Modulation method and circuit of single-stage multi-port motor driver for realizing port power control

Abstract

The invention discloses a modulation method and circuit of a single-stage multi-port motor driver for realizing port power control, relates to the technical field of motor control, and solves the technical problems of complex process, large power ripple and slow dynamic response when an extra PI controller indirectly adjusts the proportion of a redundant vector or a zero-sequence component to adjust the port power. The method comprises the following steps: converting original three-phase reference voltage into three-phase reference voltage va, vb and vc under a natural coordinate system; injecting a first zero-sequence voltage vo1 into the three-phase reference voltage to generate first direct-current modulation signals vaz1, vbz1 and vcz1; injecting a second zero sequence voltage vo2 into the first direct current type modulation signal to generate second direct current type modulation signals vaz2, vbz2 and vcz2; and comparing the second direct-current modulation signal with the asymmetric triangular carrier, generating a switching signal for driving a single-stage multi-port motor driver, and controlling a plurality of bridge arms to perform switching operation. According to the invention, the port power is accurately and rapidly controlled, the control process is simple, and the power ripple is small.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a modulation method and circuit of a single-stage multi-port motor driver for realizing port power control. Background Art

[0002] Electric vehicles are a viable solution to the energy crisis and environmental pollution problems. However, electric vehicles using a single energy source face problems such as poor endurance, long charging time and short battery life. Hybrid energy source electric vehicle drive systems use a multi-energy source system to power the system, allowing multiple energy sources to work together to complement each other, becoming an effective solution.

[0003] The topological structure of the hybrid energy source electric vehicle drive system affects the energy transmission performance of the system. At present, the topology of the hybrid energy source electric vehicle drive system mostly adopts a two-stage structure, that is, the energy source needs to be connected to the motor through a DC-DC converter and a DC-AC inverter. This structure causes the energy to be converted in two stages, which increases the transmission loss, increases the weight and volume, and reduces the power density of the system. Compared with the traditional topological structure, the single-stage multi-port motor driver removes the DC-DC converter of the previous stage and realizes the single-stage conversion of energy from the energy source to the motor. It has the advantages of small size, low cost and high power density.

[0004] The modulation method design of single-stage multi-port motor drive needs to face two major challenges: one is to output the reference voltage under unbalanced voltage, and the other is to realize the decoupling control of power distribution and motor. Most existing methods use redundant vectors or zero-sequence components as control degrees of freedom to realize the decoupling control of power distribution and motor. However, these methods indirectly adjust the proportion of redundant vectors or zero-sequence components to adjust the port power through additional PI controllers (proportional integral controllers). The process is complicated, the power ripple is large, and the dynamic response is slow. There is an urgent need for a method to achieve high-quality power distribution control by simply and directly adjusting the control degrees of freedom. Summary of the invention

[0005] The purpose of the present invention is to provide a modulation method and circuit for a single-stage multi-port motor driver that realizes port power control, so as to solve the technical problems in the prior art that the port power is adjusted by indirectly adjusting the proportion of redundant vectors or zero-sequence components through an additional PI controller, which results in a complex process, large power ripple, and slow dynamic response. The preferred technical solutions among the many technical solutions provided by the present invention can produce many technical effects as described below.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The present invention provides a modulation method for a single-stage multi-port motor driver for realizing port power control, comprising the following steps: S100: transforming the original three-phase reference voltage of the three-phase AC motor in a rotating coordinate system into a three-phase reference voltage v in a natural coordinate system a 、v b 、v c ; S200: Based on the calculation rule of the first zero-sequence voltage, generate the first zero-sequence voltage v o1 , and then inject the first zero-sequence voltage v into the three-phase reference voltage o1 , generating a first DC modulation signal v az1 、v bz1 、v cz1 S300: Divide the first DC modulation signal of one cycle into six regions, construct a port power model in each region, and solve the second zero-sequence voltage v based on the port power model o2 , and then inject the second zero-sequence voltage v into the first DC modulation signal o2 , generating a second DC modulation signal v az2 、v bz2 、v cz2 ; S400: Compare the second DC modulation signal with the asymmetric triangular carrier to generate a switching signal for driving a single-stage multi-port motor driver; S500: Transmit the switching signal to the single-stage multi-port motor driver, control multiple bridge arms to perform switching operations, and output three-phase current to the three-phase AC motor based on the switching operation of the single-stage multi-port motor driver.

