A method and motor control system for controlling a motor

Abstract

A method of controlling an electric machine (20) includes: step one, detecting the rotor angular position (Θ) of the electric machine (20); step two, detecting the values of the alternating current (ia, ib, ic) after at least two phases of input current to the electric machine (20); step three, detecting the direct current voltage (VDC) and the direct current (ice) provided by a power supply to an inverter (30); step four, processing the data collected in steps one and two to obtain an estimated torque value (Teestiwatingced) provided by the electric machine (20); step five, processing the data collected in steps one and three to obtain a calculated torque value (Tcheek) provided by the electric machine (20); and step six, comparing the estimated torque value (Teestiwatingced) and the calculated torque value (Tcheek) obtained in steps four and five, respectively. A control system and an electric machine including the control system are also described.

Description

[0001] This invention relates to a method and a control system for controlling an electric motor, and more particularly, to a method and a control system for controlling the torque of an electric motor, and more specifically, to a synchronous reluctance motor, i.e., any motor equipped with a permanent magnet device.

[0002] In electric motors, especially in high-performance motors with permanent magnets, the output torque is an important parameter that must be controlled.

[0003] To control torque, there is a method in the prior art for evaluating the torque value of a motor, in which: after the power supply circuit of the motor is powered, a position sensor is used to detect the rotor angle measurement value, and the value of the three-phase power is calculated by the current value measured by a current sensor.

[0004] However, this method for controlling motor torque has certain drawbacks. The technical solution does not check for possible errors in the torque value calculation process. These errors may be caused by incorrect readings from the current sensor and position sensor, which will lead to incorrect estimation of the motor torque value, especially for motors that use those incorrect readings.

[0005] The purpose of this invention is to provide a method and a motor control system for controlling a motor, which verifies and checks the torque provided by the motor and detects possible errors.

[0006] The independent claims of this invention disclose a method and a motor control system for controlling an electric motor. Through this method and system, and through the explanation and description below, the technical objectives and other technical effects described above will be achieved.

[0007] The contents described in the dependent claims of this invention are the preferred embodiments of this invention and other various technical variations.

[0008] All the technical solutions corresponding to the appended dependent claims are part of this invention.

[0009] It is evident that numerous technical modifications and variations can be made to the technical content disclosed in the claims of this invention without departing from the scope of this invention. These include changes to the shape and size of components, and equivalent substitutions of technical features.

[0010] The present invention can be better described through some preferred embodiments. The embodiments are disclosed below and are accompanied by corresponding drawings. These embodiments should not be construed as limiting the technical solutions: Figure 1 This is a schematic diagram of the motor control system and control method involved in the present invention.

[0011] like Figure 1 As shown, motor 20, preferably a high-performance motor with permanent magnets, includes the following control method: Step 1, Angle and Position Detection steps: The angular position of the rotor of the motor 20 is obtained using a position sensor 11, such as an electronic encoder or electronic decomposer, in the prior art. .

[0012] —Step Two, AC Current Detection Step; Performed synchronously with Step One, after supplying at least two phases of input current to motor 20, the AC current is detected by at least two AC current sensors 12. Each of the AC sensors 12 is electrically connected to a phase of the power supply circuit of the motor 20, and is in turn electrically connected to an inverter 30, which is configured to convert the DC power supplied by the power supply device into AC power used by the motor 20.

[0013] —Step 3, DC voltage and DC current detection step; performed simultaneously with steps 1 and 2, to detect the DC voltage. and DC current The DC voltage and DC current are measured by the input supplied to inverter 30 by the power supply unit. The DC voltage... and DC current The detection is performed by a DC voltage sensor 32 and a DC current sensor 31 connected to the power supply circuit of the inverter 30, respectively.

[0014] —Step four: Estimate the torque provided by motor 20 to obtain the torque Teestimatingted. This step can be executed by a microprocessor using corresponding information processing software. The input data comes from the position sensor 11 and AC current sensor 12 mentioned in steps one and two, as well as other data from motor 20 obtained through known simulation methods.

[0015] Step 5 involves calculating the torque provided by motor 20 to obtain torque Tcheck. This step can also be executed by a microprocessor using corresponding information processing software. Input data comes from DC sensor 31, DC voltage sensor 32, and other data that are available and necessary for controlling the motor using existing technology, as well as data from position sensor 11 obtained in steps 3 and 4. Based on the data from position sensor 11, the rotational speed data and other data from motor 20 can be calculated through software processing.

[0016] —Step Six, Torque Comparison Step. In this step, the torque Teestimatingted and torque Tcheck obtained in Steps Four and Five are compared to verify whether the difference between the two values ​​is below a preset value. For example, no more than 10% or 10 Nm, considering that the required accuracy for controlling the torque Teestimatingted is usually 5% or 5 Nm.

[0017] More preferably, in step five, the formula used to calculate the torque Tcheck of motor 20 is: , in, It is the speed of the rotor of motor 20, which is determined in a sub-step 5a based on the angular position of the rotor of motor 20 obtained from position sensor 11. Calculated. This is the power value supplied to motor 20 by a power supply device, such as a battery, calculated using common methods in the prior art based on the voltage value of the power supply device. The current value obtained by current sensor 31 in step three Multiply them to get the result. This is the efficiency value of motor 20.

[0018] Furthermore, the efficiency of a motor is often known, as it can be calculated through specific small-scale experiments and stored in tabular form for subsequent use by software programs.

[0019] Preferably, step four, the estimation step of the torque provided by motor 20, includes a sub-step 4a. In this step, the DC current can be calculated using the known Clark-Parker transform. and orthogonal current .

