Zero sequence excitation boost type hybrid excitation synchronous motor, driving topology thereof, motor controller and design method thereof

Abstract

The application provides a zero-sequence excitation boost type hybrid excitation synchronous motor and a driving topology, a motor controller and a design method thereof. The driving topology comprises a DC bus capacitor, a three-phase inverter, a three-phase armature winding and an excitation winding. One end of the DC bus capacitor is connected with a common anode of the three-phase inverter, the other end is connected with a common cathode of the three-phase inverter and a grounding end and is used as a negative terminal for connecting a negative pole of a DC power supply of the motor. The output ends of each phase bridge arm of the three-phase inverter are respectively connected with one end of each phase armature winding. The other ends of the phase armature windings are connected with each other to form a neutral point. One end of the excitation winding is directly connected with the neutral point, and the other end is used as a positive terminal for connecting a positive pole of the DC power supply of the motor. The driving topology provided by the application has the ability to boost the input voltage of the power supply while exciting the excitation winding, thereby significantly improving the performance of the hybrid excitation synchronous motor.

Description

Technical Field

[0001] This application belongs to the field of motor control, specifically relating to a zero-sequence excitation hybrid excitation motor and its drive topology, and a motor controller and its design method. Background Technology

[0002] The power performance and energy efficiency of new energy vehicles largely depend on the selection of the drive motor. Currently, the mainstream automotive drive motors mainly include permanent magnet synchronous motors (PMSM) and asynchronous motors (ASM). Among them, the rotor of the permanent magnet synchronous motor uses high-performance rare-earth permanent magnet materials (such as neodymium iron boron NdFeB). When three-phase AC current is applied to the stator winding, the rotating magnetic field generated interacts with the rotor permanent magnet to produce electromagnetic torque. It is currently the most widely used automotive motor solution. However, the magnetic field generated by the permanent magnet is constant and cannot be adjusted. Under high temperature, overload, or short circuit conditions, the permanent magnet may undergo irreversible demagnetization, resulting in a permanent decline in motor performance. Asynchronous motors rely on the stator rotating magnetic field to cut the rotor bars to generate induced current, and then the induced current forms the rotor magnetic field. The structure is simple and reliable and does not require rare-earth materials. However, its rotor speed must be lower than the synchronous speed to maintain electromagnetic induction. Therefore, its low-speed torque output capability is weak, and a large excitation current is required, resulting in a low power factor and low power density.

[0003] Hybrid excitation synchronous motors have become a research hotspot in recent years. They innovatively combine permanent magnet excitation with electrical excitation, with the rotor simultaneously equipped with permanent magnets and excitation windings (or employing a hybrid magnetic circuit design). By adjusting the excitation current, the air gap magnetic field can be flexibly controlled: increasing the excitation current can enhance the magnetic field (magnetization), while decreasing or reversing the excitation current can weaken the magnetic field (magnetization). Compared to traditional permanent magnet synchronous motors, the speed range is expanded by 1.5-2 times while reducing the amount of permanent magnets by 30-50%. Furthermore, the motor can always operate in the high-efficiency range across the entire speed range through optimal excitation control. Therefore, it is considered an important development direction for the next generation of high-performance automotive motors.

[0004] In conventional hybrid excitation motors, the armature winding and the excitation winding are set separately, and an additional H-bridge circuit is required to provide DC excitation to the excitation winding, resulting in a complex system structure and low torque density. To solve the above problems, a drive topology for zero-sequence current excitation motors has been proposed. This drive topology integrates the functions of excitation and armature windings. By adjusting the DC component in the current, the air gap magnetic field can be flexibly changed, thus having good magnetic field regulation capability.

[0005] Because the neutral point of a traditional three-phase motor is usually left floating or directly grounded, Kirchhoff's current law restricts the flow of zero-sequence current. To enable a zero-sequence excitation motor to operate normally, the neutral point of the three-phase windings must be opened (exposed), and a power supply / circuit capable of injecting zero-sequence current into the neutral point must be constructed. Currently known zero-sequence excitation motor drive topologies include common DC bus open winding drive topologies, dual three-phase drive topologies, and three-phase four-bridge drive topologies. However, these existing zero-sequence excitation motor drive topologies all improve the motor structure by simplifying the number of windings. Although they successfully simplify the winding structure (reducing it from two sets to one), the generation of zero-sequence current still requires additional inverter bridge arms or independent converters, leading to an increase in the number of power devices and higher system costs. Furthermore, none of these drive topologies fully utilize the boost capability of the neutral point. Summary of the Invention

[0006] The first aspect of this application provides a drive topology for a zero-sequence excitation boost-type hybrid excitation synchronous motor, including a DC bus capacitor, a three-phase inverter, three-phase armature windings, and an excitation winding. One end of the DC bus capacitor is connected to the common anode of the three-phase inverter, and the other end is connected to the common cathode and ground terminal of the three-phase inverter and serves as a negative terminal for connecting to the negative terminal of the DC power supply of the motor. The output terminals of each phase bridge arm of the three-phase inverter are respectively connected to one end of each phase armature winding, and the other ends of each phase armature winding are interconnected to form a neutral point. One end of the excitation winding is directly connected to the neutral point, and the other end serves as a positive terminal for connecting to the positive terminal of the DC power supply of the motor.

