Winding control device and control method of three-phase permanent magnet motor

Abstract

The invention provides a winding control device and control method of a three-phase permanent magnet motor, and relates to the technical field of motor driving control. According to the technical scheme, by calculating the difference value between the current vehicle speed and the target driving vehicle speed and referring to the vehicle speed interval corresponding to each group of taps, the switching scheme comprising the winding tap switching sequence arranged according to the turn number increasing sequence is planned in advance, and the smoothness of the switching process is ensured. And when the switching time is reached, a control signal is sent in time to realize accurate control. By means of the mode of combining driving demand prediction and winding switching pre-planning, dynamic switching of the winding can be conducted in time in the vehicle speed changing process, large torque output at the low speed and high performance at the high speed are both considered, and therefore the same motor can operate efficiently within the wider rotating speed range.

Description

Technical Field

[0001] This application relates to the field of motor drive control technology, specifically to a winding control device and control method for a three-phase permanent magnet motor. Background Technology

[0002] With increasing global emphasis on environmental protection and sustainable energy development, the new energy vehicle industry has ushered in a period of rapid development. Among the core drive systems of many new energy vehicles, permanent magnet synchronous motors (PMSMs) have become the mainstream technology choice due to their significant advantages such as high power density, high efficiency, wide speed range, and excellent control performance. However, a single fixed-winding parameter PMSM typically cannot maintain optimal performance across its entire operating range, and its high-efficiency region is relatively limited. To further broaden the motor's efficient operating range and optimize its performance across different speed ranges, such as extending the speed regulation capability in the constant power range, winding switching technology has emerged.

[0003] In related technologies, winding switching is often achieved by replacing different windings as a whole. This method can macroscopically switch the motor between several preset operating modes. However, in applications such as new energy vehicles, vehicles need to frequently experience full-condition operation from standstill to high-speed cruising. This switching method cannot precisely match the differentiated torque and efficiency requirements at different speeds. It cannot fully utilize the high torque output capability during low-speed starts, nor can it maintain optimal performance during high-speed driving. Therefore, the winding switching schemes in related technologies have limited switching ranges and cannot maintain a consistently efficient operating state over a wide speed range. Summary of the Invention

[0004] This application provides a winding control device and method for a three-phase permanent magnet motor. By dynamically switching the windings, it takes into account both high torque output at low speeds and high performance at high speeds, thereby enabling the same motor to maintain efficient operation over a wider speed range.

[0005] In a first aspect, this application provides a winding control device for a three-phase permanent magnet motor. The winding control device is connected to multiple sets of taps on the windings of the three-phase permanent magnet motor. The winding control device includes a control module and multiple winding control sub-devices. Each winding control sub-device includes an isolation drive module, a voltage regulator module, and an output module. The isolation drive module is connected to both the voltage regulator module and the output module. The output module is connected to the taps. The control module is connected to the isolation drive module. Wherein: The control module is used to respond to the driver's operation commands, acquire the vehicle's current speed and environmental parameters to determine the safe driving speed range; acquire the driver's historical driving data to determine the habitual speed range; determine the target driving speed based on the overlap between the safe driving speed range and the habitual speed range; and determine a winding switching scheme containing a multi-level winding tap switching sequence based on the current speed and the target driving speed, and output control signals to the corresponding winding control sub-device according to the winding switching scheme. The isolation drive module is used to control the on / off state of the voltage regulator module and the output module according to the control signal output by the control module; The voltage regulator module is used to regulate the input power supply voltage and to supply power to the output module when the voltage regulator module is connected to the output module; The output module is used to control the on / off state of the taps based on the connection status of the isolation driver module.

[0006] Optionally, the voltage regulator module includes a first resistor, a second resistor, a first transistor, a Zener diode, and a first capacitor, wherein; The external power input is connected to the collector of the first transistor via a first resistor, and the external power input is connected to the base of the first transistor via a second resistor. The negative terminal of the Zener diode is connected to the base of the first transistor, and the positive terminal of the Zener diode is connected to the output module. The emitter of the first transistor is connected to the positive terminal of the Zener diode via the first capacitor. The emitter of the first transistor is connected to the isolation drive module, and the positive terminal of the Zener diode is grounded.

[0007] Optionally, the output module includes a third resistor, a fourth resistor, a second MOSFET, a third MOSFET, a fourth MOSFET, and a second capacitor, wherein; The isolation drive module is connected to the first end of the third resistor, the second end of the third resistor is grounded through the second capacitor, and the source of the second MOSFET, the source of the third MOSFET, and the source of the fourth MOSFET are all connected to the common ground. The second end of the third resistor is connected to the gate of the second MOSFET, the gate of the third MOSFET, and the gate of the fourth MOSFET, respectively. The second end of the third resistor is connected to the source of the second MOSFET, the source of the third MOSFET, and the source of the fourth MOSFET via the fourth resistor, respectively. The drain of the second MOSFET, the drain of the third MOSFET, and the drain of the fourth MOSFET are respectively connected to the corresponding taps on the winding of the three-phase permanent magnet motor.

[0008] Optionally, the second, third, and fourth MOSFETs are all N-MOSFETs.

[0009] Optionally, the isolation driver module includes a fifth resistor and an optocoupler, wherein: The external control signal input is connected to the positive input terminal of the optocoupler via the fifth resistor, and the negative input terminal of the optocoupler is grounded; The positive output of the optocoupler is connected to the voltage regulator module, and the negative output of the optocoupler is connected to the output module.

[0010] Optionally, the windings of the three-phase permanent magnet motor are star-connected, and the windings are equipped with multiple sets of taps. Each set of taps has the same number of turns, and a winding control sub-device is connected to a corresponding set of taps.

[0011] Optionally, the multiple taps on the windings of the three-phase permanent magnet motor are set with equal number of turns and spacing.

