principle of carrier dissimilarity. The odd number can be 1, 3, 5, etc., and there is no restriction here.

[0105] In one embodiment, determining an odd number of intermediate vectors when the adjustment end vector and the carrier direction of the transition point are different includes:

[0106] An intermediate vector is set at the midpoint between the adjustment start vector and the adjustment end vector, wherein, , .

[0107] See Figure 6a It includes 3 synchronous sampling points, and the angle between two adjacent sampling points (i.e., two adjacent output vectors of synchronous modulation) is... The angular deviation between the starting point (i.e., the initial adjustment vector) and the ending point (i.e., the final adjustment vector) is... An intermediate point (i.e., an intermediate vector) is set between the starting and ending points. , combined It can be seen that, .

[0108] In one embodiment, determining the number of intermediate vectors based on the adjustment end vector and the carrier direction of the transition point includes:

[0109] When the adjustment end vector and the carrier direction of the jump point are the same, an even number of intermediate vectors are determined.

[0110] It is understandable that when the adjustment end point and the transition point have the same carrier direction, an even number of intermediate sampling points need to be set in order to ensure the principle of different carrier phases.

[0111] In one embodiment, determining an even number of intermediate vectors when the adjustment end vector and the carrier direction of the transition point are the same includes:

[0112] when When, the intermediate vector is not specified, where, , ;

[0113] when At that time, two intermediate vectors are set, and the two intermediate vectors are evenly distributed between the adjustment start vector and the adjustment end vector. , .

[0114] like Figure 6b As shown, when At this time, no intermediate vector is set between the starting point and the ending point, and the angle interval of the sampling points is adjusted during the process. , combined and It can be seen that, .

[0115] like Figure 6c As shown, when At this time, two intermediate vectors (i.e., two intermediate points) are set. These two intermediate vectors are evenly distributed between the adjustment start vector (i.e., the starting point) and the adjustment end vector (i.e., the ending point). Therefore, the adjustment vector interval angle is... , combined , It can be known that .

[0116] Step S170: Obtain the duration of the adjustment start vector, the intermediate vector, and the adjustment end vector through vector decomposition.

[0117] The PWM period equals the vector interval angle divided by the vector rotation speed. It can be seen that the vector selection above has already ensured... This ensures that the PWM period is between 0.5 and 1.5 times the normal period of synchronous modulation. The vector duration can be obtained through vector decomposition, which is no different from the method of conventional space vector modulation, and will not be described in detail here.

[0118] Step S180: Determine the carrier direction based on the carrier phase difference principle, determine the embedding mode based on the sector division, and determine the arrangement sequence of the adjustment start vector, the intermediate vector, and the adjustment end vector based on the carrier direction and the embedding mode.

[0119] In this embodiment, the vector arrangement sequence is uniquely determined by the carrier direction and the embedding mode. Taking the first sector as an example, when the carrier direction is increasing, the vector sequence is: 7210 (no embedding), 721 (embedded 1), or 210 (embedded 0); when the carrier direction is decreasing, the vector sequence is 0127 (no embedding), 127 (embedded 1), or 012 (embedded 0). Therefore, determining the vector sequence becomes determining the carrier direction and the embedding mode.

[0120] In one embodiment, determining the carrier direction of each of the sampling points includes:

[0121] Based on the principle that adjacent sampling points should have different carrier directions during the adjustment process, the carrier direction of each sampling point during the adjustment process is determined according to the carrier direction of the jump point or the carrier direction of the adjustment end vector.

[0122] In this embodiment, the preset selection principle has stipulated that the carrier direction of adjacent sampling points should be different during the adjustment process. In this way, the carrier direction of each sampling point during the adjustment process can be determined according to the carrier direction of the jump point or the vector carrier direction at the end of the adjustment.

[0123] In one embodiment, determining the embedding mode includes:

[0124] The adjustment of the initial vector is not embedded;

[0125] The adjustment end vector is a synchronization vector, which is embedded according to the corresponding synchronization space vector strategy execution method;

[0126] The embedding method of the intermediate vector is determined based on its position on the spatial vector map.

[0127] In one embodiment, determining the embedding method of the intermediate vector based on its position on the spatial vector map includes:

[0128] Each sector is divided into two symmetrical sub-sectors, and the embedding method of the intermediate vector is kept consistent with the embedding method of the synchronization vector in the same sub-sector.

[0129] It is understandable that after a phase abrupt change, the adjustment start vector and the previous pulse vector may be in different sectors of the spatial vector map. To avoid switching of more than two phases at the moment of vector switching, the adjustment start vector (i.e., the starting point) is not clipped. The adjustment end vector (i.e., the ending point) is itself a synchronization vector and is clipped according to the corresponding synchronization spatial vector modulation strategy. The clipping method of the intermediate vector (i.e., the intermediate point) is determined by its position on the spatial vector map. Each sector is divided into symmetrical upper and lower halves, resulting in 12 half-sectors in one cycle. The clipping method of the intermediate vector and its synchronization vector in the same half-sector is consistent, thus preventing the clipping consistency from being disrupted during the adjustment process.

