Motor control methods, motor controllers, electric drive systems and new energy vehicles

Abstract

This invention discloses a motor control method, a motor controller, an electric drive system, and a new energy vehicle. The motor control method includes: obtaining a torque command based on CAN control commands received from other vehicle controllers and a motor position signal; calculating a voltage vector command based on the torque command; converting the voltage vector command into three duty cycle signals using SVPWM; converting the three duty cycle signals into six initial duty cycle signals required by six IGBT switches based on a set dead time; performing narrow pulse suppression on the six initial duty cycle signals to output six target duty cycle signals; and inputting the six target duty cycle signals to a drive module to drive the IGBT switches to control the motor operation. This addresses the problem of difficulty in accurately controlling narrow pulse suppression accuracy due to device precision limitations, achieving effective and comprehensive suppression of narrow pulses and ensuring reliable IGBT operation.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a motor control method, a motor controller, an electric drive system, and a new energy vehicle. Background Technology

[0002] With the rapid development of the new energy vehicle industry and the increasing maturity of inverter technology, the requirements for the efficiency and energy density of electric drive systems are becoming increasingly stringent. Currently, the mainstream inverters for electric drive systems use IGBTs as switching devices. Both the turn-on and turn-off processes of IGBTs require a certain amount of time. To protect the IGBTs from shoot-through in the upper and lower bridge arms, dead time is typically increased. Furthermore, turn-on and turn-off pulses with excessively short durations not only fail to generate effective turn-on or turn-off, resulting in additional power losses, but also cause large surge voltage spikes and oscillations in the IGBT switching devices, threatening reliable IGBT operation, reducing IGBT lifespan, and even directly damaging the IGBT switching devices. To protect the IGBTs and increase their lifespan, narrow pulse suppression functions are generally added. Summary of the Invention

[0003] This invention provides a motor control method, a motor controller, an electric drive system, and a new energy vehicle to solve the problem that the narrow pulse suppression accuracy is difficult to control precisely due to the influence of device precision.

[0004] According to one aspect of the present invention, a motor control method is provided, the motor control method comprising:

[0005] The torque command is obtained based on the CAN control command received from other vehicle controllers and the motor position signal. The voltage vector command is then calculated based on the torque command. The voltage vector command is then converted using the SVPWM function to obtain three duty cycle signals.

[0006] Based on the set dead time, the three duty cycle signals are converted into six initial duty cycle signals required by the six IGBT switches, and narrow pulse suppression is performed on the six initial duty cycle signals to output six target duty cycle signals accordingly.

[0007] The six target duty cycle signals are input to the drive module to drive the IGBT switch to control the motor.

[0008] Optionally, the step of calculating the voltage vector command based on the torque command includes:

[0009] The torque command is preprocessed, including de-jittering, slope limiting, and smooth switching between different control modes.

[0010] The voltage vector command is calculated based on the preprocessed torque command.

[0011] Optionally, the step of calculating the voltage vector command based on the preprocessed torque command includes:

[0012] When the motor controller is operating in the non-weakening field zone, the MTPA control mode is adopted. Based on the pre-processed torque command, the id command and iq command are obtained by looking up a table, and closed-loop control is performed respectively.

[0013] When the motor controller switches from MTPA control mode to voltage vector control mode, the amplitude of the voltage vector command is set to the bus voltage / sqrt(3), and the phase angle of the voltage vector command is obtained by the closed-loop control of the command torque and the actual torque.

[0014] The voltage vector command is converted from the amplitude and phase angle mode to the dq coordinate system to obtain the voltage vector command.

[0015] Optionally, the method for setting the dead time includes:

[0016] The lower arm of the IGBT is turned off half a dead time in advance, and the upper arm of the IGBT is turned on with a delay of half a dead time. Specifically:

[0017] when hour, , ;

[0018] when hour, , ;

[0019] when hour, , ;

[0020] in, Indicates the PWM cycle time; Indicates dead time; This represents the ideal on-time of the motor's current phase duty cycle in the k-th cycle; This represents the conduction time of the upper arm of the IGBT in the k-th cycle; This represents the conduction time of the lower arm of the IGBT in the k-th cycle.