[0007] A second aspect of this application provides a zero-sequence excitation boost type hybrid excitation synchronous motor having the aforementioned drive topology.

[0008] A third aspect of this application provides a design method for a motor controller, comprising the following steps: An average motor model of a zero-sequence excitation boost hybrid excitation synchronous motor is established, wherein the zero-sequence excitation boost hybrid excitation synchronous motor has the aforementioned drive topology; A steady-state equivalent circuit of the motor is established based on the zero-sequence voltage relationship of the driving topology; The motor controller is designed based on the motor average model and steady-state equivalent circuit. The motor controller includes an internal model decoupling controller, and the control parameters of the internal model decoupling controller are calculated and determined using the motor average model based on the internal model control principle.

[0009] The fourth aspect of this application provides a motor controller for driving control of the aforementioned zero-sequence excitation boost type hybrid excitation synchronous motor, including a first coordinate transformer, a speed PI controller, a boost PI controller, an internal model decoupling controller, a second coordinate transformer, and a control signal generator. The first coordinate transformer is based on The real-time value of the shaft rotation electrical angle is used to convert the real-time value of the three-phase current output by the three-phase inverter into... axis, Real-time values ​​of the 0-axis and zero-axis currents; The speed PI controller generates a value based on the target value and real-time value of the motor rotor speed. Reference value for shaft current; The boost PI controller generates a reference value for the 0-axis current based on the target value and real-time value of the DC bus voltage. The reference value for the shaft current is 0; The internal model decoupling controller is based on axis, Reference and real-time values ​​of 0-axis and 0-axis currents are generated. axis, The reference values ​​for the 0-axis and 0-axis voltages, wherein the control parameters of the internal model decoupling controller are designed using the aforementioned motor controller design method; The second coordinate transformer is based on axis, Reference values ​​for 0-axis and 0-axis voltages and The real-time value of the shaft rotation electrical angle generates the reference value of the three-phase phase voltage; The control signal generator generates PWM control signals for each switch of the three-phase inverter based on the reference values ​​of the three-phase phase voltages and the real-time values ​​of the DC bus voltage.

[0010] The zero-sequence excitation boost type hybrid excitation synchronous motor provided in this application improves the connection relationship between the armature three-phase winding, the excitation winding, the DC bus capacitor and the DC power supply. While using the zero-sequence current output from the neutral point of the armature three-phase winding to excite the excitation winding, it also has the ability to boost the input voltage of the power supply, thereby significantly improving the performance of the hybrid excitation synchronous motor.

[0011] The design method of the motor controller provided in this application addresses the boost and coupling characteristics of the drive topology of the zero-sequence excitation boost hybrid excitation synchronous motor. By adding an internal model decoupling controller to the system through the internal model control principle, it can effectively overcome the problems of complex tuning process and poor robustness of conventional PI parameter tuning methods when determining controller parameters, which are sensitive to changes in motor parameters. It realizes analytical design of parameters and quantitative controllability of performance. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of a conventional hybrid excitation synchronous motor drive topology. Figure 2 This is a schematic diagram of the drive topology of an improved hybrid excitation synchronous motor. Figure 3 This is a schematic diagram of the drive topology of another improved hybrid excitation synchronous motor. Figure 4 This is a schematic diagram of the drive topology architecture of a zero-sequence excitation boost type hybrid excitation synchronous motor according to an embodiment of this application; Figure 5 This is a flowchart of a motor controller design method provided according to an embodiment of this application; Figure 6 This is a schematic diagram of the equivalent circuit of a motor according to an embodiment of this application; Figure 7 This is a schematic diagram of the architecture of a motor controller provided according to an embodiment of this application; Figure 8 This is a schematic diagram illustrating the principle of internal mold control. Detailed Implementation

[0013] The present application will now be further described based on preferred embodiments and with reference to the accompanying drawings.

[0014] In the description of the embodiments of this application, it should be noted that the terms "upper," "lower," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or the orientation or positional relationships commonly used when the product of this application is in use, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on this application. Furthermore, in the description of this application, the terms "first," "second," etc., are used to distinguish different units, but these are not limited by the manufacturing order, nor should they be construed as indicating or implying relative importance. Their names may differ in the detailed description and claims of this application. In addition, for ease of understanding, various components in the drawings have been enlarged or reduced, but this is not intended to limit the scope of protection of this application.

[0015] The vocabulary used in this specification is for illustrative purposes and is not intended to limit the scope of this application. It should also be noted that, unless otherwise expressly specified and limited, the terms "set," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection, a direct connection, or an indirect connection via an intermediate medium; or they can refer to the internal communication between two components. Those skilled in the art will understand the specific meaning of these terms in this application.

[0016] Hybrid excitation synchronous motor is a new type of motor that combines the advantages of permanent magnet synchronous motor and electrically excited synchronous motor. Its rotor is equipped with permanent magnets (providing basic magnetic flux) and excitation windings (generating adjustable magnetic flux), and the stator is a standard three-phase armature winding. By adjusting the current of the excitation winding, the air gap magnetic field can be strengthened or weakened.

