Space vector pulse width modulation method of two-phase four-leg inverter and related device

Abstract

The invention provides a space vector pulse width modulation method of a two-phase four-leg inverter and a related device, and belongs to the technical field of power electronics. According to a sector where a reference output voltage vector is located, whether the action time of an adjacent voltage vector and the action time of a zero voltage vector in the sector where the reference voltage vector is located after equal-proportion shortening is conducted or not is judged, and the state of a selected switching tube, the switching sequence of the switching tube and the state duration of the switching tube are determined. And according to the selected switching tube state, the switching tube switching sequence and the switching tube state duration, generating a driving signal for controlling the switching tube state switching so as to control the on-off of each switching tube of the two-phase four-leg inverter. The method solves the problems that in the prior art, the calculation process is complex, the state switching of a switching tube is frequent, and the utilization rate of direct-current voltage is too small.

Description

Technical Field

[0001] The present invention belongs to the technical field of power electronics, and in particular relates to a space vector pulse width modulation method of a two-phase four-bridge-arm inverter and a related device. Background Art

[0002] Compared with the sine pulse width modulation (SPWM), the space vector pulse width modulation (SVPWM) method has advantages in output voltage fundamental amplitude and output current harmonic content, but its calculation process is relatively complicated. However, with the continuous development and application of digital signal processing technology, the problem of insufficient computing power has been solved, and the space vector pulse width modulation method has become more popular than other pulse width modulation methods.

[0003] Among the many space vector pulse width modulation technologies, most are aimed at three-phase output application scenarios, and only a few focus on two-phase. However, the application scenarios of two-phase inverters are not uncommon, such as small and medium power induction motors, such as household appliances such as fans, hair dryers and refrigerators. Moreover, small power bearingless permanent magnet synchronous thin-film motors are also more inclined to use two-phase inverters for power supply. Compared with three-phase inverters, two-phase inverters have the following advantages: First, there is no need to convert three-phase coordinates to two-phase coordinates, reducing the amount of calculation. Second, in most household application scenarios, there is no condition for three-phase power supply. Third, the volume occupied by two-phase windings and the difficulty of winding are less than those of three-phase windings.

[0004] The SVPWM technology of two-phase inverters is concentrated on the topology of two or three bridge arms. Among them, the two-bridge-arm SVPWM technology has no zero voltage vector effect. The realization of a single reference voltage requires four voltage vectors to act in turn, the calculation process is complicated, and the output voltage and current harmonics are high. In addition, this topology requires a center-tapped voltage source or capacitor, which has a high manufacturing cost and a low utilization rate of DC voltage, only 50%. The three-bridge-arm SVPWM technology has improved in various performance indicators. However, it requires a common bridge arm to form a loop, and the current amplitude on this bridge arm is the current amplitude of the other two bridge arms. times, and its DC voltage utilization rate is only 70.7%. At the same time, the switch states of these two SVPWM algorithms switch frequently, and each switch needs to switch once in a single sampling cycle. Summary of the invention

[0005] The purpose of the present invention is to provide a space vector pulse width modulation method and related devices for a two-phase four-bridge-arm inverter, which are used to solve the problems of complex calculation process, frequent switching of switch states, and low utilization of DC voltage in the prior art.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: In a first aspect, the present invention provides a space vector pulse width modulation method for a two-phase four-bridge-arm inverter, comprising the following steps: Based on the topological structure of the two-phase four-leg inverter, the basic output voltage vector of the two-phase four-leg inverter is defined, and the spatial voltage vector diagram of the two-phase four-leg inverter is drawn; The drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter is divided into several sectors, and the sector where the reference voltage vector is located is determined according to the reference voltage vector angle or the reference output voltage value; The action time of the adjacent voltage vectors and the zero voltage vector of the sector where the reference voltage vector is located is calculated according to the volt-second equivalent principle, and whether the reference output voltage value is in the linear modulation area is determined according to the action time of the adjacent voltage vectors of the sector where the reference voltage vector is located; According to whether the reference output voltage value is in the linear modulation area, it is determined whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located; Determine the selected switch state, switch order and switch state duration of the switch according to the sector where the reference output voltage vector is located, determine whether to proportionally shorten the action time of the adjacent voltage vectors and the action time of the zero voltage vector in the sector where the reference voltage vector is located, and According to the selected switch tube state, switch tube switching sequence and switch tube state duration, a drive signal for controlling the switch tube state switching is generated to control the on and off of each switch tube of the two-phase four-bridge arm inverter.

