Vector modulation method, device and system of converter and readable storage medium

Abstract

The invention provides a vector modulation method, device and system of a converter and a readable storage medium, and the method comprises the steps: when a working sector to which a current vector corresponding to a current working mode of the converter belongs is an odd sector, and the action sequence of two adjacent current vectors in the sector is from high to low; based on the flow direction of each phase of current in the three-phase input current of the converter, determining a smooth switching condition which needs to be met when the working mode of the converter is switched from an odd sector to an even sector; calculating a target duty cycle compensation value of a target current vector in the target sector based on the smooth switching condition; and performing duty ratio adjustment on the switching tube corresponding to the target current vector according to the target duty ratio compensation value. Through the implementation of the scheme of the invention, the problem of current distortion during sector switching can be effectively improved while the realization of soft switching is ensured, and the THD of the input current can be obviously reduced.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a vector modulation method, device, system and readable storage medium of a converter. Background Art

[0002] In recent years, the global new energy vehicle market has grown rapidly, and the market demand for high-performance fast charging / supercharging has become increasingly urgent. In related technologies, electric vehicle charging systems are usually implemented using a two-stage architecture, and its shortcomings are mainly reflected in two aspects: first, the power passes through two-stage converters, so the efficiency and power density are limited; second, the intermediate bus often requires a large-capacity electrolytic capacitor, which not only increases the system cost, but also reduces the life and reliability of the system. Single-stage isolated AC / DC converters can improve efficiency and power density because energy is only converted through a single-stage power conversion; at the same time, the electrolytic capacitor on the intermediate bus is also eliminated, so it has received more and more attention and research.

[0003] When bipolar space vector modulation is performed on the converter, in order to achieve soft switching control, the vector action sequence of high vector to low vector is required in each sector; however, the vector action sequence of high vector to low vector will cause the three-phase input current to be distorted when the odd sector switches to the even sector. Figure 1 and 2 As shown, the distorted input current will bring more harmonic current content, thus affecting the power supply quality of the power grid; on the other hand, the current distortion will also cause the current calculation waveform in the dq coordinate system to be distorted, affecting the stability of the current loop. Summary of the invention

[0004] The embodiments of the present application provide a vector modulation method, device, system and readable storage medium of a converter, which can at least solve the problem that the three-phase input current of the converter in the related art is easily distorted.

[0005] In a first aspect, an embodiment of the present application provides a vector modulation method of a converter, wherein the converter includes a matrix circuit provided with a plurality of switch tubes, and the matrix circuit is used to access a three-phase alternating current; the vector modulation method includes: When the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between two adjacent current vectors in the sector is high first and low later, based on the flow direction of each phase current in the three-phase input current of the converter, the smooth switching conditions that need to be satisfied when the working mode of the converter is switched from the odd sector to the even sector are determined; wherein the odd sector and the even sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to a plurality of switching cycles, each switching cycle corresponds to a plurality of working modes, and one current vector represents one working mode; Based on the smooth switching condition, a target duty cycle compensation value of a target current vector in a target sector is calculated; wherein the target sector is an odd-numbered sector or an even-numbered sector; The duty cycle of the switch tube corresponding to the target current vector is adjusted according to the target duty cycle compensation value.

[0006] A second aspect of an embodiment of the present application provides a vector modulation device of a converter, wherein the converter includes a matrix circuit provided with a plurality of switch tubes, the matrix circuit is used to access a three-phase alternating current; the vector modulation device includes: A determination module, used for determining the smooth switching conditions that need to be satisfied when the working mode of the converter is switched from the odd-numbered sector to the even-numbered sector based on the flow direction of each phase current in the three-phase input current of the converter when the working sector to which the current vector corresponding to the current mode of the converter currently belongs is an odd-numbered sector, and the action order between two adjacent current vectors in the sector is high first and low later; wherein the odd-numbered sector and the even-numbered sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to a plurality of switching cycles, each switching cycle corresponds to a plurality of working modes, and one current vector represents one working mode; A calculation module, used for calculating a target duty cycle compensation value of a target current vector in a target sector based on a smooth switching condition; wherein the target sector is an odd-numbered sector or an even-numbered sector; The modulation module is used to adjust the duty cycle of the switch tube corresponding to the target current vector according to the target duty cycle compensation value.

[0007] The third aspect of an embodiment of the present application provides a vector modulation system, including: a converter including a matrix circuit provided with multiple switching tubes, the matrix circuit is used to access three-phase alternating current; a controller is used to implement each step of the vector modulation method of the converter provided in the first aspect of the embodiment of the present application.

[0008] The fourth aspect of the embodiments of the present application provides a computer-readable storage medium on which a computer program is stored. When the computer program is executed by a controller, each step of the vector modulation method of the converter provided in the first aspect of the embodiments of the present application is implemented.

[0009] As can be seen from the above, according to the vector modulation method, device, system and readable storage medium of the converter provided by the scheme of the present application, when the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between two adjacent current vectors in the sector is high first and then low, based on the flow direction of each phase current in the three-phase input current of the converter, the smooth switching conditions that need to be met when the working mode of the converter is switched from the odd sector to the even sector are determined; wherein the odd sectors and the even sectors are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to multiple switching cycles, each switching cycle corresponds to multiple working modes, and one current vector represents one working mode; based on the smooth switching condition, the target duty cycle compensation value of the target current vector in the target sector is calculated; and the duty cycle of the switch tube corresponding to the target current vector is adjusted according to the target duty cycle compensation value. Through the implementation of the scheme of the present application, without changing the principle of high vector to low vector and maintaining soft switching, the duty cycle of the high vector in the target sector can be dynamically increased and compensated to increase the average value of the phase current corresponding to the high vector in the target sector, and the duty cycle of the low vector in the target sector can be dynamically decreased and compensated to reduce the average value of the phase current corresponding to the low vector in the target sector. The action time of the zero vector can remain unchanged, so that each phase current can achieve smooth switching between sectors when the sectors are switched; the three-phase input current distortion is greatly improved, thereby improving the stability of the current loop and the power supply quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 A waveform diagram of current distortion in the related art; Figure 2 is another waveform diagram of current distortion in the related art; Figure 3 A schematic diagram of the structure of a converter provided in the first embodiment of the present application; Figure 4 A basic flow chart of a vector modulation method for a converter provided in the second embodiment of the present application; Figure 5 A space vector diagram provided for the second embodiment of the present application; Figure 6 A schematic diagram of a vector action sequence provided for the second embodiment of the present application; Figure 7 A waveform diagram of a current distortion provided in the second embodiment of the present application; Figure 8 A schematic diagram of a target duty cycle compensation value changing over time when an odd-numbered sector is used as a target sector, provided in accordance with a second embodiment of the present application; Fig. 9A three-phase current expansion diagram after odd-numbered sector compensation provided in the second embodiment of the present application; Fig.10 A schematic diagram of a target duty cycle compensation value changing over time when an even-numbered sector is used as a target sector, provided in accordance with a second embodiment of the present application; Fig.11 A three-phase current expansion diagram after even-numbered sector compensation provided in the second embodiment of the present application; Fig.12 A waveform diagram of input voltage and input current before compensation provided in the second embodiment of the present application; Fig.13 A waveform diagram of a compensated input voltage and input current provided in the second embodiment of the present application; Fig.14 A schematic diagram of a program module of a vector modulation device of a converter provided in the third embodiment of the present application. DETAILED DESCRIPTION