[0017] Figure 1 A classic hybrid-excitation synchronous motor drive topology is shown, such as... Figure 1 As shown, the main inverter on the left controls the current of the three-phase armature winding through the three-phase bridge arm to achieve torque and speed regulation; the excitation winding on the right is set independently relative to the three-phase armature winding, and the current flowing through the excitation winding is controlled by the H-bridge circuit to achieve regulation of the air gap magnetic field.

[0018] Classical hybrid-excitation synchronous motors have complex structures and low torque density. To address these issues, a drive topology for winding-integrated hybrid-excitation synchronous motors has been proposed. This type of drive topology integrates the excitation and armature winding functions, and by adjusting the DC component (zero-sequence current) in the current, it can flexibly change the air gap magnetic field, thus possessing excellent magnetic field regulation capabilities. Since the neutral point of traditional three-phase motors is usually floating or directly grounded, satisfying Kirchhoff's current law constraints, zero-sequence current cannot flow. To enable the normal operation of a zero-sequence excitation type motor, the neutral point of the three-phase windings needs to be opened or brought out to construct a power supply / circuit capable of injecting zero-sequence current.

[0019] Figure 2 An improved drive topology for a zero-sequence excitation hybrid-excitation synchronous motor is shown, also known as a common DC bus type dual three-phase drive topology, such as... Figure 2 As shown, both the armature winding and the excitation winding are three-phase windings, and their neutral points are connected to each other, thus obtaining an integrated winding structure consisting of two sub-windings. Each of the two sub-windings is controlled by a three-phase inverter and powered by the same DC power supply. One sub-winding satisfies the same polarity, while the other satisfies the opposite polarity. Through the control of the two three-phase inverters, the zero-sequence current required for excitation can be generated in the windings.

[0020] Figure 3Another improved zero-sequence excitation hybrid excitation synchronous motor drive topology is shown, referred to as the three-phase four-arm drive topology. As shown in the figure, this drive topology contains only one set of three-phase windings, and a zero-sequence path is formed to provide excitation by connecting an asymmetric arm to the motor neutral point.

[0021] However, the aforementioned solutions for improving the drive topology of classic hybrid-excitation synchronous motors all aim to integrate the armature winding and the excitation winding. While these solutions successfully simplify the winding structure (e.g., changing from two independent windings to one integrated winding), additional inverter arms or independent converters are still required to generate zero-sequence current for excitation, leading to an increase in the number of power devices and higher system costs. Furthermore, although... Figure 2 , Figure 3 The provided drive topologies all adopt a three-phase winding neutral point connection topology, but the DC bus voltage is consistent with the power supply voltage, which does not fully utilize the boost capability of the neutral point connection method.

[0022] Therefore, embodiments of this application provide a novel drive topology for a zero-sequence excitation boost-type hybrid excitation synchronous motor. This drive topology improves the connection relationship between the armature three-phase winding, the excitation winding, the DC bus capacitor, and the DC power supply. While using the zero-sequence current output from the neutral point of the armature three-phase winding to excite the excitation winding, it also has the ability to boost the input voltage of the power supply, thereby significantly improving the performance of the hybrid excitation synchronous motor.

[0023] Figure 4 A schematic diagram of the drive topology of a zero-sequence excitation boost-type hybrid excitation synchronous motor according to some embodiments of this application is shown, such as... Figure 4 As shown, the drive topology consists of a DC bus capacitor, a three-phase inverter, a three-phase armature winding, and a field winding.

[0024] Specifically, one end of the DC bus capacitor is connected to the common anode of the three-phase inverter, and the other end is connected to the common cathode of the three-phase inverter and the ground terminal. O The voltage across the DC bus capacitor, i.e., the DC bus voltage between the common anode and common cathode of the three-phase inverter, is, without loss of generality, expressed as: Meanwhile, the end of the DC bus capacitor connected to the ground terminal also serves as the negative terminal of the entire drive topology. This negative terminal operates when the motor is connected to a voltage of... When using a DC power supply, it is used to connect to the negative terminal of the DC power supply.

[0025] Furthermore, the three-phase armature windings are connected in a star (Y) configuration, i.e., the three-phase inverter... Mutually, Harmony The output ends of the phase bridge arms are connected to one end of each phase armature winding in the three-phase armature winding, and the other ends of each phase armature winding are connected to each other to form a neutral point.

[0026] It should be noted that, in the embodiments of this application, the structure of the three-phase inverter is not limited; that is, the three-phase inverter can adopt any of the following structures: Figure 4 The three-phase two-level form in the middle, Mutually, Harmony Each phase has only one bridge arm, and the output terminal of each phase is the midpoint between the upper and lower switching devices in that phase's bridge arm; alternatively, a parallel multi-level coupled three-phase inverter form known to those skilled in the art can be used. Mutually, Harmony Each phase contains multiple parallel bridge arms. Wires are drawn from the midpoint of each bridge arm in the same phase and coupled and wound around multiple magnetic rings to form a cascaded coupled inductor structure, and finally form a unified output terminal connected to the armature winding of the corresponding phase.