[0007] A further improvement of the present invention is that the basic output voltage vector includes 8 non-zero voltage vectors and 1 zero voltage vector.

[0008] A further improvement of the present invention lies in that, in the step of dividing the drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter into several sectors, and judging the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value, the specific judgment process is: if the angle information of the reference voltage vector is known and the driven load is a two-phase symmetrical load, the reference voltage vector angle is directly used for judgment; otherwise, the reference output voltage value is used for judgment.

[0009] A further improvement of the present invention is that, in the step of calculating the action time of the adjacent voltage vectors and the zero voltage vector in the sector where the reference voltage vector is located according to the volt-second equivalence principle, and judging whether the reference output voltage value is in the linear modulation area according to the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located, the specific process of judging whether the reference output voltage value is in the linear modulation area is: when the sum of the action time of the adjacent voltage vectors is greater than the sampling time, the reference output voltage value is not in the linear modulation area; when the sum of the action time of the adjacent voltage vectors is less than or equal to the sampling time, the reference output voltage value is in the linear modulation area.

[0010] A further improvement of the present invention is that, in the step of judging whether to proportionally shorten the action time of adjacent voltage vectors in the sector where the reference voltage vector is located based on whether the reference output voltage value is in the linear modulation region, the specific judging process is: if the reference output voltage value is not in the linear modulation region, the action time of adjacent voltage vectors in the sector where the reference voltage vector is located is proportionally shortened; if the reference output voltage value is in the linear modulation region, the action time of adjacent voltage vectors in the sector where the reference voltage vector is located is not proportionally shortened.

[0011] A further improvement of the present invention is that the calculation formula of the equal-proportional shortening is:

[0012] in, and The basic voltage vector is shortened proportionally , The action time, and is the basic voltage vector before proportional shortening , The action time, is the sampling time, and They are two adjacent basic voltage vectors in the sector where the reference voltage vector is located.

[0013] A further improvement of the present invention is that the switch tube is an IGBT or a MOSFET.

[0014] In a second aspect, the present invention provides a space vector pulse width modulation system for a two-phase four-bridge-arm inverter, comprising a space voltage vector partitioning module, a sector judgment module, an action time calculation module, an equal-proportional shortening judgment module, a switch sequence determination module, and a switch tube on-off control module; The space voltage vector partitioning module is used to define the basic output voltage vector of the two-phase four-bridge-arm inverter based on the topological structure of the two-phase four-bridge-arm inverter, and draw the space voltage vector diagram of the two-phase four-bridge-arm inverter; The sector judgment module is used to divide the drawn space voltage vector diagram of the two-phase four-bridge-arm inverter into a plurality of sectors, and judge the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value; The action time calculation module is used to calculate the action time of the adjacent voltage vectors and the zero voltage vector of the sector where the reference voltage vector is located according to the volt-second equivalent principle, and judge whether the reference output voltage value is in the linear modulation area according to the action time of the adjacent voltage vectors of the sector where the reference voltage vector is located; The proportional shortening judgment module is used to judge whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located according to whether the reference output voltage value is in the linear modulation area; The switch sequence determination module is used to determine the selected switch state, switch order and switch state duration of the switch according to the sector where the reference output voltage vector is located, the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located and the action time of the zero voltage vector after determining whether to shorten the reference voltage vector in equal proportion; The switch tube on-off control module is used to generate a drive signal for controlling the switching of the switch tube state according to the selected switch tube state, the switch tube switching sequence and the switch tube state duration, so as to control the on-off of each switch tube of the two-phase four-bridge arm inverter.

[0015] In a third aspect, the present invention provides an electronic device including a memory and a processor, wherein the memory stores a computer program, and the processor implements the steps of the space vector pulse width modulation method of the two-phase four-leg inverter introduced above when executing the computer program.

[0016] In a fourth aspect, the present invention provides a storage medium having a computer program stored thereon, wherein when the computer program is executed by a processor, the steps of the space vector pulse width modulation method of the two-phase four-leg inverter introduced above are implemented.

