Motor temperature determination method, device and vehicle

Abstract

The present invention provides a method for determining the temperature of a motor, which relates to the field of motor control and is applied to a motor controller. The method comprises: determining a first direct-axis current value and a first quadrature-axis current value of a motor based on a current motor torque value and a pre-stored current-torque function; determining a direct-axis inductance value and a quadrature-axis inductance value of the motor based on a motor rotation angle value, a first direct-axis current value of the motor, and a first quadrature-axis current value of the motor; fitting a motor stator temperature surface equation and a motor rotor temperature surface equation based on the direct-axis inductance value and the quadrature-axis inductance value of the motor; determining the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation, thereby realizing a scheme for determining the motor stator temperature and the motor rotor temperature through a motor controller without adding a motor temperature sensor, avoiding motor failure due to damage of the temperature sensor, and improving the reliability and stability of the motor.

Description

Technical Field

[0001] The present invention relates to the field of motor control, and in particular to a method and device for determining motor temperature, and a vehicle. Background Art

[0002] With the development of the motor control field, a temperature sensor is usually set on the motor stator to collect the motor stator temperature. When the motor stator temperature is detected to be too high, the motor is controlled to stop running to avoid accidents such as motor damage caused by motor overheating.

[0003] Typically, a very small positive temperature coefficient (PTC) thermistor (PTC) sensor is embedded in the motor's stator windings. Under normal circumstances, the PTC sensor maintains a low resistance and does not affect the motor's operation. However, if the motor overheats due to a fault, the PTC sensor's resistance jumps, de-energizing the associated relay and causing the motor to stop until the fault is resolved and operation can resume.

[0004] However, currently, temperature sensors (such as PTC sensors) are only set on the motor stator, and the temperature of the motor rotor cannot be collected, resulting in low reliability of temperature detection results. Moreover, if the temperature sensor fails, the motor will not work normally, reducing the reliability of the motor. Summary of the Invention

[0005] In view of this, the present invention aims to propose a method, device and vehicle for determining the temperature of a motor, so as to solve the problem that a temperature sensor is set on the motor stator, which cannot collect the temperature of the motor rotor, resulting in low reliability of the temperature detection results. Moreover, if the temperature sensor fails, the motor will not work normally, thereby reducing the reliability of the motor.

[0006] To achieve the above object, the technical solution of the present invention is achieved as follows:

[0007] In a first aspect, an embodiment of the present invention provides a method for determining a motor temperature, which is applied to a motor controller. The method includes:

[0008] Get the current motor torque value and motor resolver angle value;

[0009] Determining a first current value of the motor direct axis and a first current value of the motor quadrature axis based on the current motor torque value and a pre-stored current-torque function;

[0010] Determine the direct-axis inductance value and the quadrature-axis inductance value of the motor based on the motor rotation angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor;

[0011] Fitting a motor stator temperature surface equation and a motor rotor temperature surface equation based on the motor direct-axis inductance and the motor quadrature-axis inductance;

[0012] The motor stator temperature and the motor rotor temperature are determined based on the motor stator temperature surface equation and the motor rotor temperature surface equation.

[0013] Optionally, determining the first direct-axis current value of the motor and the first quadrature-axis current value of the motor based on the current motor torque value and a pre-stored current-torque function includes:

[0014] During the motor test calibration process, a first current value of the motor test direct axis and a first current value of the motor test quadrature axis are obtained;

[0015] Determine a current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test, wherein the current-torque function is a function of a correspondence between the first direct-axis current value of the motor test, the first quadrature-axis current value of the motor test, and the test motor torque value;

[0016] Based on the current motor torque value and the current-torque function, a first current value of the motor direct axis and a first current value of the motor quadrature axis corresponding to the current motor torque value are determined.

[0017] Optionally, the motor controller is connected to a current sensor, and determining the motor direct-axis inductance value and the motor quadrature-axis inductance value based on the motor rotation angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value includes:

[0018] Determine a motor direct-axis voltage value and a motor quadrature-axis voltage value based on the motor rotation angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value;

[0019] The direct-axis inductance value and the quadrature-axis inductance value of the motor are determined according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

[0020] Optionally, determining the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor includes:

[0021] According to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the motor direct-axis voltage value and the motor quadrature-axis voltage value, the motor direct-axis inductance value and the motor quadrature-axis inductance value are determined by iterative difference method.

[0022] Optionally, determining the current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test includes:

[0023] Get the motor test resolver angle value;

[0024] Determine a test motor torque value corresponding to the motor test resolver angle value;

[0025] Based on the test motor torque value, the motor direct axis first current value and the motor quadrature axis first current value, surface fitting is performed to obtain a current-torque function.