[0011] In order to make the purpose, features, and advantages of the invention of this application more obvious and easy to understand, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are only part of the embodiments of this application, not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0012] In the description of the embodiments of the present application, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0013] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0014] In the embodiments of the present application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0015] In order to solve the problem that the vector modulation method of the converter in the related technology is difficult to implement and easily generates electromagnetic interference, the first embodiment of the present application provides a vector modulation system, including a converter and a controller, the converter is electrically connected to the controller, and the controller is used to implement the vector modulation method of the converter.

[0016] Specifically, the converter in this embodiment may be a matrix-dual active bridge AC / DC converter, such as Figure 3 As shown, the matrix-dual active bridge AC / DC converter includes a matrix circuit, an isolation transformer and a full-bridge circuit. The matrix circuit is connected to the primary side of the isolation transformer through an inductor, and the full-bridge circuit is connected to the secondary side of the isolation transformer. The matrix circuit is used to access the three-phase AC power. The matrix-dual active bridge AC / DC converter of this embodiment has a simplified circuit structure and a low-impedance current path. The primary side matrix circuit can efficiently convert the three-phase AC input voltage into a high-frequency AC rectangular wave, and cooperate with the secondary side full-bridge circuit to perform phase shift control similar to the DC / DC dual active bridge, so as to achieve the effect of output voltage regulation and input power factor correction (PFC).

[0017] In some implementations of this embodiment, the converter includes an LC filter, a matrix circuit, an inductor, an isolation transformer, and a full-bridge circuit. The matrix circuit includes three bridge arms, each of which includes two bidirectional switches connected in series, and the bidirectional switch is composed of two switch tubes connected in series inversely. The two ends of the bridge arm of the matrix circuit are connected to the primary side of the isolation transformer through the inductor, and the three-phase alternating current is connected to the midpoints of the three bridge arms of the matrix circuit respectively after passing through the LC filter. The midpoint of the bridge arm of the full-bridge circuit is connected to the secondary side of the isolation transformer, and the two ends of the full-bridge circuit are connected to the output capacitor and then connected to an external load or battery.

[0018] Further, in some implementations of this embodiment, Figure 2As shown, the LC filter includes capacitors and inductors, that is, the converter includes three AC side inductors, three AC side capacitors, a matrix circuit, an isolation transformer, a full-bridge circuit, a DC side filter capacitor and a load; the matrix circuit has three bridge arms, one ends of the three AC side inductors are respectively connected to the three-phase AC power supply port, and the other ends of the three AC side inductors are respectively connected to the midpoints of the three bridge arms of the matrix circuit via the three AC side capacitors.

[0019] In some implementations of the present embodiment, a first switch tube S1, S2, S3, and S4 are provided in the full-bridge circuit, the emitter of the switch tube S1 is connected to the collector of the switch tube S2 as a bridge arm, and the midpoint of the bridge arm is connected to one end of the secondary side of the isolation transformer; the emitter of the switch tube S3 is connected to the collector of the switch tube S4 as a bridge arm, and the midpoint of the bridge arm is connected to the other end of the secondary side of the isolation transformer; the collector of the switch tube S1 is connected to the collector of the switch tube S3 as the positive DC side node of the full-bridge circuit connected to one end of the DC side filter capacitor Co, the emitter of the switch tube S2 is connected to the emitter of the switch tube S4 as the negative DC side node of the full-bridge circuit connected to the other end of the output capacitor Co, and the output capacitor Co can also be connected to the load R.

[0020] In some implementations of this embodiment, a plurality of second switch tubes (bidirectional switch tubes) S are provided in the matrix circuit. ap , S bp , S cp , S an , S bn , S cn , each bidirectional switch tube is composed of two switch tubes connected; the AC side inductor L a With switch tube S ap Connection: AC side inductance L b With switch tube S bp Connection: AC side inductance L c With switch tube S bp Connection: switch tube S ap Connected to one end of the primary side of the isolation transformer; switch tube S an Connected to the other end of the primary side of the isolation transformer; switch tube S bp Connected to one end of the primary side of the isolation transformer, the switch tube S bn Connected to the other end of the primary side of the isolation transformer; switch tube S cp Connected to one end of the primary side of the isolation transformer, the switch tube S cn Connect to the other end of the primary side of the isolation transformer.

[0021] The second embodiment of the present application provides a vector modulation method of a converter, which is used to implement the vector modulation method of the converter in the first embodiment above. Figure 4A basic flow chart of a vector modulation method for a converter provided in this embodiment, the vector modulation method comprises the following steps: Step 401: When the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the order of action between two adjacent current vectors in the sector is high first and then low, based on the flow direction of each phase current in the three-phase input current of the converter, determine the smooth switching conditions that need to be met when the working mode of the converter is switched from an odd sector to an even sector.

[0022] Specifically, the odd-numbered sectors and the even-numbered sectors are respectively part of the space vector diagram of the converter. Each sector in the space vector diagram corresponds to multiple switching cycles, and each switching cycle corresponds to multiple working modes. A current vector represents a working mode. Before performing vector modulation, it is necessary to first determine whether the target sector to which the current vector corresponding to the current working mode of the converter belongs is an odd-numbered sector. If it is an odd-numbered sector, it is determined that vector adjustment is required. When the action order of adjacent current vectors in a sector is from high vector to low vector, it can help the converter to achieve soft switching, improve the efficiency of the converter, and reduce switching losses. It can be understood that in some embodiments, the number of sectors of the space vector diagram can be 6, 12, 24, etc., which is not limited here.

[0023] Furthermore, in one implementation of the present embodiment, the above-mentioned vector modulation method also includes: generating a space vector diagram of the converter based on the current vectors corresponding to different working modes of the matrix circuit and the voltage values ​​of each phase in the three-phase alternating current; dividing the space vector diagram into multiple sectors based on the action order of adjacent current vectors in the space vector diagram and the relative size relationship between different phase voltage values, and determining the sector number corresponding to each sector.