[0017] Compared with the prior art, the present invention has the following beneficial effects: The present invention belongs to an improved invention. Compared with the existing space vector pulse width modulation method of the two-phase inverter, the present invention is based on the inverter topology of the two-phase four-bridge arm. On the one hand, the number of basic voltage vectors is increased, the linear working area range is expanded, and the utilization rate of the DC bus voltage is improved. On the other hand, the present invention adds an optional switch tube state, so that the number of switch state switching is greatly reduced through the specially selected switch tube state and the switch tube switching sequence, and the load current ripple is reduced, and the switching loss caused by the switch switching is reduced, thereby improving the efficiency of the power electronic equipment, thereby effectively solving the problems of complex calculation process, frequent switch tube state switching, and low utilization rate of DC voltage in the prior art. In addition, the present invention readjusts the action time of the reference voltage vector in the nonlinear modulation area to ensure that the output voltage is not distorted in phase, thereby improving the stability of the two-phase four-bridge arm inverter system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a flow chart of the space vector pulse width modulation method of the two-phase four-bridge-arm inverter of the present invention; Figure 2 Schematic diagram of a space vector pulse width modulation system of a two-phase four-bridge-arm inverter of the present invention; Figure 3 A main circuit topology diagram of a two-phase four-bridge-arm inverter provided in Embodiment 3 of the present invention; Figure 4 A spatial voltage vector diagram of a two-phase four-bridge-arm inverter of the present invention; Figure 5 This is a schematic diagram of the action time of a two-phase four-bridge-arm inverter in Embodiment 3 of the present invention; Figure 6 This is a schematic diagram of the basic voltage vector function when the reference voltage vector of the present invention is located in sector I; Figure 7 The switching sequence of the reference voltage vector of the present invention in different sectors; Figure 8 This is a two-phase ideal output voltage waveform diagram of Example 3 of the present invention; Fig. 9 for Figure 8 Waveform diagram of the enlarged area; Fig.10 A topological structure diagram of a main circuit of a two-phase four-bridge-arm inverter provided in Embodiment 4 of the present invention; Fig.11 The two-phase ideal output voltage waveform of embodiment 4 of the present invention; Fig.12 for Fig.10 Waveform diagram of the enlarged area; Fig.13 It is a schematic diagram of the structure of the electronic device of the present invention. DETAILED DESCRIPTION

[0019] In order to further understand the content of the present invention, the present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the embodiments are only for explaining the present invention and are not intended to limit it.

[0020] The space vector pulse width modulation method of the two-phase four-bridge-arm inverter proposed in the present invention generates a driving signal for controlling the switching of the switch state according to the selected switch state, the switch switching sequence and the switch state duration, thereby controlling the on and off of each switch of the two-phase four-bridge-arm inverter. Compared with the prior art, the present invention effectively solves the problems of complex calculation process, frequent switching of switch states and low utilization rate of DC voltage in the prior art.

[0021] Embodiment 1: The flow chart of the space vector pulse width modulation method of the two-phase four-bridge-arm inverter of the present invention is as follows: Figure 1 As shown, the space vector pulse width modulation method of the two-phase four-bridge-arm inverter of the present invention comprises the following steps: S1. Based on the topological structure of the two-phase four-leg inverter, the basic output voltage vector of the two-phase four-leg inverter is defined, and the spatial voltage vector diagram of the two-phase four-leg inverter is drawn.

[0022] S2. Divide the drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter into several sectors, and determine the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value.

[0023] S3. Calculate the action time of the adjacent voltage vectors and the zero voltage vector in the sector where the reference voltage vector is located according to the volt-second equivalence principle, and determine whether the reference output voltage value is in the linear modulation area according to the action time of the adjacent voltage vector in the sector where the reference voltage vector is located.

[0024] S4. According to whether the reference output voltage value is in the linear modulation region, it is determined whether the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located should be shortened in equal proportion.

[0025] S5. Determine the selected switch state, switch order and switch state duration based on the sector where the reference output voltage vector is located, determine whether to proportionally shorten the action time of adjacent voltage vectors and the action time of the zero voltage vector in the sector where the reference voltage vector is located, and the switching sequence and switch state duration.

[0026] S6. Generate a drive signal for controlling the switching of the switch state according to the selected switch state, the switch switching sequence and the switch state duration, so as to control the on and off of each switch of the two-phase four-bridge-arm inverter.

[0027] Embodiment 2: The schematic diagram of the space vector pulse width modulation system of the two-phase four-bridge-arm inverter of the present invention is as follows: Figure 2 As shown, the space vector pulse width modulation system of the two-phase four-bridge-arm inverter of the present invention includes a space voltage vector partitioning module, a sector judgment module, an action time calculation module, an equal-proportional shortening judgment module, a switch sequence determination module and a switch tube on-off control module.

[0028] The space voltage vector partitioning module is used to define the basic output voltage vector of the two-phase four-bridge-arm inverter based on the topological structure of the two-phase four-bridge-arm inverter and draw the space voltage vector diagram of the two-phase four-bridge-arm inverter.

[0029] The sector judgment module is used to divide the drawn space voltage vector diagram of the two-phase four-bridge-arm inverter into several sectors, and judge the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value.