[0008] Preferably, the step S100 specifically includes:

[0009] S110: Obtain the position angle θ of the three-phase AC motor through the position encoding module, and input the position angle θ into the speed calculation module to obtain the actual speed ω of the three-phase AC motor r ;

[0010] S120: Assume that the given speed of the three-phase AC motor is Set the speed With the actual speed ω r The difference obtained by subtraction is controlled by the speed PI control module to obtain the first given current of the q axis in the rotating coordinate system.

[0011] S130: Obtain the three-phase current i output by the single-stage multi-port motor driver through the current sampling module a 、i b 、i c , the three-phase current is converted into the first actual current i of the q axis through the T1 coordinate transformation unit qand the first actual current i of the d-axis d ;

[0012] Among them, the transformation formula of the T1 coordinate transformation unit is:

[0013]

[0014] S140: Set the first given current of the q axis The first actual current i of the q axis q The difference is then controlled by the q-axis PI control module to generate the q-axis first reference voltage v in the rotating coordinate system. q ; Let the second given current of d axis be The second given current of the d-axis The second actual current i of the d-axis d The difference is then controlled by the d-axis PI control module to generate the d-axis second reference voltage v in the rotating coordinate system. d ;

[0015] S150: Set the q-axis first reference voltage v q and the d-axis second reference voltage v d After the T2 coordinate transformation unit transforms, the three-phase reference voltage v in the natural coordinate system is obtained. a 、v b 、v c ;

[0016] Among them, the transformation formula of the T2 coordinate transformation unit is:

[0017]

[0018] Preferably, the step S200 specifically includes:

[0019] S210: Using the three-phase reference voltage and based on the calculation rule of the first zero-sequence voltage, the first zero-sequence voltage v is calculated by the first zero-sequence voltage injection module. o1 , the first zero-sequence voltage v o1 The calculation formula is: o1 =-min{v a ,v b ,v c};

[0020] S220: The calculated first zero-sequence voltage v o1 Added to the three-phase reference voltage, a first DC modulation signal v is generated az1 、v bz1 、v cz1 , the calculation formula of the first DC modulation signal is:

[0021]

[0022] Preferably, the step S300 specifically includes:

[0023] S310: Divide a period of the first DC modulation signal into the following six regions according to the phase θ:

[0024]

[0025] S320: In each region, according to the first DC modulation signal and the second DC power supply voltage v L The quantitative relationship of the first DC power supply port power P is established in four cases H and the second zero sequence voltage v o2 The mathematical model between

[0026] S330: Assume that the given value of the power of the first DC power port is Enter the power setting value of the first DC power port The first DC power supply voltage value v H , the second DC power supply voltage value v L , three-phase reference voltage v a 、v b 、v c , three-phase current i a 、i b 、i c To the second zero-sequence voltage injection module, the second zero-sequence voltage v is solved through the port power model o2 ;

[0027] S340: The second zero-sequence voltage v o2 and the second DC modulation signal to generate a second DC modulation signal v az2 、v bz2 、v cz2 , the calculation formula of the second DC modulation signal is:

[0028]

[0029] Preferably, in the step S330, the second zero-sequence voltage variation range is v o2 ∈[max(0,v L -v max ),min(v L ,v H -v max )], where v max It is the maximum value of the three-phase reference voltage at a certain moment.

[0030] Preferably, the step S400 specifically includes:

[0031] S410: dividing the second DC modulation signal into an up-modulation signal v xH and the down-modulation signal v xL , where x represents a, b, c, and the up-modulation signal v xH , down-modulation signal v xL Respectively meet:

[0032]

[0033] S420: The up-modulation signal v xH Compare the amplitude with the upper carrier in the unbalanced carrier to obtain the switching signal G x1 , where the amplitude of the upper carrier is v H -v L ; The down-modulation signal v xL Compare the amplitude with the lower carrier in the unbalanced carrier to obtain the switching signal G x2 , where the amplitude of the lower carrier is v L .

