Motor protection device and method, motor controller, motor and vehicle

Abstract

The invention discloses a motor protection device and method, a motor, a motor controller and a vehicle, and the device comprises a temperature detection unit which detects the temperature of the motor to obtain a motor temperature detection voltage representing the temperature of the motor; the temperature sampling unit at least amplifies the temperature detection voltage of the motor to obtain a temperature sampling voltage of the motor; the comparison unit outputs an over-temperature protection signal of the motor when the temperature sampling voltage of the motor is greater than or equal to a current preset temperature protection threshold value of the motor provided based on the current working condition of the motor; and the protection unit is used for reminding and / or cooling based on the over-temperature protection signal of the motor so as to realize over-temperature protection of the motor. According to the scheme, the temperature sampling voltage of the motor is compared with the preset voltage protection threshold value representing the preset temperature protection threshold value corresponding to the current working condition of the motor, reminding and / or heat dissipation are / is performed according to the comparison result, so that the motor is protected, the accuracy and reliability of motor over-temperature protection are improved, and the safety of the motor is improved.

Description

Technical Field

[0001] This invention belongs to the field of motor technology, specifically relating to a motor protection device and method, a motor controller, a motor and a vehicle, and more particularly to a motor temperature detection alarm circuit and method with an adjustable preset temperature protection threshold, a motor controller, a motor and a vehicle. Background Technology

[0002] Overheating of motors (such as those in new energy vehicles) can lead to permanent damage, including demagnetization of permanent magnets and aging of insulation materials in the stator winding insulation layer. It can also cause safety accidents such as short circuits and fires. Currently, the temperature detection solutions for motors (such as those in new energy vehicles) use fixed preset temperature protection thresholds, which cannot dynamically adapt to various operating conditions. This makes it impossible to guarantee the reliability of the motor's temperature protection, and consequently, the motor's safety.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The purpose of this invention is to provide a protection device and method for an electric motor, a motor controller, an electric motor, and a vehicle, to solve the problem in related solutions for temperature detection of electric motors (such as electric motors in new energy vehicles) where the preset temperature protection threshold of the motor is fixed, cannot dynamically adapt to various operating conditions, cannot guarantee the reliability of the motor's temperature protection, and therefore cannot guarantee the safety of the motor. The invention achieves the effect of protecting the motor by comparing the temperature sampling voltage of the motor with a preset voltage protection threshold that characterizes the preset temperature protection threshold corresponding to the current operating condition of the motor, and providing alerts and / or heat dissipation based on the comparison result, thereby improving the accuracy and reliability of the motor over-temperature protection and enhancing the safety of the motor.

[0005] This invention provides a protection device for a motor, the motor having a temperature detection unit; the protection device for the motor includes: a temperature sampling unit, a comparison unit, and a protection unit; wherein, the temperature detection unit is used to detect the temperature of the motor and obtain a voltage characterizing the temperature of the motor, denoted as the temperature detection voltage of the motor; the temperature sampling unit is used to at least amplify the temperature detection voltage of the motor to obtain a temperature sampling voltage of the motor; the comparison unit is used to provide a preset voltage protection threshold characterizing a preset temperature protection threshold corresponding to the current operating condition of the motor, denoted as the current preset voltage protection threshold of the motor; and compare the temperature sampling voltage of the motor with the current preset voltage protection threshold of the motor, to determine that the motor temperature has overheated if the temperature sampling voltage of the motor is greater than or equal to the current preset voltage protection threshold of the motor, and output an overheat protection signal of the motor; the protection unit is used to provide an alert and / or reduce the temperature based on the overheat protection signal of the motor to achieve overheat protection of the motor.

[0006] In some embodiments, the temperature sampling unit includes: an input resistor module, a sampling resistor module, a feedback resistor module, and an operational amplifier module; wherein, a preset DC power supply is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module; the inverting input terminal of the operational amplifier module is connected to the output terminal of the operational amplifier module after passing through the feedback resistor module; at this time, the input terminal of the motor's temperature detection voltage is connected to the non-inverting input terminal of the operational amplifier module after passing through the sampling resistor module; the output terminal of the operational amplifier module serves as the output terminal of the sampling unit; the voltage output by the output terminal of the operational amplifier module serves as the temperature sampling voltage of the motor.