[0012] Secondly, this application provides a winding control method for a three-phase permanent magnet motor, applied to a winding control device, the method comprising: In response to the driver's operating instructions, the vehicle's current speed and at least one environmental parameter of the vehicle in the current driving environment are obtained; Determine the safe driving speed range for the current driving environment based on at least one environmental parameter; Acquire historical driving data associated with the driver's identifier, and determine the habitual speed range under the current driving environment based on the historical driving data; Determine the target driving speed based on the overlap between the safe driving speed range and the habitual driving speed range; Based on the difference between the current vehicle speed and the target driving speed, and referring to the vehicle speed range corresponding to each set of taps on the three-phase permanent magnet motor, a winding switching scheme that meets the preset transformation constraints is determined. The winding switching scheme includes a winding tap switching sequence arranged in ascending order of the number of turns. When the switching time of the winding switching scheme is reached, a control signal will be sent to the corresponding winding control sub-device.

[0013] Optionally, a safe driving speed range for the current driving environment is determined based on at least one environmental parameter, including: Each environmental parameter is matched with the standard environmental parameter range in the preset rule set to determine the reference vehicle speed range corresponding to each environmental parameter. The preset rule set defines the mapping relationship between a combination of one or more standard environmental parameter ranges and the reference vehicle speed range. By integrating the speed ranges of each parameter, a safe driving speed range for the current driving environment can be obtained.

[0014] Optionally, the target driving speed can be determined based on the overlap between the safe driving speed range and the habitual driving speed range, including: Determine whether there is any overlap between the safe driving speed range and the habitual driving speed range; If the safe driving speed range and the habitual driving speed range overlap, the value within the overlap that is closest to the current speed will be determined as the target driving speed. If the safe driving speed range and the habitual driving speed range do not overlap, then the endpoint value within the safe driving speed range that is closest to the habitual driving speed range will be determined as the target driving speed.

[0015] In summary, the beneficial effects of the technical solution of this application include: By adopting the above technical solution, a safe driving speed range is determined based on environmental parameters, while a habitual speed range is derived by combining historical driving data. The target driving speed is determined based on the overlap between the two ranges, achieving accurate prediction of driving needs. Furthermore, by calculating the difference between the current speed and the target driving speed, and referring to the speed range corresponding to each set of taps, a switching scheme is pre-planned, including a winding tap switching sequence arranged in ascending order of turns, ensuring the smoothness of the switching process. When the switching time is reached, a control signal is promptly sent to achieve precise control. This method, combining driving demand prediction with winding switching pre-planning, enables timely dynamic switching of the windings during speed changes, balancing high torque output at low speeds and high performance at high speeds, thus allowing the same motor to maintain efficient operation over a wider speed range. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the winding and tap structure of a three-phase permanent magnet motor provided in an embodiment of this application; Figure 2 This is a schematic diagram of the winding control device for a three-phase permanent magnet motor provided in an embodiment of this application; Figure 3 This is a schematic flowchart of a winding control method for a three-phase permanent magnet motor provided in an embodiment of this application.

[0017] Reference numerals: 10, main winding; 20, iron core; 30, auxiliary winding; 5, air gap; R1, first resistor; R2, second resistor; R3, third resistor; R4, fourth resistor; R5, fifth resistor; C1, first capacitor; C2, second capacitor; Q1, first transistor; Q2, second MOSFET; Q3, third MOSFET; Q4, fourth MOSFET; Z1, Zener diode; E1, optocoupler. Detailed Implementation

[0018] To enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0019] In the description of the embodiments of this application, words such as "illustrative," "for example," or "for example" are used to indicate examples, illustrations, or explanations. Any embodiment or design described as "illustrative," "for example," or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Rather, the use of words such as "illustrative," "for example," or "for example" is intended to present the relevant concepts in a specific manner.

[0020] In the description of the embodiments of this application, the term "multiple" means two or more. For example, "multiple" means two or more, and "multiple screen terminals" means two or more screen terminals. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. The terms "comprising," "including," "having," and variations thereof all mean "including but not limited to," unless otherwise specifically emphasized.

[0021] First, combine Figure 1 For an explanation of the architecture of this application, please refer to [link / reference]. Figure 1 This is a schematic diagram of the winding and tap structure of a three-phase permanent magnet motor provided in an embodiment of this application.

[0022] As shown in the figure, this motor has a three-phase structure, consisting of U, V, and W phase windings. Each phase winding is composed of at least two coil sections connected in series, with multiple taps at the connection points and endpoints. Taking phase U as an example, its winding consists of coils A1 and A2 connected in series, with taps U1 and U2 at different positions. Similarly, phase V winding consists of coils B1 and B2 connected in series, with taps V1 and V2; phase W winding consists of coils C1 and C2 connected in series, with taps W1 and W2.

[0023] This setup allows multiple sets of taps (e.g., the first set of taps U1, V1, W1 and the second set of taps U2, V2, W2) to be selectively controlled by an external device. By activating different combinations of taps, the effective number of coil turns in the circuit can be changed, thereby switching the motor's operating characteristics (such as torque-speed characteristics) to adapt to different vehicle speed ranges.

[0024] As shown in the figure, phase A winding is divided into two segments, A1 and A2; phase B winding is divided into two segments, B1 and B2; and phase C winding is divided into two segments, C1 and C2. The three-phase windings are not connected internally within the motor. Each phase winding has three taps: phase A windings have U1, U2, and U; phase B windings have V1, V2, and V; and phase C windings have W1, W2, and W. The entire motor has a total of nine taps. The U, V, and W leads of the motor are connected to the three-phase lines of a standard motor driver. U1, V1, and W1 are connected to a special device proposed in this invention to control their on / off states, while U2, V2, and W2 are connected to another special device to control their on / off states. When the motor operates in the low-speed range, U1, V1, and W1 are connected together, while U2, V2, and W2 are disconnected, increasing the number of motor winding turns. When the motor operates in the high-speed range, U2, V2, and W2 are connected together, while U1, V1, and W1 are disconnected, reducing the number of motor winding turns.

