Motor temperature calculation method and device

Abstract

The embodiment of the invention discloses a motor temperature calculation method and device. The motor temperature calculation method is applied to a dual three-phase redundant controller. The dual three-phase redundant controller controls the dual three-phase motor; the dual three-phase redundancy controller comprises a first control module and a second control module, the first control module is connected with one path of three-phase motor, and the second control module is connected with the other path of three-phase motor; the motor temperature calculation method comprises the following steps: acquiring operation parameters of one path of three-phase motor and power loss of the other path of three-phase motor; determining the power loss of the one-way three-phase motor according to the operation parameters of the one-way three-phase motor; and determining the temperature of the three-phase motor based on a thermal network model according to the power loss of the three-phase motor, the power loss of the other three-phase motor and the reference temperature. According to the technical scheme, temperature calculation of the dual three-phase motor is achieved, the accuracy of temperature calculation of the dual three-phase motor is improved, and power derating and over-temperature protection can be conveniently carried out on the dual three-phase motor according to temperature changes.

Description

Technical Field

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

[0002] The motor is a key device for the mutual conversion of mechanical energy and electrical energy. During operation, the motor will generate a lot of heat due to its own loss, so the motor temperature must be sampled and monitored to avoid the harm caused by unexpected high temperature.

[0003] Therefore, in order to protect the motor and prevent the motor from burning out, it is necessary to calculate the motor temperature and monitor the motor temperature in real time. However, the accuracy of the motor temperature calculation in the prior art is low. Summary of the invention

[0004] The present invention provides a motor temperature calculation method and device, so as to realize the temperature calculation of a dual three-phase motor, monitor the temperature of the dual three-phase motor in real time, and improve the accuracy of the temperature calculation of the dual three-phase motor.

[0005] According to one aspect of the present invention, a motor temperature calculation method is provided, and the motor temperature calculation method is applied to a dual three-phase redundant controller; the dual three-phase redundant controller is used to control a dual three-phase motor; the dual three-phase redundant controller includes a first control module and a second control module, the first control module is connected to one three-phase motor, and the second control module is connected to another three-phase motor; the motor temperature calculation method includes:

[0006] Obtain the operating parameters of one three-phase motor and the power loss of another three-phase motor;

[0007] Determine the power loss of a three-phase motor according to the operating parameters of the three-phase motor;

[0008] The temperature of one three-phase motor is determined based on a thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature.

[0009] Optionally, the first control module and the second control module are arranged on the substrate and are respectively located on both sides of the shaft of the dual three-phase motor; before determining the temperature of one three-phase motor based on the thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the reference temperature, the method further includes:

[0010] The temperature of the substrate where the first control module is located is obtained as a reference temperature.

[0011] Optionally, a first thermistor is provided on the substrate, and the first thermistor and the first control module are located on one side of the shaft of the dual three-phase motor; obtaining the temperature of the substrate where the first control module is located includes:

[0012] The temperature of the substrate where the first control module is located is obtained through the first thermistor.

[0013] Optionally, according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature, the temperature of one three-phase motor is determined based on a thermal network model, including:

[0014] Determine a first temperature variation caused by the loss of the three-phase motor according to the power loss of the three-phase motor, the equivalent thermal resistance from the first thermistor to the stator of the three-phase motor, and the time constant from the first thermistor to the stator of the three-phase motor;

[0015] Determine a second temperature variation caused by the loss of the other three-phase motor according to the power loss of the other three-phase motor, the equivalent thermal resistance of the other three-phase motor winding coupled to the one three-phase motor winding, and the time constant of the other three-phase motor winding coupled to the one three-phase motor winding;

[0016] The temperature of a three-phase motor is determined according to the sum of the first temperature change, the second temperature change and the reference temperature.

[0017] Optionally, determining a first temperature variation caused by the loss of the three-phase motor according to the power loss of the three-phase motor, the equivalent thermal resistance from the first thermistor to the stator of the three-phase motor, and the time constant from the first thermistor to the stator of the three-phase motor includes:

[0018] The first temperature change caused by the loss of a three-phase motor is obtained from the following relationship:

[0019]

[0020] Among them, ΔT1 is the first temperature change caused by the loss of a three-phase motor, R P is the equivalent thermal resistance from the first thermistor to the stator of a three-phase motor, T P s is the time constant from the first thermistor to the stator of a three-phase motor, P Cu_P +P Fe_P is the power loss of a three-phase motor.