[0027] Back Figure 4 In the embodiment shown, in this drive topology, one end of the excitation winding is directly connected to the neutral point of the armature winding, while the other end serves as the positive terminal of the entire drive topology. This positive terminal is connected to the motor at a voltage of... When using a DC power supply, it is used to connect to the positive terminal of the DC power supply. Through Figure 4 As can be seen, when the positive extreme (i.e. Figure 4 The end of the excitation winding that is not connected to the neutral point is connected to the positive terminal of the DC power supply, and the negative terminal (i.e., the end of the DC bus capacitor connected to the ground terminal and the common cathode of the three-phase inverter) is connected to the negative terminal of the DC power supply. That is, when the motor is powered by the DC power supply, no structure is provided in the circuit between the positive terminal and the positive terminal of the DC power supply, or in the circuit between the negative terminal and the negative terminal of the DC power supply, for adjusting the direction and / or magnitude of the magnetic field generated by the excitation winding.

[0028] In the embodiments of this application, the structure for adjusting the direction and / or magnitude of the magnetic field generated by the excitation winding refers to a structure that changes the magnitude and / or direction of the current between the two terminals of the excitation winding in an inverter manner, thereby causing a change in the direction and / or magnitude of the magnetic field generated by the excitation winding. For example, Figure 1 The H-bridge structure located on the right side of the excitation winding comprises two parallel bridge arms. Each bridge arm consists of two identical switching devices connected in series, with terminals leading out from the midpoint. When these two bridge arms are powered by a DC power supply, the direction and / or magnitude of the magnetic field generated by the excitation winding can be changed by switching the on and off states of the four switching devices; For example, Figure 2A dedicated inverter with three bridge arms is installed to generate and regulate the direction and / or magnitude of the zero-sequence current, thereby causing a change in the direction and / or magnitude of the excitation magnetic field; for example, Figure 3 Another type of bridge arm is set between the midpoint of the three-phase winding integrating the armature winding and the excitation winding and the DC power supply. A diode and a MOSFET are connected in series on the bridge arm, and the midpoint of the two are connected to the neutral point of the integrated winding. The two ends of the bridge arm are connected to the positive and negative terminals of the power supply, respectively. This bridge arm and the three bridge arms of the three-phase inverter form four parallel bridge arms. The direction and / or magnitude of the zero-sequence current can be adjusted by switching the switching devices, thereby adjusting the direction and / or magnitude of the excitation magnetic field in the integrated three-phase winding.

[0029] Without loss of generality, it can be Figure 1 , Figure 2 A bridge arm is a structure in which two identical switching devices are connected in series and wires are led out from the midpoint between the two switching devices. Figure 3 The structure on the far right, which connects two different functional devices (including at least one switching device) in series and draws wires from the midpoint between the two functional devices, is called an asymmetrical structure. Therefore, in the embodiments of this application, the structure used to adjust the direction and / or magnitude of the magnetic field generated by the excitation winding includes at least the aforementioned symmetrical bridge arm and / or asymmetrical bridge arm.

[0030] and Figures 1 to 3 The various hybrid excitation synchronous motor drive topologies shown differ. In the drive topology provided in this application, when connected to a DC power supply, no structures are provided between the positive terminal formed by the excitation winding and the positive terminal of the DC power supply, or between the negative terminals of the DC power supply, to change the direction and / or magnitude of the magnetic field of the excitation winding. In other words, in the drive topology provided in this application, the zero-sequence current (i.e., the current used to adjust the direction and / or magnitude of the magnetic field generated by the excitation winding) is not present. Figure 4 The current flowing from the excitation winding to the neutral point, or from the neutral point to the excitation winding. The size and direction of the inverter are controlled only by the three-phase inverter connected to the three-phase armature winding.

[0031] Furthermore, it should be emphasized that, although Figure 4 In the illustrated embodiment, the positive terminal is directly electrically connected to the positive terminal of the DC power supply, and the negative terminal is directly connected to the negative terminal of the DC power supply via wires. Therefore, there are no other components. In other optional embodiments, those skilled in the art may, as needed, provide at least one functional component or module between the positive terminal and the positive terminal of the DC power supply, and between the negative terminal and the negative terminal of the DC power supply, as long as the provided functional component or module does not participate in the process of adjusting the direction and / or magnitude of the magnetic field generated by the excitation winding.

[0032] For example, to ensure motor safety, in some optional embodiments, components or modules for overcurrent protection can be installed between the positive terminal of the excitation winding and the positive terminal of the DC power supply, or between the negative terminal of the DC power supply and the ground terminal. These components or modules can be passive protection devices such as current-limiting resistors, fuses, thermal relays, and circuit breakers, or active protection devices composed of overcurrent detection modules and controllable switching devices such as transistors or MOSFETs. It is understood that although the active protection devices installed in the above locations may include switching devices such as MOSFETs for switching on and off states, their function is to disconnect the current path when an overcurrent occurs, rather than acting like... Figure 2 Three-phase inverter in, or Figure 3 Like the switching devices in the asymmetric bridge arm, the magnetic field of the excitation winding is adjusted in an inverter manner.

[0033] In addition, comparison Figure 4 and Figures 1 to 3 As can be seen, in the drive topology provided in this application, the common anode of the three-phase inverter is not directly connected to the DC power supply; therefore, the DC bus voltage... Voltage of DC power supply They can be the same or different, especially by controlling the on / off state of each switching device in the three-phase inverter. In this case, the drive topology can boost the input voltage of the DC power supply, thereby increasing the motor power density, expanding the speed range and reducing line losses.