[0021] Optionally, when the duty cycle output of the upper IGBT arm is 0 and the duty cycle output of the lower IGBT arm is 1 in the k-th cycle, then the duty cycle output of the upper IGBT arm is 1 and the duty cycle output of the lower IGBT arm is 0 in the (k+1)-th cycle. The dead time is set as follows:

[0022] The actual duty cycle output of the IGBT upper arm is: The actual duty cycle output of the IGBT lower arm is 0;

[0023] When the duty cycle output of the upper arm of the IGBT is 1 in the k-th cycle and the duty cycle output of the lower arm of the IGBT is 0, then the conduction time of the upper arm of the IGBT in the (k+1)-th cycle is less than... The dead time is set in the following way:

[0024] The actual duty cycle output of the IGBT upper arm is: The actual duty cycle output of the lower arm of the IGBT is .

[0025] Optionally, the principle for narrow pulse suppression of the six initial duty cycle signals includes:

[0026] when Greater than or equal to and Less than or equal to When the current phase IGBT upper arm of the motor is at that time, the actual duty cycle output is: The actual duty cycle output of the lower arm of the IGBT is ;

[0027] when Less than and Greater than or equal to Then the actual duty cycle output of the upper IGBT arm of the current phase of the motor is 0, and the actual duty cycle output of the lower IGBT arm is... ;

[0028] when Less than and Less than Then the actual duty cycle output of the upper IGBT arm of the current phase of the motor is 0, and the actual duty cycle output of the lower IGBT arm is... ;

[0029] when Greater than or equal to and Greater than At that time, if Greater than or equal to The actual duty cycle output of the current phase IGBT upper bridge arm of the motor is then... The actual duty cycle output of the lower arm of the IGBT is ;

[0030] when Greater than or equal to and Greater than At that time, if Less than If Greater than or equal to If the first method is followed, then the second method will be followed.

[0031] in, This represents the turn-off time of the lower bridge arm in the k-th cycle; This represents the conduction time of the upper arm in the (k+1)th cycle; This represents the turn-off time of the lower bridge arm in the (k+1)th cycle; For a specific time period.

[0032] Optionally, the first processing method is to keep the actual duty cycle output of the upper arm of the IGBT unchanged, and set the low-level conduction time of the actual duty cycle output of the lower arm of the IGBT to 0 in the second half of the current cycle and the first half of the next cycle.

[0033] The second processing method is to set the actual duty cycle output of the upper IGBT to be turned on in the second half of the current cycle and the first half of the next cycle, and set the actual duty cycle output of the lower IGBT to be turned off in the second half of the current cycle and the first half of the next cycle.

[0034] According to another aspect of the present invention, a motor controller is provided, which is capable of executing the motor control method described in any embodiment of the present invention.

[0035] According to another aspect of the present invention, an electric drive system is provided, the electric drive system comprising: a permanent magnet synchronous motor equipped with a resolver as a position sensor, a high-voltage power supply, a low-voltage power supply, and a motor controller as described in any embodiment of the present invention.

[0036] According to another aspect of the present invention, a new energy vehicle is provided, the new energy vehicle including the electric drive system described in any embodiment of the present invention.

[0037] The technical solution of this invention obtains a torque command based on the received CAN control commands from other vehicle controllers and the motor position signal, and calculates a voltage vector command based on the torque command. The voltage vector command is then converted using SVPWM to obtain three duty cycle signals. Based on a set dead time, the three duty cycle signals are converted into six initial duty cycle signals required by six IGBT switches. Narrow pulse suppression is applied to these six initial duty cycle signals to output six target duty cycle signals. These six target duty cycle signals are then input to the drive module to drive the IGBT switches and control the motor. To address the problem of difficulty in precisely controlling narrow pulse suppression accuracy due to device precision limitations, this embodiment distinguishes between the dead time and the target narrow pulse width. This allows for the output of PWM waveforms with more duty cycles, which is more conducive to increasing motor output power. Furthermore, it improves the power density of the electric drive system from a software perspective, reduces the hardware cost of the electric drive system, and achieves effective and comprehensive suppression of narrow pulses, ensuring reliable IGBT operation.