[0026] In a second aspect, an embodiment of the present invention provides a device for determining motor temperature, which is applied to a motor controller. The device includes:

[0027] The acquisition module is used to obtain the current motor torque value and motor rotation angle value;

[0028] A first determining module is configured to determine a first current value of a direct axis of the motor and a first current value of a quadrature axis of the motor based on the current motor torque value and a pre-stored current-torque function;

[0029] a second determining module, configured to determine a direct-axis inductance value and a quadrature-axis inductance value of the motor based on the motor resolver angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor;

[0030] A fitting module, configured to fit a temperature surface equation of a motor stator and a temperature surface equation of a motor rotor based on the direct-axis inductance value and the quadrature-axis inductance value of the motor;

[0031] The third determining module is configured to determine the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation.

[0032] Optionally, the first determining module includes:

[0033] An acquisition submodule, used for acquiring a first current value of a direct axis of the motor test and a first current value of a quadrature axis of the motor test during the motor test calibration process;

[0034] A first determining submodule is configured to determine a current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test, wherein the current-torque function is a function of a correspondence between the first direct-axis current value of the motor test, the first quadrature-axis current value of the motor test, and a test motor torque value;

[0035] The second determining submodule is configured to determine, based on the current motor torque value and the current-torque function, a first direct-axis current value of the motor and a first quadrature-axis current value of the motor corresponding to the current motor torque value.

[0036] Optionally, the motor controller is connected to a current sensor, and the second determining module includes:

[0037] A third determining submodule is configured to determine a motor direct-axis voltage value and a motor quadrature-axis voltage value based on the motor resolver angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value;

[0038] The fourth determination submodule is used to determine the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

[0039] Optionally, the fourth determining submodule includes:

[0040] The first determining unit is used to determine the direct-axis inductance value and the quadrature-axis inductance value of the motor by iterative difference method according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor and the quadrature-axis voltage value of the motor.

[0041] Optionally, the first determining submodule includes:

[0042] An acquisition unit is used to obtain the resolver angle value of the motor test;

[0043] A second determining unit is used to determine a test motor torque value corresponding to the motor test resolver angle value;

[0044] The fitting unit is used to perform surface fitting based on the test motor torque value, the motor direct axis first current value and the motor quadrature axis first current value to obtain a current-torque function.

[0045] In a third aspect, an embodiment of the present invention provides a vehicle comprising any motor temperature determination device described in the second aspect.

[0046] Compared with the prior art, the embodiments of the present invention have the following advantages:

[0047] The motor temperature determination method provided by the embodiment of the present invention can be applied to a motor controller to obtain the current motor torque value and the motor rotation angle value; based on the current motor torque value and the pre-stored current-torque function, the motor direct-axis first current value and the motor quadrature-axis first current value are determined; based on the motor rotation angle value, the motor direct-axis first current value and the motor quadrature-axis first current value, the motor direct-axis inductance value and the motor quadrature-axis inductance value are determined; based on the motor direct-axis inductance value and the motor quadrature-axis inductance value, the motor stator temperature surface equation and the motor rotor temperature surface equation are fitted; based on the motor stator temperature surface equation and the motor rotor temperature surface equation, the motor stator temperature and the motor rotor temperature are determined, thereby realizing a solution for determining the motor stator temperature and the motor rotor temperature by a motor controller, without the need to add a motor temperature sensor, reducing costs, avoiding motor failures due to damage to the temperature sensor, and improving the reliability and stability of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The accompanying drawings, which constitute part of the present invention, are provided to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are provided to explain the present invention and do not constitute an undue limitation of the present invention. In the accompanying drawings:

[0049] Figure 1 A flowchart showing the steps of a method for determining the temperature of a motor provided by the first embodiment of the present invention is shown;

[0050] Figure 2 A flow chart of a motor temperature determination system provided by an embodiment of the present invention is shown;

[0051] Figure 3 A flowchart showing the steps of a method for determining the motor temperature provided by the second embodiment of the present invention is shown;

[0052] Figure 4 A schematic structural diagram of a device for determining motor temperature provided in a fifth embodiment of the present invention is shown. DETAILED DESCRIPTION

[0053] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0054] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0055] Reference Figure 1 , shows a flowchart of the steps of a method for determining the motor temperature provided by Example 1 of the present invention, which can be applied to a motor controller (Moter Control Unit, MCU).

[0056] like Figure 1As shown, the motor temperature determination method may specifically include the following steps:

[0057] Step 101: Obtain the current motor torque value and motor resolver angle value.