[0030] The action time calculation module is used to calculate the action time of the adjacent voltage vectors and the zero voltage vector in the sector where the reference voltage vector is located according to the volt-second equivalence principle, and to determine whether the reference output voltage value is in the linear modulation area according to the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located.

[0031] The proportional shortening judgment module is used to judge whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located according to whether the reference output voltage value is in the linear modulation area.

[0032] The switch sequence determination module is used to determine the selected switch tube state, switch tube switching order and switch tube state duration based on the sector where the reference output voltage vector is located, and whether to proportionally shorten the action time of the adjacent voltage vectors and the action time of the zero voltage vector in the sector where the reference voltage vector is located.

[0033] The switch tube on-off control module is used to generate a drive signal for controlling the switching of the switch tube state according to the selected switch tube state, switch tube switching sequence and switch tube state duration, so as to control the on-off of each switch tube of the two-phase four-bridge arm inverter.

[0034] Embodiment 3: S1. Based on the topological structure of the two-phase four-leg inverter, the basic output voltage vector of the two-phase four-leg inverter is defined, and the spatial voltage vector diagram of the two-phase four-leg inverter is drawn.

[0035] The main circuit topology of the two-phase four-bridge-arm inverter in this embodiment is as follows: Figure 3 As shown, the main circuit of the two-phase four-bridge-arm inverter in this embodiment includes a parallel connection with a voltage of The four bridge arms at both ends of the DC voltage source: bridge arm A (also called bridge arm A), bridge arm B (bridge arm B), bridge arm C (bridge arm C) and bridge arm D (bridge arm D), each bridge arm includes two switching devices, and the four bridge arms include a total of 8 switching devices (also called switch tubes, specifically including switch tube S1, switch tube S2, switch tube S3, switch tube S4, switch tube S5, switch tube S6, switch tube S7, switch tube S8 in this embodiment). The switch devices in this embodiment can be composed of IGBT and reverse parallel diodes, or MOSFET. Among them, the midpoint voltage difference between bridge arm A and bridge arm B constitutes one phase of the two-phase output voltage: , the midpoint voltage difference between the C bridge arm and the D bridge arm constitutes the other phase of the two-phase output voltage: The two-phase output voltages are respectively connected to a set of series resistors and inductors with the same parameters as loads.

[0036] When each bridge arm of the two-phase four-bridge inverter is working normally, the switching states of the upper switch devices (S1, S3, S5 and S7) and the lower switch devices (S2, S4, S6 and S8) are always opposite. For convenience, only the switch state set of the four upper switch devices is used to represent the switch state of the entire inverter, with 0 representing the off state and 1 representing the on state. The eight switches of the four bridge arms can generate 16 different switch state sets, and the output voltages of the 16 switch states form 8 equally spaced There are four non-zero voltage vectors and one zero voltage vector. The four non-zero voltage vectors are located on the imaginary axis and the real axis of the complex plane, and their length is , the other four non-zero voltage vectors are located on the diagonal of the complex plane, with a length of The zero voltage vector is located at the exact center of the complex plane. These eight non-zero voltage vectors evenly divide the complex plane into eight sectors. Figure 4 is the spatial voltage vector diagram of the two-phase four-bridge-arm inverter. Each sector is an isosceles right triangle. The eight sectors form a standard square. The edge of the square is the maximum voltage trajectory, and the largest inscribed circle of the square is the maximum reference voltage vector trajectory. The 16 switch states are redundant in forming the above voltage vectors. For example, the switch states (0000), (1111), (0011), and (1100) can all output zero voltage vectors. Table 1 shows the two-phase output voltages and the overall output voltage vector corresponding to different switch states. , the output voltage vector is expressed as a phasor.

[0037] Table 1 Basic voltage vectors corresponding to different switch states

[0038] S2. Divide the drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter into several sectors, and determine the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value.

[0039] The spatial voltage vector diagram of the drawn two-phase four-arm inverter is divided into several sectors (in this embodiment, the spatial voltage vector diagram of the drawn two-phase four-arm inverter is divided into 8 sectors, sector I, sector II, sector III, sector IV, sector V, sector VI, sector VII and sector VIII).

[0040] The specific judgment process of the sector where the reference voltage vector is located is as follows: if the angle information of the reference voltage vector is known and the driven load is a two-phase symmetrical load, it is directly judged by the reference voltage vector angle; otherwise, it is judged according to the reference output voltage value.