[0038] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a flowchart of a motor control method provided according to Embodiment 1 of the present invention;

[0041] Figure 2 This is a schematic diagram of the structure of a motor controller according to Embodiment 2 of the present invention;

[0042] Figure 3 This is a schematic diagram of the high-voltage topology in the motor controller provided according to an embodiment of the present invention, which adopts a traditional three-phase bridge circuit.

[0043] Figure 4 This is a schematic diagram of the PWM waveform after adding dead time according to an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of a PWM waveform for a dead-time addition method according to an embodiment of the present invention;

[0045] Figure 6This is a schematic diagram of a PWM waveform showing another method of adding dead time according to an embodiment of the present invention;

[0046] Figure 7 This is a schematic diagram of a PWM waveform for narrow pulse suppression processing according to an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of a PWM waveform for suppressing narrow pulses according to an embodiment of the present invention;

[0048] Figure 9 This is a schematic diagram of another PWM waveform for suppressing narrow pulses provided by an embodiment of the present invention;

[0049] Figure 10 This is a schematic diagram of the structure of an electric drive system according to Embodiment 3 of the present invention;

[0050] Figure 11 This is a structural schematic diagram of a new energy vehicle provided according to Embodiment 4 of the present invention. Detailed Implementation

[0051] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0052] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0053] Example 1

[0054] Figure 1The flowchart of a motor control method provided in Embodiment 1 of the present invention is applicable to situations where a PWM waveform with a larger duty cycle can be output by separately considering dead time and narrow pulse, thereby increasing the output power of the motor system. This motor control method can be executed by a motor controller, which can be implemented in hardware and / or software. This motor controller can be configured in the electric drive system of new energy vehicles. Figure 1 As shown, the motor control method includes:

[0055] S110. Obtain torque command based on CAN control command from other vehicle controllers and motor position signal, and calculate voltage vector command based on torque command. Then, convert the voltage vector command and use SVPWM function to obtain three duty cycle signals.

[0056] The motor controller includes a control board that receives CAN control commands from other vehicle controllers and motor position signals. The main control chip on the control board includes torque control, voltage conversion, SVPWM, and PWM post-processing functions, such as... Figure 2 As shown, this embodiment provides a detailed description of the improvements to the torque control function and the PWM post-processing section. The remaining parts can be implemented using common industry practices and will not be described in detail here.

[0057] CAN control commands refer to CAN signals from other controllers in the vehicle. When the electric drive system is on a test bench, this part can also refer to control commands from the host computer. Motor position signals refer to all other signals required for the operation of the motor system, such as IG switch signals and airbag collision signals from the vehicle.

[0058] Specifically, the motor controller processes the torque command obtained from the CAN bus, and preprocesses the torque command, including debouncing, slope limiting, and smooth switching between different control modes, so as to ensure that the processed torque command involved in subsequent control links is smooth and continuous.

[0059] Furthermore, in order to effectively utilize the bus voltage and improve voltage utilization, this embodiment calculates the voltage vector command based on the preprocessed torque command and the measured three-phase current and other information.

[0060] Specifically, when the motor controller is operating in the non-weakening field region, the MTPA control mode is adopted. Based on the pre-processed torque command, the id command and iq command are obtained by looking up a table, and closed-loop control is performed respectively. The MTPA control mode, i.e. maximum torque-current ratio, is a common operation state optimization control method in the vector control of permanent magnet synchronous motors.

[0061] As the motor speed increases, or the torque command increases, or the bus voltage decreases, the motor's operating point will gradually move closer to the field weakening region. When the difference between the calculated voltage vector and the bus voltage / sqrt(3) is less than a certain value, the motor controller's control mode switches from MTPA control to voltage vector control. Here, the certain value can be selected as 5V, or it can be selected according to the test results of different systems. This embodiment does not impose any restrictions on this. Furthermore, when the motor controller's control mode switches from MTPA control to voltage vector control, the amplitude of the voltage vector command is set to the bus voltage / sqrt(3), and the phase angle of the voltage vector command is set to be obtained based on the closed-loop control of the command torque and the actual torque. The actual torque used in the closed-loop control is calculated based on information such as the motor's three-phase current, rotor position angle, and motor parameters.