[0058] Figure 2 FIG. 1 shows a flow chart of a motor temperature determination system provided by the present invention, such as Figure 2 As shown, the motor temperature determination system includes: a motor controller 01, a motor 02 connected to the motor controller, an angle sensor 03, and a current sensor 04. The angle sensor 03 can obtain the motor resolver angle value and send the resolver angle value to the MCU 01. The current motor torque value can be determined based on the motor resolver angle value.

[0059] After obtaining the current motor torque value and the motor resolver angle value, step 102 is executed.

[0060] Step 102: Determine a first direct-axis current value of the motor and a first quadrature-axis current value of the motor based on the current motor torque value and a pre-stored current-torque function.

[0061] Optionally, during the motor test calibration process, the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test are obtained; based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test, a current-torque function is determined, and the current-torque function is a correspondence function between the first direct-axis current value of the motor test, the first quadrature-axis current value of the motor test and the test motor torque value; based on the current motor torque value and the current-torque function, the first direct-axis current value of the motor and the first quadrature-axis current value of the motor corresponding to the current motor torque value are determined.

[0062] See also Figure 2 The current sensor 04 can obtain the three-phase current values ​​of the motor and perform coordinate transformation on the three-phase current values ​​in the three-phase stationary coordinate system, converting the three-phase current values ​​into the first current values ​​of the motor's direct axis and the first current values ​​of the motor's quadrature axis in the two-phase rotating coordinate system. The motor controller 01 can obtain the motor temperature and control the motor's operating state based on the motor temperature.

[0063] Among them, the first current value of the motor direct axis (d axis) is recorded as i d The first current value of the motor quadrature axis (q axis) is recorded as i q .

[0064] Specifically, the current motor torque value can be determined based on the motor rotation angle value; and surface fitting is performed based on the current torque value, the first direct-axis current value of the motor test, and the first quadrature-axis current value of the motor test to obtain a current-torque function.

[0065] For example, you can use i d 、i q And the current motor torque value, perform surface fitting, and obtain the current torque function through stepless surface fitting:

[0066] f(x,y)=ρ00+ρ10*x+ρ01*y+ρ20*x ^2 +ρ11*x*y+ρ02*y ^2 +ρ30*x ^3 +ρ21*x ^2 *y

[0067] +ρ12*x*y ^2 +ρ03*y ^3 +ρ40*x ^4 +ρ31*x ^3 *y+ρ22*x ^2 *y ^2 +ρ13*x*y ^3 +ρ04*y ^4

[0068] +ρ40*x ^4 +ρ31*x ^3 *y+ρ22*x ^2 *y ^2 +ρ13*x*y ^3 +ρ04*y ^4

[0069] +ρ50*x ^5 +ρ41*x ^4 *y+ρ32*x ^3 *y ^2 +ρ23*x ^2 *y ^3 +ρ14*x*y ^4 +ρ05*y ^5

[0070] Among them, the current torque function f(x,y) is obtained by testing i d 、i q The torque value of the motor is automatically fitted into the software and the result is i d 、i q is the independent variable, the motor torque value is the function of the dependent variable, a set of i d 、i q There is a corresponding motor torque value.

[0071] After determining the first direct-axis current value of the motor and the first quadrature-axis current value of the motor based on the current motor torque value and the pre-stored current-torque function, step 103 is executed.

[0072] Step 103: Determine the direct-axis inductance value and the quadrature-axis inductance value of the motor based on the motor rotation angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor.

[0073] Optionally, the specific implementation of step 103 may include the following sub-steps:

[0074] Sub-step A1: Determine the motor direct-axis voltage value and the motor quadrature-axis voltage value based on the motor rotation angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value.

[0075] Specifically, the motor direct-axis target current value and the motor quadrature-axis target current value are determined based on the current-torque function; the motor direct-axis voltage value and the motor quadrature-axis voltage value are determined based on the motor direct-axis target current value and the motor quadrature-axis target current value.

[0076] Optionally, according to the current torque value, substitute it into the current torque function to obtain the motor direct axis target current value (i d ) and the motor quadrature axis target current value (i q ), the motor direct axis voltage value (U d ) and the motor quadrature axis voltage value (U q ).

[0077] Among them, the PI regulator is a linear controller, which forms a control deviation based on the given value and the actual output value, and forms a control quantity by linearly combining the proportion and integral of the deviation to control the controlled object.

[0078] Sub-step A2: Determine the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

[0079] Specifically, according to the steady-state voltage equation in the direct-axis quadrature-axis coordinate system, the motor direct-axis voltage value (U d ) and the motor quadrature axis voltage value (U q ), and determine the motor direct-axis inductance and the motor quadrature-axis inductance by iterative difference method.