[0021] Optionally, determining a second temperature variation caused by the loss of the other three-phase motor according to the power loss of the other three-phase motor, the equivalent thermal resistance of the other three-phase motor winding coupled to the one three-phase motor winding, and the time constant of the other three-phase motor winding coupled to the one three-phase motor winding includes:

[0022] The second temperature variation caused by the loss of the other three-phase motor is obtained from the following relationship:

[0023]

[0024] Among them, ΔT2 is the second temperature change caused by the loss of another three-phase motor, R D is the equivalent thermal resistance of another three-phase motor winding coupled to a three-phase motor winding, T D s is the time constant of coupling another three-phase motor winding to one three-phase motor winding, P Cu_D +P Fe_D is the power loss of another three-phase motor.

[0025] Optionally, the motor temperature calculation method further includes:

[0026] When another three-phase motor fails, the power loss of the other three-phase motor is 0.

[0027] According to another aspect of the present invention, a motor temperature calculation method is provided, and the motor temperature calculation method is applied to a dual three-phase redundant controller; the dual three-phase redundant controller is used to control a dual three-phase motor; the dual three-phase redundant controller includes a first control module and a second control module, the first control module and the second control module are communicatively connected, the first control module is connected to one three-phase motor, and the second control module is connected to another three-phase motor; the motor temperature calculation method includes:

[0028] The first control module obtains the operating parameters of one three-phase motor, and the second control module obtains the operating parameters of another three-phase motor;

[0029] The first control module determines the power loss of one three-phase motor according to the operating parameters of the one three-phase motor, and the second control module determines the power loss of another three-phase motor according to the operating parameters of the other three-phase motor;

[0030] The first control module determines the temperature of one three-phase motor based on the first thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the first reference temperature; the second control module determines the temperature of another three-phase motor based on the second thermal network model according to the power loss of the other three-phase motor, the power loss of one three-phase motor and the second reference temperature.

[0031] Optionally, the first control module and the second control module are arranged on the substrate and are respectively located on both sides of the shaft of the dual three-phase motor; the first thermistor and the second thermistor are arranged on the substrate, the first thermistor and the first control module are located on one side of the shaft of the dual three-phase motor, and the second thermistor and the second control module are located on the other side of the shaft of the dual three-phase motor; before the first control module determines the temperature of one three-phase motor based on the first thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the first reference temperature, it also includes:

[0032] Acquiring the temperature of the substrate where the first control module is located through the first thermistor as a first reference temperature;

[0033] Before the second control module determines the temperature of another three-phase motor based on the second thermal network model according to the power loss of another three-phase motor, the power loss of one three-phase motor and the second reference temperature, the method further includes:

[0034] The temperature of the substrate where the second control module is located is obtained through the second thermistor as the second reference temperature.

[0035] According to another aspect of the present invention, a motor temperature calculation device is provided, the motor temperature calculation device comprising:

[0036] A parameter acquisition module is used to acquire the operating parameters of one three-phase motor and the power loss of another three-phase motor;

[0037] A power loss determination module, used to determine the power loss of one three-phase motor according to the operating parameters of the three-phase motor;

[0038] The temperature determination module is used to determine the temperature of one three-phase motor based on a thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature.

[0039] The technical solution of the embodiment of the present invention obtains the operating parameters of one three-phase motor and the power loss of another three-phase motor, and then determines the power loss of one three-phase motor according to the operating parameters of one three-phase motor, and finally determines the temperature of one three-phase motor based on the thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the reference temperature, so as to realize the temperature calculation of the dual three-phase motor. Since the winding of one three-phase motor itself has heat transfer, and there is thermal coupling between the winding of another three-phase motor, the temperature of one three-phase motor is determined based on the thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the reference temperature, so as to improve the accuracy of the temperature calculation of the dual three-phase motor, and the dual three-phase redundant controller monitors the temperature of the dual three-phase motor in real time, so as to facilitate the power derating and over-temperature protection of the dual three-phase motor according to the temperature change.

