阅读说明：本技术 Psm的转子温度的确定 (Determination of rotor temperature of PSM ) 是由 B·卡尔 M·亚当 S·黑贝尔 F·洪康普 于 2020-09-09 设计创作，主要内容包括：本发明涉及一种用于确定电驱动的车辆的永磁同步电机(PSM)转子温度T-(转子)的方法,其中,在不需要永磁同步电机(10)的力矩的行驶状态下,在电流调节模式中运行为永磁同步电机(10)供给能量的功率电子器件(20)并且调节为：在功率电子器件的AC侧(21)设定交流电流为零,测量在功率电子器件(20)的DC侧(22)的直流电压以及永磁同步电机(10)的电角速度ω-(el),从中计算出转子温度T-(转子)。本发明还涉及一种用于确定永磁同步电机(10)的转子温度T-(转子)的设备。(The invention relates to a method for determining the rotor temperature T of a permanent magnet synchronous motor (PSM) of an electrically driven vehicle Rotor In a driving state in which no torque of the permanent magnet synchronous machine (10) is required, the power electronics (20) supplying the permanent magnet synchronous machine (10) with energy are operated in a current regulation mode and are regulated to: an alternating current is set to zero on the AC side (21) of the power electronics, and the direct voltage on the DC side (22) of the power electronics (20) and the electrical angular velocity ω of the permanent magnet synchronous machine (10) are measured el From which the rotor temperature T is calculated Rotor . The invention also relates to a method for determining the rotor temperature T of a permanent magnet synchronous machine (10) Rotor The apparatus of (1).)

1. Method for determining the rotor temperature T of a permanent magnet synchronous machine (10) in an electrically driven vehicle_RotorIn a driving state in which no torque of the permanent magnet synchronous machine (10) is required, the power electronics (20) supplying the permanent magnet synchronous machine (10) with energy are operated in a current regulation mode and are regulated to: an alternating current is set to zero on the AC side (21) of the power electronics, and the direct voltage on the DC side (22) of the power electronics (20) and the electrical angular velocity ω of the permanent magnet synchronous machine (10) are measured_elFrom which the rotor temperature T is calculated_Rotor。

2. The method of claim 1, wherein the measured values are used to determine the position of the target objectThe DC voltage and the duty cycle of the power electronic device (20) calculate the AC voltage u applied to the AC side (21) of the power electronic device (20)_q。

3. The method of claim 2, wherein the method is based on T_Rotor≈u_q/ω_elBy an alternating voltage u applied on the AC side (21) of the power electronics (20)_qAnd the electrical angular velocity omega of the permanent magnet synchronous motor (10)_elCalculating the rotor temperature T_Rotor。

4. Method according to one of claims 1 to 3, characterized in that the driving situation in which no torque of the permanent magnet synchronous machine (10) is required is a coasting mode.

5. A rotor temperature T for confirming PMSM (10)_RotorThe apparatus of (1), comprising:

a) a power electronics device (20) which supplies an alternating current to the permanent magnet synchronous motor (10);

b) at least one current sensor (23) arranged on the AC side (21) of the power electronics (20) for measuring an alternating current in at least one phase for supplying the permanent magnet synchronous machine (10);

c) at least one voltage sensor (24) arranged on the DC side (22) of the power electronics (20) for measuring a direct voltage applied on the DC side (22) of the power electronics (20);

d) at least one rotational speed sensor for measuring a rotational speed of the permanent magnet synchronous motor (10); and

e) at least one sensor for controlling the power electronics (20) and receiving and processing the measurement data of the sensors (23, 24) and calculating the rotor temperature T of the permanent magnet synchronous machine (10)_RotorThe apparatus of (1).

6. The apparatus according to claim 5, characterized in that said at least one is for controlling power electronics (20) and receiving and processingMeasuring data of the physical sensors (23, 24) and calculating the rotor temperature T of the permanent magnet synchronous machine (10)_RotorFor setting the alternating current on the AC side (21) of the power electronics (20) to zero.

7. The device according to claim 5 or 6, characterized in that the at least one device for controlling the power electronics (20) and receiving and processing the measurement data of the sensors (23, 24) and calculating the rotor temperature T of the permanent magnet synchronous machine (10)_RotorFor determining an alternating voltage u applied to an AC side (21) of the power electronics (20) from a direct voltage measured by at least one voltage sensor (24) arranged on the DC side (22) of the power electronics (20)_q。

8. The device according to one of claims 5 to 7, characterized in that the at least one device is used for controlling the power electronics (20) and for receiving and processing the measurement data of the sensors (23, 24) and for calculating the rotor temperature T of the permanent magnet synchronous machine (10)_RotorFor determining the electrical angular velocity ω of the permanent magnet synchronous machine (10) from the rotational speed of the permanent magnet synchronous machine (10) measured by at least one rotational speed sensor_el。