[0080] Among them, the steady-state voltage equation in the direct-axis quadrature-axis coordinate system is:

[0081] U d =R×i d -ω e ×Lq×i q ;

[0082]

[0083] Where R represents the motor resistance; ω e Indicates the electrical angle value (that is, the resolver angle value); represents the permanent magnet flux, which is a known quantity; Lq represents the quadrature-axis inductance of the motor; and Ld represents the direct-axis inductance of the motor.

[0084] Specifically, for the calculation of Lq, fix i d ,but:

[0085] U d1 =R×i d1 -ω e ×Lq1×i q1 ;

[0086] U d2 =R×i d2 -ω e ×Lq2×i q2 ;

[0087] ΔU d1 =R×(i d1 -i d2 )-ω e ×Lq2×(i q1 -i q2 );

[0088] Where: R×(i d1 -i d2 ) is equal to zero, and Lq1≈Lq2, then:

[0089] ΔU d1 =-ω e ×Lq2×(i q1 -i q2 );

[0090] Also because Where n represents the number of turns and ω represents the angle, then:

[0091] Similarly, we can get:

[0092] ΔU d2 =ω e ×(Lq2×i q2 -Lq3×i q3 );

[0093]

[0094] Specifically, for the calculation of Ld, fix i q ,but:

[0095]

[0096] again but:

[0097] U q =R×i q +ω e ×Ld×i d ;

[0098] ΔU q1 =R×(i q2 -i q1 )+ω e ×(L d2 ×i d2 -L d1 ×i d1 );

[0099] Due to the fixed q , then i q2 -i q1 ≈0;L d1 ≈L d2 ;

[0100]

[0101] U d3 -U d2 =R×(i q3 -i q2 )+ω e ×(L d3 ×i d3 -L d2 ×i d2 );

[0102]

[0103] After determining the direct-axis inductance value and the quadrature-axis inductance value of the motor based on the motor resolver angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor, step 104 is performed.

[0104] Step 104: fitting a motor stator temperature surface equation and a motor rotor temperature surface equation based on the motor direct-axis inductance and the motor quadrature-axis inductance.

[0105] Based on the motor direct-axis inductance and the motor quadrature-axis inductance calculated in step 102, combined with the motor electronic temperature relationship and the motor rotor temperature relationship determined by temperature sensors respectively provided at the motor stator and motor rotor positions during the motor calibration process, a motor stator temperature surface and an electronic rotor temperature surface are fitted, respectively, to obtain a motor stator temperature surface equation and an electronic rotor temperature surface equation. The motor stator temperature surface equation and the motor rotor temperature surface equation can be fifth-order equations, which are not specifically limited in the present embodiment.

[0106] After fitting the motor stator temperature surface equation and the motor rotor temperature surface equation based on the motor direct-axis inductance and the motor quadrature-axis inductance, step 105 is performed.

[0107] Step 105: Determine the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation.

[0108] The motor stator temperature can be determined based on the motor stator temperature surface equation, and the electronic rotor temperature can be determined based on the motor rotor temperature surface equation. This realizes the solution of determining the motor stator temperature and motor rotor temperature through the motor controller. There is no need to add a motor temperature sensor, which reduces costs, avoids motor failure due to damage to the temperature sensor, and improves the reliability and stability of the motor.

[0109] The motor temperature determination method provided by the embodiment of the present invention can be applied to a motor controller to obtain the current motor torque value and the motor rotation angle value; based on the current motor torque value and the pre-stored current-torque function, the motor direct-axis first current value and the motor quadrature-axis first current value are determined; based on the motor rotation angle value, the motor direct-axis first current value and the motor quadrature-axis first current value, the motor direct-axis inductance value and the motor quadrature-axis inductance value are determined; based on the motor direct-axis inductance value and the motor quadrature-axis inductance value, the motor stator temperature surface equation and the motor rotor temperature surface equation are fitted; based on the motor stator temperature surface equation and the motor rotor temperature surface equation, the motor stator temperature and the motor rotor temperature are determined, thereby realizing a solution for determining the motor stator temperature and the motor rotor temperature by a motor controller, without the need to add a motor temperature sensor, reducing costs, avoiding motor failures due to damage to the temperature sensor, and improving the reliability and stability of the motor.

[0110] Reference Figure 3 , shows a flow chart of the steps of a method for determining the motor temperature provided by embodiment 2 of the present invention, which can be applied to a motor controller.