[0034] Preferably, in the step S500, the relationship between the switch signal and the controlled single-stage multi-port motor driver is: the switch signal G x1 Control switch tube S x1 , switch signal G x1 The complementary signal G x3 Control switch tube S x3 , switch signal G x2 Control switch tube S x2 , switch signal G x2 The complementary signal G x4 Control switch tube S x4 ; where x represents a, b, c, S x1 , S x2 , S x3 , S x4 The first switch tube, the second switch tube, the third switch tube and the fourth switch tube respectively correspond to each bridge arm.

[0035] A modulation circuit of a single-stage multi-port motor driver for realizing port power control, used to realize a modulation method of a single-stage multi-port motor driver for realizing port power control as described in any of the above items, comprising: a single-stage multi-port motor driver, a three-phase AC motor, a first DC power supply, a second DC power supply, a voltage stabilizing capacitor C1, a voltage stabilizing capacitor C2, a current sampling module, a motor control module and a power control module.

[0036] Preferably, the motor control module includes a position encoding module, a speed calculation module, a T1 coordinate transformation unit, a T2 coordinate transformation unit, a q-axis PI control module, a d-axis PI control module, a speed PI control module, a first difference operation unit, a second difference operation unit, and a third difference operation unit; the power control module includes a first zero-sequence voltage injection module, a second zero-sequence voltage injection module and a switching signal generating module connected in sequence.

[0037] Preferably, the single-stage multi-port motor driver is improved based on a three-level midpoint clamped inverter, having two DC input ports and one AC output port, including a first bridge arm, a second bridge arm and a third bridge arm, each bridge arm including four switching tubes and two diodes; the first DC power supply is connected in parallel with the first bridge arm, the second bridge arm and the third bridge arm; the second DC power supply and the voltage stabilizing capacitor C2 are connected in parallel between the midpoint of the first bridge arm, the second bridge arm, the third bridge arm and the negative electrode of the first DC power supply; the voltage stabilizing capacitor C1 is connected in parallel between the midpoint of the first bridge arm, the second bridge arm, the third bridge arm and the positive electrode of the first DC power supply; the output ends of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected to the current sampling module, and then connected to the first stator winding, the second stator winding and the third stator winding of the three-phase AC motor.

[0038] Implementing one of the above technical solutions of the present invention has the following advantages or beneficial effects:

[0039] In this application, a single-stage multi-port motor driver is used to replace the existing two-stage topology structure, which can improve the power density and energy transmission efficiency of the system and reduce the cost. At the same time, the second zero-sequence voltage is obtained based on the power model solution and is directly used to adjust the port power, which can achieve accurate and rapid control of the port power, and the control process is simple and the power ripple is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. It is obvious that the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work. In the drawings:

[0041] Figure 1 is a flow chart of a modulation method of a single-stage multi-port motor driver for realizing port power control according to a first embodiment of the present invention;

[0042] Figure 2 Schematic diagram of a modulation method of a single-stage multi-port motor driver for realizing port power control according to a first embodiment of the present invention;

[0043] Figure 3yes Figure 1 Flow chart of step S100;

[0044] Figure 4 yes Figure 1 Flow chart of step S200;

[0045] Figure 5 yes Figure 1 Flow chart of step S300;

[0046] Figure 6 is a schematic diagram of a first DC modulation signal and an asymmetric triangular carrier in Embodiment 1 of the present invention;

[0047] Figure 7 is the second zero-sequence voltage v injected in the embodiment of the present invention o2 Schematic diagram of four situations where the second DC modulation signal exists in region S1;

[0048] Figure 8 yes Figure 1 Flow chart of step S400;

[0049] Fig. 9 The working conditions of the single-stage multi-port motor drive system under three port voltages in the embodiment of the present invention;

[0050] Fig.10 It is the working condition of the single-stage multi-port motor drive system in the embodiment of the present invention when the port power given value changes;

[0051] Fig.11 is a comparison diagram of port power control performance of a single-stage multi-port motor drive system according to an embodiment of the present invention implemented according to a traditional method and according to the present invention;

[0052] Fig.12 is a circuit diagram of a modulation circuit of a single-stage multi-port motor driver for realizing port power control according to a second embodiment of the present invention;