[0007] In some embodiments, the temperature sampling unit further includes at least one of the following: a first voltage divider module, a second voltage divider module, a first filter module, a second filter module, a third filter module, a fourth filter module, and a fifth filter module; the first voltage divider module includes a first voltage divider resistor module and a second voltage divider resistor module, and the second voltage divider module includes a third voltage divider resistor module and a fourth voltage divider resistor module; wherein, a preset DC power supply is grounded after passing through the first voltage divider resistor module and the second voltage divider resistor module; the common terminal of the first voltage divider resistor module and the second voltage divider resistor module is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module; the preset DC power supply is connected to the temperature detection circuit of the motor after passing through the third voltage divider resistor module. The input terminal of the voltage sensor is connected to the common terminal of the sampling resistor module; the input terminal of the motor temperature detection voltage is grounded after passing through the sampling resistor module and the fourth voltage divider resistor module; at this time, the common terminal of the sampling resistor module and the fourth voltage divider resistor module is connected to the non-inverting input terminal of the operational amplifier module; the preset DC power supply is grounded after passing through the first filter module; the input terminal of the motor temperature detection voltage is grounded after passing through the second filter module; the common terminal of the motor temperature detection voltage and the sampling resistor module is grounded after passing through the third filter module; the non-inverting input terminal of the operational amplifier module is grounded after passing through the fourth filter module; the inverting input terminal of the operational amplifier module is connected to the output terminal of the operational amplifier module after passing through the fifth filter module.

[0008] In some embodiments, the sampling unit further includes at least one of a clamping module, a first current-limiting resistor module, and a sixth filter module; wherein the output terminal of the operational amplifier module is connected to the clamping terminal of the clamping module; in this case, the clamping terminal of the clamping module serves as the output terminal of the sampling unit; the voltage output from the output terminal of the operational amplifier module obtained from the clamping terminal of the clamping module serves as the temperature sampling voltage of the motor; the output terminal of the operational amplifier module is connected to the input terminal of the comparator unit after passing through the first current-limiting resistor module; in this case, the common terminal of the first current-limiting resistor module and the input terminal of the comparator unit serves as the output terminal of the sampling unit; the common terminal of the first current-limiting resistor module and the input terminal of the comparator unit is grounded after passing through the sixth filter module.

[0009] In some embodiments, the comparison unit includes: a comparison module, a reference resistor module, and a threshold adjustment module; wherein, the output terminal of the sampling unit is connected to the non-inverting input terminal of the comparison module; a preset reference power supply is grounded after passing through the reference resistor module and the threshold adjustment module; the common terminal of the reference resistor module and the threshold adjustment module is connected to the inverting input terminal of the comparison module; the output terminal of the comparison module serves as the output terminal of the comparison unit; wherein, the threshold adjustment module is used to adjust its own resistance value based on the current operating condition of the motor, and after adjustment, together with the reference resistor module, it provides a preset temperature protection threshold corresponding to the current operating condition of the motor, denoted as the current preset voltage protection threshold of the motor.

[0010] In some embodiments, the protection unit includes: a switching transistor module, a second current-limiting resistor module, an alert module, and a heat dissipation module; wherein, the output terminal of the comparison unit is connected to the control terminal of the switching transistor module; a preset DC power supply is connected to the first connection terminal of the switching transistor module; the second connection terminal of the switching transistor module is connected to the drive terminal of the heat dissipation module; the second connection terminal of the switching transistor module is also grounded via the second current-limiting resistor module and the alert module.

[0011] In conjunction with the above-described device, the present invention further provides a motor controller, including: the motor protection device described above.

[0012] In conjunction with the above-described device, the present invention further provides a motor, comprising: the motor protection device described above, or the motor controller described above.

[0013] In conjunction with the above-described device, the present invention further provides a vehicle comprising: the motor protection device described above, or the motor controller described above, or the motor described above.

[0014] In conjunction with the aforementioned device, the present invention further provides a method for protecting a motor, comprising: detecting the temperature of the motor through the temperature detection unit to obtain a voltage characterizing the temperature of the motor, denoted as the temperature detection voltage of the motor; amplifying the temperature detection voltage of the motor through the temperature sampling unit to obtain a temperature sampling voltage of the motor; providing a preset voltage protection threshold characterizing a preset temperature protection threshold corresponding to the current operating condition of the motor through the comparison unit, denoted as the current preset voltage protection threshold of the motor; comparing the temperature sampling voltage of the motor with the current preset voltage protection threshold of the motor to determine that the motor temperature is over-temperature when the temperature sampling voltage of the motor is greater than or equal to the current preset voltage protection threshold of the motor, and outputting an over-temperature protection signal of the motor; providing a reminder and / or cooling based on the over-temperature protection signal of the motor through the protection unit to achieve over-temperature protection of the motor; and / or performing software protection based on the temperature sampling voltage of the motor to achieve over-temperature protection of the motor.