[0041] The specific determination process of the sector where the reference voltage vector is located is described in detail below: If the angle information of the reference voltage vector is known, and the driven load is a two-phase symmetrical load, the reference voltage vector angle is used for direct judgment. Specifically, in sector I, In Sector II, In sector III, In sector IV, In sector V, In sector VI, . In Sector VII, . In Sector VIII, .

[0042] Otherwise, according to the reference output voltage value and Make a judgment and determine the sector based on the following four criteria: Criterion 1: , Criterion 2: Criterion 3: And criterion 4: .

[0043] Specifically, in sector I, criterion 1, criterion 2, and criterion 3 are satisfied. In sector II, criterion 1 and criterion 2 are satisfied, but criterion 3 is not satisfied. In sector III, criterion 2 and criterion 4 are satisfied, but criterion 1 is not satisfied. In sector IV, criterion 2 is satisfied, but criterion 1 and criterion 4 are not satisfied. In sector V, criterion 1, criterion 2, and criterion 3 are not satisfied. In sector VI, criterion 3 is satisfied, but criterion 1 and criterion 2 are not satisfied. In sector VII, criterion 1 is satisfied, but criterion 2 and criterion 4 are not satisfied. In sector VIII, criterion 1 and criterion 4 are satisfied, but criterion 2 is not satisfied.

[0044] The angle ranges of the eight sectors and the satisfaction of the criteria are shown in Table 2.

[0045] Table 2 Angle ranges of eight sectors and compliance with the criteria

[0046] In Table 2, 1 indicates that the condition is met, 0 indicates that the condition is not met, and * indicates that the criterion is not concerned during the judgment.

[0047] S3. Calculate the action time of the adjacent voltage vectors and the zero voltage vector in the sector where the reference voltage vector is located according to the volt-second equivalence principle, and determine whether the reference output voltage value is in the linear modulation area according to the action time of the adjacent voltage vector in the sector where the reference voltage vector is located.

[0048] According to the volt-second equivalent principle, the action time of the adjacent voltage vector and the zero voltage vector in the sector where the reference voltage vector is located is calculated using the following formula:

[0049] in, is the reference output voltage vector, , are two adjacent basic voltage vectors in the sector where the reference voltage vector is located, is the basic voltage vector The action time, is the basic voltage vector The action time, Zero basic voltage vector The action time, is the sampling time, is the sector number where the reference output voltage vector is located ( When, define ).

[0050] In this step, intermediate variables X, Y, Z, and W are also introduced to simplify the action time of the adjacent voltage vectors and the zero voltage vector in the sector where the reference voltage vector is located. The calculation formulas of the intermediate variables X, Y, Z, and W are:

[0051] in, , called the inverter modulation ratio, when the value is between 0 and 1, the inverter is in the linear working area. After introducing the above intermediate variables, the expression of the action time becomes simple. Taking sector I as an example, , The calculation results are -Z and X. When the reference voltage falls in sector II, the results are Y and Z. Table 3 shows the action time of all sectors. Figure 5 is the action time of each sector ( , , ), in this embodiment, the basic sampling period is 50 ms, the modulation wave period is 0.02s, and the inverter modulation ratio is set to 1. In all sectors, the action time of the zero voltage vector is calculated by the following formula:

[0052] The action time summary of the eight sectors is shown in Table 3.

[0053] Table 3 Summary of action time of eight sectors

[0054] The specific judgment process of judging whether the reference output voltage value is in the linear modulation area is as follows: when the sum of the action times of adjacent voltage vectors is greater than the sampling time, the reference output voltage value is not in the linear modulation area; when the sum of the action times of adjacent voltage vectors is less than or equal to the sampling time, the reference output voltage value is in the linear modulation area.

[0055] S4. According to whether the reference output voltage value is in the linear modulation region, it is determined whether the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located should be shortened in equal proportion.

[0056] The specific judgment process of whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located is as follows: if the reference output voltage value is not within the linear modulation area, the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located is proportionally shortened; if the reference output voltage value is within the linear modulation area, the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located is not proportionally shortened.

[0057] The calculation formula for proportional shortening is:

[0058] in, and The basic voltage vector is shortened proportionally , The action time, and is the basic voltage vector before proportional shortening , The action time, is the sampling time, and They are two adjacent basic voltage vectors in the sector where the reference voltage vector is located.

[0059] S5. Determine the selected switch state, switch order and switch state duration based on the sector where the reference output voltage vector is located, determine whether to proportionally shorten the action time of adjacent voltage vectors and the action time of the zero voltage vector in the sector where the reference voltage vector is located, and the switching sequence and switch state duration.