[0024] For example, in one implementation of this embodiment, the matrix circuit can transform the three-phase power frequency input into a volt-second balanced high-frequency AC square wave and send it to the primary side of the isolation transformer. To ensure the normal operation of the circuit, the input end is not allowed to be short-circuited and the output end is not allowed to be open-circuited. Nine current vectors can be set, as shown in Table 1. The on / off state of the switch tube corresponding to each vector is represented by 1 / 0, and one current vector corresponds to one working mode.

[0025] Table 1:

[0026] According to the size of the adjacent vectors and the voltage values ​​of each phase in the three-phase AC, the space vector diagram of the converter is constructed and divided into 12 small sectors, such as Figure 5 The vector selection and corresponding vector action duty ratio in each small sector are shown in Table 2, where D RRepresents the duty cycle of the effective vector to the right of the reference vector, D L represents the duty cycle of the effective vector to the left of the reference vector, and D0 represents the duty cycle of the zero effective vector. M is the modulation ratio of the matrix circuit; Table 2:

[0027] After determining the vector selection and action time of the sector, it is necessary to further determine the current vector action sequence, which can be controlled by using two vector action sequences: from high to low and from low to high. Preferably, the present embodiment selects a vector action sequence from high to low, which can help achieve soft switching and help improve the efficiency of the converter, such as Figure 6 shown.

[0028] Step 402: Calculate a target duty cycle compensation value of a target current vector in a target sector based on a smooth switching condition.

[0029] Specifically, the target sector is an odd sector or an even sector. It can be understood that the target current vector in this embodiment can be one or more, which can be determined by presetting the initial compensation moment, and is not limited here. In some specific implementations, the smooth switching condition can be: keep the average value of each phase current in the three-phase input current unchanged in the last switching cycle of the target sector (odd sector) and the first switching cycle of the next sector (even sector) of the target sector. Based on the above smooth switching conditions, combined with the inductor current expression of the corresponding switching cycle, the ideal target duty cycle compensation value can be calculated; wherein, the expression of the inductor current under different switching cycles and different working modes can be determined based on the structure of the matrix circuit and the full-bridge circuit in the converter. In some embodiments, when calculating the target duty cycle compensation value of the target current vector in the target sector, a compensation model such as a linear function, a quadratic function, a piecewise linear function, a cubic function, a power function, etc. can be used for compensation calculation, and is not limited here.

[0030] Further, in an implementation manner of the present embodiment, the step of determining the smooth switching condition that needs to be satisfied when the working mode of the converter is switched from an odd sector to an even sector based on the flow direction of each phase current in the three-phase input current of the converter comprises: when the flow direction of the b-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are both opposite to the flow direction of the a-phase current, determining the first smooth switching condition that needs to be satisfied when the working mode of the converter is switched from an odd sector to an even sector; wherein the first smooth switching condition is defined based on the following first calculation formula group:

[0031] in, Indicates the sector number corresponding to the odd sector. is a positive odd number; represents the b-phase current value of the last switching cycle in the target sector; Indicates the b-phase current value of the first switching cycle in the next sector; The c-phase current value of the last switching cycle in the target sector; Represents the c-phase current value of the first switching cycle in the next sector.

[0032] In some implementations of this embodiment, the above-mentioned step of determining the smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector based on the flow direction of each phase current in the three-phase input current of the converter further includes: when the flow direction of the a-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are both opposite to the flow direction of the b-phase current, determining the second smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector; wherein the second smooth switching condition is defined based on the following second calculation formula group:

[0033] in, Indicates the sector number corresponding to the odd sector, is a positive odd number; represents the a-phase current value of the last switching cycle in the target sector; represents the a-phase current value of the first switching cycle in the next sector; a c-phase current value of the last switching cycle in the target sector; Represents the c-phase current value of the first switching cycle in the next sector.

[0034] In some implementations of this embodiment, the above-mentioned step of determining the smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector based on the flow direction of each phase current in the three-phase input current of the converter further includes: when the flow direction of the b-phase current and the flow direction of the a-phase current in the three-phase input current of the converter are both opposite to the flow direction of the c-phase current, determining the second smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector; wherein the second smooth switching condition is defined based on the following compensation calculation formula:

[0035] in, Indicates the sector number corresponding to the odd sector, is a positive odd number; represents the a-phase current value of the last switching cycle in the target sector; represents the a-phase current value of the first switching cycle in the next sector; a b-phase current value of the last switching cycle in the target sector; Represents the b-phase current value of the first switching cycle in the next sector.

[0036] Further, in some specific implementations, for a 12-sector space vector diagram, when the working mode of the converter is switched from an odd-numbered sector to an even-numbered sector, the following smooth switching conditions must be met: Sector 1 switches to sector 2:

[0037] Sector 3 switches to sector 4:

[0038] Sector 5 switches to sector 6:

[0039] Sector 7 switches to sector 8:

[0040] Sector 9 switches to sector 10:

[0041] Sector 11 switches to sector 12:

[0042] For example, Figure 7 As shown, the switching from sector 1 to sector 2 is analyzed as an example: in sector 1, the currents of phase b and phase c are u AB and u AC The inductor current waveform in the time period is equal to the a-phase current in magnitude and opposite in direction, that is, at this time, the current flows from a-phase into b-phase or c-phase. When the first sector is switched to the second sector, the shape and position of the b-phase current and the c-phase current are exchanged because the vector action sequence must follow the principle of high vector to low vector. That is, the average value of the b-phase current in the last switching cycle of the first sector is equal to the average value of the c-phase current in the first switching cycle of the second sector, and the average value of the c-phase current in the last switching cycle of the first sector is equal to the average value of the b-phase current in the first switching cycle of the second sector. This sudden change in the current average value will inevitably cause an increase in the average current of the b-phase and a decrease in the average current of the c-phase, thereby causing distortion in the input current waveform.

[0043] Further, in a preferred embodiment, when the flow direction of the b-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are opposite to the flow direction of the a-phase current, the above-mentioned smooth switching condition can also be defined based on the following formula group:

[0044] Based on the selection control of the above-mentioned smooth switching conditions, the switching between adjacent sectors can be achieved more efficiently, which is beneficial to reducing the probability of current distortion and reducing the input current THD.

[0045] For example, when the sector number of the target sector is 1, the duty cycle of the high vector in the odd sector can be dynamically increased to increase the average value of the phase current corresponding to the high vector in the last switching cycle of the odd sector, and the duty cycle of the low vector can be dynamically decreased to reduce the average value of the phase current corresponding to the low vector in the last switching cycle of the odd sector, and the zero vector time remains unchanged. The average value of each phase current in the last switching cycle of the odd sector and the first switching cycle of the even sector is kept unchanged to achieve smooth switching between sectors, so that the following smooth switching conditions can be determined:

[0046] Among them, I b_avg (t 2初 ) represents the average current of phase b in the first switching cycle of sector 2, I b_avg (t 1末 ) represents the average current of phase b in the last switching cycle of sector 1; I c_avg (t 2初 ) represents the average current of phase c in the first switching cycle of sector 2, I c_avg (t 1末 ) represents the average current of phase C in the last switching cycle of sector 1.