[0025] It is necessary to understand that Figure 1 To explain the specific connection relationship of the taps, only two sets of taps are shown. In practice, it is not limited to two sets. Multiple sets of taps can be divided according to the specific situation of the three-phase permanent magnet motor winding.

[0026] To achieve this intelligent switching control, the winding control device proposed in this application is connected to multiple sets of taps on the windings of a three-phase permanent magnet motor. The winding control device includes a control module and multiple winding control sub-devices. The winding control device is connected to a specially designed three-phase permanent magnet motor. This motor has multiple sets of taps on its windings, similar to pre-setting multiple different "physical gears" for the motor. The winding control device adopts a master-slave architecture: one control module is responsible for complex calculations and decisions. Each of the multiple winding control sub-devices corresponds to controlling one set of taps on the motor. This design ensures precise execution of commands.

[0027] For the specific structure of the winding control sub-device, please refer to [reference needed]. Figure 2 , Figure 2 This is a schematic diagram of the winding control device for a three-phase permanent magnet motor provided in an embodiment of this application.

[0028] Figure 2 The control module is not shown. To clearly understand the working principle of the technical solution of this application, the control signals output by the control module are used to illustrate it.

[0029] The winding control sub-device includes an isolation drive module, a voltage regulator module, and an output module. The isolation drive module is connected to both the voltage regulator module and the output module. The output module is connected to the taps. The control module is connected to the isolation drive module. The control module is used to respond to the driver's operation commands, acquire the vehicle's current speed and environmental parameters to determine the safe driving speed range; acquire the driver's historical driving data to determine the habitual speed range; determine the target driving speed based on the overlap between the safe driving speed range and the habitual speed range; and determine a winding switching scheme containing a multi-level winding tap switching sequence based on the current speed and the target driving speed, and output control signals to the corresponding winding control sub-device according to the winding switching scheme. The isolation drive module is used to control the on / off state of the voltage regulator module and the output module according to the control signal output by the control module; The voltage regulator module is used to regulate the input power supply voltage and to supply power to the output module when the voltage regulator module is connected to the output module; The output module is used to control the on / off state of the taps based on the connection status of the isolation driver module.

[0030] It should be understood that the isolated drive module in this application specifically includes at least one control module and multiple isolated drive sub-devices.

[0031] In practice, when it is necessary to switch from high-speed cruise mode to medium-speed mode, the control module will determine that more windings need to be activated to optimize torque output at low and medium speeds, and send a start control signal to the specific winding control sub-device of the control target tap (e.g., U1, V1, W1).

[0032] The winding control sub-device consists of an isolation drive module, a voltage regulator module, and an output module. The control signals from the control module are input to the isolation drive module, whose output logic controls the connection between the voltage regulator module and the output module. The voltage regulator module processes the input power and supplies power to the output module. The final output terminal of the output module is directly connected to the physical taps of the motor.

[0033] When the control module does not output a valid control signal, the isolation drive module maintains its internal isolation barrier to ensure no logical connection with subsequent circuits. At this time, the output module is in a defined off state; its internal circuit design ensures that the charge at the control nodes of its power switching elements is completely discharged, resulting in a high-resistance state between the output module and the motor taps, achieving reliable disconnection. During this standby phase, the voltage regulator module is not idle but performs a crucial pre-charging operation. It obtains the input voltage from the main power supply, performs voltage regulation through its internal circuitry, and charges an internal energy storage unit until its voltage reaches a stable value precisely set for driving the output module. This process reserves the necessary drive energy for subsequent instantaneous actuation.

[0034] When the control module outputs a valid control signal, the isolation drive module responds to this signal, establishing an internal logic path while maintaining electrical isolation between the input and output. This path triggers the coordinated action of subsequent circuits: the pre-charged energy storage unit in the voltage regulator module is instantaneously switched to the control input of the output module, forming a high instantaneous current drive pulse. This pulse quickly establishes the gate voltage of the power switching element inside the output module, enabling it to rapidly and completely switch from the off state to the on state. Simultaneously, the voltage regulator module also establishes a continuous power supply path, providing a stable sustaining voltage to the output module to ensure it remains in a stable on state during the duration of the control signal. Ultimately, a stable low-resistance path is formed between the power output terminal of the output module and the motor tap.

[0035] Based on the above embodiments, as an optional implementation, the voltage regulator module includes a first resistor, a second resistor, a first transistor, a Zener diode, and a first capacitor, wherein; The external power input is connected to the collector of the first transistor via a first resistor, and the external power input is connected to the base of the first transistor via a second resistor. The negative terminal of the Zener diode is connected to the base of the first transistor, and the positive terminal of the Zener diode is connected to the output module. The emitter of the first transistor is connected to the positive terminal of the Zener diode via the first capacitor. The emitter of the first transistor is connected to the isolation drive module, and the positive terminal of the Zener diode is grounded.

[0036] In practice, the external power input is divided into two paths: the main power path is connected to the collector of the first transistor via a first resistor, providing the operating current for the entire circuit; the bias path is connected to the base of the first transistor via a second resistor. The function of the second resistor is to provide the necessary reverse bias current to the Zener diode, ensuring it operates in the stable breakdown region. In this state, the negative terminal of the Zener diode (connected to the base of the first transistor) is clamped to a precise reference voltage determined by its own characteristics. Since the positive terminal of the Zener diode is grounded, this reference voltage is relative to ground.

[0037] The first transistor, serving as the core regulating element in this circuit, is configured as an emitter follower. Its base voltage is firmly locked by a Zener diode, ensuring that its emitter voltage precisely follows the base voltage, resulting in only a small and essentially constant base-emitter voltage drop. The key advantage of this configuration is its significant current amplification capability: the base draws only a small current from the bias circuit, while the emitter can output a much larger current, sufficient to drive subsequent loads. The emitter of the first transistor is directly connected to the power supply terminals of the isolated driver and output modules, providing them with this stable voltage.