[0034] Some embodiments of this application provide a zero-sequence excitation boost type hybrid excitation synchronous motor, which has Figure 4 The diagram shows the drive topology of a zero-sequence excitation boost-type hybrid excitation synchronous motor. It is understood that... Figure 4 The driving topology shown defines the armature winding, excitation winding, three-phase inverter, DC bus capacitor, and their connection relationship with the DC power supply that powers the motor. The hybrid excitation synchronous motor provided in this application does not limit the coordination method between the permanent magnet and the excitation winding. Those skilled in the art can flexibly choose the coordination method between the permanent magnet and the excitation winding that they know, such as surface-mount type, built-in straight type, etc.

[0035] Obviously, due to Figure 4 The zero-sequence excitation boost-type hybrid excitation synchronous motor shown is a novel drive topology. Therefore, a matching controller needs to be designed for this new drive topology to achieve good control. To this end, embodiments of this application also provide a motor controller design method for designing... Figure 4 The controller shown is for a zero-sequence excitation boost-type hybrid excitation synchronous motor. For example... Figure 5As shown, in some embodiments, the motor controller design method includes the following steps: Step S1: Establish the average motor model of the zero-sequence excitation boost hybrid excitation synchronous motor, wherein the zero-sequence excitation boost hybrid excitation synchronous motor has the aforementioned drive topology; Step S2: Establish the motor steady-state equivalent circuit based on the zero-sequence voltage relationship of the driving topology; Step S3: Design the motor controller based on the motor average model and steady-state equivalent circuit. The motor controller includes an internal model decoupling controller, and the control parameters of the internal model decoupling controller are calculated and determined using the motor average model based on the internal model control principle.

[0036] Figure 6 , Figure 7 The circuit diagrams of the steady-state equivalent circuit of the motor established in step S2 above are shown, as well as the final designed motor controller architecture for controlling the zero-sequence excitation boost-type hybrid excitation synchronous motor. The following is a combination of... Figures 5 to 7 The design method for this motor controller is explained in detail for each step.

[0037] <Establishing an average motor model> Step S1 according to Figure 4 The driving topology shown is used to derive and establish the average model of a zero-sequence excitation boost-type synchronous motor using this driving topology. The reference coordinate system of this average model is... The derivation process of the axial coordinate system in some specific embodiments is as follows: axial coordinate system and electric angular velocity The magnetic flux of the rotating rotor permanent magnet rotates synchronously, wherein, ω is the angular velocity of the rotor. For extreme logarithms, the direct axis ( d The magnetic flux direction of the zero-sequence excitation boost-type hybrid excitation synchronous motor is aligned with that of the permanent magnet. Considering the magnetic field component generated by the current in the excitation winding, and referring to the method for establishing the magnetic flux equation of a permanent magnet synchronous motor, the magnetic flux direction of the zero-sequence excitation boost-type hybrid excitation synchronous motor is obtained. Magnetic flux equation in coordinate system: (1), In equation (1), , and stator axis, 0-axis and 0-axis magnetic flux The magnetic flux of the excitation winding, , and stator axis, 0-axis and 0-axis inductors This refers to the mutual inductance between the excitation winding and the permanent magnet. The inductance of the excitation winding, , and stator axis, Axis and 0-axis currents, This is the current in the excitation winding. The magnetic flux of a permanent magnet. The coupling flux of the permanent magnet to the excitation winding reflects the influence of the permanent magnet on the magnetic flux generated by the excitation winding.

[0038] The voltage equation for this zero-sequence excitation boost-type synchronous motor can be obtained from the flux equation: (2), in, , , They are motors , , shaft voltage, This is the voltage of the excitation winding. For stator resistance, For the excitation winding resistance, As mentioned above, for The rotational electric angular velocity of the axial coordinate system.

[0039] Substituting equation (1) into equation (2) yields: (3).

[0040] The electromagnetic torque equation of the hybrid excitation synchronous motor is: (4), in, It is electromagnetic torque.

[0041] Assuming the three-phase inverter is an ideal inverter, with no voltage drop and dead time, according to Figure 4 The driving topology shown has the following characteristics: Since the current flowing through the excitation winding is... Since the voltage drop direction in the NO circuit is defined as positive, a voltage equation can be established: (5), in, , , Three-phase inverters Mutually, Mutually, The output terminal of the phase is relative to the ground terminal voltage, , , Three-phase inverters Mutually, Mutually, Phase switch duty cycle, This is the DC bus voltage. , , They are motors Mutually, Mutually, Phase voltage (i.e.) Mutually, Mutually, (Voltage across the armature winding of the phase) Neutral point of the motor Relative to the ground terminal The voltage, according to Figure 4 The driving topology shown is This refers to the voltage of the DC power supply.

[0042] Using the following Park transformation matrix The physical quantities in the ABC three-phase coordinate system can be transformed to Axis coordinate system: (6), in, for The electrical angle of rotation in the axial coordinate system.

[0043] exist In the axial coordinate system, the three-phase inverter , , Axis voltage is defined as , , ,Will , , Defined as a three-phase inverter , , The axis duty cycle is determined by , , After performing the Park transformation, the voltage equation in the ABC coordinate system is transformed into... Expression in axial coordinate system: (7).