[0111] like Figure 3 As shown, the motor temperature determination method may specifically include the following steps:

[0112] Step 201: Obtain the current motor torque value and motor resolver angle value.

[0113] Figure 2 FIG. 1 shows a flow chart of a motor temperature determination system provided by the present invention, such as Figure 2 As shown, the motor temperature determination system includes: a motor controller 01, a motor 02 connected to the motor controller, an angle sensor 03, and a current sensor 04. The angle sensor 03 can obtain the motor resolver angle value and send the resolver angle value to the MCU 01. The current motor torque value can be determined based on the motor resolver angle value.

[0114] After obtaining the current motor torque value and the motor resolver angle value, step 202 is executed.

[0115] Step 202: During the motor test calibration process, obtain a first direct-axis current value and a first quadrature-axis current value of the motor test, and determine a current-torque function based on the first direct-axis current value and the first quadrature-axis current value of the motor test.

[0116] The current-torque function is a function of the corresponding relationship between the first current value of the motor direct axis test, the first current value of the motor quadrature axis test, and the test motor torque value.

[0117] See also Figure 2 The current sensor 04 can obtain the three-phase current values ​​of the motor and perform coordinate transformation on the three-phase current values ​​in the three-phase stationary coordinate system, converting the three-phase current values ​​into the first current values ​​of the motor's direct axis and the first current values ​​of the motor's quadrature axis in the two-phase rotating coordinate system. The motor controller 01 can obtain the motor temperature and control the motor's operating state based on the motor temperature.

[0118] Among them, the first current value of the motor direct axis (d axis) is recorded as i d The first current value of the motor quadrature axis (q axis) is recorded as i q .

[0119] Specifically, the current motor torque value can be determined based on the motor rotation angle value; and surface fitting is performed based on the current torque value, the first direct-axis current value of the motor test, and the first quadrature-axis current value of the motor test to obtain a current-torque function.

[0120] For example, you can use i d 、i q And the current motor torque value, perform surface fitting, and obtain the current torque function through stepless surface fitting:

[0121] f(x,y)=ρ00+ρ10*x+ρ01*y+ρ20*x^2 +ρ11*x*y+ρ02*y ^2 +ρ30*x ^3 +ρ21*x ^2 *y

[0122] +ρ12*x*y ^2 +ρ03*y ^3 +ρ40*x ^4 +ρ31*x ^3 *y+ρ22*x ^2 *y ^2 +ρ13*x*y ^3 +ρ04*y ^4

[0123] +ρ40*x ^4 +ρ31*x ^3 *y+ρ22*x ^2 *y ^2 +ρ13*x*y ^3 +ρ04*y ^4

[0124] +ρ50*x ^5 +ρ41*x ^4 *y+ρ32*x ^3 *y ^2 +ρ23*x ^2 *y ^3 +ρ14*x*y ^4 +ρ05*y ^5

[0125] Among them, the current torque function f(x,y) is obtained by testing i d 、i q The torque value of the motor is automatically fitted into the software and the result is i d 、i q is the independent variable, the motor torque value is the function of the dependent variable, a set of i d 、i q There is a corresponding motor torque value.

[0126] After the current-torque function is determined based on the first direct-axis current value and the first quadrature-axis current value of the motor test, step 203 is executed.

[0127] Step 203: Based on the current motor torque value and the current-torque function, determine the first direct-axis current value of the motor and the first quadrature-axis current value of the motor corresponding to the current motor torque value.

[0128] Substitute the current motor torque value into the current-torque function to obtain the motor direct-axis first current value and the motor quadrature-axis first current value corresponding to the current motor torque value.

[0129] After determining the first direct-axis current value of the motor and the first quadrature-axis current value of the motor corresponding to the current motor torque value based on the current motor torque value and the current-torque function, step 204 is performed.

[0130] Step 204: Determine a motor direct-axis voltage value and a motor quadrature-axis voltage value based on the motor rotation angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value.

[0131] Specifically, the motor direct-axis target current value and the motor quadrature-axis target current value are determined based on the current-torque function; the motor direct-axis voltage value and the motor quadrature-axis voltage value are determined based on the motor direct-axis target current value and the motor quadrature-axis target current value.

[0132] Optionally, according to the current torque value, substitute it into the current torque function to obtain the motor direct axis target current value (i d ) and the motor quadrature axis target current value (i q ), the motor direct axis voltage value (U d ) and the motor quadrature axis voltage value (U q ).

[0133] Among them, the PI regulator is a linear controller, which forms a control deviation based on the given value and the actual output value, and forms a control quantity by linearly combining the proportion and integral of the deviation to control the controlled object.