[0060] S6. Generate a drive signal for controlling the switching of the switch state according to the selected switch state, the switch switching sequence and the switch state duration, so as to control the on and off of each switch of the two-phase four-bridge-arm inverter.

[0061] The basic voltage vector to be acted on is determined according to the sector in which it is located. The basic voltage vector and the zero vector will act in turn to generate the target reference voltage vector. Since multiple basic voltage vectors can be realized through multiple switching states, 9 specific switching states among the 16 switching states are selected as the required 8 non-zero basic voltage vectors and 1 zero basic voltage vector, which are: , , , , , , , and .

[0062] The action order of the basic voltage vector is determined according to the sector in which it is located, and a five-segment symmetrical modulation strategy is adopted. and Each is equally divided into two sections for symmetrical action, and a zero voltage vector is applied in the middle. In the symmetrical action mode, in the odd-numbered sectors, the action order of the basic voltage vectors is: ; In even-numbered sectors, the order of action of the basic voltage vectors is . Figure 6 is the basic voltage vector when the reference voltage vector falls in sector I and , and the zero voltage vector Schematic diagram of the action sequence. According to the selected switch state and the symmetrical five-segment switch modulation strategy, a switch signal of the switch device is generated to control the opening and closing of the switch. The drive signals of the upper and lower switches of the same bridge arm are opposite. Specifically, the action sequence of the basic voltage vector in each sector is as follows: In sector I, the sequence is ; In sector II, the order is ; In sector III, the order is ; In sector IV, the order is ; In sector V, the order is ; In sector VI, the order is ; In sector VII, the order is ; In sector VIII, the order is . Figure 7 It is the switching state of the upper switches of the four bridge arms when the reference voltage is located in different sectors.

[0063] In order to better illustrate the space vector pulse width modulation method of the two-phase four-bridge-arm inverter proposed in the present invention, this embodiment connects the load after the space vector pulse width modulation of the two-phase four-bridge-arm inverter is completed. In this embodiment, the driven load is a two-phase symmetrical load, and the two-phase modulation voltage (i.e., the two-phase reference voltage) has equal amplitude and a phase difference of The sine quantity can be expressed as follows:

[0064] in, is the reference output phase voltage between the midpoints of the A bridge arm and the B bridge arm, is the reference output phase voltage between the midpoints of the C bridge arm and the D bridge arm, is the amplitude of the reference output voltage, is the current angular frequency.

[0065] Figure 8 It is the ideal output voltage waveform of two phases of two-phase four-bridge-arm inverter. Fig. 9 for Figure 8 In this embodiment, the sampling frequency used is 20 kHz and the current angular frequency is 100 rad / s (corresponding to a current frequency of 50 Hz).

[0066] Embodiment 4: The main circuit topology of the two-phase four-bridge-arm inverter in this embodiment is as follows: Fig.10 As shown, the main circuit of the two-phase four-bridge-arm inverter in this embodiment includes a parallel connection with a voltage of The four bridge arms at both ends of the DC voltage source: bridge arm A (also called bridge arm A), bridge arm B (bridge arm B), bridge arm C (bridge arm C) and bridge arm D (bridge arm D), each bridge arm includes two switching devices, and the four bridge arms include a total of 8 switching devices (also called switch tubes, specifically including switch tube S1, switch tube S2, switch tube S3, switch tube S4, switch tube S5, switch tube S6, switch tube S7, switch tube S8 in this embodiment). The switch devices in this embodiment can be composed of IGBT and reverse parallel diodes, or MOSFET. Among them, the midpoint voltage difference between bridge arm A and bridge arm B constitutes one phase of the two-phase output voltage: , the midpoint voltage difference between the C bridge arm and the D bridge arm constitutes the other phase of the two-phase output voltage: , the two-phase output voltages are respectively connected to the two-phase windings of the asymmetric two-phase induction motor.

[0067] Asymmetric two-phase induction motors are widely used in industrial or household applications, especially in low-power applications. Asymmetric two-phase induction motors have two windings: the main winding and the auxiliary winding. The number of turns of the two windings is different. Usually, the number of turns of the auxiliary winding is higher than that of the main winding. To drive such a motor, the auxiliary winding needs a higher voltage supply than the main winding, and the phase difference between the two phase voltages is always To achieve good performance. Usually use represents the winding turns ratio, which is obtained by dividing the turns of the auxiliary winding by the turns of the main winding. In this embodiment, in order to drive an asymmetric two-phase induction motor, the two-phase reference output voltage should satisfy:

[0068] in, is the reference output phase voltage between the midpoints of the A bridge arm and the B bridge arm, which is output to the auxiliary winding of the motor. It is the reference output phase voltage between the midpoint of the C bridge arm and the D bridge arm, and this phase voltage is output to the main winding of the motor. is the amplitude of the reference output voltage, is the current angular frequency.