[0053] In the figure: 1. Single-stage multi-port motor driver; 2. Three-phase AC motor; 3. First DC power supply; 4. Second DC power supply; 5. Voltage stabilizing capacitor C1; 6. Voltage stabilizing capacitor C2; 7. Current sampling module; 8. Position encoding module; 9. Speed ​​calculation module; 10. T1 coordinate transformation unit; 11. T2 coordinate transformation unit; 12. Q-axis PI control module; 13. D-axis PI control module; 14. Speed ​​PI control module; 15. First difference operation unit; 16. Second difference operation unit; 17. Third difference operation unit; 18. First zero-sequence voltage injection module; 19. Second zero-sequence voltage injection module; 20. Switch signal generation module. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the present invention clearer, the various exemplary embodiments to be described below will refer to the corresponding drawings, which constitute a part of the exemplary embodiments, wherein various exemplary embodiments that may be used to implement the present invention are described. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The implementation methods described in the following exemplary embodiments do not represent all implementation methods consistent with the present disclosure. It should be understood that they are only examples of processes, methods, devices, etc. that are consistent with some aspects of the present disclosure as detailed in the attached claims, and other embodiments may also be used, or the embodiments listed herein may be modified in structure and function without departing from the scope and essence of the present invention.

[0055] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", etc. indicate the orientation or positional relationship based on the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the elements referred to must have a specific orientation, be constructed and operated in a specific orientation. The terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. The term "multiple" means two or more. The terms "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, an integral connection, a mechanical connection, an electrical connection, a communication connection, a direct connection, an indirect connection through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more related listed items. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to the specific circumstances.

[0056] In order to illustrate the technical solution of the present invention, a specific embodiment is used below for description, and only the parts related to the embodiment of the present invention are shown.

[0057] Embodiment 1:

[0058] like Figure 1 , Figure 2 As shown, the present invention provides a modulation method for a single-stage multi-port motor driver for realizing port power control, comprising the following steps: S100: transforming the original three-phase reference voltage of the three-phase AC motor in the rotating coordinate system into the three-phase reference voltage v in the natural coordinate system a 、v b 、v c The three-phase AC motor is a symmetrical three-phase AC motor, that is, a three-phase AC motor with the same frequency, equal amplitude, and a phase difference of 120°. S200: Based on the calculation rule of the first zero-sequence voltage, generate the first zero-sequence voltage v o1, and then inject the first zero-sequence voltage v into the three-phase reference voltage o1 , generating a first DC modulation signal v az1 、v bz1 、v cz1 The first zero-sequence voltage injection unifies the AC and DC forms of the modulation signal and the port power, which can simplify the port power modeling analysis. The modulation process is simple and easy, and the amount of calculation is small. S300: Divide the first DC modulation signal of one cycle into six regions, construct a port power model in each region, and solve the second zero-sequence voltage v based on the port power model. o2 , and then inject the second zero-sequence voltage v into the first DC modulation signal o2 , generating a second DC modulation signal v az2 、v bz2 、v cz2 ; S400: Compare the second DC type modulation signal with the asymmetric triangular carrier to generate a switch signal for driving a single-stage multi-port motor driver. The upper and lower carrier amplitudes of the asymmetric triangular carrier change with the port voltage, which solves the problem of time-varying port voltage, and uses zero-sequence voltage as the power control freedom that does not affect the output voltage of the inverter, so that the decoupling control of the motor and power distribution can be realized, and flexible port power distribution is realized under unbalanced port voltage. S500: Transmit the switch signal to the single-stage multi-port motor driver, control multiple bridge arms to perform switching operations, and output three-phase current based on the switching operation of the three-phase AC motor. In this embodiment, a single-stage multi-port motor driver is used to replace the existing two-stage topology structure, which can improve the power density and energy transmission efficiency of the system and reduce the cost. At the same time, the second zero-sequence voltage is obtained based on the power model solution and is directly used to adjust the port power, which can realize accurate and fast control of the port power, and the control process is simple and the power ripple is small.

