A motor control method for operating data of a permanent magnet synchronous motor of a multi-mode pure electric vehicle

Abstract

The present invention proposes a motor control method for operating data of a permanent magnet synchronous motor of a multi-mode pure electric vehicle, which belongs to the field of motor control technology. First, a multi-mode motor control model based on the experimental data of the permanent magnet synchronous motor is established; secondly, the active current and reactive current that need to be adjusted are determined according to the speed and active current; thirdly, the torque current setting and the magnetic field control current setting are controlled according to the active current setting value and the reactive current setting value; finally, the motor experimental data is queried by the speed setting and the real-time motor speed feedback to determine the working condition of the motor, and the motor control is realized. The technical problem that the motor model existing in the prior art is extremely complex and it is difficult to realize high-performance control is solved. The closed-loop control combining the speed and the current is realized to realize the high-performance control of the permanent magnet synchronous motor.

Description

Technical Field

[0001] The present application relates to a motor control method, and more particularly to a motor control method for operating data of a permanent magnet synchronous motor of a multi-modal pure electric vehicle, and belongs to the technical field of motor control. Background Art

[0002] An accurate model is the basis for high-performance control of permanent magnet synchronous motors. Due to the nonlinearity of the motor magnetic circuit, the non-smoothness of the motor stator and rotor surfaces, and the discontinuous distribution of the windings, it is difficult to obtain an accurate model of the motor. Even if an ideal motor model is obtained, the motor model will be extremely complex and it will be difficult to achieve high-performance control. Summary of the invention

[0003] A brief overview of the present invention is provided below in order to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important parts of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is merely to present certain concepts in a simplified form as a prelude to a more detailed description discussed later.

[0004] In view of this, in order to solve the technical problem in the prior art that the model of the motor is extremely complex and it is difficult to achieve high-performance control, the present invention provides a motor control method for operating data of a permanent magnet synchronous motor of a multi-modal pure electric vehicle.

[0005] A motor control method for operating data of a permanent magnet synchronous motor of a multi-mode pure electric vehicle comprises the following steps:

[0006] Step 1: Establish a multi-mode motor control model based on permanent magnet synchronous motor experimental data;

[0007] Step 2: Determine the active current and reactive current that need to be adjusted according to the rotation speed and active current;

[0008] Step 3, controlling the torque current setting and the magnetic field control current setting according to the active current setting value and the reactive current setting value;

[0009] Step 4: Query the motor experimental data based on the speed setting and real-time motor speed feedback to determine the motor working condition and realize motor control.

[0010] Preferably, the model in step one includes a motor steady-state model and a motor dynamic model; the motor steady-state model includes steady-state experimental data of various working conditions of the motor; and the motor dynamic model is dynamic experimental data of various working conditions of the motor.

[0011] Preferably, the steady-state model of the motor includes testing the motor voltage, current, power factor, active power and reactive power when the motor changes from no-load to 120% load and the current is minimum at a certain speed, and calculating the voltage amplitude, torque, active current and reactive current of the motor; the experimental data corresponding to the speed are tested, including experimental data of the motor under various working conditions in the constant torque zone and the constant power zone.

[0012] Preferably, the motor dynamic model includes climbing and gear acceleration; testing the voltage, frequency, current, power factor, active power and reactive power of the motor in the typical working condition of acceleration to steady-state dynamic process when the motor is loaded, and calculating the motor voltage amplitude, torque, active current and reactive current corresponding to the voltage and frequency in the motor dynamic process, including constant torque zone and constant power zone data, as a dynamic adjustment process control model of the motor during acceleration and speed regulation.

[0013] Preferably, in step 2, the active current and reactive current that need to be adjusted are determined according to the rotation speed and the active current;

[0014] Determine the mode according to the motor running speed and active current, find the corresponding motor torque in the mode, calculate the motor torque that needs to be controlled for the corresponding speed setting, and query the active current given value and reactive current given value of the torque corresponding to the motor mode of the given speed in the experimental data.

[0015] Preferably, the specific method for implementing motor control in step 4 is as follows:

[0016] If the real-time motor speed is equal to zero, it is the motor starting condition. The motor active current setting and reactive current setting are controlled according to the motor acceleration curve determined by the motor dynamic model. After reaching the steady state, the steady-state operation reactive current setting is determined by the motor steady-state model.

[0017] If the speed is not zero, it is the motor speed regulation working condition. The active current setting and reactive current setting of the motor are determined according to the speed setting. After reaching the steady state, the steady-state operation reactive current setting is determined by the motor steady-state model.

[0018] If the motor speed is greater than zero, the active current compensation of the motor is determined based on the wind speed sensor and the slope sensor according to the active current compensation given.