[0130] To further illustrate this method, a CSVS simulation with N=3 sector sampling points was performed in SIMULINK. The simulation used 18 synchronous sampling points at 10°, 30°, 50°, 70°, ..., 350°. In the simulation, a desired output voltage of 200Hz was given in the open loop. To simulate the phase transition in reality, a 56° transition was applied when the desired voltage vector phase was 70°.

[0131] See Figure 7 The dynamic response when using only a phase angle regulator shows a relatively long adjustment time, only achieving synchronization again at 250°. During the adjustment process, there is always a deviation between the output voltage phase and the desired phase, and the PWM carrier period is relatively short.

[0132] Figure 8 The method proposed in this invention involves outputting three vectors after a phase transition: 146° (adjustment start point), 158° (adjustment midpoint), and 170° (adjustment end point), achieving resynchronization at 170°. The adjustment time is very short. Although the carrier wave decreases during adjustment, it is limited and will not fall below 50% of its original size. Throughout the adjustment process, the output voltage phase remains perfectly aligned with the desired voltage phase.

[0133] The synchronous modulation phase alignment method provided in this embodiment ensures that the output vector deviates from the desired vector during the adjustment process, resulting in accurate voltage output and improved dynamic performance. It accelerates the adjustment speed, improves dynamic response, and the maximum adjustment time does not exceed two synchronization intervals. By limiting the angle of the adjustment vector interval, it avoids the problem of excessively long PWM periods reducing output voltage quality, or excessively short periods shortening program calculation time and increasing the number of switching operations. Through reasonable settings of carrier direction and clamping mode, it avoids the simultaneous switching of two or more transistors, maintains clamping consistency, and prevents an increase in the number of switching operations.

[0134] Example 2

[0135] In addition, this application provides a synchronous modulation phase alignment device.

[0136] like Figure 9 As shown, the synchronous modulation phase alignment device 900 includes:

[0137] Setting module 910 is used to set the first phase alignment mode and the second phase alignment mode;

[0138] The calculation module 920 is used to calculate the phase deviation between the phase angle of the desired output voltage vector and the phase angle of the actual output voltage vector;

[0139] The startup module 930 is used to start the second phase alignment mode when the phase deviation is greater than a set deviation threshold. In the second phase alignment mode, the output frequency of the actual output voltage is equal to the expected frequency of the expected output voltage. The expected output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector after the target vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point.

[0140] The first determining module 940 is used to determine multiple sampling points in the adjustment process according to a preset selection principle, wherein the first sampling point is the target vector, the last sampling point is the second synchronization vector; the first sampling point is named the adjustment start vector, the last sampling point is named the adjustment end vector, and the other sampling points are named intermediate vectors;

[0141] Recording module 950 is used to record the angle between two adjacent output vectors of synchronous modulation. Let the angle between the output vectors during the adjustment process be denoted as . Let the angular deviation between the adjustment start vector and the adjustment end vector be denoted as . ,in, ;

[0142] The second determining module 960 is used to determine the number of intermediate vectors based on the adjustment end vector and the carrier direction of the jump point;

[0143] The acquisition module 970 is used to acquire the durations of the adjustment start vector, the intermediate vector, and the adjustment end vector through vector decomposition;

[0144] The third determining module 980 is used to determine the carrier direction based on the carrier phase difference principle, determine the embedding mode based on the sector division, and determine the arrangement sequence of the adjustment start vector, the intermediate vector, and the adjustment end vector based on the carrier direction and the embedding mode.

[0145] The synchronous modulation phase alignment device 900 provided in this embodiment can realize the synchronous modulation phase alignment method provided in Embodiment 1. To avoid repetition, it will not be described again here.

[0146] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal 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 terminal. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal that includes that element.

[0147] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of this application.

[0148] The embodiments of this application have been described above with reference to the accompanying drawings. However, this application is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of this application without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of this application.

Claims

1. A synchronous modulation phase alignment method, characterized in that, The method includes: Set the first phase alignment mode and the second phase alignment mode; Calculate the phase deviation between the phase angle of the desired output voltage vector and the phase angle of the actual output voltage vector; When the phase deviation is greater than the set deviation threshold, the second phase alignment mode is activated. In the second phase alignment mode, the output frequency of the actual output voltage is equal to the expected frequency of the desired output voltage. The desired output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector after the target vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point. Multiple sampling points are determined during the adjustment process according to a preset selection principle. The first sampling point is the target vector, and the last sampling point is the second synchronization vector. The first sampling point is named the adjustment start vector, the last sampling point is named the adjustment end vector, and the other sampling points are named intermediate vectors. Let the angle between two adjacent output vectors of synchronous modulation be . Let the angle between the output vectors during the adjustment process be denoted as . Let the angular deviation between the adjustment start vector and the adjustment end vector be denoted as . ,in, ; The number of intermediate vectors is determined based on the adjustment end vector and the carrier direction of the jump point; The durations of the adjustment start vector, the intermediate vector, and the adjustment end vector are obtained through vector decomposition. The carrier direction is determined based on the principle that the carrier directions of adjacent sampling points are different. The embedding mode is determined based on the sector division. The arrangement sequence of the adjustment start vector, the intermediate vector, and the adjustment end vector is determined based on the carrier direction and the embedding mode. The preset selection principles include: The deviation between the actual output voltage vector and the desired output voltage vector during the adjustment process is less than or equal to a preset deviation threshold. The duration of the adjustment process is less than or equal to a preset time threshold; The carrier direction corresponding to each sampling point during the adjustment process is different from the carrier direction corresponding to the sampling points before and after it; During the adjustment process, the PWM period is greater than or equal to 0.5 times the normal interval, and during the adjustment process, the PWM period is less than or equal to 1.5 times the normal interval; Determining the number of intermediate vectors based on the adjustment end vector and the carrier direction of the transition point includes: When the adjustment end vector and the carrier direction of the jump point are different, an odd number of intermediate vectors are determined. When the adjustment end vector and the carrier direction of the jump point are the same, an even number of intermediate vectors are determined.