9. The device according to one of claims 5 to 8, characterized in that the at least one device is used for controlling the power electronics (20) and for receiving and processing the measurement data of the sensors (23, 24) and for calculating the rotor temperature T of the permanent magnet synchronous machine (10)_RotorBy an alternating voltage u applied to the AC side (21) of the power electronics (20)_qAnd the electrical angular velocity omega of the permanent magnet synchronous motor (10)_elDetermining a rotor temperature T of a permanent magnet synchronous machine (10)_Rotor。

Technical Field

The invention relates to a method and a device for determining the rotor temperature of a permanent magnet synchronous machine (PSM) of an electrically driven vehicle.

Background

According to the prior art, the rotor temperature of a permanent magnet synchronous machine cannot be determined directly in a vehicle, since a temperature sensor cannot be installed in the rotor. The rotor temperature is critical for component protection of the electrical machine.

The rotor temperature can be deduced from the load profile and from the measured data of the sensors located nearby using a temperature model stored in the converter. The model is only able to estimate the rotor temperature, but is not able to achieve an accurate determination. There is also an initial value problem when the vehicle is parked. The rotor temperature after restart is unknown. The controller has no information about how long the vehicle has been parked and the temperature the rotor has at that point in time.

Document DE 102012209057 a1 proposes a method and a device for monitoring the temperature of a permanent magnet motor. An alternating current voltage is applied to a permanent magnet motor of a vehicle and the direct current voltage output of the motor is monitored. The temperature of the permanent magnet machine is deduced from the measured resistance values of the stator windings.

Document DE 102012221757 a1 discloses a control device for a synchronous machine. Estimating the temperature of the permanent magnet synchronous motor by: the permanent magnet motor is energized and the permanent magnet temperature is inferred based on the resulting current.

Document DE 102014216312 a1 describes a method for sensorless measurement of the temperature of a direct current motor. The method is used for analyzing the time constant and the resistance and the inductance of the permanent magnet synchronous motor based on the temperature, and the temperature of the permanent magnet synchronous motor is calculated.

Disclosure of Invention

On this background it is an object of the present invention to provide a method and an apparatus for determining the rotor temperature of a permanent magnet synchronous motor (PSM) in an electric vehicle, which method and apparatus enable the initial value problem to be overcome and the rotor temperature to be determined more accurately.

According to the invention, this object is achieved by a method having the features of claim 1 and by an apparatus having the features of claim 5. Embodiments and developments of the invention result from the dependent claims and the description.

The invention relates to a method for determining the rotor temperature T of a permanent magnet synchronous machine (PSM) in an electrically driven vehicle_RotorIn a driving mode in which no torque of the PSM is required, the power electronics/power semiconductors supplying the PSM with energy are operated in a current regulation mode, in a regulation mode in which: setting the AC current to zero on the AC side of the power electronics, measuring the DC voltage on the DC side of the power electronics and the electrical angular velocity ω of the PSM_elFrom which the rotor temperature T is calculated_Rotor。

According to the invention, the rotor temperature is determined in driving situations in which no torque is required, for example in a coasting mode (segelbettrie) in which the driver does not step on the gas.

In one embodiment of the method, the alternating voltage u applied to the AC side of the power electronics is calculated from the measured direct voltage and the known duty cycle of the power electronics_q。

In a further embodiment of the process, according to T_Rotor≈u_q/ω_elFrom an alternating voltage u applied on the AC side of the power electronics_qAnd the electrical angular velocity ω of the permanent magnet synchronous motor_elCalculating the rotor temperature T_Rotor。

If the power electronics are operated in the current regulation mode and the AC current is set to zero, the AC voltage is determined from the measured DC voltage and scaled by the Duty Cycle of the power electronics. From the AC voltage, the induced voltage of the permanent magnets can be determined, leading to conclusions about the rotor temperature.

The regulation of the AC voltage is performed in a dp coordinate system, which is another representation of the three-phase UVW system. Both systems can be interconverted without content changes.

The AC voltage in a dp coordinate system fixed to the rotor generally applies to the following equation:

wherein:

permanent magnet flux turns psi_PMAnd its temperature T_PMDirectly proportional. Temperature T of permanent magnet_PM[K]Corresponding to the rotor temperature T_Rotor[K]。

Equation (1) is important for the determination of the rotor temperature. If it will be i_qAnd i_dSet to zero, the equation reduces to:

the rotor temperature T is determined by the following relationship_Rotor：

u_q～ψ_PM、ψ_PM～T_PMAnd T_PM＝T_Rotor (4)

T_Rotor≈u_q/ω_el (5)

u_qω can be determined by a DC voltage sensor as described above_elDetermined by a rotational speed sensor.