[0019] The beneficial effects of the present invention are as follows: the present invention uses a permanent magnet synchronous motor for driving a pure electric vehicle as a control object, adopts a motor dynamic and steady-state performance experiment, measures dynamic data and steady-state data of different motor operation modes as the model basis of the motor control, and combines the closed-loop control of the speed and current to achieve high-performance control of the permanent magnet synchronous motor. The technical problem that the motor model in the prior art is extremely complex and difficult to achieve high-performance control is solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0021] Figure 1 It is a schematic diagram of the process of the present invention;

[0022] Figure 2 Schematic diagram of the control principle of the present invention;

[0023] Figure 3 Schematic diagram of the multi-modal motor control model;

[0024] Figure 4 Speed ​​controller structure diagram;

[0025] Figure 5 Current controller structure diagram;

[0026] Figure 6 Schematic diagram of the torque and speed experimental data of permanent magnet synchronous motor;

[0027] Figure 7 Schematic diagram of voltage law for controlling motor;

[0028] Figure 8 Calculate the power factor angle diagram. DETAILED DESCRIPTION

[0029] In order to make the technical solutions and advantages in the embodiments of the present application more clearly understood, the exemplary embodiments of the present application are further described in detail below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present application, rather than an exhaustive list of all the embodiments. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0030] Example 1, reference Figure 1-Figure 8 The present embodiment describes a motor control method for operating data of a permanent magnet synchronous motor of a multi-mode pure electric vehicle, comprising the following steps:

[0031] Step 1: Establish a multi-modal motor control model based on permanent magnet synchronous motor experimental data; including a motor steady-state model and a motor dynamic model, including steady-state experimental data of various working conditions of the motor; the motor dynamic model is dynamic experimental data of various working conditions of the motor.

[0032] Based on the operating conditions of permanent magnet synchronous motors used to drive pure electric vehicles, a large amount of steady-state operation and dynamic adjustment process data of permanent magnet synchronous motors in various operating conditions are obtained through experimental tests. Due to the different operating conditions of each operating condition, the electrical parameters of the magnetic circuit state in the motor are different, and a data-based model of the motor operating under different conditions is obtained. The motor experimental data model obtained for each operating condition is called a mode, and the state data group of the motor operation model measured under multiple conditions is called a multi-mode.

[0033] The inductance in the motor parameters shows nonlinearity as the magnetic circuit changes during motor operation, and the resistance parameters change with the motor temperature. When the motor reaches a stable temperature rise, the current measured when a voltage of a certain frequency is applied to the motor contains information about the parameter changes.

[0034] By testing the steady-state experimental data of various working conditions of the motor, the steady-state model of the motor can be obtained; by testing the dynamic adjustment experimental data of various working conditions of the motor, the key information of the dynamic adjustment process of the motor can be obtained, and a multi-modal control model of the motor based on the permanent magnet synchronous motor experimental data can be established, and a motor control system model including speed closed loop and current closed loop can be constructed to realize motor control.

[0035] Under the premise of meeting the maximum torque and maximum power of the permanent magnet synchronous motor, the steady-state data of the motor under various working conditions are tested. The motor voltage, current, power factor, active power and reactive power are tested from no-load to 120% load and the current is minimum at a certain speed, and the voltage amplitude, torque, active current and reactive current of the motor are calculated. The experimental data corresponding to the speed are tested, including the experimental data of the motor under various working conditions in the constant torque zone and the constant power zone, so as to determine the steady-state model of the motor based on the experimental data.

[0036] Under the premise of meeting the maximum torque and maximum power of the permanent magnet synchronous motor, the dynamic data of various working conditions of the motor are tested, including climbing and gear acceleration. The voltage, frequency, current, power factor, active power and reactive power of the motor in the typical working condition of acceleration to steady-state dynamic process under load are tested, and the motor voltage amplitude, torque, active current and reactive current corresponding to the voltage and frequency in the dynamic process of the motor are calculated, including the data of the constant torque area and constant power area, as the control model of the dynamic adjustment process of the motor during acceleration and speed regulation.

[0037] Step 2: Determine the active current and reactive current that need to be adjusted according to the rotation speed and active current;

[0038] Step 3, controlling the torque current setting and the magnetic field control current setting according to the active current setting value and the reactive current setting value;

[0039] The current corresponding to the torque in the experimental data obtained from steady-state and dynamic tests of the permanent magnet synchronous motor includes the influence of magnetic circuit changes in various operating conditions of the motor on the parameters. According to control needs, the active current and reactive current in the experimental data are used as the torque control current given and the magnetic field control current given during system control to achieve motor control that is independent of inductance and resistance parameters.

[0040] Step 4: Query the motor experimental data based on the speed setting and real-time motor speed feedback to determine the motor working condition and realize motor control.