[0015] Therefore, the solution of this invention addresses the problem of motor protection (such as over-temperature protection) by establishing a sampling unit (such as a sampling circuit), a comparison unit (such as a comparison circuit with an adjustable preset temperature protection threshold), and a protection unit (such as an alarm circuit) based on a motor temperature detection unit (i.e., a motor temperature sensor, such as an NTC thermistor installed on the insulation layer at the end of the motor stator winding). The sampling circuit amplifies the temperature detection voltage (such as the motor's MOTORT+ signal) detected by the motor temperature detection unit to obtain a motor temperature sampling voltage (such as the voltage output by operational amplifier U1 before clamping or the voltage Vc after clamping). The comparison circuit compares the motor temperature sampling voltage with a preset voltage protection threshold corresponding to the preset temperature protection threshold under the current operating condition of the motor. If the motor temperature sampling voltage exceeds the corresponding preset voltage protection threshold, the protection unit is triggered to provide an alert and / or dissipate heat to protect the motor. Thus, by comparing the motor temperature sampling voltage with the preset voltage protection threshold corresponding to the preset temperature protection threshold under the current operating condition of the motor, and providing an alert and / or dissipating heat based on the comparison result to protect the motor, the accuracy and reliability of motor over-temperature protection are improved, thereby enhancing motor safety.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of a structure of an embodiment of the motor protection device of the present invention; Figure 2 A schematic diagram of a motor temperature detection and alarm circuit with an adjustable preset temperature protection threshold; Figure 3 This is a schematic diagram of the logic function of a motor temperature detection and alarm circuit with an adjustable preset temperature protection threshold. Figure 4 This is a schematic flowchart of an embodiment of the motor protection method of the present invention. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below in conjunction with specific embodiments and corresponding drawings. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0020] Considering that in the temperature detection schemes for motors (such as those in new energy vehicles), the preset temperature protection threshold for the motor is fixed, it cannot dynamically adapt to various operating conditions, thus failing to guarantee the reliability of the motor's temperature protection and consequently, its safety. Specifically, in the relevant schemes, the temperature detection schemes for mainstream motors (such as those in new energy vehicles) mostly adopt analog detection circuits based on negative temperature coefficient thermistors (NTC thermistors). A typical structure is as follows: the NTC thermistor and a fixed resistor form a voltage divider network. The output voltage of this voltage divider network is compared with the preset temperature protection threshold by a comparator to trigger an alarm. However, the preset temperature protection threshold of this scheme is fixed and cannot dynamically adapt to various operating conditions. For example, the motor's safe temperature boundary will dynamically change under different operating conditions such as low-temperature start-up, high-speed climbing, and continuous high load. For example, when the motor starts in a low-temperature environment, the temperature rise is slow, and the fixed safe temperature boundary is prone to triggering false alarms.

[0021] The NTC thermistor is installed on the insulation layer at the end of the stator winding and measures the temperature of the insulating material in the insulation layer at the end of the stator winding (i.e., the hot spot temperature of the winding). Because the stator winding (especially the ends of the stator winding) is the main heat source when the motor is running (current passing through the copper wires of the stator winding generates Joule heat, and the heat dissipation conditions at the ends of the stator winding are the worst), most motor burnouts are caused by insulation failure due to overheating and aging of the insulating material in the insulation layer at the ends of the stator winding (such as inter-turn short circuits).

[0022] Furthermore, for electric motors in new energy vehicles, with the large-scale popularization of these vehicles, the motor, as a core component of the drive system, directly affects the vehicle's safety, range, and lifespan. In new energy vehicle systems, to prevent motor overheating from causing short circuits, fires, and other safety accidents, the motor controller in relevant solutions typically incorporates a temperature detection circuit: a thermistor and a fixed resistor form a voltage divider network, and the output voltage of the voltage divider network is compared with a preset temperature protection threshold by a comparator to trigger an alarm. However, this often suffers from problems such as inaccurate temperature sampling, fixed temperature protection thresholds, and an inability to dynamically adapt to various operating conditions.

[0023] Therefore, the present invention proposes a motor protection device, specifically a motor temperature detection alarm circuit with an adjustable preset temperature protection threshold. The circuit includes a motor temperature sampling circuit, a comparison circuit, and an alarm circuit. The preset temperature protection threshold of the comparison circuit can be adjusted according to the motor operating conditions. When the motor temperature reaches the preset temperature protection threshold adjusted according to the current operating conditions, the alarm indicator light immediately illuminates and the cooling fan is activated to protect the motor.