[0069] Fig.11 The ideal output voltage waveform of two-phase four-leg inverter is shown in Figure 1. Fig.12 for Fig.11 The waveform of the enlarged area. In this embodiment, the sampling frequency used is 5 kHz, and the current angular frequency is 100 rad / s (corresponding to a current frequency of 50 Hz), .

[0070] Embodiment 5: See also Fig.13 As shown, the present invention also provides an electronic device 100 for a space vector pulse width modulation method of a two-phase four-leg inverter; the electronic device 100 includes a memory 101, at least one processor 102, a computer program 103 stored in the memory 101 and executable on the at least one processor 102, and at least one communication bus 104.

[0071] The memory 101 can be used to store the computer program 103, and the processor 102 implements the steps of the space vector pulse width modulation method of the two-phase four-bridge arm inverter described in Example 1 by running or executing the computer program stored in the memory 101 and calling the data stored in the memory 101. The memory 101 may mainly include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function (such as a sound playback function, an image playback function, etc.), etc.; the data storage area may store data (such as audio data) created according to the use of the electronic device 100, etc. In addition, the memory 101 may include a non-volatile memory, such as a hard disk, a memory, a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) card, a flash card (Flash Card), at least one disk storage device, a flash memory device, or other non-volatile solid-state storage devices.

[0072] The at least one processor 102 may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The processor 102 may be a microprocessor or any conventional processor, etc. The processor 102 is the control center of the electronic device 100, and uses various interfaces and lines to connect various parts of the entire electronic device 100.

[0073] The memory 101 in the electronic device 100 stores a plurality of instructions to implement a space vector pulse width modulation method for a two-phase four-leg inverter, and the processor 102 can execute the plurality of instructions to implement: Based on the topological structure of the two-phase four-leg inverter, the basic output voltage vector of the two-phase four-leg inverter is defined, and the spatial voltage vector diagram of the two-phase four-leg inverter is drawn; The drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter is divided into several sectors, and the sector where the reference voltage vector is located is determined according to the reference voltage vector angle or the reference output voltage value; The action time of the adjacent voltage vectors and the zero voltage vector of the sector where the reference voltage vector is located is calculated according to the volt-second equivalent principle, and whether the reference output voltage value is in the linear modulation area is determined according to the action time of the adjacent voltage vectors of the sector where the reference voltage vector is located; According to whether the reference output voltage value is in the linear modulation area, it is determined whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located; Determine the selected switch state, switch order and switch state duration of the switch according to the sector where the reference output voltage vector is located, determine whether to proportionally shorten the action time of the adjacent voltage vectors and the action time of the zero voltage vector in the sector where the reference voltage vector is located, and According to the selected switch tube state, switch tube switching sequence and switch tube state duration, a drive signal for controlling the switch tube state switching is generated to control the on and off of each switch tube of the two-phase four-bridge arm inverter.

[0074] Embodiment 6: If the module / unit integrated in the electronic device 100 is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer program can implement the steps of the above-mentioned method embodiments when executed by the processor. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device that can carry the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory and read-only memory (ROM, Read-Only Memory).

[0075] It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0076] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0077] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0078] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A space vector pulse width modulation method for a two-phase four-bridge-arm inverter, characterized in that: The following steps are involved: Based on the topological structure of the two-phase four-leg inverter, the basic output voltage vector of the two-phase four-leg inverter is defined, and the spatial voltage vector diagram of the two-phase four-leg inverter is drawn; The drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter is divided into several sectors, and the sector where the reference voltage vector is located is determined according to the reference voltage vector angle or the reference output voltage value; The action time of the adjacent voltage vectors and the zero voltage vector of the sector where the reference voltage vector is located is calculated according to the volt-second equivalent principle, and whether the reference output voltage value is in the linear modulation area is determined according to the action time of the adjacent voltage vectors of the sector where the reference voltage vector is located; According to whether the reference output voltage value is in the linear modulation area, it is determined whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located; Determine the selected switch state, switch order and switch state duration of the switch according to the sector where the reference output voltage vector is located, determine whether to proportionally shorten the action time of the adjacent voltage vectors and the action time of the zero voltage vector in the sector where the reference voltage vector is located, and According to the selected switch tube state, switch tube switching sequence and switch tube state duration, a drive signal for controlling the switch tube state switching is generated to control the on and off of each switch tube of the two-phase four-bridge arm inverter.