[0134] After determining the motor direct-axis voltage value and the motor quadrature-axis voltage value based on the motor resolver angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value, step 205 is performed.

[0135] Step 205: Determine the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

[0136] Specifically, according to the steady-state voltage equation in the direct-axis quadrature-axis coordinate system, the motor direct-axis voltage value (U d ) and the motor quadrature axis voltage value (U q ), and determine the motor direct-axis inductance and the motor quadrature-axis inductance by iterative difference method.

[0137] Among them, the steady-state voltage equation in the direct-axis quadrature-axis coordinate system is:

[0138] U d =R×i d -ω e ×Lq×i q ;

[0139]

[0140] Where R represents the motor resistance; ω e Indicates the electrical angle value (that is, the resolver angle value); represents the permanent magnet flux, which is a known quantity; Lq represents the quadrature-axis inductance of the motor; and Ld represents the direct-axis inductance of the motor.

[0141] Specifically, for the calculation of Lq, fix i d ,but:

[0142] U d1 =R×i d1 -ω e ×Lq1×i q1 ;

[0143] U d2 =R×i d2 -ω e ×Lq2×i q2 ;

[0144] ΔU d1 =R×(i d1 -i d2 )-ω e ×Lq2×(i q1 -i q2 );

[0145] Where: R×(i d1 -i d2 ) is equal to zero, and Lq1≈Lq2, then:

[0146] ΔU d1 =-ω e ×Lq2×(i q1 -i q2 );

[0147] Also because Where n represents the number of turns and ω represents the angle, then:

[0148]

[0149] Similarly, we can get:

[0150] ΔU d2 =ω e ×(Lq2×iq2 -Lq3×i q3 );

[0151]

[0152] Specifically, for the calculation of Ld, fix i q ,but:

[0153]

[0154] again but:

[0155] U q =R×i q +ω e ×Ld×i d ;

[0156] ΔU q1 =R×(i q2 -i q1 )+ω e ×(L d2 ×i d2 -L d1 ×i d1 );

[0157] Due to the fixed q , then i q2 -i q1 ≈0;L d1 ≈L d2 ;

[0158]

[0159] U d3 -U d2 =R×(i q3 -i q2 )+ω e ×(L d3 ×i d3 -L d2 ×i d2 );

[0160]

[0161] After determining the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor, step 206 is executed.

[0162] Step 206: Based on the direct-axis inductance value of the motor and the quadrature-axis inductance value of the motor, a temperature surface equation of the motor stator and a temperature surface equation of the motor rotor are fitted.

[0163] Based on the motor direct-axis inductance and the motor quadrature-axis inductance calculated in step 103, combined with the motor electronic temperature relationship and the motor rotor temperature relationship determined by temperature sensors respectively provided at the motor stator and motor rotor positions during the motor calibration process, a motor stator temperature surface and an electronic rotor temperature surface are fitted, respectively, to obtain a motor stator temperature surface equation and an electronic rotor temperature surface equation. The motor stator temperature surface equation and the motor rotor temperature surface equation can be fifth-order equations, which are not specifically limited in the present embodiment.

[0164] After fitting the motor stator temperature surface equation and the motor rotor temperature surface equation based on the motor direct-axis inductance and the motor quadrature-axis inductance, step 207 is executed.

[0165] Step 207: Determine the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation.

[0166] The motor stator temperature can be determined based on the motor stator temperature surface equation, and the electronic rotor temperature can be determined based on the motor rotor temperature surface equation. This realizes the solution of determining the motor stator temperature and motor rotor temperature through the motor controller. There is no need to add a motor temperature sensor, which reduces costs, avoids motor failure due to damage to the temperature sensor, and improves the reliability and stability of the motor.

[0167] The motor temperature determination method provided by the embodiment of the present invention can be applied to a motor controller to obtain the current motor torque value and the motor rotation angle value; based on the current motor torque value and the pre-stored current-torque function, the motor direct-axis first current value and the motor quadrature-axis first current value are determined; based on the motor rotation angle value, the motor direct-axis first current value and the motor quadrature-axis first current value, the motor direct-axis inductance value and the motor quadrature-axis inductance value are determined; based on the motor direct-axis inductance value and the motor quadrature-axis inductance value, the motor stator temperature surface equation and the motor rotor temperature surface equation are fitted; based on the motor stator temperature surface equation and the motor rotor temperature surface equation, the motor stator temperature and the motor rotor temperature are determined, thereby realizing a solution for determining the motor stator temperature and the motor rotor temperature by a motor controller, without the need to add a motor temperature sensor, reducing costs, avoiding motor failures due to damage to the temperature sensor, and improving the reliability and stability of the motor.