[0059] As an optional implementation, Figure 3 As shown, step S100 specifically includes: S110: obtaining the position angle θ of the three-phase AC motor through the position encoding module, and inputting the position angle θ into the speed calculation module to obtain the actual speed ω of the three-phase AC motor r ; S120: Assume the given speed of the three-phase AC motor is Set the speed With the actual speed ω r The difference obtained by subtraction is controlled by the speed PI control module to obtain the first given current of the q axis in the rotating coordinate system. S130: Obtain the three-phase current i output by the single-stage multi-port motor driver through the current sampling module a 、i b 、i c, the three-phase current is converted into the first actual current i of the q axis through the T1 coordinate transformation unit q and the first actual current i of the d-axis d ; Among them, the transformation formula of the T1 coordinate transformation unit is:

[0060]

[0061] S140: Set the first given current of the q axis The first actual current i of the q axis q The difference is then controlled by the q-axis PI control module to generate the q-axis first reference voltage v in the rotating coordinate system. q ; Let the second given current of d axis be The second given current of the d-axis The second actual current i of the d-axis d The difference is then controlled by the d-axis PI control module to generate the d-axis second reference voltage v in the rotating coordinate system. d ; S150: Set the q-axis first reference voltage v q and the d-axis second reference voltage v d After the T2 coordinate transformation unit transforms, the three-phase reference voltage v in the natural coordinate system is obtained. a 、v b 、v c ; Among them, the transformation formula of the T2 coordinate transformation unit is:

[0062]

[0063] As an optional implementation, Figure 4 As shown, step S200 specifically includes: S210: using the three-phase reference voltage, based on the calculation rule of the first zero-sequence voltage, the first zero-sequence voltage v is calculated by the first zero-sequence voltage injection module o1 , the first zero sequence voltage v o1 The calculation formula is: o1 =-min{v a ,v b ,v c}; S220: The calculated first zero-sequence voltage v o1 Added to the three-phase reference voltage, a first DC modulation signal v is generated az1 、v bz1 、v cz1 , the calculation formula of the first DC modulation signal is:

[0064] As an optional implementation, Figure 5 As shown, step S300 specifically includes:

[0065] S310: Figure 6 As shown, a first DC modulation signal of one cycle is divided into the following six regions according to the phase θ:

[0066]

[0067] S320: In each region, according to the first DC modulation signal and the second DC power supply voltage v L The quantitative relationship, such as Figure 7 As shown, the port power P of the first DC power supply is established in four cases. H and the second zero sequence voltage v o2 The mathematical model between is specifically shown in Table 1. S330: Assume that the given value of the power of the first DC power port is Enter the power setting value of the first DC power supply port The first DC power supply voltage value v H , the second DC power supply voltage value v L , three-phase reference voltage v a 、v b 、v c , three-phase current i a 、i b 、i c To the second zero-sequence voltage injection module, the second zero-sequence voltage v is solved through the port power model o2 In step S330, the second zero-sequence voltage variation range is v o2 ∈[max(0,v L -v max ),min(v L ,v H -v max )], where v max is the maximum value of the three-phase reference voltage at a certain moment. To ensure that the power degree of freedom exists and the single-stage multi-port motor driver works in the linear modulation area. S340: The second zero-sequence voltage v o2 Added to the first DC modulation signal, a second DC modulation signal v is generated az2 、v bz2 、v cz2 , the calculation formula of the second DC modulation signal is:

[0068] Table 1 Port power model for four cases in each area

[0069]

[0070]

[0071] As an optional implementation, Figure 8 As shown, step S400 specifically includes: S410: dividing the second DC modulation signal into an upper modulation signal v xH and the down-modulation signal v xL , where x represents a, b, c, and the up-modulation signal v xH , down-modulation signal v xL Respectively meet:

[0072]

[0073] S420: Up-modulation signal v xH Compare the amplitude with the upper carrier in the unbalanced carrier to obtain the switching signal G x1 , where the amplitude of the upper carrier is v H -v L ; The down-modulation signal v xL Compare the amplitude with the lower carrier in the unbalanced carrier to obtain the switching signal G x2 , where the amplitude of the lower carrier is v L .

[0074] As an optional implementation, in step S500, the relationship between the switch signal and the controlled single-stage multi-port motor driver is: x1 Control switch tube S x1 , switch signal G x1 The complementary signal G x3 Control switch tube S x3 , switch signal G x2 Control switch tube S x2 , switch signal G x2 The complementary signal G x4 Control switch tube S x4 ; where x represents a, b, c, S x1 , S x2 , S x3 , S x4 The first switch tube, the second switch tube, the third switch tube and the fourth switch tube of each bridge arm correspond to each other. In this embodiment, the switch tube state of the single-stage multi-port inverter is as described in Table 2. Taking the first bridge arm as an example, 1 represents that the switch tube is turned on, and 0 represents that the switch tube is turned off.