[0024] According to an embodiment of the present invention, a protection device for an electric motor is provided. See also: Figure 1 The diagram shows a structural schematic of an embodiment of the device of the present invention. The motor has a temperature detection unit, specifically, the motor controller of the motor has a temperature detection unit, which is a motor temperature sensor, such as... Figure 2 The MOTORT+ signal of the motor shown is obtained by sampling from an NTC thermistor located on the insulation layer at the end of the motor stator winding; in the solution of this invention, as... Figure 1 As shown, the motor protection device includes: a temperature sampling unit, a comparison unit, and a protection unit. The temperature sampling unit is as follows: Figure 2 The sampling circuit shown, the comparison unit is as follows Figure 2 The comparison circuit shown, the protection unit as follows Figure 2 The alarm circuit shown. Figure 2 This is a schematic diagram of a motor temperature detection and alarm circuit with an adjustable preset temperature protection threshold. Figure 2In the diagram, the circuit within the dashed box is the motor temperature sampling circuit, while the circuit outside the dashed box is the motor temperature comparison circuit and alarm circuit.

[0025] The temperature detection unit is used to detect the temperature of the motor and obtain a voltage characterizing the temperature of the motor, denoted as the motor temperature detection voltage; the motor temperature detection voltage is as follows: Figure 2 The MOTORT+ signal of the motor is shown.

[0026] The temperature sampling unit is used to sample the temperature detection voltage of the motor and amplify the temperature detection voltage of the motor to obtain the temperature sampling voltage of the motor; the temperature sampling voltage of the motor, such as... Figure 2 The voltage output of the operational amplifier U1 before clamping or the voltage after clamping is Vc.

[0027] The comparison unit is configured to provide a preset voltage protection threshold, denoted as the current preset voltage protection threshold of the motor, based on the current operating condition of the motor; and to compare the temperature sampling voltage of the motor with the current preset voltage protection threshold of the motor, so as to determine that the motor temperature has over-temperature when the temperature sampling voltage of the motor is greater than or equal to the current preset voltage protection threshold of the motor, and to output the over-temperature protection signal of the motor.

[0028] The protection unit is used to provide alerts and / or reduce the temperature based on the motor's over-temperature protection signal, thereby achieving over-temperature protection for the motor.

[0029] The present invention proposes a motor temperature detection and alarm circuit design with an adjustable preset temperature protection threshold, which can adapt to different operating states of the motor (such as...). Figure 2 The motor shown can be configured to operate under various conditions such as low-temperature start-up, high-speed climbing, and continuous high load. The preset temperature protection thresholds for different operating conditions can be manually adjusted to achieve dynamic matching across all operating conditions. Furthermore, it is purely hardware controlled, requiring no program control, resulting in low cost and high reliability.

[0030] In some embodiments, the temperature sampling unit includes: an input resistor module, a sampling resistor module, a feedback resistor module, and an operational amplifier module, wherein the input resistor module is as follows: Figure 2 The resistor R4 shown is used in the sampling resistor module. Figure 2 The resistor R5 shown is the feedback resistor module as follows: Figure 2 The resistor R7 shown is used in the operational amplifier module. Figure 2 The operational amplifier U1 shown is shown.

[0031] The preset DC power supply is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module; the inverting input terminal of the operational amplifier module is connected to the output terminal of the operational amplifier module after passing through the feedback resistor module.

[0032] At this time, the input terminal of the motor's temperature detection voltage is connected to the non-inverting input terminal of the operational amplifier module after passing through the sampling resistor module; the output terminal of the operational amplifier module serves as the output terminal of the sampling unit; the voltage output by the operational amplifier module serves as the motor's temperature sampling voltage. At this time, the motor's temperature sampling voltage is as follows: Figure 2 The voltage output of operational amplifier U1 before clamping is shown.

[0033] This invention proposes a motor temperature detection and alarm circuit design with an adjustable preset temperature protection threshold. Based on the motor temperature detection circuit, an additional alarm circuit with an adjustable preset temperature protection threshold is added. When the motor temperature reaches the preset temperature protection threshold adjusted according to the current operating conditions, the alarm indicator light immediately illuminates, and the cooling fan is activated to protect the motor. The cooling fan is a separate component for heat dissipation; it can be independently installed on the side of the motor to accelerate the expulsion of hot air generated by the motor from the vehicle.