[0062] See also Figure 2 The voltage vector command is converted from amplitude and phase angle mode to dq coordinate system to obtain voltage vector command (Ud*, Uq*). Further, the voltage vector command is transformed to obtain voltage vector command (Uα*, Uβ*), and then the voltage vector command (Uα*, Uβ*) is used to obtain three duty cycle signals using SVPWM function.

[0063] S120. Based on the set dead time, the three duty cycle signals are converted into six initial duty cycle signals required by the six IGBT switches, and the six initial duty cycle signals are subjected to narrow pulse suppression to output six target duty cycle signals.

[0064] The main function of PWM post-processing is to convert the three duty cycle signals calculated by the SVPWM function into six initial duty cycle signals required by the six IGBT switches by adding a dead time; and to perform narrow pulse judgment and suppression on the six initial duty cycle signals.

[0065] Since the three-phase bridge arms are completely independent, please refer to Figure 3 The following description uses one phase as an example; the other two phases are exactly the same, so they will not be described again.

[0066] Specifically, the methods for setting the dead time include:

[0067] The lower arm of the IGBT is turned off half a dead time in advance, and the upper arm of the IGBT is turned on with a delay of half a dead time. Specifically:

[0068] when hour, , ;

[0069] when hour, , ;

[0070] when hour, , ;

[0071] in, Indicates the PWM cycle time; Indicates dead time; This represents the ideal on-time of the motor's current phase duty cycle in the k-th cycle; This represents the conduction time of the upper arm of the IGBT in the k-th cycle; This represents the conduction time of the lower arm of the IGBT in the k-th cycle.

[0072] The PWM waveform after adding dead time is a centrally symmetrical PWM waveform, a typical waveform is as follows: Figure 4 As shown, there are two special cases:

[0073] When the duty cycle output of the upper IGBT arm is 0 (i.e., always low) and the duty cycle output of the lower IGBT arm is 1 (i.e., always high) in the k+1th cycle, and the duty cycle output of the upper IGBT arm is 1 (i.e., always high) and the duty cycle output of the lower IGBT arm is 0 (i.e., always low), the dead time is set as follows:

[0074] The actual duty cycle output of the IGBT upper arm is: The actual duty cycle output of the lower IGBT arm is 0. See details. Figure 5 As shown;

[0075] When the duty cycle output of the upper IGBT is 1 (i.e., always high) in the k-th cycle and the duty cycle output of the lower IGBT is 0 (i.e., always low), then the conduction time of the upper IGBT in the (k+1)-th cycle is less than [a certain value]. The dead time is set in the following way:

[0076] The actual duty cycle output of the IGBT upper arm is: The actual duty cycle output of the lower arm of the IGBT is See details Figure 6 As shown.

[0077] Furthermore, the high-level time of the IGBT upper arm, the low-level time of the IGBT upper arm, the high-level time of the IGBT lower arm, and the low-level time of the IGBT lower arm are each judged separately to ensure that no high-level or low-level signal occurs for less than a specific time (i.e., the following). Narrow pulses. Furthermore, for narrow pulses formed by splicing two cycles, the latter half of the k-th cycle and the first half of the (k+1)-th cycle are spliced ​​together, and corresponding processing is performed. See the specific processing logic diagram. Figure 7 As shown.

[0078] Specifically, the principle for narrow pulse suppression of the six initial duty cycle signals includes:

[0079] Because the main control chip of an electric drive system generally has limited performance, it is necessary to ensure that the execution time is as short as possible in most cases when suppressing narrow pulses. Greater than or equal to and Less than or equal to When this is the case, the PWM signals of both the upper and lower bridge arms of the current phase of the motor can be directly output, meaning the actual duty cycle output of the upper bridge arm of the IGBT in the current phase of the motor is... The actual duty cycle output of the lower arm of the IGBT is ;

[0080] when Less than and Greater than or equal to Then the actual duty cycle output of the upper IGBT arm of the current phase of the motor is 0, and the actual duty cycle output of the lower IGBT arm is... ;

[0081] when Less than and Less than If the current phase of the motor has an IGBT upper arm, the actual duty cycle output is 0, and the actual duty cycle output of the IGBT lower arm is 0.