[0041] The motor operating condition is determined by the speed setting and the real-time motor speed feedback. Specifically, the motor acceleration or speed regulation query experimental data is judged to perform specific modal control.

[0042] The control system is equipped with a wind speed sensor and a slope sensor to calculate the corresponding motor output torque current increment to provide torque compensation.

[0043] The speed controller and the current controller contain a switching function with an initial value not equal to zero to select the coarse adjustment and fine adjustment control reference outputs, wherein the coarse adjustment is an increase and decrease control function with an initial value not equal to zero to control the initial control reference output of the dynamic process. When the closed-loop control responds to a certain error, the error control participates in the control reference value output, thereby realizing a method of motor control.

[0044] Specifically, the speed controller uses the torque current determined by the given speed as the initial value to control the given output of the torque current according to the rising and falling curves; the magnetic field current of the current controller uses the initial value determined by the given speed to control the given output of the magnetic field current according to the rising and falling curves; the comprehensive torque current and magnetic field current are determined by the current controller to output the given voltage output of the control motor. The determination process is the process of querying dynamic and steady-state experimental data.

[0045] The torque current component and magnetic field current component of the calculated feedback current are compared with the corresponding torque control current given and magnetic field control current given. The voltage amplitude is output by the current controller, and the voltage phase and speed given corresponding frequency are calculated by the rotor magnetic field position feedback, and then the power controller outputs the voltage to control the motor in real time.

[0046] Example 2, reference Figure 1-Figure 8 The present embodiment is described as a motor control method for operating data of a permanent magnet synchronous motor of a multi-mode pure electric vehicle. Figure 2 This is a schematic diagram of the multi-mode control of a permanent magnet synchronous motor based on experimental data. Figure 3 The motor multimodal data model unit based on experimental data is shown, Figure 4 Speed ​​controller shown, Figure 5The active current controller and reactive current controller, modulation voltage generator, power controller, current feedback power factor calculation unit, rotor position detection unit, and permanent magnet synchronous motor are shown.

[0047] Figure 3 It is a multi-mode motor model of permanent magnet synchronous motor. It includes input parameters, such as wind speed, slope, speed setting, motor speed and current; output parameters, such as voltage amplitude, torque current setting, magnetic field current setting and frequency setting. Its function is to determine the motor operation mode according to the system state based on the input parameters, such as acceleration and climbing, and give torque current setting, magnetic field current setting and frequency setting.

[0048] The multi-mode motor model is determined by the steady-state data of various motor working conditions obtained from the test and the dynamic data of various motor working conditions obtained from the test, such as Figure 6 As shown, the torque and speed experimental data of the permanent magnet synchronous motor corresponding to the working conditions and the definition of the motor constant torque area and constant power area; the theoretical calculation of the resistance torque generated by wind speed and slope and the torque current corresponding to the steady-state experimental measurement of the motor.

[0049] When accelerating from zero speed, according to Figure 6 The typical acceleration curve is determined to control the motor start, and Figure 3 The wind speed and slope input into the motor multi-modal model are queried to obtain the resistance torque, and the power angle characteristics of the motor operation are combined to give the torque current reference for torque compensation.

[0050] Figure 7 The voltage control law based on the power factor angle, motor active current and reactive current is given, that is, when the power factor angle is leading, the voltage amplitude needs to be increased to control the reactive current to decrease; when the power factor angle is lagging, the voltage amplitude needs to be reduced to control the reactive current to decrease; when the power factor angle is zero, the reactive current is zero.

[0051] Since the speed of a permanent magnet synchronous motor is strictly related to the frequency, the speed can be controlled more effectively by controlling the frequency. Figure 4 The speed controller contains a switching function, which n The compensation amount of the output torque current is given to the active current controller in the current controller.

[0052] Figure 5 is a current controller, where the input of the active current controller includes the output of the speed controller given i * pn The active current given by the motor multi-mode model is determined by i * p .i * p According to the set time k pThe active current increases linearly to i * p . There are functions:

[0053]

[0054] where i p0 is the initial value.

[0055] Start acceleration time p0 =0, when the gear shift speed is switched p0 =i * p ,i * p It is the difference between the given active current corresponding to the new gear speed and the original given current, which is negative during deceleration.

[0056] The active current controller contains two switching functions, one is the speed controller output i * pn When it is not equal to zero, the switch function k1 is set to "1" state; the other is the active current comparison output Δi p , when the error is less than e ip When the switch function k2 is set to "1", the total output of the active current controller is:

[0057]

[0058] The input of the reactive current controller is determined by the motor multi-mode model and the output reactive current given i * Q Compare the reactive current output Δi Q .i * Q According to the set time k Q The reactive current increases linearly to i * Q The reactive current controller contains a switch function to select the input reactive current comparison output Δi Q , when the error is less than e iQ When the switch function k3 is set to "1", the total output of the reactive current controller is:

[0059]

[0060] where i Q0 is the initial value, when starting acceleration i Q0 =0.