[0034] In some embodiments, the temperature sampling unit further includes at least one of the following: a first voltage divider module, a second voltage divider module, a first filter module, a second filter module, a third filter module, a fourth filter module, and a fifth filter module; the first voltage divider module includes a first voltage divider resistor module and a second voltage divider resistor module, and the second voltage divider module includes a third voltage divider resistor module and a fourth voltage divider resistor module; the first voltage divider resistor module is as follows: Figure 2 The resistor R2 shown, the second voltage divider resistor module as shown Figure 2 The resistor R3 shown is the third voltage divider resistor module as follows: Figure 2 The resistor R1 shown is the fourth voltage divider resistor module as follows: Figure 2 The resistor R6 shown is used in the first filter module. Figure 2 The capacitor C1 shown, the second filter module as shown Figure 2 The capacitor C2 shown, the third filter module as shown Figure 2 The capacitor C3 shown, the fourth filter module as... Figure 2 The capacitor C4 shown, the fifth filter module as... Figure 2 The capacitor C5 is shown.

[0035] In the case where the sampling unit further includes the first voltage divider module, the preset DC power supply is grounded after passing through the first voltage divider resistor module and the second voltage divider resistor module; the common terminal of the first voltage divider resistor module and the second voltage divider resistor module is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module.

[0036] When the sampling unit further includes the second voltage divider module, the preset DC power supply is connected to the common terminal of the motor temperature detection voltage input terminal and the sampling resistor module after passing through the third voltage divider resistor module; the motor temperature detection voltage input terminal is grounded after passing through the sampling resistor module and the fourth voltage divider resistor module; at this time, the common terminal of the sampling resistor module and the fourth voltage divider resistor module is connected to the non-inverting input terminal of the operational amplifier module.

[0037] When the sampling unit further includes the first filtering module, the preset DC power supply is grounded after passing through the first filtering module. When the sampling unit further includes the second filtering module, the input terminal of the motor's temperature detection voltage is grounded after passing through the second filtering module. When the sampling unit further includes the third filtering module, the common terminal of the motor's temperature detection voltage and the sampling resistor module is grounded after passing through the third filtering module. When the sampling unit further includes the fourth filtering module, the non-inverting input terminal of the operational amplifier module is grounded after passing through the fourth filtering module. When the sampling unit further includes the fifth filtering module, the inverting input terminal of the operational amplifier module is connected to the output terminal of the operational amplifier module after passing through the fifth filtering module.

[0038] Figure 2 In the diagram, the area within the dashed box represents the motor temperature sampling circuit. The "MOTORT+" signal at the motor's MOTORT+ terminal is the motor temperature signal collected by the temperature sensor, which is actually a voltage signal and serves as the sampling voltage for the motor temperature signal. The "MOTORT-" signal at the motor's MOTORT- terminal is the ground signal. The sampled voltage of the motor temperature signal is amplified by operational amplifier U1, and the output voltage at point c is Vc. Resistor R7 is the feedback resistor, and resistor R4 is the input resistor. The gain Av of operational amplifier U1 is: Av = 1 + R7 / R4, where R7 represents the resistance value of resistor R7, and R4 represents the resistance value of resistor R4. The voltage Vc, i.e., signal M.TEM, is input to the main control chip to complete the motor temperature sampling.

[0039] Resistors R1, R5, and R6 act as voltage dividers, determining the voltage value input to the positive terminal of op-amp U1; resistors R2 and R3 also act as voltage dividers, determining the voltage value input to the negative terminal of op-amp U1. Resistor R4 serves as the input resistor for the op-amp, determining its gain coefficient. Capacitors C1, C2, C3, C4, C5, C6, and C7 all function as filters. M.TEM is an abbreviation for "motor temperature." The main control chip is located at M.TEM, which is the definition of one of the pins of the main control chip, and its function is to receive the M.TEM signal. Motor temperature sampling is only complete when the main control chip receives the sampling signal. Only after the main control chip receives the sampling signal can subsequent software operations be performed, such as displaying the current motor temperature on the screen for the user to see directly; or adjusting the motor speed through software when the motor temperature is slightly high.

[0040] The present invention addresses the problems frequently encountered in new energy vehicle systems, such as inaccurate motor temperature sampling, fixed temperature protection thresholds, and inability to dynamically adapt to various operating conditions. It designs a signal amplification circuit and a temperature alarm circuit with an adjustable preset temperature protection threshold. The preset temperature protection threshold can be set to match different operating conditions. When the sampled temperature reaches the threshold, an alarm is immediately triggered and protection measures are activated, thereby achieving the effect of over-temperature warning and protection under all operating conditions.