[0047] Further, in one implementation of this embodiment, when each sector in the space vector diagram is provided with N When there are switching cycles, the calculation formulas for the average current values ​​in the above calculation formula group are respectively expressed as: The average value of phase b current in the last switching cycle of sector 1 is: , The average value of phase c current in the last switching cycle of sector 1 is:

[0048] The average value of phase c current in the first switching cycle of sector 2 is: , The average value of phase b current in the first switching cycle of sector 2 is:

[0049] in, N represents the number of switching cycles of the target sector, T s represents the switching cycle, i L (t) express t The inductor current of the converter at that moment.

[0050] Specifically, the corresponding inductor current expression can be substituted into the above calculation formula, and combined with the first calculation formula group of the above smooth switching conditions, the target duty cycle compensation value can be obtained: d_cmp(N*T s ) The expression of, combined with the preset compensation initial moment t 0, the complete expression of the compensation function can be determined.

[0051] In one implementation of the present embodiment, before the above-mentioned step of calculating the target duty cycle compensation value of the target current vector in the target sector based on the smooth switching condition, it also includes: when the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between two adjacent current vectors in the sector is high first and then low, the working sector or the next sector of the working sector is determined as the target sector; accordingly, the above-mentioned step of calculating the target duty cycle compensation value of the target current vector in the target sector based on the smooth switching condition includes: according to a preset compensation calculation formula, calculating the target duty cycle compensation value when the target current vector in the target sector meets the smooth switching condition.

[0052] Further, in an implementation of this embodiment, the space vector map includes twelve sectors; wherein, when the sector number of the target sector is 1, the compensation calculation formula is expressed as:

[0053] When the sector number of the target sector is 2, the compensation calculation formula is expressed as:

[0054] When the sector number of the target sector is 3, the compensation calculation formula is expressed as:

[0055] When the sector number of the target sector is 4, the compensation calculation formula is expressed as:

[0056] When the sector number of the target sector is 5, the compensation calculation formula is expressed as:

[0057] When the sector number of the target sector is 6, the compensation calculation formula is expressed as:

[0058] When the sector number of the target sector is 7, the compensation calculation formula is expressed as:

[0059] When the sector number of the target sector is 8, the compensation calculation formula is expressed as:

[0060] When the sector number of the target sector is 9, the compensation calculation formula is expressed as:

[0061] When the sector number of the target sector is 10, the compensation calculation formula is expressed as:

[0062] When the sector number of the target sector is 11, the compensation calculation formula is expressed as:

[0063] When the sector number of the target sector is 12, the compensation calculation formula is expressed as:

[0064] in, express I AB The corresponding target duty cycle compensation value, express I AC The corresponding target duty cycle compensation value, express I BC The corresponding target duty cycle compensation value, express I BA The corresponding target duty cycle compensation value, express I CA The corresponding target duty cycle compensation value, express I CB The corresponding target duty cycle compensation value, d AB_cmp ( t ) indicates that after duty cycle adjustment I AB The duty cycle, d AC_cmp ( t ) indicates that after duty cycle adjustment I AC The duty cycle, Indicates that after duty cycle adjustment I BA The duty cycle, Indicates that after duty cycle adjustment I BC The duty cycle, Indicates that after duty cycle adjustment I CA The duty cycle, Indicates that after duty cycle adjustment I CB The duty cycle, express I AB The duty cycle reference value, express I AC The duty cycle reference value, express I BC The duty cycle reference value, express I BA The duty cycle reference value, express I CA The duty cycle reference value, express I CB The duty cycle reference value, Represents zero current vector I AA The duty cycle reference value, Represents zero current vector I BB The duty cycle reference value, Indicates zero current vector I AA The duty cycle reference value, K 1. K 2 represent the preset constant coefficients, I AB represents the first target current vector, I ACrepresents the second target current vector, I BA represents the third target current vector, I BC represents the fourth target current vector, I CA represents the fifth target current vector, I CB represents the sixth target current vector.

[0065] Furthermore, in an implementation of this embodiment, when the sector number of the target sector is 1, the smooth switching condition of switching from sector 1 to sector 2 is achieved, and the target duty cycle compensation values ​​satisfy the following first compensation calculation formula:

[0066] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the first target current vector or the second target current vector at the end time of the target sector; In an implementation of this embodiment, when the sector number of the target sector is 2, the smooth switching condition of switching from sector 1 to sector 2 is achieved, and the target duty cycle compensation values ​​satisfy the following second compensation calculation formula:

[0067] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the start time of the target sector, the target duty cycle compensation value corresponding to the first target current vector or the second target current vector; In an implementation of this embodiment, when the sector number of the target sector is 3, the smooth switching condition of switching from sector 3 to sector 4 is achieved, and the target duty cycle compensation values ​​satisfy the following third compensation calculation formula:

[0068] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the second target current vector or the fourth target current vector at the end time of the target sector; In an implementation of this embodiment, when the sector number of the target sector is 4, the smooth switching condition of switching from sector 3 to sector 4 is achieved, and the target duty cycle compensation values ​​satisfy the following fourth compensation calculation formula:

[0069] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the start time of the target sector, the target duty cycle compensation value corresponding to the second target current vector or the fourth target current vector; In one implementation of this embodiment, when the sector number of the target sector is 5, the smooth switching condition of switching from sector 5 to sector 6 is achieved, and the target duty cycle compensation values ​​satisfy the following fifth compensation calculation formula:

[0070] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fourth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 6, the smooth switching condition of switching from sector 5 to sector 6 is achieved, and the target duty cycle compensation values ​​satisfy the following sixth compensation calculation formula:

[0071] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fourth target current vector at the start time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 7, the smooth switching condition of switching from sector 7 to sector 8 is achieved, and the target duty cycle compensation values ​​satisfy the following seventh compensation calculation formula:

[0072] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fifth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 8, the smooth switching condition of switching from sector 7 to sector 8 is achieved, and the target duty cycle compensation values ​​satisfy the following eighth compensation calculation formula:

[0073] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fifth target current vector at the start time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 9, the smooth switching condition of switching from sector 9 to sector 10 is achieved, and the target duty cycle compensation values ​​satisfy the following ninth compensation calculation formula:

[0074] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the fifth target current vector or the sixth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 10, the smooth switching condition of switching from sector 9 to sector 10 is achieved, and the target duty cycle compensation values ​​satisfy the following tenth compensation calculation formula:

[0075] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the fifth target current vector or the sixth target current vector at the start time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 11, the smooth switching condition of switching from sector 11 to sector 12 is achieved, and the target duty cycle compensation values ​​satisfy the following eleventh compensation calculation formula:

[0076] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the first target current vector or the sixth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 12, the smooth switching condition of switching from sector 11 to sector 12 is achieved, and the target duty cycle compensation values ​​satisfy the following twelfth compensation calculation formula:

[0077] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; Represents the start time of the target sector, and the target duty cycle compensation value corresponding to the first target current vector or the sixth target current vector.