[0040] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0042] Figure 1 is a dual three-phase motor control principle diagram provided according to an embodiment of the present invention;

[0043] Figure 2 is a structural schematic diagram of a dual three-phase redundant controller provided according to an embodiment of the present invention;

[0044] Figure 3 is a flow chart of a method for calculating motor temperature provided according to an embodiment of the present invention;

[0045] Figure 4 is a flow chart of another motor temperature calculation method provided according to an embodiment of the present invention;

[0046] Figure 5 is a schematic diagram of motor temperature calculation provided according to an embodiment of the present invention;

[0047] Figure 6 is a flow chart of another motor temperature calculation method provided by an embodiment of the present invention;

[0048] Figure 7 is a flow chart of another motor temperature calculation method provided by an embodiment of the present invention;

[0049] Figure 8 is a schematic diagram of motor temperature calculation of a dual three-phase redundant controller provided according to an embodiment of the present invention;

[0050] Fig. 9 Schematic diagram of the structure of a motor temperature calculation device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0051] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0052] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0053] Figure 1 A dual three-phase motor control principle diagram provided according to an embodiment of the present invention. Figure 2 Schematic diagram of a dual three-phase redundant controller provided according to an embodiment of the present invention. Figure 1 and Figure 2 As shown, the motor temperature calculation method of an embodiment of the present invention is applied to a dual three-phase redundant controller; the dual three-phase redundant controller is used to control a dual three-phase motor 200; the dual three-phase redundant controller includes a first control module 101 and a second control module 102, the first control module 101 is connected to one three-phase motor, and the second control module 102 is connected to another three-phase motor.

[0054] In the embodiment of the present invention, the first control module 101 and the second control module 102 can both be single-chip microcomputers. The dual three-phase redundant controller also includes a control board 103, a drive board 104, a main board three-phase connector 105, and an auxiliary board three-phase connector 106. Exemplarily, the main board three-phase connector 105 is used to connect the first control module 101 and a three-phase motor controlled by the first control module 101. The auxiliary board three-phase connector 106 is used to connect the second control module 102 and another three-phase motor controlled by the second control module 102.

[0055] Figure 3 1 is a flow chart of a motor temperature calculation method provided according to an embodiment of the present invention. The embodiment of the present invention can be applied to the calculation of the temperature of a dual three-phase motor. The motor temperature calculation method can be executed by a motor temperature calculation device, and the motor temperature calculation device can be implemented in the form of hardware and / or software. Figure 3 As shown, the motor temperature calculation method includes:

[0056] S110, obtaining operating parameters of one three-phase motor and power loss of another three-phase motor.

[0057] Specifically, the dual three-phase redundant controller includes a first control module and a second control module. Taking a unilateral controller as an example, the first control module is used as a unilateral main controller, and the second control module is used as an auxiliary controller. The operating parameters of a three-phase motor controlled by the first control module are obtained. The operating parameters of the three-phase motor include but are not limited to operating current, operating voltage and speed. The operating current of the three-phase motor can be obtained by a current sensor. The operating voltage of the three-phase motor can be obtained by a voltage sensor. The speed of the three-phase motor can be obtained by a tachometer.

[0058] The other three-phase motor is a three-phase motor controlled by the second control module. Exemplarily, the first control module is connected to the second control module in communication, and the power loss of the three-phase motor controlled by the second control module can be transmitted to the first control module through communication. The power loss of the other three-phase motor is obtained because the power loss of the other three-phase motor controlled by the second control module will have a temperature effect on the winding of the three-phase motor controlled by the first control module, for example, causing the temperature of the winding of the three-phase motor controlled by the first control module to rise.

[0059] S120: Determine the power loss of the three-phase motor according to the operating parameters of the three-phase motor.

[0060] Specifically, power loss mainly includes copper loss and iron loss. Power loss can be calculated by working current, working voltage and speed. Among them, copper loss can be obtained by multiplying the square of working current by resistance, and iron loss can be obtained by offline calibration and table lookup.

[0061] S130, determining the temperature of one three-phase motor based on a thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature.