[0082] when Greater than or equal to and Greater than At this point, it is necessary to calculate the PWM duty cycle for k+1 cycles simultaneously to obtain the specific processing logic. Specifically: when Greater than or equal to and Greater than At that time, if Greater than or equal to The actual duty cycle output of the current phase IGBT upper bridge arm of the motor is then... The actual duty cycle output of the lower arm of the IGBT is ;

[0083] when Greater than or equal to and Greater than At that time, if Less than If Greater than or equal to If the first method is followed, then the second method will be followed.

[0084] in, This represents the turn-off time of the lower bridge arm in the k-th cycle; This represents the conduction time of the upper arm in the (k+1)th cycle; This represents the turn-off time of the lower bridge arm in the (k+1)th cycle; For a specific time period.

[0085] Based on the above, the first processing method involves keeping the actual duty cycle output of the IGBT upper arm unchanged, while setting the low-level conduction time of the actual duty cycle output of the IGBT lower arm to 0 during the latter half of the current cycle and the first half of the next cycle. See details... Figure 8 As shown;

[0086] The second processing method involves setting the actual duty cycle output of the IGBT upper arm to "on" (continuously high level during this period) for the switching command in the latter half of the current cycle and the first half of the next cycle, while setting the actual duty cycle output of the IGBT lower arm to "off" (continuously low level during this period) for the switching command in the latter half of the current cycle and the first half of the next cycle. See details... Figure 9 As shown.

[0087] S130. Input the six target duty cycle signals to the drive module to drive the IGBT switch to control the motor.

[0088] Specifically, based on the characteristics of the IGBT, the drive module performs level conversion and necessary signal processing on the six target duty cycle signals output by the control board to drive the IGBT, making the output waveform of the IGBT consistent with the PWM waveform output by the control board, thereby controlling the motor.

[0089] It should be noted that, in the embodiments of the present invention, the motor may be a permanent magnet synchronous motor, as detailed below.

[0090] The technical solution of this invention obtains a torque command based on the received CAN control commands from other vehicle controllers and the motor position signal, and calculates a voltage vector command based on the torque command. The voltage vector command is then converted using SVPWM to obtain three duty cycle signals. Based on a set dead time, the three duty cycle signals are converted into six initial duty cycle signals required by six IGBT switches. Narrow pulse suppression is applied to these six initial duty cycle signals to output six target duty cycle signals. These six target duty cycle signals are then input to the drive module to drive the IGBT switches and control the motor. To address the problem of difficulty in precisely controlling narrow pulse suppression accuracy due to device precision limitations, this embodiment distinguishes between the dead time and the target narrow pulse width. This allows for the output of PWM waveforms with more duty cycles, which is more conducive to increasing motor output power. Furthermore, it improves the power density of the electric drive system from a software perspective, reduces the hardware cost of the electric drive system, and achieves effective and comprehensive suppression of narrow pulses, ensuring reliable IGBT operation.

[0091] Example 2

[0092] Figure 2 This is a schematic diagram of a motor controller provided in Embodiment 2 of the present invention. The motor controller provided in this embodiment can execute the motor control method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects for executing the motor control method. Figure 2 As shown, the motor controller includes a control board, IGBTs, and a drive module. The control board receives CAN control commands from other vehicle controllers and motor position signals. The main control chip on the control board includes torque control, voltage conversion, SVPWM, and PWM post-processing functions. The drive module, based on the IGBT characteristics, performs level conversion and necessary signal processing on the six target duty cycle signals output from the control board to drive the IGBT, ensuring that the IGBT's output waveform matches the PWM waveform output from the control board.

[0093] The motor controller provided in this embodiment of the invention obtains a torque command based on the received CAN control commands from other vehicle controllers and the motor position signal, and calculates a voltage vector command based on the torque command. The voltage vector command is then converted using SVPWM to obtain three duty cycle signals. Based on a set dead time, the three duty cycle signals are converted into six initial duty cycle signals required by six IGBT switches. Narrow pulse suppression is applied to these six initial duty cycle signals, resulting in the output of six target duty cycle signals. These six target duty cycle signals are input to the drive module to drive the IGBT switches and control the motor operation. To address the problem of difficulty in precisely controlling narrow pulse suppression accuracy due to device precision limitations, this embodiment distinguishes between the dead time and the target narrow pulse width. This allows for the output of PWM waveforms with more duty cycles, which is more conducive to increasing motor output power. Furthermore, it improves the power density of the electric drive system from a software perspective, reduces the hardware cost of the electric drive system, and achieves effective and comprehensive suppression of narrow pulses, ensuring reliable IGBT operation.