[0038] To further improve power quality and meet transient response requirements, a first capacitor is connected in parallel between the emitter of the first transistor and ground (i.e., the positive terminal of the Zener diode). This capacitor serves two main functions: first, it acts as a filter to smooth the DC voltage output from the first transistor, absorbing potential ripple and noise; second, it functions as a local energy storage unit, rapidly releasing charge when the output module requires a large instantaneous current (e.g., charging its gate capacitor when the power switch is turned on), thus compensating for the dynamic response limitations of the first transistor.

[0039] The final result is that the voltage regulator module, through the coordinated operation of the first resistor, the second resistor, the first transistor, the Zener diode and the first capacitor, successfully transforms a wide-range, unstable high-voltage input into a low-voltage DC output with constant voltage, extremely low ripple and good transient response.

[0040] Based on the above embodiments, as an optional implementation, the output module includes a third resistor, a fourth resistor, a second MOSFET, a third MOSFET, a fourth MOSFET, and a second capacitor, wherein; The isolation drive module is connected to the first end of the third resistor, the second end of the third resistor is grounded through the second capacitor, and the source of the second MOSFET, the source of the third MOSFET, and the source of the fourth MOSFET are all connected to the common ground. The second end of the third resistor is connected to the gate of the second MOSFET, the gate of the third MOSFET, and the gate of the fourth MOSFET, respectively. The second end of the third resistor is connected to the source of the second MOSFET, the source of the third MOSFET, and the source of the fourth MOSFET via the fourth resistor, respectively. The drain of the second MOSFET, the drain of the third MOSFET, and the drain of the fourth MOSFET are respectively connected to the corresponding taps on the winding of the three-phase permanent magnet motor.

[0041] When there is no control signal, the isolation drive module does not provide drive voltage. In this case, the output module must ensure that its connection to the motor tap is explicitly disconnected to prevent any false turn-on. This function is mainly achieved by the fourth resistor. The fourth resistor is connected between the gate and source (common ground) of the second, third, and fourth MOSFETs, forming a pull-down resistor network. Its key role is to provide a fixed discharge path to ground for the gates of the three MOSFETs. Any floating charge that may have accumulated on the gate due to electromagnetic interference, or any charge remaining from the previous turn-on process, will be quickly discharged to the common ground through the fourth resistor. This allows the gate-source voltage (Vgs) of the three MOSFETs to be reliably clamped at zero volts, far below their turn-on threshold voltage, thus ensuring that they are in a stable off state. At this time, the drain of each MOSFET (connected to the corresponding motor tap) presents a high impedance with its source, physically disconnecting the motor tap from the common ground.

[0042] When the control module issues an on command, the isolation drive module applies a stable positive voltage provided by the voltage regulator module to the first terminal of the third resistor. Current then flows through the third resistor to the subsequent circuitry. The third resistor acts as a gate current-limiting resistor, controlling the instantaneous current charging the gate capacitance and second capacitor of the MOSFETs, preventing excessive surge current from damaging the output stage of the isolation drive module. After flowing through the third resistor, the current begins to charge the parallel second capacitor and the equivalent input capacitance of the second, third, and fourth MOSFETs. The gate-source voltage (Vgs) rises accordingly. When Vgs exceeds the turn-on threshold voltage of these three MOSFETs, a conductive channel begins to form between their drain and source. As the charging process continues, Vgs eventually reaches a stable high level, causing the three MOSFETs to enter the full saturation region.

[0043] In the saturation region, the drain-source of the MOSFET exhibits extremely low on-resistance, equivalent to a closed switch. During this process, the second capacitor, besides forming an RC delay and filtering network with the third resistor to enhance anti-interference, also plays a role in stabilizing the gate voltage during charging. The final effect is that the drains of the second, third, and fourth MOSFETs each form a stable, low-resistance path between themselves and their common source. This is equivalent to simultaneously and reliably connecting the three motor taps connected to them to a common ground, thus completing the predetermined switch of the motor winding topology.

[0044] Based on the above embodiments, as an optional implementation, the second MOSFET, the third MOSFET, and the fourth MOSFET are all N-MOSFETs.

[0045] From the circuit topology analysis, the output module adopts a "low-side switch" configuration. In this configuration, the power switching element (MOSFET) is placed between the load (motor winding tap) and the circuit's common ground. Specifically, the sources of the second, third, and fourth MOSFETs are connected to the common ground, while their drains are connected to the load respectively. Using N-MOSFETs offers a natural driving advantage for this low-side switch configuration. The turn-on condition for an N-MOSFET is that its gate-source voltage (Vgs) exceeds its threshold voltage. Since its source is directly grounded (0V reference potential), it only needs a positive voltage relative to ground applied to the gate to reliably turn it on. This positive voltage can be conveniently provided by the standard positive voltage supply circuit (i.e., the voltage regulator module in this solution), eliminating the need for complex level shifting or negative voltage drive circuits, thus greatly simplifying the drive circuit design and reducing cost and power consumption.

[0046] Based on the above embodiments, as an optional implementation, the isolation drive module includes a fifth resistor and an optocoupler, wherein: The external control signal input is connected to the positive input terminal of the optocoupler via the fifth resistor, and the negative input terminal of the optocoupler is grounded; The positive output of the optocoupler is connected to the voltage regulator module, and the negative output of the optocoupler is connected to the output module.

[0047] When the external control signal input is low, there is insufficient forward bias voltage across the LED at the input of the optocoupler. Therefore, no effective current flows through the fifth resistor and the LED, causing it to not emit light. Since the input and output sides of the optocoupler are coupled only by light, the off state of the input LED causes the phototransistor (or other photosensitive element) on the output side to remain in a high-impedance cutoff state because it does not receive photon excitation. At this time, the positive and negative output terminals of the optocoupler are equivalent to an open switch. Therefore, although the voltage regulator module continuously provides a stable operating voltage to the positive output terminal of the optocoupler, this voltage cannot reach the negative output terminal through the optocoupler, i.e., it cannot be transmitted to the input terminal of the output module.