The subject matter of the present invention also includes an apparatus for determining a rotor temperature of a permanent magnet synchronous motor (PSM). The device according to the invention comprises:

-power electronics supplying the PSM with an alternating current;

-at least one current sensor arranged on the AC side of the power electronics, the current sensor being arranged for measuring an alternating current in at least one phase powering the PSM;

-at least one voltage sensor arranged on the DC side of the power electronics, the voltage sensor being arranged for measuring a direct voltage applied on the DC side of the power electronics;

-at least one rotation speed sensor arranged for measuring the rotation speed of the PSM; and

-at least one means for controlling the power electronics, receiving and processing the measurement data of the sensors and calculating the rotor temperature of the PSM.

The rotor temperature can be calculated back from the measurements of the sensors as described above.

In one embodiment of the device, the at least one sensor is used for controlling the power electronics and for receiving and processing the measurement data of the sensor and for calculating the rotor temperature T of the PSM_RotorIs arranged for setting the alternating current on the AC side of the power electronics to zero.

In a further embodiment of the device, at least one of the sensors is used for controlling the power electronics and for receiving and processing the measurement data of the sensor and for calculating the rotor temperature T of the PSM_RotorIs arranged for determining an alternating voltage u applied on the AC side of the power electronics from a direct voltage measured by at least one voltage sensor arranged on the DC side of the power electronics_q。

In a further embodiment of the device, the at least one sensor is used for detecting the temperature of the rotor of the PSM and for receiving and processing the measurement data of the sensor and for calculating the rotor temperature T of the PSM_RotorIs arranged to determine the electrical angular velocity ω of the PSM from the PSM rotation speed measured by the at least one rotation speed sensor_el。

In a further embodiment of the device, the at least one sensor is used for detecting the temperature of the rotor of the PSM and for receiving and processing the measurement data of the sensor and for calculating the rotor temperature T of the PSM_RotorIs arranged to be driven by an alternating voltage u applied on the AC side of the power electronics_qAnd the electrical angular velocity ω of the PSM_elDetermining rotor temperature T of PSM_Rotor。

The method and the device overcome the initial value problem when determining the rotor temperature, and can calculate the rotor temperature more accurately to support a rotor temperature model. Furthermore, this helps to ensure that the components of the PSM are protected. Further advantages and embodiments of the invention emerge from the description and the drawing.

The features mentioned above and those yet to be described below can of course be used not only in the respectively specified combination but also in other combinations or alone without departing from the scope of the invention.

Drawings

The invention is schematically illustrated according to embodiments in the drawings and further explained with the aid of the drawings. The figures show:

fig. 1 shows a drive train of an electric vehicle arranged for carrying out a method according to the invention;

fig. 2 shows schematically the voltages occurring in the drive train of fig. 1 during the execution of the method according to the invention.

Detailed Description

Fig. 1 schematically shows a powertrain of an electric vehicle arranged for carrying out the method according to the invention. The powertrain includes a permanent magnet synchronous motor (PSM)10, power electronics 20 to supply the PSM10 with electrical power, and an HV battery (high voltage battery) 30. The AC side 21 of the power electronics 20 has three phases that are connected to the PSM 10. The DC side 22 of the power electronics 20 is connected to the HV battery 30.

The power electronics 20 has a current sensor 23 in one of the three phases leading to PSM10 on the AC side 21 and a voltage sensor 24 on the DC side 22. The measurements of the two sensors of the power electronics can be used to determine the rotor temperature.

If the power electronics 20 are operated in the current regulation mode and are regulated such that the alternating current on the AC side 21 is zero, the alternating voltage on the AC side 21 is determined from the DC voltage measured by the voltage sensor 24 by scaling of the duty cycle of the power electronics 20. From this alternating voltage, the induced voltage of the permanent magnet can be deduced.

FIG. 2 schematically shows the power in FIG. 1The alternating voltage present on the AC side 21 in the drive train when the method according to the invention is performed. The permanent magnet of PSM10 induces a voltage U on the AC side 21 of power electronics 20 through its motion₁. In order to prevent the current flow, the power electronics 20 generate a reverse voltage U of the same magnitude in value₂. AC voltage U₁And U₂Corresponding in value to the alternating voltage u_q。

Can be according to T_Rotor≈u_q/ω_elFrom an alternating voltage u_qAnd the electrical angular velocity ω of the PSM10 determined via a not shown rotational speed sensor_elThe rotor temperature T of PSM10 was calculated_Rotor。

List of reference numerals

10 electric motor (PSM)

20 power electronic device

21 AC side with three phases

22 DC side

23 AC current sensor

24 DC voltage sensor

30 HV battery

U₁Permanent magnet (Ψ)_PM) Induced voltage

U₂Reverse voltage generated by power electronic device