[0041] In some embodiments, the sampling unit further includes at least one of a clamping module, a first current-limiting resistor module, and a sixth filtering module, wherein the clamping module is as follows: Figure 2 The clamping diode D1 shown, the first current-limiting resistor module as follows Figure 2 The resistor R8 shown is the sixth filter module as follows. Figure 2 The capacitor C7 is shown.

[0042] In the case where the sampling unit further includes a clamping module, the output terminal of the operational amplifier module is connected to the clamping terminal of the clamping module; in this case, the clamping terminal of the clamping module serves as the output terminal of the sampling unit; the voltage output from the output terminal of the operational amplifier module, obtained from the clamping terminal of the clamping module, is used as the temperature sampling voltage of the motor. At this time, the temperature sampling voltage of the motor is as follows: Figure 2 The voltage after clamping is Vc.

[0043] When the sampling unit further includes a first current-limiting resistor module, the output terminal of the operational amplifier module is connected to the input terminal of the comparator unit after passing through the first current-limiting resistor module; in this case, the common terminal of the first current-limiting resistor module and the input terminal of the comparator unit serves as the output terminal of the sampling unit. When the sampling unit further includes a sixth filtering module, the common terminal of the first current-limiting resistor module and the input terminal of the comparator unit is grounded after passing through the sixth filtering module.

[0044] Figure 2 In the circuit, clamping diode D1 controls the voltage Vc within the range of 0V to VCC to protect the main control chip from damage. When the voltage at point c (i.e., point d) is greater than VCC, the right diode (the first diode) of clamping diode D1 conducts, pulling the voltage at point d back to VCC. When the voltage at point d is less than 0V, the left diode (the second diode) of clamping diode D1 conducts, grounding point d and pulling the voltage at point d to 0V. Resistor R8 limits current to prevent excessive current from the input comparator U2 from burning out its chip. Besides current limiting, resistor R8, together with capacitor C7, forms an "RC filter module" to filter the output signal of U1.

[0045] The motor temperature sampling circuit in the present invention can filter and amplify the motor temperature signal (i.e., the sampling voltage of the motor temperature signal) collected by the temperature sensor, and clamp the amplified signal (i.e. the signal output by the operational amplifier U1) within a safe range through the clamping diode D1 to obtain the voltage Vc at point c. Finally, the voltage Vc is input to the main control chip and then input to the comparison circuit to be compared with the preset temperature protection threshold.

[0046] In this invention, under different operating conditions of the motor (such as low-temperature start-up, high-speed climbing, and continuous high load), the preset temperature protection threshold of the comparator circuit can be manually adjusted via a sliding rheostat without the need for program control. In this invention, when the motor temperature reaches the preset temperature protection threshold adjusted according to the current operating conditions, the alarm indicator light immediately illuminates and drives the cooling fan, serving both alarm and protection functions.

[0047] In some embodiments, the comparison unit includes: a comparison module, a reference resistor module, and a threshold adjustment module, wherein the comparison module is as follows: Figure 2 The comparator U2 shown, the reference resistor module as follows Figure 2 The resistor R9 shown is used in the threshold adjustment module. Figure 2 The adjustable resistor R10 is shown.

[0048] The output of the sampling unit is connected to the non-inverting input of the comparison module. A preset reference power supply is grounded after passing through the reference resistor module and the threshold adjustment module; the common terminal of the reference resistor module and the threshold adjustment module is connected to the inverting input of the comparison module; the output of the comparison module serves as the output of the comparison unit.

[0049] The threshold adjustment module is used to adjust its own resistance value based on the current operating condition of the motor. After adjustment, it and the reference resistor module jointly provide a preset temperature protection threshold corresponding to the current operating condition of the motor. That is, after adjusting the resistance value of the threshold adjustment module, the threshold adjustment module and the reference resistor module jointly provide a preset temperature protection threshold corresponding to the current operating condition of the motor, which is denoted as the current preset voltage protection threshold of the motor.

[0050] The comparator circuit in this invention compares the sampling signal (i.e., voltage Vc) transmitted from the motor temperature sampling circuit with a preset voltage threshold (i.e., a reference voltage determined by resistor R9 and adjustable resistor R10, corresponding to the preset temperature protection threshold under the current operating condition). The preset voltage threshold can be set by manually adjusting the adjustable resistor R10. When the received sampling signal (i.e., voltage Vc) is greater than or equal to the preset voltage threshold, comparator U2 outputs a high level, thereby activating the alarm circuit. When the received sampling signal is less than the preset voltage threshold, comparator U2 outputs a low level, and the alarm circuit is not activated. The comparator circuit uses an adjustable resistor R10, allowing manual adjustment of the preset temperature protection threshold for different operating conditions. This enables dynamic matching across all operating conditions; it is purely hardware-controlled, requiring no program control, resulting in low cost and high reliability. Specific operating conditions are determined by the customer's actual driving environment or route. For example, if the customer's driving needs are in a colder northern region, then corresponding low-temperature operating conditions need to be matched. Resistor R10 can be adjusted manually. For example, R10 can be a variable resistance box, and its specific resistance value can be adjusted by turning the knob, just like changing gears. Adjust the resistance value of resistor R10 to the preset temperature protection threshold corresponding to the corresponding operating conditions.