[0062] Specifically, the reference temperature may be the temperature measured by the first control module. The power loss of one three-phase motor is determined according to the operating parameters of one three-phase motor. The power loss of another three-phase motor is obtained through a communication connection. The thermal network model may be the sum of all temperatures that cause temperature changes in the one three-phase motor controlled by the first control module. For example, when determining the temperature of one three-phase motor controlled by the first control module, in addition to considering the temperature of the first control module itself, it is also necessary to calculate the temperature change caused by the power loss of one three-phase motor and the temperature change caused by the power loss of another three-phase motor on the temperature of one three-phase motor. By adding the above three temperature values, the temperature of one three-phase motor to be monitored is obtained. Then, a protection action is performed according to the calculated temperature of one three-phase motor. For example, when the temperature of one three-phase motor is too high, power derating or over-temperature protection is performed.

[0063] Exemplarily, when calculating the temperature of another three-phase motor, first obtain the operating parameters of the other three-phase motor and the power loss of one three-phase motor; then determine the power loss of the other three-phase motor based on the operating parameters of the other three-phase motor; use the temperature of the substrate where the second control module is located as the reference temperature when calculating the temperature of the other three-phase motor, and add the power loss of the other three-phase motor, the acquired power loss of one three-phase motor, and the reference temperature to obtain the temperature of the other three-phase motor.

[0064] The technical solution of the embodiment of the present invention obtains the operating parameters of one three-phase motor and the power loss of another three-phase motor, determines the power loss of the three-phase motor according to the operating parameters of the three-phase motor, and finally determines the temperature of the three-phase motor based on the power loss of the three-phase motor, the power loss of the other three-phase motor and the reference temperature based on the thermal network model, thereby realizing the temperature calculation of the dual three-phase motors. Since there is heat transfer in the winding of the three-phase motor itself and there is thermal coupling with the winding of the other three-phase motor, the temperature of the three-phase motor is determined based on the thermal network model according to the power loss of the three-phase motor, the power loss of the other three-phase motor and the reference temperature, thereby improving the accuracy of the temperature calculation of the dual three-phase motors. The dual three-phase redundant controller monitors the temperature of the dual three-phase motor in real time, so as to facilitate power derating and over-temperature protection of the dual three-phase motor according to temperature changes.

[0065] refer to Figure 2 The first control module 101 and the second control module 102 are arranged on a substrate and are respectively located on both sides of the shaft 201 of the dual three-phase motor 200. In the embodiment of the present invention, the substrate may be a printed circuit board. Figure 4 FIG. 1 is a flow chart of another method for calculating motor temperature according to an embodiment of the present invention. Figure 4 As shown, the motor temperature calculation method includes:

[0066] S210: Obtain operating parameters of one three-phase motor and power loss of another three-phase motor.

[0067] S220: Determine the power loss of the three-phase motor according to the operating parameters of the three-phase motor.

[0068] S230 , obtaining a substrate temperature where the first control module is located as a reference temperature.

[0069] In other optional embodiments of the present invention, reference Figure 2 A first thermistor 107 is disposed on the substrate, and the first thermistor 107 and the first control module 101 are located on one side of the shaft 201 of the dual three-phase motor 200. Obtaining the substrate temperature where the first control module 101 is located includes: obtaining the substrate temperature where the first control module 101 is located through the first thermistor 107.

[0070] Specifically, the first control module 101 and the second control module 102 are each provided with a thermistor on the control board 103, which is used to collect the temperature of the substrate as a reference temperature. Exemplarily, the first thermistor 107 may be connected to the first control module 101, and the second thermistor 108 may be connected to the second control module 102. The reference temperature may be obtained by the first thermistor 107. In other optional embodiments of the present invention, the reference temperature may also be obtained by a temperature sensor disposed on the substrate, which is not specifically limited herein.

[0071] S240, determining the temperature of one three-phase motor based on a thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature.

[0072] Figure 5 FIG. 1 is a schematic diagram of a motor temperature calculation according to an embodiment of the present invention. Figure 5 As shown, the power loss 501 of one three-phase motor is calculated according to the current, voltage and speed of one three-phase motor, the power loss 502 of another three-phase motor is obtained through board communication, and then the temperature 503 of the substrate where the first control module is located is obtained, the power loss 501 of one three-phase motor, the power loss 502 of another three-phase motor and the temperature 503 of the substrate where the first control module is located are input into the thermal network model 504, and the temperature 505 of the three-phase motor is output.