[0020] As a preferred embodiment, if motor 20 is a synchronous motor with permanent magnets, step four further includes a second sub-step 4b, in which the calculation of Teestimatingted is referenced to a rotating system synchronized with the rotor, and specifically uses the following formula: Where p is the number of polar torques of the engine, and DC current. and orthogonal current As already obtained in 4a mentioned above, It is direct current. Through the DC inductor, It is an orthogonal current The orthogonal inductance at the point of connection, λ is a series current generated by the permanent magnet rotor and connected in series by the stator windings.

[0021] This invention discloses a control system 10 for a motor 20, particularly a control system for a high-performance motor with permanent magnets, comprising: a position sensor 11 of a known type, such as an encoder or resolver, configured to detect the angular position of the rotor of the motor 20. The control system 10 also includes at least two AC sensors 12, each configured to detect AC current after an input phase is applied to the motor 20. The AC current sensor 12 is electrically connected to a phase of the power supply circuit of the motor 20 and is in turn electrically connected to an inverter 30, which is configured to convert the DC power supplied by the power supply device into AC power used by the motor 20. The control system 10 also includes a DC voltage sensor 32 and a DC current sensor 31, which are configured to detect the DC voltage supplied by the power supply device (e.g., a battery) as input to the inverter 30. and DC current .

[0022] The control system 10 for the motor 20 involved in this invention further includes an electronic control unit, which can be a product of the prior art and includes a microprocessor and a storage device. This electronic control unit receives data from sensors, processes it, and ultimately drives the motor 20 to achieve the control method described above.

[0023] The present invention further includes a high-performance motor with a permanent magnet, the high-performance motor including the control system 10 described above.

Claims

1. A method for controlling a motor, characterized in that, It includes the following steps: S01, Angle Position Testing steps; In this step, the angular position of the rotor of the motor (20) is detected. ); S02, AC current testing procedures; This step is performed synchronously with S01. The motor (20) is electrically connected to an inverter (30). After at least two phases of input current are supplied to the motor (20), the value of the AC current is detected by at least two AC current sensors (12). ); S03, DC voltage and DC current detection steps; This step is performed synchronously with S01 and S02, and applies DC voltage ( ) and direct current ( The DC voltage is detected. ) and direct current ( ) is the power input provided to the inverter (30) by the power supply device; S04, Torque Calculation Steps; The input data for this step comes from the data of the position sensor (11) involved in S01 and S02, the data of the AC current sensor (12), and the data of the motor (20) obtained by analog means. By processing these input data, the torque budget value of the motor (20) is finally obtained. S05, Torque Calculation Steps; The input data for this step comes from the data obtained in S01 and S03 and the parameters of the motor (20). By processing these input data, the torque calculation value of the motor (20) is finally obtained. S06, Torque comparison step; Compare the torque budget value and torque calculation value obtained in S04 and S05 respectively; In S05, the calculation formula for generating the torque calculation value is as follows: , in, It is the speed of the rotor of the motor (20), which is the angular position of the rotor of the motor (20) obtained in a sub-step 5a based on the position sensor (11). Calculated; It is the power value provided by the power supply device to the motor (20); It is the efficiency value of the motor (20); S04 also includes a sub-step (S04a), in which the DC current value is... and orthogonal current values It is calculated that the motor (20) is a synchronous motor with permanent magnets, and S04 also includes a second sub-step (S04b), in which the torque budget value is calculated with reference to the rotating system synchronized with the rotor, and specifically using the following formula: ， Where p is the number of polar torques of the motor, and the DC current. and orthogonal current As already obtained in sub-step one (S04a), It is direct current. Through the DC inductor, It is an orthogonal current The orthogonal inductance at the point of passage, λ is a series current generated by the permanent magnet rotor and connected in series by the stator windings; In S06, the range of possible errors is narrowed down to the corresponding sensor group by using the values ​​of the torque budget value and the torque calculation value.

2. A method for controlling a motor as described in claim 1, characterized in that: In S01, the angular position of the rotor of the motor (20) is ( The detection is performed by a position sensor (11); In S02, the value of alternating current ( The detection is performed by at least two AC sensors (12), each of which is electrically connected to a phase of the power supply circuit of the motor 20; In S03, for DC voltage ( ) and direct current ( The detection of the current is performed by a DC voltage sensor (32) and a DC current sensor (31) connected to the power supply circuit of the inverter (30), respectively. In S04, the input data for the torque budget value comes from the data of the position sensor (11) involved in S01 and S02, the data of the AC current sensor (12), and the data of the motor (20) obtained by analog means; In S05, the input data for the torque calculation value comes from the DC sensor (31), the DC voltage sensor (32), the data obtained by the position sensor (11) in S03 and S01, and the parameters of the motor (20); In S06, the torque budget value and the torque calculation value are compared to verify whether the difference between the two is less than a preset threshold.

3. A motor control system for implementing the method for controlling a motor as described in claim 1 or 2, characterized in that, This type of motor control system (10) includes: A position sensor (11) is configured to detect the angular position of the rotor of the motor (20); At least two AC sensors (12), each AC sensor 12 being configured to detect AC current after the motor (20) receives an input phase. The value of the AC sensor (12) is connected to the inverter (30) in sequence; A DC voltage sensor (32) and a DC current sensor (31) are configured to detect the DC voltage supplied by the power supply unit as the input to the inverter (30), respectively. and DC current .

4. A motor control system as described in claim 3, characterized in that: It includes an electronic control unit, which contains a microprocessor and a storage device; the electronic control unit is configured to receive sensor data, perform calculations, and ultimately drive the motor (20) to perform the method for controlling the motor as described in claim 1 or 2 via a software program.

5. A high-performance motor with a permanent magnet, characterized in that, It includes the motor control system (10) as described in claim 3 or 4.

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