[0048] When winding switching is required, the external control signal input goes high. A forward voltage is applied to the circuit consisting of the fifth resistor and the LED connected in series at the optocoupler input. The fifth resistor acts as a current-limiting resistor here; its precise resistance setting ensures that the forward current flowing through the LED is limited to a safe range that allows it to emit light stably and fully while remaining well below its maximum rated value, thus protecting the optocoupler and ensuring its long-term reliability. The photons emitted by the LED pass through the internal transparent insulating medium and illuminate the base region of the phototransistor on the output side. Upon receiving the light signal, the phototransistor quickly transitions from the cutoff state to the saturated conduction state, forming an extremely low-resistance path between its collector and emitter (i.e., between the positive and negative output terminals of the optocoupler). This is equivalent to closing a switch, applying the stable voltage provided by the voltage regulator module without attenuation to the input terminal of the output module connected to the negative output terminal of the optocoupler, thereby driving the subsequent power MOSFET to conduct.

[0049] The complete circuit working principle of the winding control sub-device is explained below: When CTRLx is low, this low-level signal cannot provide sufficient forward bias current to the LED on the input side of optocoupler E1, so optocoupler E1 is in the off state. Its output phototransistor presents high impedance, effectively physically isolating the control circuit from the drive circuit.

[0050] At this point, the circuit's primary task is to ensure that the power switching elements (the second, third, and fourth MOSFETs, all N-MOSFETs) are in a definitively off state. This task is accomplished by the fourth resistor (R4). As a gate-source pull-down resistor, the fourth resistor (R4) provides a charge discharge path from the N-MOSFET's gate to its source (common ground). Any induced charge that may accumulate on the gate or residual charge from the previous operation will be dissipated through the fourth resistor (R4), thus firmly clamping the gate-source voltage (Vgs) at 0V, well below the N-MOSFET's turn-on threshold, ensuring it is reliably off.

[0051] Meanwhile, the circuit uses this standby phase to perform a crucial preparatory task: pre-charging the drive capacitor C1. Based on your specific circuit description, the charge from the high-voltage power supply VCC first passes through the current-limiting resistor R1 and the bias resistor R2, reaching the regulating transistor Q1. R2 provides bias to the base of Q1, while the Zener diode Z1 (typically a 15V Zener diode to match the drive voltage requirements of the N-MOSFET) precisely clamps the base voltage of Q1 to its breakdown voltage (approximately 15V). Since Q1 is configured as an emitter follower, its emitter voltage will stabilize at a level approximately 0.7V lower than the base voltage, or approximately 14.3V. This stabilized voltage is used to charge capacitor C1.

[0052] The charging current loop is quite unique: charge flows from the emitter of Q1 into C1, then sequentially through the off N-MOSFET, and into the motor windings. Since the main drive stage (U, V, W phases) of the motor controller typically includes a path to GND in its design (e.g., through its own low-side switch or freewheeling path), these tiny charging currents flow through the motor windings and ultimately converge to the controller's ground, forming a complete charging loop. The end result of this process is that, before activation, capacitor C1 is pre-charged to a stable and ideal drive voltage (approximately 14.3V), like a fully loaded arsenal, ready for the upcoming rapid start-up.

[0053] When the CTRLx port is set to high, the TTL level voltage is sufficient to drive the LED on the input side of optocoupler E1 to conduct and emit light. The optical signal then activates the phototransistor on the output side of optocoupler E1, causing it to quickly enter a saturated conduction state, forming a low-impedance path between its output terminals (collector and emitter).

[0054] The establishment of this pathway instantly connects the pre-charged capacitor C1 from the standby phase to the subsequent drive input network. The charge stored in C1 then acts as a powerful instantaneous current source, rapidly charging capacitor C2 and the gate-source capacitors of the three parallel N-MOSFETs (Q2, Q3, Q4) through the conducting optocoupler E1. This direct capacitor-powered method provides a peak current much greater than the steady-state output of the voltage regulator circuit, enabling the gate voltage of the N-MOSFETs to quickly cross their turn-on threshold, thus achieving rapid power switching.

[0055] After the N-MOSFET turns on and enters a stable operating state, the drive voltage requirement changes from a momentary high current to a continuous stable voltage. At this time, the series regulator circuit consisting of VCC, R1, R2, Q1, and Z1 continues to operate. It continuously replenishes the charge of C1 and provides a stable supply of approximately 14.3V to the gate of the N-MOSFET through the conducting optocoupler E1. As you pointed out, during the operation of the motor controller, the high voltage VCC at the source is always much greater than the winding tap voltage (U1, V1, W1) pulled low by the N-MOSFET. This ensures that the front-end regulator circuit always has a sufficient voltage difference to operate stably, thus providing a rock-solid power supply guarantee for the gate-source of the N-MOSFET, allowing it to firmly remain in a fully saturated conduction state.

[0056] Based on the above embodiments, as an optional implementation method, the windings of the three-phase permanent magnet motor are star-connected, and the windings are provided with multiple sets of taps. Each set of taps has the same number of turns, and a winding control sub-device is connected to a corresponding set of taps.

[0057] In practical implementation, this scheme first defines the basic structure of the motor windings as a star connection. In this connection, one end of each of the three-phase windings (U, V, and W phases) is led out as the power input terminal of the motor, while the other ends converge at a common center point, i.e., the physical neutral point. The key to the design is that the windings are not treated as a single unit, but rather multiple sets of taps are set on each phase winding extending from the physical neutral point to the power input terminal. For example, on the U phase winding, multiple taps such as U1 and U2 can be set sequentially. A core constraint of this scheme is that the taps must be grouped and symmetrical, i.e., "each group of taps has the same number of turns." This means that the first group of taps consists of three taps: U1, V1, and W1, each with the same number of turns (e.g., N1 turns) from the physical neutral point. Similarly, the second group of taps (U2, V2, and W2) also has the same number of turns (e.g., N2 turns, where N2 > N1). This symmetry is a necessary condition to ensure that the motor can maintain three-phase balance and operate smoothly in any working mode.