[0075] Table 2 Switch state of the first bridge arm of the single-stage multi-port motor driver

[0076] <![CDATA[S a1 ]]> <![CDATA[S a2 ]]> <![CDATA[S a3 ]]> <![CDATA[S a4 ]]> The first bridge arm output voltage state 1 1 0 0 <![CDATA[v H ]]> P 0 1 1 0 <![CDATA[v L ]]> O 0 0 1 1 0 N

[0077] This embodiment is described with reference to examples. Figure 9-11 As shown. Assume that the first DC power supply voltage is v H =300V, the second DC power supply voltage is vL =125V~175V, the output power of the first DC power supply is given as The given speed of the three-phase AC motor is Rated torque is T N =8N·m, Fig. 9 The steady-state performance of the motor at different terminal voltages is shown, where Fig. 9 (a) v L =125V, Fig. 9 (b) v L =150V, Fig. 9 (c) v L =175V. By observing the motor speed ω r , d / q axis current i d 、i q , phase voltage v an and a phase current i a It can be seen that under the power distribution scheme proposed in this embodiment, the motor can stably operate under unbalanced port voltage conditions, and the operating state is not affected by the change of port voltage. Fig.10 As shown, the motor operates under the rated speed and rated torque conditions, by changing the given value of the output power of the first DC power supply, By jumping from 800W to 1400W and then to 800W, the operating status of the single-stage multi-port motor driver and the output power of the first DC power supply are observed. It can be seen that the port power of the first DC power supply can accurately and quickly track the change of the given value, and the phase current remains stable and sinusoidal, indicating that the scheme proposed in the present invention successfully realizes flexible port power allocation. Fig.11 As shown, the conventional solution and the solution proposed by the present invention are Fig.11 The power steady-state control performance shown in (a) and Fig.11 From the power dynamic control performance results shown in (b), it can be seen that the solution proposed in this embodiment has smaller power control ripple and faster power response speed than the traditional solution, that is, it has a higher quality port power control effect.

[0078] The embodiment is only a specific example and does not represent only one implementation mode of the present invention.

[0079] Embodiment 2:

[0080] The second embodiment provides a modulation circuit of a single-stage multi-port motor driver for realizing port power control, which is used to realize a modulation method of a single-stage multi-port motor driver for realizing port power control in the first embodiment, such as Fig.12As shown, it includes: a single-stage multi-port motor driver 1, a three-phase AC motor 2, a first DC power supply 3, a second DC power supply 4, a voltage stabilizing capacitor C15, a voltage stabilizing capacitor C26, a current sampling module 7, a motor control module and a power control module.

[0081] As an optional implementation, Fig.12 As shown, the motor control module includes a position encoding module 8, a speed calculation module 9, a T1 coordinate transformation unit 10, a T2 coordinate transformation unit 11, a q-axis PI control module 12, a d-axis PI control module 13, a speed PI control module 14, a first difference operation unit 15, a second difference operation unit 16, and a third difference operation unit 17; the power control module includes a first zero-sequence voltage injection module 18, a second zero-sequence voltage injection module 19 and a switch signal generation module 20 connected in sequence.

[0082] As an optional implementation, Fig.12 As shown, the single-stage multi-port motor driver 1 is improved based on a three-level midpoint clamped inverter (NPC type). It has two DC input ports and one AC output port, including a first bridge arm, a second bridge arm and a third bridge arm, each bridge arm includes four switch tubes and two diodes; the first DC power supply 3 is connected in parallel with the first bridge arm, the second bridge arm and the third bridge arm; the second DC power supply 4 and the voltage stabilizing capacitor C26 are connected in parallel between the midpoints of the first bridge arm, the second bridge arm and the third bridge arm and the negative electrode of the first DC power supply 3; the voltage stabilizing capacitor C15 is connected in parallel between the midpoints of the first bridge arm, the second bridge arm and the third bridge arm and the positive electrode of the first DC power supply 3; the output ends of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected to the current sampling module 7, and then connected to the first stator winding, the second stator winding and the third stator winding of the three-phase AC motor 2. In this embodiment, the switch tubes are all IGBTs (i.e., insulated gate bipolar transistors).