[0078] In some specific implementations, by combining the first calculation formula group of the smooth switching condition and the compensation calculation formula corresponding to the target sector with the sector number 1, a calculation model of a linear function can be constructed, and then a schematic diagram of the change of the target duty cycle compensation value in the odd-numbered sector can be determined, such as Figure 8 As shown, the compensation curve is a straight line; the duty cycle of the target current vector is compensated by using the compensation curve corresponding method; Fig. 9 As shown, in the last switching cycle of sector 1, after compensation I AB Duty cycle ratio IAC The duty cycle is larger, which increases the average value of the b-phase current and reduces the average value of the c-phase current, so that in the process of switching from the first sector to the second sector, smooth switching of the b-phase current and the c-phase current can be achieved.

[0079] In combination with the first calculation formula group of the smooth switching condition and the compensation calculation formula corresponding to the target sector with the sector number of 2, a calculation model of a linear function can also be constructed to determine a schematic diagram of the change of the target duty cycle compensation value in the odd-numbered sector, such as Fig.10 As shown in , its compensation curve is a straight line. Fig.11 As shown, in the first switching cycle of sector 2, after compensation I AC Duty cycle ratio I AB The duty cycle is larger, which increases the average value of the c-phase current and reduces the average value of the b-phase current, so that in the process of switching from the first sector to the second sector, smooth switching of the b-phase current and the c-phase current can be achieved.

[0080] Step 403: adjust the duty cycle of the switch tube corresponding to the target current vector according to the target duty cycle compensation value.

[0081] Specifically, by reasonably compensating the action duty cycle of the target current vector in the target sector, the current distortion is improved and the total harmonic distortion (THD) of the input current is reduced without losing the action sequence of the soft switching vector.

[0082] Further, in one implementation of the present embodiment, the above-mentioned step of adjusting the duty cycle of the switch tube corresponding to the target current vector according to the target duty cycle compensation value includes: determining the target action time of the target current vector according to the target duty cycle compensation value; outputting a corresponding PWM control signal to the switch tube corresponding to the target current vector according to the target action time; wherein the PWM control signal is used to control the compensation current required for the output of the matrix circuit of the converter.

[0083] Specifically, a corresponding PWM control signal is generated based on the target duty cycle compensation value, and the time when the corresponding switch is turned on or off is adjusted by the PWM control signal, that is, the actual action time of the target current vector is adjusted, thereby improving the current distortion. Taking the switching from the first sector to the second sector as an example, the vector modulation method of this embodiment is used for compensation, and the three-phase current expansion diagram after compensation can be obtained, as shown in FIG. Fig. 9 As shown in Figure 11, it can be seen that no matter whether compensation is performed in the last switching cycle of the first sector or in the first switching cycle of the second sector, after switching from the first sector to the second sector, the average values ​​of the b-phase current and the c-phase current after switching remain unchanged from the previous switching cycle. Fig.12(Waveform diagram of input voltage and input current before compensation) and Fig.13 (Waveforms of input voltage and input current after compensation) It can also be found that under the same hardware parameters, after adding compensation, there is no current mutation at the junction of odd and even sectors, and the input current THD of the converter is significantly improved.

[0084] It can be seen that based on the technical solution of the embodiment of the present application, when the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between the two adjacent current vectors in the sector is high first and low later, the smooth switching conditions that need to be satisfied when the working mode of the converter is switched from the odd sector to the even sector are determined based on the flow direction of the current of each phase in the three-phase input current of the converter; wherein the odd sector and the even sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to multiple switching cycles, each switching cycle corresponds to multiple working modes, and one current vector represents one working mode; based on the smooth switching condition, the target duty cycle compensation value of the target current vector in the target sector is calculated; and the duty cycle of the switch tube corresponding to the target current vector is adjusted according to the target duty cycle compensation value. In this embodiment, by dynamically compensating the duty cycle of the vector action in the target sector, the current distortion is improved and the THD of the input current is reduced without losing the soft switching vector action sequence.

[0085] Fig.14 A vector modulation device for a converter is provided in the third embodiment of the present application. The vector modulation device for the converter can be applied to the vector modulation method of the above converter. The converter includes a matrix circuit, an isolation transformer and a full-bridge circuit. The matrix circuit is connected to the primary side of the isolation transformer through an inductor, and the full-bridge circuit is connected to the secondary side of the isolation transformer. The matrix circuit is used to access three-phase alternating current; the matrix circuit is used to access three-phase alternating current; and the matrix circuit is provided with a plurality of bidirectional switch tubes. Fig.14 As shown, the vector modulation device of the converter mainly includes: A determination module 1401 is used to determine the smooth switching conditions that need to be satisfied when the working mode of the converter is switched from the odd-numbered sector to the even-numbered sector based on the flow direction of each phase current in the three-phase input current of the converter when the working sector to which the current vector corresponding to the current mode of the converter currently belongs is an odd-numbered sector and the action order between two adjacent current vectors in the sector is high first and low later; wherein the odd-numbered sector and the even-numbered sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to a plurality of switching cycles, each switching cycle corresponds to a plurality of working modes, and one current vector represents one working mode; A calculation module 1402 is used to calculate a target duty cycle compensation value of a target current vector in a target sector based on a smooth switching condition; wherein the target sector is an odd-numbered sector or an even-numbered sector; The modulation module 1403 is used to adjust the duty cycle of the switch tube corresponding to the target current vector according to the target duty cycle compensation value.

[0086] In some implementations of this embodiment, a construction module is also included, which is used to: generate a space vector diagram of the converter based on the current vectors corresponding to different working modes of the matrix circuit and the voltage values ​​of each phase in the three-phase alternating current; divide the space vector diagram into multiple sectors based on the action order of adjacent current vectors in the space vector diagram and the relative size relationship between different phase voltage values, and determine the sector number corresponding to each sector.

[0087] In some implementations of this embodiment, the determination module is specifically used to: when the flow direction of the b-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are opposite to the flow direction of the a-phase current, determine the first smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector; wherein the first smooth switching condition is defined based on the following first calculation formula group:

[0088] in, Indicates the sector number corresponding to the odd sector, is a positive odd number; The b-phase current value representing the last switching cycle in the target sector; represents the b-phase current value of the first switching cycle in the next sector; a c-phase current value of the last switching cycle in the target sector; Represents the c-phase current value of the first switching cycle in the next sector.