[0094] Example 3

[0095] Figure 10 This is a schematic diagram of an electric drive system provided in Embodiment 3 of the present invention. The electric drive system provided in this embodiment of the present invention has the corresponding functional modules of a motor controller and beneficial effects. For example... Figure 10 As shown, the electric drive system includes: a motor controller, a permanent magnet synchronous motor equipped with a resolver as a position sensor, a high-voltage power supply, and a low-voltage power supply. The motor controller consists of a control board, a drive module, and IGBTs. The motor controller is connected to the permanent magnet synchronous motor equipped with the resolver as a position sensor, the high-voltage power supply, and the low-voltage power supply. The high-voltage power supply provides high-voltage power to the entire electric drive system for controlling motor rotation. The low-voltage control voltage powers the internal control board of the motor controller, performs signal processing, and provides corresponding drive signals.

[0096] The electric drive system provided in this embodiment of the invention includes a motor controller. It obtains a torque command based on CAN control commands received from other vehicle controllers and a motor position signal, and calculates a voltage vector command based on the torque command. The voltage vector command is then converted using SVPWM to obtain three duty cycle signals. Based on a set dead time, the three duty cycle signals are converted into six initial duty cycle signals required by six IGBT switches. Narrow pulse suppression is applied to these six initial duty cycle signals, resulting in the output of six target duty cycle signals. These six target duty cycle signals are input to the drive module to drive the IGBT switches and control the motor operation. To address the problem of difficulty in precisely controlling narrow pulse suppression accuracy due to device precision limitations, this embodiment distinguishes between the dead time and the target narrow pulse width. This allows for the output of PWM waveforms with more duty cycles, which is more conducive to increasing motor output power. Furthermore, it improves the power density of the electric drive system from a software perspective, reduces the hardware cost of the electric drive system, and achieves effective and comprehensive suppression of narrow pulses, ensuring reliable IGBT operation.

[0097] Example 4

[0098] Figure 11 This is a schematic diagram of the structure of a new energy vehicle provided in Embodiment 4 of the present invention. The new energy vehicle provided in this embodiment of the present invention has the corresponding functional modules and beneficial effects of an electric drive system.

[0099] The new energy vehicle provided in this embodiment of the invention includes an electric drive system, which includes a motor controller. The controller obtains a torque command based on CAN control commands received from other vehicle controllers and a motor position signal. A voltage vector command is then calculated based on the torque command. This voltage vector command is transformed using SVPWM to obtain three duty cycle signals. Based on a set dead time, these three duty cycle signals are converted into six initial duty cycle signals required by six IGBT switches. Narrow pulse suppression is applied to these six initial duty cycle signals, resulting in six target duty cycle signals. These six target duty cycle signals are then input to the drive module to drive the IGBT switches and control the motor. To address the problem of difficulty in precisely controlling narrow pulse suppression accuracy due to device precision limitations, this embodiment distinguishes between the dead time and the target narrow pulse width. This allows for the output of PWM waveforms with more duty cycles, which is more conducive to increasing motor output power. Furthermore, it improves the power density of the electric drive system from a software perspective, reduces the hardware cost of the electric drive system, and achieves effective and comprehensive suppression of narrow pulses, ensuring reliable IGBT operation.