[0073] Figure 6 FIG. 1 is a flow chart of another method for calculating motor temperature according to an embodiment of the present invention. Figure 6 As shown, the motor temperature calculation method includes:

[0074] S310: Obtain operating parameters of one three-phase motor and power loss of another three-phase motor.

[0075] S320: Determine the power loss of the three-phase motor according to the operating parameters of the three-phase motor.

[0076] S330 , obtaining a substrate temperature where the first control module is located as a reference temperature.

[0077] S340, determining a first temperature variation caused by the loss of the three-phase motor according to the power loss of the three-phase motor, the equivalent thermal resistance from the first thermistor to the stator of the three-phase motor, and the time constant from the first thermistor to the stator of the three-phase motor.

[0078] Optionally, the first temperature variation caused by the loss of a three-phase motor is obtained by the following relationship:

[0079]

[0080] Among them, ΔT1 is the first temperature change caused by the loss of a three-phase motor, R P is the equivalent thermal resistance from the first thermistor to the stator of a three-phase motor, T P s is the time constant from the first thermistor to the stator of a three-phase motor, P Cu_P +P Fe_P is the power loss of a three-phase motor.

[0081] Specifically, the loss of the three-phase motor controlled by the first control module mainly comes from copper loss and iron loss. The temperature change is caused by its own copper loss and iron loss, and this temperature change is recorded as the first temperature change ΔT1. The equivalent thermal resistance R from the first thermistor to the stator of the three-phase motor is P It can be obtained by offline calibration. The time constant T from the first thermistor to the stator of a three-phase motor P s can also be obtained through offline calibration. The power loss of a three-phase motor mainly includes copper loss and iron loss, which are expressed as P Cu_P +P Fe_P After obtaining the various parameters, the first temperature variation ΔT1 caused by the loss of the three-phase motor is determined according to the relational expression of the first temperature variation.

[0082] S350, determining a second temperature variation caused by the loss of the other three-phase motor according to the power loss of the other three-phase motor, the equivalent thermal resistance of the other three-phase motor winding coupled to the one three-phase motor winding, and the time constant of the other three-phase motor winding coupled to the one three-phase motor winding.

[0083] The second temperature variation caused by the loss of the other three-phase motor is obtained from the following relationship:

[0084]

[0085] Among them, ΔT2 is the second temperature change caused by the loss of another three-phase motor, R D is the equivalent thermal resistance of another three-phase motor winding coupled to a three-phase motor winding, T D s is the time constant of coupling another three-phase motor winding to one three-phase motor winding, P Cu_D +P Fe_D is the power loss of another three-phase motor.

[0086] Specifically, the power loss of the other three-phase motor controlled by the second control module will have a temperature impact on the winding of the three-phase motor controlled by the first control module, for example, causing the temperature of the winding of the three-phase motor controlled by the first control module to rise. Therefore, when calculating the temperature of the three-phase motor, it is necessary to consider the temperature change caused by the power damage of the other three-phase motor. The temperature change caused by the loss of the other three-phase motor is recorded as the second temperature change ΔT2. The equivalent thermal resistance R of the other three-phase motor winding coupled to the three-phase motor winding is D The time constant T of coupling another three-phase motor winding to a three-phase motor winding D s can be obtained by offline calibration. The power loss of the other three-phase motor mainly includes copper loss and iron loss, which are expressed as P Cu_D +P Fe_D After obtaining the various parameters, the second temperature variation ΔT2 caused by the loss of another three-phase motor is determined according to the relationship of the second temperature variation.

[0087] S360, determining the temperature of a three-phase motor according to the sum of the first temperature change, the second temperature change and the reference temperature.

[0088] Based on the technical solution of the above-mentioned embodiment of the invention, optionally, the motor temperature calculation method also includes: when another three-phase motor fails, the power loss of the other three-phase motor is 0.

[0089] In the embodiment of the present invention, when one side of the three-phase motor controlled by the first control module and the other side of the three-phase motor controlled by the second control module stops due to a fault, the corresponding transmission loss will be set to 0. This is because when one side stops due to a fault, it will not affect the temperature of the other side.