[0168] Reference Figure 4 , shows a schematic structural diagram of a motor temperature determination device provided by a fifth embodiment of the present invention, which is applied to a motor controller. The motor temperature determination device 300 includes:

[0169] The acquisition module 301 is used to obtain the current motor torque value and the motor rotation angle value;

[0170] A first determining module 302 is configured to determine a first current value of a direct axis of the motor and a first current value of a quadrature axis of the motor based on the current motor torque value and a pre-stored current-torque function;

[0171] A second determining module 303 is configured to determine a direct-axis inductance value and a quadrature-axis inductance value of the motor based on the motor resolver angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor;

[0172] A fitting module 304 is configured to fit a temperature surface equation of a motor stator and a temperature surface equation of a motor rotor based on the direct-axis inductance value and the quadrature-axis inductance value of the motor;

[0173] The third determining module 305 is configured to determine the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation.

[0174] Optionally, the first determining module includes:

[0175] An acquisition submodule, used for acquiring a first current value of a direct axis of the motor test and a first current value of a quadrature axis of the motor test during the motor test calibration process;

[0176] A first determining submodule is configured to determine a current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test, wherein the current-torque function is a function of a correspondence between the first direct-axis current value of the motor test, the first quadrature-axis current value of the motor test, and a test motor torque value;

[0177] The second determining submodule is configured to determine, based on the current motor torque value and the current-torque function, a first direct-axis current value of the motor and a first quadrature-axis current value of the motor corresponding to the current motor torque value.

[0178] Optionally, the motor controller is connected to a current sensor, and the second determining module includes:

[0179] A third determining submodule is configured to determine a motor direct-axis voltage value and a motor quadrature-axis voltage value based on the motor resolver angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value;

[0180] The fourth determination submodule is used to determine the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

[0181] Optionally, the fourth determining submodule includes:

[0182] The first determining unit is used to determine the direct-axis inductance value and the quadrature-axis inductance value of the motor by iterative difference method according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor and the quadrature-axis voltage value of the motor.

[0183] Optionally, the first determining submodule includes:

[0184] An acquisition unit is used to obtain the resolver angle value of the motor test;

[0185] A second determining unit is used to determine a test motor torque value corresponding to the motor test resolver angle value;

[0186] The fitting unit is configured to perform surface fitting based on the test motor torque value, the motor direct axis first current value, and the motor quadrature axis first current value to obtain a current-torque function. The specific implementation of the motor temperature determination device in the embodiment of the present invention has been described in detail in the method side and will not be repeated here.

[0187] The motor temperature determination device provided by the embodiment of the present invention can be applied to a motor controller to obtain the current motor torque value and the motor rotation angle value; determine the motor direct axis first current value and the motor quadrature axis first current value based on the current motor torque value and the pre-stored current-torque function; determine the motor direct axis inductance value and the motor quadrature axis inductance value based on the motor rotation angle value, the motor direct axis first current value and the motor quadrature axis first current value; based on the motor direct axis inductance value and the motor quadrature axis inductance value, fit the motor stator temperature surface equation and the motor rotor temperature surface equation; based on the motor stator temperature surface equation and the motor rotor temperature surface equation, determine the motor stator temperature and the motor rotor temperature, and realize the scheme of determining the motor stator temperature and the motor rotor temperature through the motor controller, without adding a motor temperature sensor, reducing costs, avoiding motor failure caused by damage to the temperature sensor, and improving the reliability and stability of the motor.

[0188] An embodiment of the present invention further provides a vehicle, comprising any motor temperature determination device according to any embodiment of the present invention.

[0189] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referenced to each other.

[0190] Although alternative embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they become aware of the basic creative concepts. Therefore, the appended claims are intended to be interpreted as including alternative embodiments and all changes and modifications that fall within the scope of the embodiments of the present invention.

[0191] Finally, it should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity from another, and do not necessarily require or imply any actual relationship or order between these entities. Moreover, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that an article or terminal device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such article or terminal device. In the absence of further limitations, an element defined by the phrase "comprising a..." does not exclude the presence of additional identical elements in the article or terminal device comprising the element.

[0192] The technical solutions provided by the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the present invention. At the same time, for those skilled in the art, according to the principles and implementation methods of the present invention, there may be changes in the specific implementation methods and application scopes. In summary, the contents of this specification should not be understood as limiting the present invention.