[0100] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0101] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A motor control method, characterized in that, The motor control method is executed by the motor controller and includes: The torque command is obtained based on the CAN control command received from other vehicle controllers and the motor position signal. The voltage vector command is then calculated based on the torque command. The voltage vector command is then converted using the SVPWM function to obtain three duty cycle signals. Based on the set dead time, the three duty cycle signals are converted into six initial duty cycle signals required for the six IGBT switches, and narrow pulse suppression is applied to the six initial duty cycle signals to output six target duty cycle signals. The set dead time is achieved by: the lower IGBT arm turning off half a dead time in advance, and the upper IGBT arm turning on half a dead time later. Specifically: when hour, , ; when hour, , ; when hour, , ; in, Indicates the PWM cycle time; Indicates dead time; This represents the ideal on-time of the motor's current phase duty cycle in the k-th cycle; This represents the conduction time of the upper arm of the IGBT in the k-th cycle; This represents the conduction time of the lower arm of the IGBT in the k-th cycle; The principles for narrow pulse suppression of the six initial duty cycle signals include: when Greater than or equal to and Less than or equal to When the current phase IGBT upper arm of the motor is at that time, the actual duty cycle output is: The actual duty cycle output of the lower arm of the IGBT is ; when Less than and Greater than or equal to Then the actual duty cycle output of the upper IGBT arm of the current phase of the motor is 0, and the actual duty cycle output of the lower IGBT arm is... ; when Less than and Less than Then the actual duty cycle output of the upper IGBT arm of the current phase of the motor is 0, and the actual duty cycle output of the lower IGBT arm is... ; when Greater than or equal to and Greater than At that time, if Greater than or equal to The actual duty cycle output of the current phase IGBT upper bridge arm of the motor is then... The actual duty cycle output of the lower arm of the IGBT is ; when Greater than or equal to and Greater than At that time, if Less than If Greater than or equal to If the first method is followed, then the second method will be followed. in, This represents the turn-off time of the lower bridge arm in the k-th cycle; This represents the conduction time of the upper arm in the (k+1)th cycle; This represents the turn-off time of the lower bridge arm in the (k+1)th cycle; For a specific time; The six target duty cycle signals are input to the drive module to drive the IGBT switch to control the motor.

2. The motor control method according to claim 1, characterized in that, The step of calculating the voltage vector command based on the torque command includes: The torque command is preprocessed, including de-jittering, slope limiting, and smooth switching between different control modes. The voltage vector command is calculated based on the preprocessed torque command.

3. The motor control method according to claim 2, characterized in that, The step of calculating the voltage vector command based on the preprocessed torque command includes: When the motor controller is operating in the non-weakening field zone, the MTPA control mode is adopted. Based on the pre-processed torque command, the id command and iq command are obtained by looking up a table, and closed-loop control is performed respectively. When the motor controller switches from MTPA control mode to voltage vector control mode, the amplitude of the voltage vector command is set to the bus voltage / sqrt(3), and the phase angle of the voltage vector command is obtained by the closed-loop control of the torque command and the actual torque. The voltage vector command is converted from the amplitude and phase angle mode to the dq coordinate system to obtain the voltage vector command.

4. The motor control method according to claim 1, characterized in that, When the duty cycle output of the upper IGBT arm is 0 and the duty cycle output of the lower IGBT arm is 1 in the k-th cycle, then when the duty cycle output of the upper IGBT arm is 1 and the duty cycle output of the lower IGBT arm is 0 in the (k+1)-th cycle, the dead time is set as follows: The actual duty cycle output of the IGBT upper arm is: The actual duty cycle output of the IGBT lower arm is 0; When the duty cycle output of the upper arm of the IGBT is 1 in the k-th cycle and the duty cycle output of the lower arm of the IGBT is 0, then the conduction time of the upper arm of the IGBT in the (k+1)-th cycle is less than... The dead time is set in the following way: The actual duty cycle output of the IGBT upper arm is: The actual duty cycle output of the lower arm of the IGBT is .

5. The motor control method according to claim 1, characterized in that, The first processing method is to keep the actual duty cycle output of the upper arm of the IGBT unchanged, and set the low-level conduction time of the actual duty cycle output of the lower arm of the IGBT to 0 in the second half of the current cycle and the first half of the next cycle. The second processing method is to set the actual duty cycle output of the upper IGBT to be turned on in the second half of the current cycle and the first half of the next cycle, and set the actual duty cycle output of the lower IGBT to be turned off in the second half of the current cycle and the first half of the next cycle.

6. A motor controller, characterized in that, The motor controller is capable of executing the motor control method according to any one of claims 1-5.

7. An electric drive system, characterized in that, The electric drive system includes: a permanent magnet synchronous motor equipped with a resolver as a position sensor, a high-voltage power supply, a low-voltage power supply, and the motor controller as described in claim 6.

8. A new energy vehicle, characterized in that, The new energy vehicle includes the electric drive system as described in claim 7.

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