[0090] Figure 7 : is a flowchart of another motor temperature calculation method provided by an embodiment of the present invention. The motor temperature calculation method is applied to a dual three-phase redundant controller; the dual three-phase redundant controller is used to control a dual three-phase motor; the dual three-phase redundant controller includes a first control module and a second control module, the first control module and the second control module are communicatively connected, the first control module is connected to one three-phase motor, and the second control module is connected to another three-phase motor. Figure 7 As shown, the motor temperature calculation method includes:

[0091] S410, the first control module obtains operating parameters of one three-phase motor, and the second control module obtains operating parameters of another three-phase motor.

[0092] S420, the first control module determines the power loss of one three-phase motor according to the operating parameters of the one three-phase motor, and the second control module determines the power loss of another three-phase motor according to the operating parameters of the other three-phase motor.

[0093] S430, the first control module determines the temperature of one three-phase motor based on the first thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the first reference temperature; the second control module determines the temperature of another three-phase motor based on the second thermal network model according to the power loss of another three-phase motor, the power loss of one three-phase motor and the second reference temperature.

[0094] In an embodiment of the present invention, the first control module and the second control module work simultaneously to respectively calculate the temperature of one three-phase motor and the temperature of another three-phase motor. Through the motor temperature calculation method of the embodiment of the present invention, the temperature of any one of the dual three-phase motors can be obtained at the same time, and the temperature of the dual three-phase motor can be monitored in real time, so as to facilitate power derating and over-temperature protection of the dual three-phase motor according to temperature changes.

[0095] Figure 8 1 is a schematic diagram of a motor temperature calculation of a dual three-phase redundant controller provided according to an embodiment of the present invention. Figure 8 As shown, in an embodiment of the invention, the dual three-phase redundant controller further includes a communication module, and the communication module includes a first inter-board communication module 701 and a second inter-board communication module 702, wherein the first inter-board communication module 701 is connected to the first control module 101, and the second inter-board communication module 702 is connected to the second control module 102. The first inter-board communication module 701 and the second inter-board communication module 702 are connected to each other. In the temperature calculation 703 of one three-phase motor, the loss calculation 704 of one three-phase motor and the loss transmission 705 of another three-phase motor are received, and the loss calculation 704 of one three-phase motor is transmitted to the second inter-board communication module 702 through the first inter-board communication module 701. For the temperature calculation 706 of another three-phase motor, the loss calculation 707 of another three-phase motor and the loss transmission 708 of one three-phase motor are received, and the loss calculation 707 of another three-phase motor is transmitted to the first inter-board communication module 701 through the second inter-board communication module 702.

[0096] refer to Figure 2 The first control module 101 and the second control module 102 are arranged on the substrate and are respectively located on both sides of the shaft 201 of the dual three-phase motor 200; the first thermistor 107 and the second thermistor 108 are arranged on the substrate, the first thermistor 107 and the first control module 101 are located on one side of the shaft 201 of the dual three-phase motor 200, and the second thermistor 108 and the second control module 102 are located on the other side of the shaft 201 of the dual three-phase motor 200.

[0097] In an optional embodiment of the present invention, before the first control module determines the temperature of one three-phase motor based on the first thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and the first reference temperature, it also includes: obtaining the substrate temperature where the first control module is located through a first thermistor as the first reference temperature; before the second control module determines the temperature of another three-phase motor based on the second thermal network model according to the power loss of the other three-phase motor, the power loss of one three-phase motor and the second reference temperature, it also includes: obtaining the substrate temperature where the second control module is located through a second thermistor as the second reference temperature.

[0098] In the embodiment of the present invention, reference Figure 2 , the first control module 101 and the second control module 102 are each provided with a thermistor on the control board 103, which is used to collect the temperature of the substrate as a reference temperature. Exemplarily, the first thermistor 107 may be connected to the first control module 101, and the second thermistor 108 may be connected to the second control module 102. The first reference temperature may be obtained by the first thermistor 107, and the second reference temperature may be obtained by the second thermistor 108. In other optional embodiments of the present invention, the first reference temperature and the second reference temperature may also be obtained by a temperature sensor disposed on the substrate, which is not specifically limited herein.

[0099] Fig. 9 Schematic diagram of the structure of a motor temperature calculation device provided according to an embodiment of the present invention.

[0100] like Fig. 9 As shown, the motor temperature calculation device includes:

[0101] The parameter acquisition module 10 is used to acquire the operating parameters of one three-phase motor and the power loss of another three-phase motor.