[0089] In some implementations of this embodiment, the determination module is specifically used to: when the flow direction of the a-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are opposite to the flow direction of the b-phase current, determine the second smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector; wherein the second smooth switching condition is defined based on the following second calculation formula group:

[0090] in, Indicates the sector number corresponding to the odd sector, is a positive odd number; represents the a-phase current value of the last switching cycle in the target sector; represents the a-phase current value of the first switching cycle in the next sector; a c-phase current value of the last switching cycle in the target sector; Represents the c-phase current value of the first switching cycle in the next sector.

[0091] In some implementations of this embodiment, the determination module is specifically used to: when the flow direction of the b-phase current and the flow direction of the a-phase current in the three-phase input current of the converter are opposite to the flow direction of the c-phase current, determine the second smooth switching condition that needs to be satisfied when the working mode of the converter is switched from the odd sector to the even sector; wherein the second smooth switching condition is defined based on the following compensation calculation formula:

[0092] in, Indicates the sector number corresponding to the odd sector, is a positive odd number; represents the a-phase current value of the last switching cycle in the target sector; represents the a-phase current value of the first switching cycle in the next sector; a b-phase current value of the last switching cycle in the target sector; Represents the b-phase current value of the first switching cycle in the next sector.

[0093] In some implementations of this embodiment, the determination module is further used to: when the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd-numbered sector, and the action order between two adjacent current vectors in the sector is high first and low later, determine the working sector or the next sector of the working sector as the target sector. Accordingly, when the above-mentioned calculation module performs the function of calculating the target duty cycle compensation value of the target current vector in the target sector based on the smooth switching condition, it is specifically used to: calculate the target duty cycle compensation value when the target current vector in the target sector meets the smooth switching condition according to a preset compensation calculation formula.

[0094] Further, in some implementations of this embodiment, the space vector diagram includes twelve sectors; the calculation module is further specifically used to: when calculating the target duty cycle compensation value of the target current vector in the target sector, the following compensation calculation formula is sampled for execution: when the sector number of the target sector is 1, the compensation calculation formula is expressed as:

[0095] When the sector number of the target sector is 2, the compensation calculation formula is expressed as:

[0096] When the sector number of the target sector is 3, the compensation calculation formula is expressed as:

[0097] When the sector number of the target sector is 4, the compensation calculation formula is expressed as:

[0098] When the sector number of the target sector is 5, the compensation calculation formula is expressed as:

[0099] When the sector number of the target sector is 6, the compensation calculation formula is expressed as:

[0100] When the sector number of the target sector is 7, the compensation calculation formula is expressed as:

[0101] When the sector number of the target sector is 8, the compensation calculation formula is expressed as:

[0102] When the sector number of the target sector is 9, the compensation calculation formula is expressed as:

[0103] When the sector number of the target sector is 10, the compensation calculation formula is expressed as:

[0104] When the sector number of the target sector is 11, the compensation calculation formula is expressed as:

[0105] When the sector number of the target sector is 12, the compensation calculation formula is expressed as:

[0106] in, express I AB The corresponding target duty cycle compensation value, express I AC The corresponding target duty cycle compensation value, express I BC The corresponding target duty cycle compensation value, expressI BA The corresponding target duty cycle compensation value, express I CA The corresponding target duty cycle compensation value, express I CB The corresponding target duty cycle compensation value, d AB_cmp ( t ) indicates that after duty cycle adjustment I AB The duty cycle, d AC_cmp ( t ) indicates that after duty cycle adjustment I AC The duty cycle, Indicates that after duty cycle adjustment I BA The duty cycle, Indicates that after duty cycle adjustment I BC The duty cycle, Indicates that after duty cycle adjustment I CA The duty cycle, Indicates that after duty cycle adjustment I CB The duty cycle, express I AB The duty cycle reference value, express I AC The duty cycle reference value, express I BC The duty cycle reference value, express I BA The duty cycle reference value, express I CA The duty cycle reference value, express I CB The duty cycle reference value, Indicates zero current vector I AA The duty cycle reference value, Indicates zero current vector I BB The duty cycle reference value, Indicates zero current vector I AA The duty cycle reference value, K 1.K 2 represent the preset constant coefficients, I AB represents the first target current vector, I AC represents the second target current vector, I BA represents the third target current vector, I BC represents the fourth target current vector, I CA represents the fifth target current vector, I CB represents the sixth target current vector.

[0107] Further, in some implementations of this embodiment, the calculation module is further specifically used to: when the sector number of the target sector is 1, implement the smooth switching condition of switching from sector 1 to sector 2, so that the corresponding target duty cycle compensation values ​​satisfy the following first compensation calculation formula:

[0108] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the first target current vector or the second target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 2, the smooth switching condition of switching from sector 1 to sector 2 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following second compensation calculation formula:

[0109] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the start time of the target sector, the target duty cycle compensation value corresponding to the first target current vector or the second target current vector; In an implementation of this embodiment, when the sector number of the target sector is 3, the smooth switching condition of switching from sector 3 to sector 4 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following third compensation calculation formula:

[0110] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the second target current vector or the fourth target current vector at the end time of the target sector; In an implementation of this embodiment, when the sector number of the target sector is 4, the smooth switching condition of switching from sector 3 to sector 4 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following fourth compensation calculation formula:

[0111] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the start time of the target sector, the target duty cycle compensation value corresponding to the second target current vector or the fourth target current vector; In one implementation of this embodiment, when the sector number of the target sector is 5, the smooth switching condition of switching from sector 5 to sector 6 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following fifth compensation calculation formula:

[0112] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fourth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 6, the smooth switching condition of switching from sector 5 to sector 6 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following sixth compensation calculation formula:

[0113] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fourth target current vector at the start time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 7, the smooth switching condition of switching from sector 7 to sector 8 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following seventh compensation calculation formula:

[0114] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fifth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 8, the smooth switching condition of switching from sector 7 to sector 8 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following eighth compensation calculation formula:

[0115] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fifth target current vector at the start time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 9, the smooth switching condition of switching from sector 9 to sector 10 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following ninth compensation calculation formula:

[0116] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the fifth target current vector or the sixth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 10, the smooth switching condition of switching from sector 9 to sector 10 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following tenth compensation calculation formula:

[0117] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the fifth target current vector or the sixth target current vector at the start time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 11, the smooth switching condition of switching from sector 11 to sector 12 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following eleventh compensation calculation formula:

[0118] in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the first target current vector or the sixth target current vector at the end time of the target sector; In one implementation of this embodiment, when the sector number of the target sector is 12, the smooth switching condition of switching from sector 11 to sector 12 is implemented so that the corresponding target duty cycle compensation values ​​satisfy the following twelfth compensation calculation formula:

[0119] in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; Represents the start time of the target sector, and the target duty cycle compensation value corresponding to the first target current vector or the sixth target current vector.