Claims

1. A method for determining motor temperature, applied to a motor controller, characterized in that: The method comprises: Get the current motor torque value and motor resolver angle value; Determining a first current value of the motor direct axis and a first current value of the motor quadrature axis based on the current motor torque value and a pre-stored current-torque function; Determine the direct-axis inductance value and the quadrature-axis inductance value of the motor based on the motor rotation angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor; Fitting a motor stator temperature surface equation and a motor rotor temperature surface equation based on the motor direct-axis inductance and the motor quadrature-axis inductance; Determining the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation; The determining, based on the current motor torque value and the pre-stored current-torque function, a first current value of the motor direct axis and a first current value of the motor quadrature axis includes: During the motor test calibration process, a first current value of the motor test direct axis and a first current value of the motor test quadrature axis are obtained; Determine a current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test, wherein the current-torque function is a function of a correspondence between the first direct-axis current value of the motor test, the first quadrature-axis current value of the motor test, and the test motor torque value; Based on the current motor torque value and the current-torque function, a first current value of the motor direct axis and a first current value of the motor quadrature axis corresponding to the current motor torque value are determined.

2. The method according to claim 1, wherein the motor controller is connected to the current sensor, characterized in that: The determining of the direct-axis inductance value and the quadrature-axis inductance value of the motor based on the motor rotation angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor includes: Determine a motor direct-axis voltage value and a motor quadrature-axis voltage value based on the motor rotation angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value; The direct-axis inductance value and the quadrature-axis inductance value of the motor are determined according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

3. The method according to claim 2, characterized in that The determining of the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor comprises: According to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the motor direct-axis voltage value and the motor quadrature-axis voltage value, the motor direct-axis inductance value and the motor quadrature-axis inductance value are determined by iterative difference method.

4. The method according to claim 1, wherein The determining of the current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test includes: Get the motor test resolver angle value; Determine a test motor torque value corresponding to the motor test resolver angle value; Based on the test motor torque value, the motor direct axis first current value and the motor quadrature axis first current value, surface fitting is performed to obtain a current-torque function.

5. A motor temperature determination device, applied to a motor controller, characterized in that: The device comprises: The acquisition module is used to obtain the current motor torque value and motor rotation angle value; A first determining module is configured to determine a first current value of a direct axis of the motor and a first current value of a quadrature axis of the motor based on the current motor torque value and a pre-stored current-torque function; a second determining module, configured to determine a direct-axis inductance value and a quadrature-axis inductance value of the motor based on the motor resolver angle value, the first direct-axis current value of the motor, and the first quadrature-axis current value of the motor; A fitting module, configured to fit a temperature surface equation of a motor stator and a temperature surface equation of a motor rotor based on the direct-axis inductance value and the quadrature-axis inductance value of the motor; a third determining module, configured to determine the motor stator temperature and the motor rotor temperature based on the motor stator temperature surface equation and the motor rotor temperature surface equation; The first determining module includes: An acquisition submodule, used for acquiring a first current value of a direct axis of the motor test and a first current value of a quadrature axis of the motor test during the motor test calibration process; A first determining submodule is configured to determine a current-torque function based on the first direct-axis current value of the motor test and the first quadrature-axis current value of the motor test, wherein the current-torque function is a function of a correspondence between the first direct-axis current value of the motor test, the first quadrature-axis current value of the motor test, and a test motor torque value; The second determining submodule is configured to determine, based on the current motor torque value and the current-torque function, a first direct-axis current value of the motor and a first quadrature-axis current value of the motor corresponding to the current motor torque value.

6. The device according to claim 5, wherein the motor controller is connected to a current sensor, The second determining module includes: A third determining submodule is configured to determine a motor direct-axis voltage value and a motor quadrature-axis voltage value based on the motor resolver angle value, the motor direct-axis first current value, and the motor quadrature-axis first current value; The fourth determination submodule is used to determine the direct-axis inductance value and the quadrature-axis inductance value of the motor according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor, and the quadrature-axis voltage value of the motor.

7. The device according to claim 6, characterized in that The fourth determining submodule includes: The first determining unit is used to determine the direct-axis inductance value and the quadrature-axis inductance value of the motor by iterative difference method according to the steady-state voltage equation in the direct-axis and quadrature-axis coordinate system, the direct-axis voltage value of the motor and the quadrature-axis voltage value of the motor.

8. The device according to claim 5, characterized in that The first determining submodule includes: An acquisition unit is used to obtain the motor test resolver angle value; A second determining unit is used to determine a test motor torque value corresponding to the motor test resolver angle value; The fitting unit is used to perform surface fitting based on the test motor torque value, the first current value of the motor direct axis and the first current value of the motor quadrature axis to obtain a current-torque function.

9. A vehicle, characterized in that: The device comprises the motor temperature determination device according to any one of claims 5 to 8.

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