[0102] Specifically, the operating parameters of one three-phase motor and the power loss of another three-phase motor transmitted through communication can be obtained through the parameter acquisition module 10. The operating parameters of one three-phase motor can include the operating current, operating voltage and speed of the three-phase motor.

[0103] The power loss determination module 20 is used to determine the power loss of one three-phase motor according to the operating parameters of the one three-phase motor.

[0104] Specifically, the power loss mainly includes copper loss and iron loss. Through the power loss determination module 20, the power loss of one three-phase motor can be calculated according to the working current, working voltage and speed.

[0105] The temperature determination module 30 is used to determine the temperature of one three-phase motor based on a thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature.

[0106] Specifically, the reference temperature may be the temperature measured by the first control module. The power loss of one three-phase motor is determined according to the operating parameters of one three-phase motor. The power loss of another three-phase motor is obtained through a communication connection. The thermal network model may be the sum of all temperatures that cause temperature changes in one three-phase motor controlled by the first control module. For example, when determining the temperature of one three-phase motor controlled by the first control module, in addition to considering the temperature of the first control module itself, it is also necessary to calculate the temperature change caused by the power loss of one three-phase motor and the temperature change caused by the power loss of another three-phase motor on the temperature of one three-phase motor. The temperature determination module 30 is used to sum the temperature values ​​of the above three parts to obtain the temperature of one three-phase motor to be monitored. Afterwards, a protection action is performed based on the calculated temperature of one three-phase motor. For example, when the temperature of one three-phase motor is too high, power reduction or over-temperature protection is performed.

[0107] The technical solution of the embodiment of the present invention obtains the operating parameters of one three-phase motor and the power loss of another three-phase motor through a parameter acquisition module, and then determines the power loss of the three-phase motor according to the operating parameters of the three-phase motor through a power loss determination module. Finally, the temperature of the three-phase motor is determined based on a thermal network model according to the power loss of one three-phase motor, the power loss of another three-phase motor and a reference temperature through a temperature determination module, thereby realizing temperature calculation of dual three-phase motors. The dual three-phase redundant controller monitors the temperature of the dual three-phase motor in real time, so as to facilitate power derating and over-temperature protection of the dual three-phase motor according to temperature changes.

[0108] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0109] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for calculating motor temperature, characterized in that: Applied to a dual three-phase redundant controller; the dual three-phase redundant controller is used to control a dual three-phase motor; the dual three-phase redundant controller includes a first control module and a second control module, the first control module is connected to one three-phase motor, and the second control module is connected to another three-phase motor; the motor temperature calculation method includes: Obtaining the operating parameters of the three-phase motor and the power loss of the other three-phase motor; Determining the power loss of the three-phase motor according to the operating parameters of the three-phase motor; The temperature of the three-phase motor is determined based on a thermal network model according to the power loss of the three-phase motor, the power loss of the other three-phase motor and a reference temperature.

2. The motor temperature calculation method according to claim 1, characterized in that: The first control module and the second control module are arranged on a substrate and are respectively located on both sides of the shaft of the dual three-phase motor; before determining the temperature of the one three-phase motor based on a thermal network model according to the power loss of the one three-phase motor, the power loss of the other three-phase motor and the reference temperature, the method further includes: The temperature of the substrate where the first control module is located is obtained as the reference temperature.

3. The motor temperature calculation method according to claim 2, characterized in that: A first thermistor is disposed on the substrate, and the first thermistor and the first control module are located on one side of the shaft of the dual three-phase motor; obtaining the temperature of the substrate where the first control module is located includes: The temperature of the substrate where the first control module is located is obtained through the first thermistor.

4. The motor temperature calculation method according to claim 3, characterized in that: The method of determining the temperature of the three-phase motor based on a thermal network model according to the power loss of the three-phase motor, the power loss of the other three-phase motor and a reference temperature includes: Determine a first temperature variation caused by the loss of the three-phase motor according to the power loss of the three-phase motor, the equivalent thermal resistance from the first thermistor to the stator of the three-phase motor, and the time constant from the first thermistor to the stator of the three-phase motor; Determine a second temperature variation caused by the loss of the other three-phase motor according to the power loss of the other three-phase motor, the equivalent thermal resistance of the other three-phase motor winding coupled to the one three-phase motor winding, and the time constant of the other three-phase motor winding coupled to the one three-phase motor winding; The temperature of the three-phase motor is determined according to the sum of the first temperature change, the second temperature change and the reference temperature.