[0051] In some embodiments, the protection unit includes: a switching transistor module, a second current-limiting resistor module, an alert module, and a heat dissipation module, wherein the switching transistor module is as follows: Figure 2 The transistor Q1 shown, and the second current-limiting resistor module as follows Figure 2 The resistor R11 shown is used in the reminder module. Figure 2 The alarm indicator D2 shown, the heat dissipation module as follows Figure 2 The cooling fan shown.

[0052] The output of the comparison unit is connected to the control terminal of the switching transistor module; a preset DC power supply is connected to the first connection terminal of the switching transistor module; the second connection terminal of the switching transistor module is connected to the drive terminal of the heat dissipation module; the second connection terminal of the switching transistor module is also grounded after passing through the second current-limiting resistor module and the reminder module. The control terminal of the switching transistor module is like the base of transistor Q1, the first connection terminal of the switching transistor module is like the collector of transistor Q1, and the second connection terminal of the switching transistor module is like the emitter of transistor Q1.

[0053] like Figure 2 As shown, the motor temperature detection alarm circuit with adjustable preset temperature protection threshold includes: capacitors C1, C2, C3, C4, C5, C6, and C7; resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, and R11; an adjustable resistor R10; operational amplifier U1; comparator U2; clamping diode D1; alarm indicator D2; transistor Q1; and a fan. Among them, capacitors C1, C2, C3, C4, C5, C6, and C7 are fixed capacitors; resistors R1, R2, R3, R4, R5, R6, R7, R8, R9, and R11 are fixed resistors; operational amplifier U1 amplifies the sampled signal; comparator U2 outputs a high level when the anode voltage of comparator U2 is greater than the cathode voltage, and a low level when the anode voltage of comparator U2 is less than the cathode voltage; adjustable resistor R10 is a sliding rheostat, which can change the preset temperature protection threshold by adjusting its resistance value; transistor Q1 is an NPN BJT; clamping diode D1 controls the voltage output of operational amplifier U1 within the range of 0V~VCC to prevent the main control chip from being damaged by excessive input voltage; alarm indicator D2 is an LED.

[0054] The DC power supply VCC is grounded via capacitor C1. VCC is also connected to the non-inverting input of operational amplifier U1 via resistors R1 and R5. VCC is further grounded via resistors R2 and R3. The common terminal of resistors R2 and R3 is connected to the inverting input of operational amplifier U1 via resistor R4. The motor's MOTORT+ terminal is connected to the motor's MOTORT- terminal via capacitor C2, and the MOTORT- terminal is grounded. The motor's MOTORT+ terminal is also connected to the common terminal of resistors R1 and R5, which is grounded via capacitor C3. The non-inverting input of operational amplifier U1 is also grounded via parallel capacitors C4 and R6. The ground terminal of operational amplifier U1 is grounded. The power supply terminal of operational amplifier U1 is connected to the DC power supply VCC and grounded via capacitor C6. The inverting input of operational amplifier U1 is also connected to the output terminal of operational amplifier U1 via parallel capacitor C5 and resistor R7. The output of operational amplifier U1 is also connected to the clamping terminal (point d) of clamping diode D1. Clamping diode D1 has a first diode and a second diode. The DC power supply VCC is connected to the cathode of the first diode, the anode of the first diode is connected to the cathode of the second diode, the anode of the second diode is grounded, and the common terminal of the anode of the first diode and the cathode of the second diode serves as the clamping terminal (point d) of clamping diode D1. The output of operational amplifier U1 is grounded through resistor R8 and capacitor C7. The common terminal of resistor R8 and capacitor C7 is connected to the non-inverting input terminal (anode of comparator U2). The DC power supply V1 is grounded through resistor R9 and adjustable resistor R10. The common terminal of resistor R9 and adjustable resistor R10 is connected to the inverting input terminal (cathode of comparator U2). The power supply terminal of comparator U2 is connected to the DC power supply VCC, and the ground terminal of comparator U2 is grounded. The output of comparator U2 is connected to the base of transistor Q1, and the DC power supply VCC is connected to the collector of transistor Q1. The emitter of transistor Q1 is grounded via resistor R11 and alarm indicator D2. The emitter of transistor Q1 is also connected to the fan driver to drive the fan for heat dissipation. The common terminal of the output of operational amplifier U1 and resistor R8 is denoted as point c. The common terminal of resistor R8 and the non-inverting input of comparator U2 is denoted as point e and connected to the M.TEM terminal. The common terminal of resistor R9 and adjustable resistor R10 is denoted as point f.