[0120] According to the vector modulation device of the converter provided in this embodiment, when the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between two adjacent current vectors in the sector is high first and low later, the smooth switching condition required to be satisfied when the working mode of the converter is switched from the odd sector to the even sector is determined based on the flow direction of each phase current in the three-phase input current of the converter; wherein the odd sector and the even sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to multiple switching cycles, each switching cycle corresponds to multiple working modes, and one current vector represents one working mode; based on the smooth switching condition, the target duty cycle compensation value of the target current vector in the target sector is calculated; and the duty cycle of the switch tube corresponding to the target current vector is adjusted according to the target duty cycle compensation value. In this embodiment, by dynamically compensating the duty cycle of the vector action in the target sector, the current distortion is improved and the THD of the input current is reduced without losing the soft switching vector action sequence.

[0121] The fourth embodiment of the present application provides a vector modulation system. The vector modulation system can be used to implement the vector modulation method of the converter in the aforementioned embodiment, and mainly includes: a converter and a controller electrically connected to the converter; the converter includes a matrix circuit provided with multiple switch tubes, and the matrix circuit is used to access three-phase alternating current; the controller can be configured with a memory, a processor, and a computer program stored in the memory and run on the processor, and the memory and the processor are connected by communication. When the processor executes the computer program, the method in the aforementioned embodiment 2 is implemented. Among them, the number of processors can be one or more.

[0122] The memory can be a high-speed random access memory (RAM) memory or a non-volatile memory, such as a disk memory. The memory is used to store executable program codes, and the processor is coupled to the memory.

[0123] Furthermore, an embodiment of the present application also provides a computer-readable storage medium, which may be arranged in the above-mentioned vector modulation system, and the computer-readable storage medium may be the memory in the aforementioned embodiment.

[0124] The computer readable storage medium stores a computer program, and when the program is executed by the processor, the vector modulation method of the converter in the aforementioned embodiment is implemented. Furthermore, the computer storable medium can also be a U disk, a mobile hard disk, a read-only memory (ROM), a RAM, a magnetic disk or an optical disk, and other media that can store program codes.

[0125] In the several embodiments provided in the present application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of modules is only a logical function division. There may be other division methods in actual implementation, such as multiple modules or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or modules, which can be electrical, mechanical or other forms.

[0126] The modules described as separate components may or may not be physically separated, and the components shown as modules may or may not be physical modules, that is, they may be located in one place or distributed on multiple network modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0127] In addition, each functional module in each embodiment of the present application can be integrated into a processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The above integrated modules can be implemented in the form of hardware or software functional modules.

[0128] If the integrated module is implemented in the form of a software function module and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, or all or part of the technical solution can be embodied in the form of a software product, and the computer software product is stored in a readable storage medium, including a number of instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the various embodiments of the present application. The aforementioned readable storage medium includes: U disk, mobile hard disk, ROM, RAM, disk or CD-ROM and other media that can store program codes.

[0129] It should be noted that, for the above-mentioned method embodiments, for the sake of simplicity of description, they are all expressed as a series of action combinations, but those skilled in the art should be aware that the present application is not limited by the described action sequence, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0130] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0131] The above is a description of the vector modulation method, device, system and readable storage medium of the converter provided in the present application. For technicians in this field, according to the ideas of the embodiments of the present application, there may be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A vector modulation method for a converter, characterized in that: The converter includes a matrix circuit provided with a plurality of switch tubes, and the matrix circuit is used to access three-phase alternating current; the vector modulation method includes: When the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between two adjacent current vectors in the sector is high first and low later, based on the flow direction of each phase current in the three-phase input current of the converter, the smooth switching condition to be satisfied when the working mode of the converter is switched from the odd sector to the even sector is determined; wherein the odd sector and the even sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to a plurality of switching cycles, each of the switching cycles corresponds to a plurality of the working modes, and one current vector represents one working mode; Based on the smooth switching condition, a target duty cycle compensation value of a target current vector in a target sector is calculated; wherein the target sector is the odd-numbered sector or the even-numbered sector; The duty cycle of the switch tube corresponding to the target current vector is adjusted according to the target duty cycle compensation value.

2. The vector modulation method of the converter according to claim 1, characterized in that: The determining, based on the flow direction of each phase current in the three-phase input current of the converter, a smooth switching condition to be satisfied when the working mode of the converter is switched from the odd sector to the even sector comprises: When the flow direction of the b-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are opposite to the flow direction of the a-phase current, a first smooth switching condition to be satisfied when the working mode of the converter is switched from the odd sector to the even sector is determined; wherein the first smooth switching condition is defined based on the following first calculation formula group: in, Indicates the sector number corresponding to the odd sector, is a positive odd number; The b-phase current value representing the last switching cycle in the target sector; represents the b-phase current value of the first switching cycle in the next sector; a c-phase current value of the last switching cycle in the target sector; Represents the c-phase current value of the first switching cycle in the next sector.

3. The vector modulation method of the converter according to claim 1, characterized in that: The step of determining the smooth switching condition to be satisfied when the working mode of the converter is switched from the odd-numbered sector to the even-numbered sector based on the flow direction of each phase current in the three-phase input current of the converter further includes: When the flow direction of the a-phase current and the flow direction of the c-phase current in the three-phase input current of the converter are opposite to the flow direction of the b-phase current, a second smooth switching condition to be satisfied when the working mode of the converter is switched from the odd sector to the even sector is determined; wherein the second smooth switching condition is defined based on the following second calculation formula group: in, Indicates the sector number corresponding to the odd sector, is a positive odd number; represents the a-phase current value of the last switching cycle in the target sector; represents the a-phase current value of the first switching cycle in the next sector; a c-phase current value of the last switching cycle in the target sector; Represents the c-phase current value of the first switching cycle in the next sector.

4. The vector modulation method of the converter according to claim 1, characterized in that: The step of determining the smooth switching condition to be satisfied when the working mode of the converter is switched from the odd-numbered sector to the even-numbered sector based on the flow direction of each phase current in the three-phase input current of the converter further includes: When the flow direction of the b-phase current and the flow direction of the a-phase current in the three-phase input current of the converter are opposite to the flow direction of the c-phase current, a second smooth switching condition to be satisfied when the working mode of the converter is switched from the odd sector to the even sector is determined; wherein the second smooth switching condition is defined based on the following compensation calculation formula: in, Indicates the sector number corresponding to the odd sector, is a positive odd number; represents the a-phase current value of the last switching cycle in the target sector; represents the a-phase current value of the first switching cycle in the next sector; a b-phase current value of the last switching cycle in the target sector; Represents the b-phase current value of the first switching cycle in the next sector.