5. The method for calculating the motor temperature according to claim 4, characterized in that: The first temperature variation caused by the loss of the three-phase motor is determined according to the power loss of the three-phase motor, the equivalent thermal resistance from the first thermistor to the stator of the three-phase motor, and the time constant from the first thermistor to the stator of the three-phase motor, including: The first temperature variation caused by the loss of the three-phase motor is obtained by the following relationship: Wherein, ΔT1 is the first temperature variation caused by the loss of the three-phase motor, R P is the equivalent thermal resistance from the first thermistor to the stator of the three-phase motor, T P s is the time constant from the first thermistor to the stator of the three-phase motor, P Cu_P +P Fe_P is the power loss of the three-phase motor.

6. The method for calculating the motor temperature according to claim 4, characterized in that: The method of determining the second temperature variation caused by the loss of the other three-phase motor according to the power loss of the other three-phase motor, the equivalent thermal resistance of the other three-phase motor winding coupled to the one three-phase motor winding, and the time constant of the other three-phase motor winding coupled to the one three-phase motor winding comprises: The second temperature variation caused by the loss of the other three-phase motor is obtained by the following relationship: Wherein, ΔT2 is the second temperature variation caused by the loss of the other three-phase motor, R D is the equivalent thermal resistance of the other three-phase motor winding coupled to the one three-phase motor winding, T D s is the time constant of coupling the other three-phase motor winding to the one three-phase motor winding, P Cu_D +P Fe_D is the power loss of the other three-phase motor.

7. The motor temperature calculation method according to claim 1, characterized in that: The motor temperature calculation method further includes: When the other three-phase motor fails, the power loss of the other three-phase motor is zero.

8. A method for calculating motor temperature, characterized in that: Applied to a dual three-phase redundant controller; the dual three-phase redundant controller is used to control a dual three-phase motor; the dual three-phase redundant controller includes a first control module and a second control module, the first control module and the second control module are communicatively connected, the first control module is connected to one three-phase motor, and the second control module is connected to another three-phase motor; the motor temperature calculation method includes: The first control module obtains the operating parameters of the three-phase motor, and the second control module obtains the operating parameters of the other three-phase motor; The first control module determines the power loss of the three-phase motor according to the operating parameters of the three-phase motor, and the second control module determines the power loss of the other three-phase motor according to the operating parameters of the other three-phase motor; The first control module determines the temperature of the three-phase motor based on a first thermal network model according to the power loss of the three-phase motor, the power loss of the other three-phase motor and a first reference temperature; the second control module determines the temperature of the other three-phase motor based on a second thermal network model according to the power loss of the other three-phase motor, the power loss of the three-phase motor and a second reference temperature.

9. The method for calculating the motor temperature according to claim 8, characterized in that: The first control module and the second control module are arranged on a substrate and are respectively located on both sides of the shaft of the dual three-phase motor; a first thermistor and a second thermistor are arranged on the substrate, the first thermistor and the first control module are located on one side of the shaft of the dual three-phase motor, and the second thermistor and the second control module are located on the other side of the shaft of the dual three-phase motor; before the first control module determines the temperature of the one three-phase motor based on the first thermal network model according to the power loss of the one three-phase motor, the power loss of the other three-phase motor and the first reference temperature, it also includes: Acquiring the temperature of the substrate where the first control module is located through the first thermistor as the first reference temperature; Before the second control module determines the temperature of the other three-phase motor based on the second thermal network model according to the power loss of the other three-phase motor, the power loss of the one three-phase motor and the second reference temperature, the method further includes: The temperature of the substrate where the second control module is located is obtained through the second thermistor as the second reference temperature.

10. A motor temperature calculation device, characterized in that: include: A parameter acquisition module is used to acquire the operating parameters of one three-phase motor and the power loss of another three-phase motor; A power loss determination module, used to determine the power loss of the three-phase motor according to the operating parameters of the three-phase motor; The temperature determination module is used to determine the temperature of the three-phase motor based on a thermal network model according to the power loss of the three-phase motor, the power loss of the other three-phase motor and a reference temperature.

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