2. The method according to claim 1, characterized in that, When the adjustment end vector and the carrier direction of the jump point are different, determining an odd number of intermediate vectors includes: An intermediate vector is set at the midpoint between the adjustment start vector and the adjustment end vector, wherein, , .

3. The method according to claim 1, characterized in that, When the adjustment end vector and the carrier direction of the jump point are the same, an even number of intermediate vectors are determined, including: when When, the intermediate vector is not specified, where, , ; when At that time, two intermediate vectors are set, and the two intermediate vectors are evenly distributed between the adjustment start vector and the adjustment end vector. , .

4. The method according to claim 1, characterized in that, Determining the carrier direction of each of the sampling points includes: Based on the principle that adjacent sampling points should have different carrier directions during the adjustment process, the carrier direction of each sampling point during the adjustment process is determined according to the carrier direction of the jump point or the carrier direction of the adjustment end vector. Determining the embedding mode includes: The adjustment of the initial vector is not embedded; The adjustment end vector is a synchronization vector, which is embedded according to the corresponding synchronization space vector strategy execution method; The embedding method of the intermediate vector is determined based on its position on the spatial vector map.

5. The method according to claim 4, characterized in that, The step of determining the embedding method of the intermediate vector based on its position on the spatial vector map includes: Each sector is divided into two symmetrical sub-sectors, upper and lower, and the embedding method of the vector in the middle is kept consistent with the embedding method of the synchronization vector in the same sub-sector.

6. The method according to claim 1, characterized in that, The method further includes: When the phase deviation is less than the set deviation threshold, the first phase alignment mode is activated; in the first phase alignment mode, a proportional-integral regulator is used to align the phase angle of the desired output voltage with the phase angle of the actual output voltage.

7. A synchronous modulation phase alignment device, characterized in that, The device includes: The settings module is used to set the first phase alignment mode and the second phase alignment mode; The calculation module is used to calculate the phase deviation between the phase angle of the desired output voltage vector and the phase angle of the actual output voltage vector; The startup module is used to activate the second phase alignment mode when the phase deviation is greater than a set deviation threshold. In the second phase alignment mode, the output frequency of the actual output voltage is equal to the expected frequency of the expected output voltage. The expected output voltage vector after the phase jump is named the target vector. Along the rotation direction of the voltage vector, the first synchronization vector after the target vector is named the first synchronization vector, and the second vector after the target vector is named the second synchronization vector. The synchronization output sampling point one beat before the phase jump is named the jump point. The first determining module is used to determine multiple sampling points in the adjustment process according to a preset selection principle, wherein the first sampling point is the target vector, the last sampling point is the second synchronization vector; the first sampling point is named the adjustment start vector, the last sampling point is named the adjustment end vector, and the other sampling points are named intermediate vectors; The recording module is used to record the angle between two adjacent output vectors of synchronous modulation. Let the angle between the output vectors during the adjustment process be denoted as . Let the angular deviation between the adjustment start vector and the adjustment end vector be denoted as . ,in, ; The second determining module is used to determine the number of intermediate vectors based on the adjustment end vector and the carrier direction of the jump point; The acquisition module is used to acquire the durations of the adjustment start vector, the intermediate vector, and the adjustment end vector through vector decomposition; The third determining module is used to determine the carrier direction based on the principle that the carrier directions of adjacent sampling points are different, determine the embedding mode based on the sector division, and determine the arrangement sequence of the adjustment start vector, the intermediate vector, and the adjustment end vector based on the carrier direction and the embedding mode. The preset selection principles include: The deviation between the actual output voltage vector and the desired output voltage vector during the adjustment process is less than or equal to a preset deviation threshold. The duration of the adjustment process is less than or equal to a preset time threshold; The carrier direction corresponding to each sampling point during the adjustment process is different from the carrier direction corresponding to the sampling points before and after it; During the adjustment process, the PWM period is greater than or equal to 0.5 times the normal interval, and during the adjustment process, the PWM period is less than or equal to 1.5 times the normal interval; Determining the number of intermediate vectors based on the adjustment end vector and the carrier direction of the transition point includes: When the adjustment end vector and the carrier direction of the jump point are different, an odd number of intermediate vectors are determined. When the adjustment end vector and the carrier direction of the jump point are the same, an even number of intermediate vectors are determined.

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