[0061] Figure 2 The modulation voltage generator in the speed response sets the time k n Control the change of voltage frequency f. By control function:

[0062]

[0063] Among them, f0 is the initial value, and f0=0 when starting acceleration.

[0064] In order to make the current and speed response consistent, let k n =k p =k Q , where t≤k n . Then the A phase modulation voltage is:

[0065]

[0066] in The air gap magnetic field formed by controlling the current determined by the detected rotor position angle is orthogonal to the rotor magnetic field.

[0067] The other two are 120° electrical angle apart from each other.

[0068] Figure 2 The current feedback unit in Figure 8 Calculate the power factor, calculate the power factor angle from the feedback current and then calculate the active current i P and reactive current i Q .

[0069] Specifically, the two-phase current i is detected a and i c Calculate the phase difference between current and voltage Get the torque current component i P and the magnetic field current component i Q .

[0070]

[0071] when i a +2i c ≠0 hours

[0072] We can get:

[0073]

[0074]

[0075] Find:

[0076]

[0077] The torque current component and magnetic field current component of the calculated feedback current are compared with the corresponding torque control current given and magnetic field control current given. The voltage amplitude is output by the current controller, and the voltage phase and speed given corresponding frequency are calculated by the rotor magnetic field position feedback, and then the power controller outputs the voltage to control the motor in real time.

[0078] Although the present invention has been described according to a limited number of embodiments, it will be apparent to those skilled in the art, with the benefit of the above description, that other embodiments may be envisioned within the scope of the invention thus described. In addition, it should be noted that the language used in this specification is selected primarily for readability and didactic purposes, rather than for explaining or defining the subject matter of the present invention. Therefore, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is illustrative, not restrictive, with respect to the scope of the present invention, which is defined by the appended claims.

Claims

1. A motor control method for operating data of a permanent magnet synchronous motor of a multi-mode pure electric vehicle, characterized in that: The following steps are involved: Step 1: Establish a multi-mode motor control model based on permanent magnet synchronous motor experimental data; Step 2: Determine the active current and reactive current that need to be adjusted according to the rotation speed and active current; Step 3, controlling the torque current setting and the magnetic field control current setting according to the active current setting value and the reactive current setting value; Step 4: Query the motor experimental data based on the given speed and real-time motor speed feedback to determine the working condition of the motor and realize motor control; The model in step 1 includes a motor steady-state model and a motor dynamic model; the motor steady-state model includes steady-state experimental data of various working conditions of the motor; the motor dynamic model is dynamic experimental data of various working conditions of the motor; The motor steady-state model includes testing the motor voltage, current, power factor, active power and reactive power of the motor from no-load to 120% load and minimum current at a certain speed, and calculating the voltage amplitude, torque, active current and reactive current of the motor; testing the experimental data corresponding to the speed including experimental data of the motor under various working conditions in the constant torque zone and the constant power zone; The motor dynamic model includes climbing and gear acceleration; The voltage, frequency, current, power factor, active power and reactive power of the motor in the process of acceleration to steady-state dynamic under typical working conditions when the motor is loaded are tested. The motor voltage amplitude, torque, active current and reactive current corresponding to the voltage and frequency in the dynamic process of the motor are calculated, including data in the constant torque area and constant power area, as a control model for the dynamic adjustment process of the motor during acceleration and speed regulation.

2. The method according to claim 1, characterized in that: In step 2, the active current and reactive current to be adjusted are determined according to the rotation speed and the active current; Determine the mode according to the motor running speed and active current, find the corresponding motor torque in the mode, calculate the motor torque that needs to be controlled for the corresponding speed setting, and query the active current given value and reactive current given value of the torque corresponding to the motor mode of the given speed in the experimental data.

3. The method according to claim 2, characterized in that The specific method for implementing motor control described in step 4 is as follows: If the real-time motor speed is equal to zero, it is the motor starting condition. The motor active current setting and reactive current setting are controlled according to the motor acceleration curve determined by the motor dynamic model. After reaching the steady state, the steady-state operation reactive current setting is determined by the motor steady-state model. If the speed is not zero, it is the motor speed regulation working condition. The active current setting and reactive current setting of the motor are determined according to the speed setting. After reaching the steady state, the steady-state operation reactive current setting is determined by the motor steady-state model. If the motor speed is greater than zero, the active current compensation of the motor is determined based on the wind speed sensor and the slope sensor according to the active current compensation given.

Images