[0044] By combining equation (5) with equation (7), we can establish Figure 4The complete zero-sequence excitation boost type permanent magnet synchronous motor drive topology shown corresponds to... The axis voltage equations are expressed in equation (8): (8), in, , , These are three-phase inverters using a zero-sequence excitation boost-type permanent magnet synchronous motor drive topology. , , Shaft voltage.

[0045] With this drive topology, the DC bus current It can be represented as: (9), in, This is the capacitance value of the DC bus capacitor. , , They are respectively Mutually, Mutually, Phase current of phase, superscript This indicates the transpose operation. Let A, B, and C be the duty cycle vectors of the three-phase inverter. Let be the phase current vector of phases ABC.

[0046] According to the Park transform principle Figure 4 In the zero-sequence excitation boost-type hybrid excitation synchronous motor drive topology shown, the neutral line current... Excitation winding current Zero-sequence current With three-phase current , , The following relationship exists between them: (10).

[0047] By extending equation (7), we finally obtain the result. Figure 4 The average motor model of the zero-sequence excitation boost-type permanent magnet synchronous motor with the drive topology shown is as follows: (11).

[0048] <Establishing the steady-state equivalent circuit of the motor> Step S2 is based on Figure 4 Based on the zero-sequence voltage relationship defined by the driving topology shown, a steady-state equivalent circuit for a zero-sequence excitation boost-type hybrid excitation synchronous motor is established. In some specific embodiments, the steady-state equivalent circuit of this motor can be established through the following steps: Based on equations (7) and (11), we can obtain Figure 4 The zero-sequence voltage relationship of the drive topology of the zero-sequence excitation boost-type hybrid excitation synchronous motor is shown below: (12).

[0049] For ease of analysis, we can let , , Then, the form of equation (12) is similar to the average model of a single-phase DC / DC converter, where the mutual inductance term is equivalently expressed as It can be used as an equivalent parasitic resistance. As an equivalent filter inductor This serves as the equivalent duty cycle of the chopper; therefore, from the perspective of the average model, Figure 4 The driving topology shown essentially possesses DC / DC bus voltage regulation capability. According to equation (12), the DC bus voltage of the system in steady state is... and , as well as Since they are directly related, the relationship between the DC bus voltage and the motor operation can be clarified by establishing a steady-state equivalent circuit of the motor.

[0050] Specifically, using the Parker transformation matrix, equation (9) is transformed as follows: DC bus current It can be represented as: (13).

[0051] Combining equations (12) and (13), it is possible to rotate in the same direction as the rotor magnetic field. A steady-state equivalent circuit for the motor is established in the axial coordinate system, and the hybrid excitation synchronous motor is equivalent to a DC motor model. By establishing the steady-state equivalent circuit, independent control of electromagnetic torque and flux linkage can be achieved, thus enabling the adoption of a control strategy similar to that of a DC motor. Subsequently, the control variables in the steady-state equivalent circuit of the motor ( The system is inversely transformed back to the three-phase stationary coordinate system in the axial coordinate system to achieve control.

[0052] As mentioned above, we can see from equation (12) that... , There is an equivalent duty cycle. Therefore, a virtual chopper can be set up in the equivalent circuit, and the voltage, current, magnetic field and boost relationship embodied in equations (12) and (13) can be used to establish a virtual chopper. Figure 6 The diagram shows the motor steady-state equivalent circuit, which includes an equivalent DC motor drive topology and an equivalent DC-DC converter.

[0053] exist Figure 6 In the illustrated embodiment, the equivalent DC motor drive topology includes four equivalent bridge arms connected in parallel across the DC bus, wherein the first equivalent bridge arm is connected in series with an equivalent switch. and The second equivalent bridge arm is connected in series with an equivalent switch. and The third equivalent bridge arm is connected in series with an equivalent switch. and The fourth equivalent bridge arm is connected in series with an equivalent switch. and .

[0054] Furthermore, a stator resistor is connected in series between the midpoint of the first equivalent bridge arm and the midpoint of the fourth equivalent bridge arm. , Shaft inductor as well as Back electromotive force of the shaft Thus forming shaft current The current path; a stator resistor is connected in series between the midpoints of the second and third equivalent bridge arms. , Shaft inductor as well as Back electromotive force of the shaft Thus forming shaft current The current path, according to equation (11), and The values ​​are respectively and .

[0055] The upper half of each bridge arm is equivalent to a switch ( , , , ) and the corresponding equivalent switch of the lower half-bridge arm ( , , , The two sides have complementary PWM signals, in which the equivalent switch in the first equivalent bridge arm can be... Equivalent switch in the fourth equivalent bridge arm The difference in their respective duty cycles is expressed as The equivalent switch in the second equivalent bridge arm Equivalent switch in the third equivalent bridge arm The difference in their respective duty cycles is expressed as .

[0056] The equivalent DC-DC converter includes a virtual chopper and equivalent parasitic resistance. Equivalent filter inductance Equivalent back electromotive force The virtual chopper is used to characterize the input voltage of the DC power supply in the drive topology of the zero-sequence excitation boost hybrid excitation synchronous motor. DC bus voltage Its boost characteristics.