2. According to the space vector pulse width modulation method of the two-phase four-bridge-arm inverter according to claim 1, the basic output voltage vector includes 8 non-zero voltage vectors and 1 zero voltage vector.

3. The space vector pulse width modulation method of the two-phase four-bridge-arm inverter according to claim 1, characterized in that: In the step of dividing the drawn spatial voltage vector diagram of the two-phase four-bridge-arm inverter into a plurality of sectors, and judging the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value, the specific judgment process is: if the angle information of the reference voltage vector is known and the driven load is a two-phase symmetrical load, the reference voltage vector angle is directly used for judgment; otherwise, the reference output voltage value is used for judgment.

4. The space vector pulse width modulation method of a two-phase four-arm inverter according to claim 1, wherein the action time of the adjacent voltage vectors and the zero voltage vector in the sector where the reference voltage vector is located is calculated according to the volt-second equivalent principle, and according to the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located, in the step of judging whether the reference output voltage value is in the linear modulation area, the specific process of judging whether the reference output voltage value is in the linear modulation area is: when the sum of the action times of the adjacent voltage vectors is greater than the sampling time, the reference output voltage value is not in the linear modulation area; when the sum of the action times of the adjacent voltage vectors is less than or equal to the sampling time, the reference output voltage value is in the linear modulation area.

5. The space vector pulse width modulation method of the two-phase four-bridge-arm inverter according to claim 1, characterized in that: In the step of judging whether to proportionally shorten the action time of adjacent voltage vectors in the sector where the reference voltage vector is located according to whether the reference output voltage value is in the linear modulation region, the specific judging process is as follows: if the reference output voltage value is not in the linear modulation region, the action time of adjacent voltage vectors in the sector where the reference voltage vector is located is proportionally shortened; if the reference output voltage value is in the linear modulation region, the action time of adjacent voltage vectors in the sector where the reference voltage vector is located is not proportionally shortened.

6. The space vector pulse width modulation method of the two-phase four-bridge-arm inverter according to claim 5, characterized in that: The calculation formula of the proportional shortening is: in, and The basic voltage vector is shortened proportionally , The action time, and is the basic voltage vector before proportional shortening , The action time, is the sampling time, and They are two adjacent basic voltage vectors in the sector where the reference voltage vector is located.

7. The space vector pulse width modulation method of the two-phase four-bridge-arm inverter according to claim 1, characterized in that: The switch tube is an IGBT or a MOSFET.

8. A space vector pulse width modulation system for a two-phase four-bridge-arm inverter, characterized in that: It includes a space voltage vector partitioning module, a sector judgment module, an action time calculation module, an equal proportion shortening judgment module, a switch sequence determination module and a switch tube on-off control module; The space voltage vector partitioning module is used to define the basic output voltage vector of the two-phase four-bridge-arm inverter based on the topological structure of the two-phase four-bridge-arm inverter, and draw the space voltage vector diagram of the two-phase four-bridge-arm inverter; The sector judgment module is used to divide the drawn space voltage vector diagram of the two-phase four-bridge-arm inverter into a plurality of sectors, and judge the sector where the reference voltage vector is located according to the reference voltage vector angle or the reference output voltage value; The action time calculation module is used to calculate the action time of the adjacent voltage vectors and the zero voltage vector of the sector where the reference voltage vector is located according to the volt-second equivalent principle, and judge whether the reference output voltage value is in the linear modulation area according to the action time of the adjacent voltage vectors of the sector where the reference voltage vector is located; The proportional shortening judgment module is used to judge whether to proportionally shorten the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located according to whether the reference output voltage value is in the linear modulation area; The switch sequence determination module is used to determine the selected switch state, switch order and switch state duration of the switch according to the sector where the reference output voltage vector is located, the action time of the adjacent voltage vectors in the sector where the reference voltage vector is located and the action time of the zero voltage vector after determining whether to shorten the reference voltage vector in equal proportion; The switch tube on-off control module is used to generate a drive signal for controlling the switching of the switch tube state according to the selected switch tube state, the switch tube switching sequence and the switch tube state duration, so as to control the on-off of each switch tube of the two-phase four-bridge arm inverter.

9. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, wherein: When the processor executes the computer program, the steps of the space vector pulse width modulation method of the two-phase four-leg inverter according to any one of claims 1 to 7 are implemented.

10. A storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the space vector pulse width modulation method of the two-phase four-leg inverter according to any one of claims 1 to 7 are implemented.

Images