[0058] Based on this physical structure, a winding control sub-device is introduced as the actuator. The scheme specifies that "one winding control sub-device is connected to a corresponding set of taps." This means that the three output terminals of the first winding control sub-device (i.e., the drains of its internal second, third, and fourth MOS transistors) will be connected to the first set of taps U1, V1, and W1, respectively. Similarly, the three output terminals of the second winding control sub-device are connected to the second set of taps U2, V2, and W2, and so on.

[0059] When the upper-level main controller requires the motor to operate in "high-speed" mode, it sends an actuation signal to the first winding control sub-device. Once activated, this sub-device simultaneously turns on its three internal N-MOSFETs, firmly connecting the three taps U1, V1, and W1 to the common ground. This effectively creates a new "virtual neutral point." At this time, the current applied to the U, V, and W phases by the motor driver flows only through the winding portion from the power input to this set of grounded taps, while the portion of the winding between the taps and the physical neutral point is bypassed. Because this set of taps is closest to the physical neutral point (minimum number of turns N1), the motor operates with fewer effective turns. According to motor principles, fewer turns correspond to a lower back electromotive force constant, allowing the motor to reach a higher maximum speed under the same voltage drive.

[0060] Conversely, when the motor needs to operate in "high torque" mode (typically during start-up or hill climbing), the main controller shuts down the first winding control sub-device and activates the second winding control sub-device connected to the second set of taps (U2, V2, W2). This makes the effective number of working turns of the motor N2 (N2>N1). More turns correspond to a higher back electromotive force constant and torque constant, allowing the motor to output greater torque at the same current.

[0061] Based on the above embodiments, as an optional implementation method, the multiple taps on the winding of the three-phase permanent magnet motor are set with equal number of turns and spacing.

[0062] Since key performance indicators of a motor, such as its back electromotive force constant and torque constant, are basically proportional to the effective number of turns in the winding, if the difference in the number of turns between each group of taps is random and irregular, then the performance changes brought about by each "gear" switch will also be unpredictable and fluctuate greatly.

[0063] By mandating a constant difference in the number of turns between each group of taps (i.e., "equal turn spacing"), the change in motor performance parameters (such as torque capacity) caused by each "gear shift" becomes constant or a fixed proportion.

[0064] Based on the above embodiments, as an optional implementation method, the multiple taps on the windings of the three-phase permanent magnet motor are set according to the constant speed range under standard driving conditions.

[0065] The specific approach involves a non-linear, precisely calculated layout of the tap positions during the motor design and manufacturing phases. For example, if the design goal is for the motor's "speeds" to cover several arithmetic (ΔV=20km / h) speed ranges: 0-60km / h, 60-80km / h, 80-100km / h, and 100-120km / h, then the winding turns must follow the aforementioned inverse proportional relationship. Assuming a maximum speed of 60km / h requires N1 turns, then to increase the maximum speed to 80km / h (60*4 / 3), the required number of turns N2 must be 3 / 4 of N1. And to further increase the maximum speed to 100km / h (60*5 / 3), the required number of turns N3 must be 3 / 5 of N1.

[0066] Calculations show that the difference in the number of turns between the first and second tap groups is N1 - N2 = N1 / 4, while the difference between the second and third tap groups is N2 - N3 = (3 / 4)N1 - (3 / 5)N1 = 3 / 20 * N1. Clearly, N1 / 4 > 3 / 20 * N1. This proves that to achieve a constant speed increase, the distance between the taps must decrease. That is, in the low-speed range (more turns), the difference in the number of turns between adjacent "gears" is larger; while in the high-speed range (fewer turns), the difference in the number of turns between adjacent "gears" becomes smaller.

[0067] The following are embodiments of the method of this application, which can be further implemented based on the device embodiments of this application. Please refer to the following for details. Figure 3 , Figure 3 This is a flowchart illustrating a winding control method for a three-phase permanent magnet motor provided in an embodiment of this application. The method specifically includes the following steps.

[0068] S101: In response to the driver's operation command, acquire the vehicle's current speed and at least one environmental parameter of the vehicle in the current driving environment; S102: Determine the safe driving speed range for the current driving environment based on at least one environmental parameter; S103: Obtain historical driving data associated with the driver's identification, and determine the habitual speed range under the current driving environment based on the historical driving data; S104: Determine the target driving speed based on the overlap between the safe driving speed range and the habitual driving speed range; S105: Based on the difference between the current vehicle speed and the target driving speed, and referring to the vehicle speed range corresponding to each group of taps on the three-phase permanent magnet motor, determine the winding switching scheme that meets the preset transformation constraints. The winding switching scheme includes a winding tap switching sequence arranged in ascending order of the number of turns. S106: When the switching time of the winding switching scheme is reached, a control signal will be sent to the corresponding winding control sub-device.

[0069] In response to the driver's commands, the winding control unit immediately collects two types of basic data required for decision-making: firstly, the vehicle's own dynamic state parameters, i.e., the current vehicle speed; and secondly, at least one environmental parameter affecting driving safety. The necessity of this step lies in the fact that any effective control decision must be based on an accurate perception of the vehicle's current operating state and its external environment. The effect of this step is to provide real-time and accurate input for the subsequent logical judgments and control planning of the winding control unit, forming the foundation of the entire adaptive speed regulation process.

[0070] Next, the winding control device proceeds to step S102. In this step, the winding control device determines the safe driving speed range for the current driving environment by querying its internally stored preset rule set based on the acquired environmental parameters. The purpose of this step is to pre-define a speed constraint boundary with functional safety as the highest priority based on external objective conditions. This rule set defines the mapping relationship between various environmental parameters and the reference speed range. By matching real-time environmental information with established safety standards, the output of this step functionally constitutes a mandatory constraint on speed adjustment, ensuring that all subsequent operations are performed within this framework.