5. The vector modulation method of the converter according to claim 1, characterized in that: Before calculating the target duty cycle compensation value of the target current vector in the target sector based on the smooth switching condition, the method further includes: When the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd-numbered sector, and the action order between two adjacent current vectors in the sector is high first and low later, the working sector or the next sector of the working sector is determined as the target sector; The step of calculating a target duty cycle compensation value of a target current vector in a target sector based on the smooth switching condition comprises: According to a preset compensation calculation formula, a target duty cycle compensation value is calculated when the target current vector in the target sector meets the smooth switching condition.

6. The vector modulation method of the converter according to claim 6, characterized in that: The space vector diagram includes twelve sectors; wherein, When the sector number of the target sector is 1, the compensation calculation formula is expressed as: When the sector number of the target sector is 2, the compensation calculation formula is expressed as: When the sector number of the target sector is 3, the compensation calculation formula is expressed as: When the sector number of the target sector is 4, the compensation calculation formula is expressed as: When the sector number of the target sector is 5, the compensation calculation formula is expressed as: When the sector number of the target sector is 6, the compensation calculation formula is expressed as: When the sector number of the target sector is 7, the compensation calculation formula is expressed as: When the sector number of the target sector is 8, the compensation calculation formula is expressed as: When the sector number of the target sector is 9, the compensation calculation formula is expressed as: When the sector number of the target sector is 10, the compensation calculation formula is expressed as: When the sector number of the target sector is 11, the compensation calculation formula is expressed as: When the sector number of the target sector is 12, the compensation calculation formula is expressed as: in, express I AB The corresponding target duty cycle compensation value, express I AC The corresponding target duty cycle compensation value, express I BC The corresponding target duty cycle compensation value, express I BA The corresponding target duty cycle compensation value, express I CA The corresponding target duty cycle compensation value, express I CB The corresponding target duty cycle compensation value, d AB_cmp ( t ) indicates that after duty cycle adjustment I AB The duty cycle, d AC_cmp ( t ) indicates that after duty cycle adjustment I AC The duty cycle, Indicates that after duty cycle adjustment I BA The duty cycle, Indicates that after duty cycle adjustment I BC The duty cycle, Indicates that after duty cycle adjustment I CA The duty cycle, Indicates that after duty cycle adjustment I CB The duty cycle, express I AB The duty cycle reference value, express I AC The duty cycle reference value, express I BC The duty cycle reference value, express I BA The duty cycle reference value, express I CA The duty cycle reference value, express I CB The duty cycle reference value, Represents zero current vector I AA The duty cycle reference value, Represents zero current vector I BB The duty cycle reference value, Represents zero current vector I AA The duty cycle reference value, K 1. K 2 represent the preset constant coefficients, I AB represents the first target current vector, I AC represents the second target current vector, I BA represents the third target current vector, I BC represents the fourth target current vector, I CA represents the fifth target current vector, I CB represents the sixth target current vector.

7. The vector modulation method of the converter according to claim 6, characterized in that: When the sector number of the target sector is 1, the target duty cycle compensation values ​​also satisfy the following first compensation calculation formula: in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the first target current vector or the second target current vector at the end time of the target sector; Alternatively, when the sector number of the target sector is 2, the target duty cycle compensation values ​​also satisfy the following second compensation calculation formula: in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the start time of the target sector, the target duty cycle compensation value corresponding to the first target current vector or the second target current vector; Alternatively, when the sector number of the target sector is 3, the target duty cycle compensation values ​​also satisfy the following third compensation calculation formula: in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the second target current vector or the fourth target current vector at the end time of the target sector; Alternatively, when the sector number of the target sector is 4, the target duty cycle compensation values ​​also satisfy the following fourth compensation calculation formula: in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the start time of the target sector, the target duty cycle compensation value corresponding to the second target current vector or the fourth target current vector; Alternatively, when the sector number of the target sector is 5, the target duty cycle compensation values ​​also satisfy the following fifth compensation calculation formula: in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fourth target current vector at the end time of the target sector; Alternatively, when the sector number of the target sector is 6, the target duty cycle compensation values ​​further satisfy the following sixth compensation calculation formula: in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fourth target current vector at the start time of the target sector; Alternatively, when the sector number of the target sector is 7, the target duty cycle compensation values ​​also satisfy the following seventh compensation calculation formula: in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fifth target current vector at the end time of the target sector; Alternatively, when the sector number of the target sector is 8, the target duty cycle compensation values ​​also satisfy the following eighth compensation calculation formula: in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the third target current vector or the fifth target current vector at the start time of the target sector; Alternatively, when the sector number of the target sector is 9, the target duty cycle compensation values ​​also satisfy the following ninth compensation calculation formula: in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the fifth target current vector or the sixth target current vector at the end time of the target sector; Alternatively, when the sector number of the target sector is 10, the target duty cycle compensation values ​​also satisfy the following tenth compensation calculation formula: in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the fifth target current vector or the sixth target current vector at the start time of the target sector; Alternatively, when the sector number of the target sector is 11, the target duty cycle compensation values ​​also satisfy the following eleventh compensation calculation formula: in, represents the start compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; represents the target duty cycle compensation value corresponding to the first target current vector or the sixth target current vector at the end time of the target sector; Alternatively, when the sector number of the target sector is 12, the target duty cycle compensation values ​​also satisfy the following twelfth compensation calculation formula: in, represents the end compensation time in the target sector; represents the initial time of the target sector; represents the initial time of the target sector; Represents the start time of the target sector, and the target duty cycle compensation value corresponding to the first target current vector or the sixth target current vector.

8. A vector modulation device for a converter, characterized in that: The converter includes a matrix circuit provided with a plurality of switch tubes, and the matrix circuit is used to access three-phase alternating current; the vector modulation device includes: A determination module, used for determining, when the working sector to which the current vector corresponding to the current working mode of the converter belongs is an odd sector, and the action order between two adjacent current vectors in the sector is high first and low later, based on the flow direction of each phase current in the three-phase input current of the converter, the smooth switching condition to be satisfied when the working mode of the converter is switched from the odd sector to the even sector; wherein the odd sector and the even sector are respectively part of the space vector diagram of the converter, each sector in the space vector diagram corresponds to a plurality of switching cycles, each switching cycle corresponds to a plurality of the working modes, and one current vector represents one working mode; A calculation module, configured to calculate a target duty cycle compensation value of a target current vector in the target sector based on the smooth switching condition; wherein the target sector is the odd-numbered sector or the even-numbered sector; A modulation module is used to adjust the duty cycle of the switch tube corresponding to the target current vector according to the target duty cycle compensation value.

9. A vector modulation system, characterized in that: The invention comprises a converter and a controller electrically connected to the converter, wherein: The converter includes a matrix circuit provided with a plurality of switch tubes, and the matrix circuit is used to access three-phase alternating current; The controller is used to execute the steps in the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a controller, the steps in the method according to any one of claims 1 to 7 are implemented.

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