[0083] The above are only preferred embodiments of the present invention. Those skilled in the art will appreciate that various changes or equivalent substitutions may be made to these features and embodiments without departing from the spirit and scope of the present invention. In addition, under the teachings of the present invention, these features and embodiments may be modified to adapt to specific circumstances and materials without departing from the spirit and scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application belong to the protection scope of the present invention.

Claims

1. A modulation method for a single-stage multi-port motor driver for realizing port power control, characterized in that: The following steps are involved: S100: transform the original three-phase reference voltage of the three-phase AC motor in the rotating coordinate system into the three-phase reference voltage v in the natural coordinate system a 、v b 、v c ; S200: Based on the calculation rule of the first zero-sequence voltage, generate the first zero-sequence voltage v o1 , and then inject the first zero-sequence voltage v into the three-phase reference voltage o1 , generating a first DC modulation signal v az1 、v bz1 、v cz1 ; S300: Divide the first DC modulation signal of one cycle into six regions, construct a port power model in each region, and solve the second zero-sequence voltage v based on the port power model o2 , and then inject the second zero-sequence voltage v into the first DC modulation signal o2 , generating a second DC modulation signal v az2 、v bz2 、v cz2 ; S400: Compare the second DC modulation signal with an asymmetric triangular carrier to generate a switch signal for driving a single-stage multi-port motor driver; S500: Transmitting the switching signal to the single-stage multi-port motor driver, controlling multiple bridge arms to perform switching operations, and outputting three-phase current to the three-phase AC motor based on the switching operations of the single-stage multi-port motor driver.

2. A modulation method for a single-stage multi-port motor driver for realizing port power control according to claim 1, characterized in that: The step S100 specifically includes: S110: Obtain the position angle θ of the three-phase AC motor through the position encoding module, and input the position angle θ into the speed calculation module to obtain the actual speed ω of the three-phase AC motor r ; S120: Assume that the given speed of the three-phase AC motor is Set the speed With the actual speed ω r The difference obtained by subtraction is controlled by the speed PI control module to obtain the first given current of the q axis in the rotating coordinate system. S130: Obtain the three-phase current i output by the single-stage multi-port motor driver through the current sampling module a 、i b 、i c , the three-phase current is converted into the first actual current i of the q axis through the T1 coordinate transformation unit q and the first actual current i of the d-axis d ; Among them, the transformation formula of the T1 coordinate transformation unit is: S140: Set the first given current of the q axis The first actual current i of the q axis q The difference is then controlled by the q-axis PI control module to generate the q-axis first reference voltage v in the rotating coordinate system. q ; Let the second given current of d axis be The second given current of the d-axis The second actual current i of the d-axis d The difference is then controlled by the d-axis PI control module to generate the d-axis second reference voltage v in the rotating coordinate system. d ; S150: Set the q-axis first reference voltage v q and the d-axis second reference voltage v d After the T2 coordinate transformation unit transforms, the three-phase reference voltage v in the natural coordinate system is obtained. a 、v b 、v c ; Among them, the transformation formula of the T2 coordinate transformation unit is:

3. The modulation method of a single-stage multi-port motor driver for realizing port power control according to claim 1, characterized in that: The step S200 specifically includes: S210: Using the three-phase reference voltage and based on the calculation rule of the first zero-sequence voltage, the first zero-sequence voltage v is calculated by the first zero-sequence voltage injection module. o1 , the first zero-sequence voltage v o1 The calculation formula is: o1 =-min{v a ,v b ,v c }; S220: The calculated first zero-sequence voltage v o1 Added to the three-phase reference voltage, a first DC modulation signal v is generated az1 、v bz1 、v cz1 , the calculation formula of the first DC modulation signal is:

4. The modulation method of a single-stage multi-port motor driver for realizing port power control according to claim 1, characterized in that: The step S300 specifically includes: S310: Divide a period of the first DC modulation signal into the following six regions according to the phase θ: S320: In each region, according to the first DC modulation signal and the second DC power supply voltage v L The quantitative relationship of the first DC power supply port power P is established in four cases H and the second zero sequence voltage v o2 The mathematical model between S330: Assume that the given value of the power of the first DC power port is Enter the power setting value of the first DC power port The first DC power supply voltage value v H , the second DC power supply voltage value v L , three-phase reference voltage v a 、v b 、v c , three-phase current i a 、i b 、i c To the second zero-sequence voltage injection module, the second zero-sequence voltage v is solved through the port power model o2 ; S340: The second zero-sequence voltage v o2 The first DC modulation signal is added to generate a second DC modulation signal v az2 、v bz2 、v cz2 , the calculation formula of the second DC modulation signal is:

5. The modulation method of a single-stage multi-port motor driver for realizing port power control according to claim 4, characterized in that: In the step S330, the second zero-sequence voltage variation range is v o2 ∈[max(0,v L -v max ),min(v L ,v H -v max )], where v max It is the maximum value of the three-phase reference voltage at a certain moment.

6. The modulation method of a single-stage multi-port motor driver for realizing port power control according to claim 1, characterized in that: The step S400 specifically includes: S410: dividing the second DC modulation signal into an up-modulation signal v xH and the down-modulation signal v xL , where x represents a, b, c, and the up-modulation signal v xH , down-modulation signal v xL Respectively meet: S420: The up-modulation signal v xH Compare the amplitude with the upper carrier in the unbalanced carrier to obtain the switching signal G x1 , where the amplitude of the upper carrier is v H -v L ; The down-modulation signal v xL Compare the amplitude with the lower carrier in the unbalanced carrier to obtain the switching signal G x2 , where the amplitude of the lower carrier is v L .

7. The modulation method of a single-stage multi-port motor driver for realizing port power control according to claim 1, characterized in that: In the step S500, the relationship between the switch signal and the controlled single-stage multi-port motor driver is: x1 Control switch tube S x1 , switch signal G x1 The complementary signal G x3 Control switch tube S x3 , switch signal G x2 Control switch tube S x2 , switch signal G x2 The complementary signal G x4 Control switch tube S x4 ; where x represents a, b, c, S x1 , S x2 , S x3 , S x4 The first switch tube, the second switch tube, the third switch tube and the fourth switch tube respectively correspond to each bridge arm.

8. A modulation circuit for a single-stage multi-port motor driver for realizing port power control, characterized in that: A modulation method for a single-stage multi-port motor driver for realizing port power control, used to implement any one of claims 1-7, comprising: a single-stage multi-port motor driver (1), a three-phase AC motor (2), a first DC power supply (3), a second DC power supply (4), a voltage-stabilizing capacitor C1 (5), a voltage-stabilizing capacitor C2 (6), a current sampling module (7), a motor control module and a power control module.

9. The modulation circuit of a single-stage multi-port motor driver for realizing port power control according to claim 8, characterized in that: The motor control module comprises a position encoding module (8), a speed calculation module (9), a T1 coordinate transformation unit (10), a T2 coordinate transformation unit (11), a q-axis PI control module (12), a d-axis PI control module (13), a speed PI control module (14), a first difference operation unit (15), a second difference operation unit (16), and a third difference operation unit (17); the power control module comprises a first zero-sequence voltage injection module (18), a second zero-sequence voltage injection module (19), and a switch signal generation module (20) which are connected in sequence.

10. The modulation circuit of a single-stage multi-port motor driver for realizing port power control according to claim 8, characterized in that: The single-stage multi-port motor driver (1) is improved based on a three-level midpoint clamped inverter, has two DC input ports and one AC output port, comprises a first bridge arm, a second bridge arm and a third bridge arm, each bridge arm comprises four switch tubes and two diodes; the first DC power supply (3) is connected in parallel with the first bridge arm, the second bridge arm and the third bridge arm; the second DC power supply (4) and the voltage stabilizing capacitor C2 (6) are connected in parallel between the midpoints of the first bridge arm, the second bridge arm and the third bridge arm and the negative electrode of the first DC power supply (3); the voltage stabilizing capacitor C1 (5) is connected in parallel between the midpoints of the first bridge arm, the second bridge arm and the third bridge arm and the positive electrode of the first DC power supply (3); The output ends of the first bridge arm, the second bridge arm and the third bridge arm are respectively connected to a current sampling module (7), and then connected to a first stator winding, a second stator winding and a third stator winding of the three-phase AC motor (2).

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