[0071] After establishing the safety boundaries, to improve the compatibility of human-machine interaction, the winding control device executes step S103. Based on the identified driver's identifier, the winding control device retrieves and analyzes their associated historical driving data. By performing data mining on the driver's driving behavior patterns in similar environments, the winding control device can infer the habitual speed range for the current driving environment that aligns with the driver's personal preferences. The purpose of this step is to quantify the driver's personalized characteristics and integrate them into the control model, avoiding conflicts between speed adjustment behavior and the driver's subjective intentions. The effect is to make subsequent speed adjustments closer to the driver's expectations, thereby improving the comfort and acceptability of the vehicle's driving process.

[0072] Subsequently, in step S104, the winding control device determines the final target driving speed based on the safe driving speed range and the habitual driving speed range determined in the preceding steps. The internal decision-making logic of the winding control device is as follows: when the two ranges intersect, the optimal value within this intersection is selected as the target; when the two ranges do not intersect, the safe driving speed range is used as the standard, and the endpoint value closest to the habitual driving speed range is selected as the target. The core of this step lies in resolving the potential conflict between safety and comfort goals through algorithmic logic. Its effect is to output a unique target driving speed that satisfies both the hard safety constraints and, to the greatest extent possible, takes into account the driver's habits.

[0073] Once the target driving speed is determined, the winding control device in step S105 begins planning the specific execution path, i.e., determining the winding switching scheme. This step aims to ensure a smooth and shock-free transition from the current vehicle speed to the target driving speed. Based on the speed difference between the two speeds and referring to the speed range characteristics corresponding to each set of taps on the three-phase permanent magnet motor, the winding control device plans a switching scheme that satisfies preset transformation constraints. The core of this scheme is to generate a winding tap switching sequence arranged in ascending order of turns. This step decomposes the macroscopic speed regulation task into a series of ordered, timed microscopic operation commands at the motor physical level. The preset transformation constraints may include at least one of the following: maximum impact during the switching process, maximum acceleration / deceleration, and the shortest time interval between two adjacent tap switchings.

[0074] Finally, in S106, the winding control device executes the predetermined switching scheme. When the switching time of the winding switching scheme is reached, the winding control device generates a control signal and sends it to the corresponding winding control sub-device. The sub-device receiving the signal immediately drives its output module to switch the on / off state of the motor winding taps. This action directly changes the effective number of turns of the motor winding, thereby adjusting its output characteristics and making the vehicle's dynamic response follow the predetermined scheme. The execution of this final step transforms the algorithmic planning into physical reality, and its direct effect is that the vehicle speed smoothly converges to the target driving speed, allowing the driver to seamlessly take control of the vehicle in a dynamically stable and expected state.

[0075] Based on the above embodiments, as an optional implementation method, step S102 specifically includes: Each environmental parameter is matched with the standard environmental parameter range in the preset rule set to determine the reference vehicle speed range corresponding to each environmental parameter. The preset rule set defines the mapping relationship between a combination of one or more standard environmental parameter ranges and the reference vehicle speed range. By integrating the speed ranges of each parameter, a safe driving speed range for the current driving environment can be obtained.

[0076] In practice, the pre-defined rule set rigorously defines the mapping relationship between a combination of one or more standard environmental parameter ranges and a reference vehicle speed range, transforming expert knowledge and massive amounts of data into machine-executable logic. During actual vehicle operation, various real-time environmental parameters are continuously collected, and a matching operation is immediately performed. This involves using these real-time parameters to query the pre-defined rule set, thereby determining a corresponding reference vehicle speed range for each relevant environmental parameter. Since the real-world driving environment is a superposition of multi-dimensional factors, this matching process simultaneously yields multiple parameter speed ranges constrained by different environmental factors.

[0077] Finally, these independent parameter speed ranges obtained from different dimensions must be integrated. The integration logic is to take the intersection of all parameter speed ranges to ensure that the final speed range simultaneously meets the safety requirements of all environmental factors. This final intersection is the safe driving speed range for the current driving environment. The ultimate goal is to dynamically generate an optimal driving speed window based on the complex and ever-changing real-time environment.

[0078] Based on the above embodiments, as an optional implementation method, step S104 specifically includes: Determine whether there is any overlap between the safe driving speed range and the habitual driving speed range; If the safe driving speed range and the habitual driving speed range overlap, the value within the overlap that is closest to the current speed will be determined as the target driving speed. If the safe driving speed range and the habitual driving speed range do not overlap, then the endpoint value within the safe driving speed range that is closest to the habitual driving speed range will be determined as the target driving speed.

[0079] The winding control device first activates its internal decision-making algorithm to make logical judgments on the two intervals. Specifically, it determines whether there is any overlap between the safe driving speed interval and the habitual driving speed interval.

[0080] If the safe driving speed range overlaps with the habitual driving speed range, it indicates that the driver's habitual driving speed is within the safe limits of the current environment. This is the ideal operating condition, where the goals of safety and comfort are unified within this range. In this case, the winding control device will determine the value within the intersection that is closest to the current vehicle speed as the target driving speed. This is done because selecting a value within the intersection satisfies both safety and personalization constraints; selecting the value closest to the current vehicle speed aims to minimize the absolute amount of speed adjustment, thus making acceleration and deceleration processes smoother, reducing impact, and improving the smoothness of the driving process and ride comfort. The effect of this is to achieve optimized transition dynamics while ensuring safety and respecting habits, allowing the driver to perceive the speed changes as naturally as possible.

[0081] Conversely, if the safe driving speed range and the habitual speed range do not overlap, it indicates a conflict between the driver's habits and the safety requirements of the current environment, necessitating arbitration. In this case, the winding control device will strictly adhere to the fundamental principle of "safety first." Specifically, the winding control device will determine the target driving speed as the endpoint within the safe driving speed range that is closest to the habitual speed range. The fundamental purpose of this is that when personalized habits conflict with basic safety requirements, safety must be unconditionally prioritized, forcibly adjusting the vehicle to the safe speed range. Choosing the endpoint closest to the habitual range is a compromise that best reflects the driver's intentions while adhering to the bottom line of safety, minimizing subjective perception deviations caused by speed correction.