[0057] exist Figure 6 In the illustrated embodiment, the virtual chopper consists of a first virtual switch. Second virtual switch constitute, and The series-connected bridge arm circuit is connected to both ends of the DC bus, and at the same time... With equivalent parasitic resistance Equivalent filter inductance Equivalent back electromotive force Connected in series between the positive and negative terminals of a DC power supply. , , The specific value is as described above and is determined by equation (12).

[0058] According to Kirchhoff's laws, the zero-sequence voltage relationship expressed by equation (12) is... Figure 6 The contour line “Ⅰ” represents the current, and at point “P”, the current relationship according to equation (13) is satisfied. Therefore, Figure 6 The motor steady-state equivalent circuit shown clearly reveals that the zero-sequence excitation boost drive topology proposed in this application has an equivalent DC / DC boost function.

[0059] Figure 6 In the illustrated embodiment, the virtual chopper is located between the equivalent DC motor drive topology and the DC power supply topology. As the main switch As a freewheeling switch, without loss of generality, Duty cycle is expressed as , The duty cycle is expressed as Then by adjusting and It can produce The equivalent duty cycle reflects the value shown in equation (12). arrive Its boost characteristics.

[0060] <Building the motor controller architecture and determining control parameters> Step S3 is used to establish the adoption Figure 4The control architecture of the motor controller in the illustrated drive topology is shown, and its preferred control parameters are determined. In some preferred embodiments, the motor controller design can be completed through the following steps: First, based on the steady-state equivalent circuit of the motor established in step S2, the architecture of the motor controller is determined. In the figure, HESM represents the three-phase armature winding and the excitation winding. Figure 7 As shown, the core components of this motor controller include a first coordinate transformer, a speed PI controller, a boost PI controller, an internal model decoupling controller, a second coordinate transformer, and a control signal generator. The first coordinate transformer is based on measured values... Axis rotation electrical angle The real-time value of the three-phase current output by the three-phase inverter. , , Real-time values ​​converted axis, Axis and 0-axis current , and The real-time value.

[0061] The speed PI controller is based on the target value of the motor rotor speed. and the motor rotor speed measured and fed back. Real-time values, generating Reference value of shaft current The boost PI controller is based on the target value of the DC bus voltage. and the DC bus voltage measured and fed back The real-time value is used to generate a reference value for the 0-axis current (i.e., the neutral point current). Obviously, This represents the input voltage Boost to The target value of the zero-sequence current that needs to be injected into the excitation winding; furthermore, in the embodiments of this application, d Reference value of shaft current It is preferable to set it to 0.

[0062] , and Each is fed back from the first coordinate transformer. , and The real-time value is subtracted from the actual value, and then input into the internal model decoupling controller. The internal model structure controller generates the decoupling compensation value. axis, Voltage reference values ​​for the 0 axis and 1 axis , and .

[0063] , and Further input to the second coordinate transformer, combined with the measured values... Axis rotation electrical angle The real-time values ​​are subjected to inverse Park transformation to obtain reference values ​​of the three-phase phase voltages in the ABC coordinate system. , , .

[0064] , , Input control signal generator, combined with the measured DC bus voltage The real-time value is used to generate PWM control signals for each switch of the three-phase inverter through PWM signal generation algorithms such as SPWM (Sinusoidal Pulse Width Modulation).

[0065] From the average motor model shown in equation (11), it can be seen that... The severe coupling of shaft parameters is caused by the fact that, in the drive topology provided in this application, the neutral point of the three-phase armature winding is connected to the excitation winding, and the zero-sequence excitation and boost control of the excitation winding are only achieved through a three-phase inverter. The conventional PI parameter tuning method is used, which is complex, and the tuned PI parameters are sensitive to changes in motor resistance, inductance, and other parameters, exhibiting poor adaptability and insufficient system robustness. Therefore, in this application, an equivalent internal model decoupling controller with analytical parameter relationships is established based on the internal model control principle to achieve analytical parameter design and quantitative controllability of performance.

[0066] Internal model control is a control strategy based on process models. Its core idea is to embed a mathematical model of the controlled object within the control system. By comparing the actual output With model prediction output Feedback control is achieved by addressing the differences between them. Figure 8 The principle of internal mold control is shown, such as... Figure 8 As shown, the setting value With modeling error Entering the internal mold controller If the model is perfect ,but The modeling error is zero, and the system exhibits open-loop characteristics. When there is model mismatch or external interference, the modeling error is non-zero, and feedback correction is automatically generated. This structure essentially realizes a dual mechanism of "model compensation + error correction". Its design process is intuitive and robust.

[0067] In practical engineering applications, it is often necessary to equate the internal model controller to a classic form of feedback controller, according to... Figure 8 The control topology shown has the following equivalent feedback controller form: (14) in It is an identity matrix.

[0068] The following describes the specific steps of constructing an internal model decoupling controller based on the above-mentioned internal model control principle in the embodiments of this application.

[0069] First, the average motor model in equation (11) is converted into a voltage equation in the S-domain: (15) in, For complex operators in the field S, , , They are respectively under the S domain axis, shaft and shaft voltage, , , They are respectively under the S domain axis, shaft and Axis current.

[0070] make: (16) We can obtain: (17).

[0071] Combining equations (16) and (17), the internal mold controller can be... Equivalent to an internal model decoupling controller with a classical feedback control structure, its S-domain expression is... for: (18) in, This refers to the bandwidth factor; by adjusting the bandwidth factor, the desired result can be achieved. Adjustment of the three-axis control parameters.