[0082] In the several embodiments provided in this application, it should be understood that the disclosed apparatus can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some service interface; the indirect coupling or communication connection between apparatuses or units may be electrical or other forms.

[0083] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0084] Furthermore, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

Claims

1. A winding control device for a three-phase permanent magnet motor, characterized in that, The winding control device is connected to multiple taps on the windings of the three-phase permanent magnet motor. The winding control device includes a control module and multiple winding control sub-devices. Each winding control sub-device includes an isolation drive module, a voltage regulator module, and an output module. The isolation drive module is connected to both the voltage regulator module and the output module. The output module is connected to the taps. The control module is connected to the isolation drive module. Wherein: The control module is used to respond to the driver's operation commands, acquire the vehicle's current speed and environmental parameters to determine a safe driving speed range; acquire the driver's historical driving data to determine a habitual speed range; determine a target driving speed based on the overlap between the safe driving speed range and the habitual speed range; and determine a winding switching scheme containing a multi-stage winding tap switching sequence based on the current speed and the target driving speed, and output control signals to the corresponding winding control sub-device according to the winding switching scheme. The isolation drive module is used to control the on / off state of the voltage regulator module and the output module according to the control signal output by the control module; The voltage regulator module is used to regulate the input power supply voltage and to supply power to the output module when the voltage regulator module is connected to the output module. The output module is used to control the on / off state of the tap according to the connection status of the isolation drive module.

2. The winding control device according to claim 1, characterized in that, The voltage regulator module includes a first resistor, a second resistor, a first transistor, a Zener diode, and a first capacitor, wherein; The external power input is connected to the collector of the first transistor via the first resistor, and the external power input is connected to the base of the first transistor via the second resistor; The negative terminal of the Zener diode is connected to the base of the first transistor, and the positive terminal of the Zener diode is connected to the output module. The emitter of the first transistor is connected to the positive terminal of the Zener diode via the first capacitor. The emitter of the first transistor is connected to the isolation drive module. The positive terminal of the Zener diode is grounded.

3. The winding control device according to claim 1, characterized in that, The output module includes a third resistor, a fourth resistor, a second MOSFET, a third MOSFET, a fourth MOSFET, and a second capacitor, wherein; The isolation drive module is connected to the first end of the third resistor, the second end of the third resistor is grounded through the second capacitor, and the source of the second MOS transistor, the source of the third MOS transistor, and the source of the fourth MOS transistor are all connected to a common ground. The second end of the third resistor is connected to the gate of the second MOS transistor, the gate of the third MOS transistor, and the gate of the fourth MOS transistor, respectively. The second end of the third resistor is connected to the source of the second MOS transistor, the source of the third MOS transistor, and the source of the fourth MOS transistor via the fourth resistor, respectively. The drain of the second MOS transistor, the drain of the third MOS transistor, and the drain of the fourth MOS transistor are respectively connected to the corresponding taps on the winding of the three-phase permanent magnet motor.

4. The winding control device according to claim 3, wherein the second MOSFET, the third MOSFET, and the fourth MOSFET are all N-MOSFETs.

5. The winding control device according to claim 1, characterized in that, The isolation driver module includes a fifth resistor and an optocoupler, wherein: An external control signal is input and connected to the positive input terminal of the optocoupler via the fifth resistor, while the negative input terminal of the optocoupler is grounded. The positive output of the optocoupler is connected to the voltage regulator module, and the negative output of the optocoupler is connected to the output module.

6. The winding control device according to claim 1, characterized in that, The windings of the three-phase permanent magnet motor are star-connected, and the windings are provided with multiple sets of taps. Each set of taps has the same number of turns. One winding control sub-device is connected to a corresponding set of taps.

7. The winding control device according to claim 1, characterized in that, The multiple taps on the winding of the three-phase permanent magnet motor are arranged with equal number of turns and spacing.

8. A winding control method for a three-phase permanent magnet motor, characterized in that, The method, applied to the winding control device according to any one of claims 1-7, comprises: In response to the driver's operation command, the vehicle's current speed and at least one environmental parameter of the vehicle in the current driving environment are obtained; Based on at least one of the environmental parameters, determine the safe driving speed range for the current driving environment; Obtain historical driving data associated with the driver's identifier, and determine the habitual speed range under the current driving environment based on the historical driving data; The target driving speed is determined based on the overlap between the safe driving speed range and the habitual driving speed range. Based on the difference between the current vehicle speed and the target driving speed, and referring to the vehicle speed range corresponding to each set of taps on the three-phase permanent magnet motor, a winding switching scheme that satisfies the preset transformation constraint conditions is determined. The winding switching scheme includes a winding tap switching sequence arranged in ascending order of the number of turns. When the switching time of the winding switching scheme is reached, a control signal is sent to the corresponding winding control sub-device.

9. The method according to claim 8, characterized in that, Determining the safe driving speed range for the current driving environment based on at least one of the environmental parameters includes: Each environmental parameter is matched with a standard environmental parameter range in a preset rule set to determine a reference vehicle speed range corresponding to each environmental parameter. The preset rule set defines a mapping relationship between a combination of one or more standard environmental parameter ranges and a reference vehicle speed range. By integrating the speed ranges of each parameter, the safe driving speed range for the current driving environment is obtained.

10. The method according to claim 8, characterized in that, Determining the target driving speed based on the overlap between the safe driving speed range and the habitual driving speed range includes: Determine whether there is any overlap between the safe driving speed range and the habitual driving speed range; If the safe driving speed range intersects with the habitual driving speed range, then the value within the intersection that is closest to the current speed is determined as the target driving speed. If the safe driving speed range and the habitual speed range do not overlap, then the endpoint value within the safe driving speed range that is closest to the habitual speed range is determined as the target driving speed.

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