[0072] Finally, the control parameters of the internal model decoupling controller are obtained according to equation (18): (19) in, , , These are the internal model decoupling controllers. axis, axis, Shaft proportionality factor, , and These are the internal model decoupling controllers. axis, axis, Axis integral coefficient.

[0073] The specific embodiments of this application have been described in detail above. For those skilled in the art, several improvements and modifications can be made to this application without departing from the principle of this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

Claims

1. A design method for a motor controller, characterized in that, Includes the following steps: An average model of a zero-sequence excitation boost-type hybrid excitation synchronous motor is established. The driving topology of the zero-sequence excitation boost-type hybrid excitation synchronous motor includes a DC bus capacitor, a three-phase inverter, three-phase armature windings, and an excitation winding. One end of the DC bus capacitor is connected to the common anode of the three-phase inverter, and the other end is connected to the common cathode and ground terminal of the three-phase inverter and serves as the negative terminal for connecting to the negative terminal of the DC power supply of the motor. The output terminals of each phase bridge arm of the three-phase inverter are respectively connected to one end of each phase armature winding, and the other ends of each phase armature winding are interconnected to form a neutral point. One end of the excitation winding is directly connected to the neutral point, and the other end serves as the positive terminal for connecting to the positive terminal of the DC power supply of the motor. A steady-state equivalent circuit of the motor is established based on the zero-sequence voltage relationship of the driving topology; The motor controller is designed based on the motor average model and steady-state equivalent circuit. The motor controller includes an internal model decoupling controller, and the control parameters of the internal model decoupling controller are calculated and determined using the motor average model based on the internal model control principle. The average model of the motor is: （11）， in, , , These are three-phase inverters using a zero-sequence excitation boost-type permanent magnet synchronous motor drive topology. , , shaft voltage, For stator resistance, For the excitation winding resistance, , and stator axis, Axis and 0-axis currents, , and stator axis, 0-axis and 0-axis inductors This refers to the mutual inductance between the excitation winding and the permanent magnet. The inductance of the excitation winding, for The electric angular velocity of rotation in the axial coordinate system For the magnetic flux of a permanent magnet; The control parameters of the internal model decoupling controller are determined based on the following formula: （18）， in, This is the S-domain expression for the internal model decoupling controller. For complex operators in the field S, This represents the bandwidth coefficient.

2. The design method of the motor controller according to claim 1, characterized in that, When the positive terminal and the negative terminal are connected to the positive and negative terminals of the DC power supply, respectively, no structure for adjusting the direction and / or magnitude of the excitation magnetic field generated by the excitation winding is provided in the circuit between the positive terminal and the positive terminal of the DC power supply, or in the circuit between the negative terminal and the negative terminal of the DC power supply.

3. The design method of the motor controller according to claim 1, characterized in that, When the drive topology is connected to a DC power supply and the three-phase inverter is working, the DC bus voltage across the DC bus capacitor is greater than or equal to the voltage of the DC power supply.

4. The design method of the motor controller according to claim 1, characterized in that, The steady-state equivalent circuit of the motor includes an equivalent DC motor drive topology and an equivalent DC-DC converter. The equivalent DC-DC converter includes a virtual chopper, which is used to characterize the boost characteristics from input voltage to DC bus voltage in the drive topology of the zero-sequence excitation boost hybrid excitation synchronous motor.

5. The design method of the motor controller according to claim 4, characterized in that, The topology of the steady-state equivalent circuit of the motor is determined based on the following formula: （12）， in, This is the DC bus voltage. Input voltage, The equivalent duty cycle of the virtual chopper.

6. A zero-sequence excitation boost-type hybrid excitation synchronous motor, characterized in that, The zero-sequence excitation boost type hybrid excitation synchronous motor has the drive topology involved in the design method of the motor controller as described in claim 1.

7. A motor controller for driving and controlling the zero-sequence excitation boost-type hybrid excitation synchronous motor as described in claim 6, characterized in that, It includes a first coordinate transformer, a speed PI controller, a boost PI controller, an internal model decoupling controller, a second coordinate transformer, and a control signal generator; The first coordinate transformer is based on The real-time value of the shaft rotation electrical angle is used to convert the real-time value of the three-phase current output by the three-phase inverter into... axis, Real-time values ​​of the 0-axis and zero-axis currents; The speed PI controller generates a value based on the target value and real-time value of the motor rotor speed. Reference value for shaft current; The boost PI controller generates a reference value for the 0-axis current based on the target value and real-time value of the DC bus voltage. The reference value for the shaft current is 0; The internal model decoupling controller is based on axis, Reference and real-time values ​​of 0-axis and 0-axis currents are generated. axis, Reference values ​​for the 0-axis and 0-axis voltages, wherein the control parameters of the internal model decoupling controller are designed using the motor controller design method described in claim 1; The second coordinate transform is based on axis, Reference values ​​for 0-axis and 0-axis voltages and The real-time value of the shaft rotation electrical angle generates the reference value of the three-phase phase voltage; The control signal generator generates PWM control signals for each switch of the three-phase inverter based on the reference values ​​of the three-phase phase voltages and the real-time values ​​of the DC bus voltage.

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