[0055] exist Figure 2 In the example shown, the voltage signal (i.e., voltage Vc) output by the motor temperature sampling circuit is transmitted to the main control chip and also input to the anode of comparator U2. When the voltage Ve at point e is greater than the voltage Vf at point f, comparator U2 outputs a high level, then transistor Q1 is turned on, alarm indicator D2 lights up, and the cooling fan is driven to run.

[0056] The alarm circuit in this invention serves to alert the driver of motor overheating via a warning light (such as alarm indicator D2) and to assist in motor cooling via a cooling fan. When the motor overheats, alarm indicator D2 illuminates to remind the driver; simultaneously, the cooling fan is driven to run, assisting in motor cooling. The voltage at point f can be adjusted via the sliding rheostat R10, i.e.: Vf = V1 * R10 / (R9 + R10). This method can be used to adjust the preset temperature protection threshold. VCC supplies power to the operational amplifier, comparator, cooling fan, etc. The voltage range can be found in the datasheets of the operational amplifier, comparator, etc. Theoretically, the voltage range is 3V to 15V. V1 only determines the input voltage of comparator U2; refer to the datasheets of the specific components for further information.

[0057] In this invention, the temperature sensor converts the motor temperature into a voltage signal (i.e., the sampling voltage of the motor temperature signal) and inputs it to the temperature sampling circuit. The operational amplifier U1 amplifies this signal (i.e., the sampling voltage of the motor temperature signal) to obtain the sampling signal (i.e., voltage Vc) transmitted from the motor temperature sampling circuit. This sampling signal (i.e., voltage Vc) is then input to the comparator U2 and compared with a preset value Vf (i.e., the voltage Vf at point f). If the motor temperature exceeds the preset temperature protection threshold, then Ve > Vf, and the alarm circuit is activated. Compared to software program control, hardware circuit control offers faster response speed, stronger anti-interference capability, and longer service life, thus resulting in higher reliability.

[0058] By employing the technical solution of this invention, addressing the problem of motor protection (such as over-temperature protection), based on the motor temperature detection unit (i.e., the motor temperature sensor, such as an NTC thermistor installed on the insulation layer at the end of the motor stator winding), a sampling unit (such as a sampling circuit), a comparison unit (such as a comparison circuit with an adjustable preset temperature protection threshold), and a protection unit (such as an alarm circuit) are set. The sampling circuit amplifies the temperature detection voltage (such as the motor's MOTORT+ signal) detected by the motor temperature detection unit to obtain the motor temperature sampling voltage (such as the voltage output by the operational amplifier U1 before clamping or the clamping voltage). The voltage after the comparison is Vc. The motor temperature sampling voltage is compared with the preset voltage protection threshold, which is used to characterize the preset temperature protection threshold corresponding to the current operating condition of the motor. If the motor temperature sampling voltage exceeds the corresponding preset voltage protection threshold, the protection unit is triggered to provide an alert and / or dissipate heat to protect the motor. Thus, by comparing the motor temperature sampling voltage with the preset voltage protection threshold, which is used to characterize the preset temperature protection threshold corresponding to the current operating condition of the motor, and providing an alert and / or dissipating heat according to the comparison result to protect the motor, the accuracy and reliability of the motor over-temperature protection are improved, and the safety of the motor is enhanced.

[0059] According to an embodiment of the present invention, a motor controller corresponding to a protection device for a motor is also provided. The motor controller may include the motor protection device described above. The motor protection device includes: a temperature sampling unit, a comparison unit, and a protection unit, wherein the temperature sampling unit is as follows: Figure 2 The sampling circuit shown, the comparison unit is as follows Figure 2 The comparison circuit shown, the protection unit as follows Figure 2 The alarm circuit shown.

[0060] The temperature detection unit is used to detect the temperature of the motor and obtain a voltage characterizing the temperature of the motor, denoted as the motor temperature detection voltage; the motor temperature detection voltage is as follows: Figure 2 The MOTORT+ signal of the motor is shown. The temperature sampling unit is used to sample the temperature detection voltage of the motor and amplify the temperature detection voltage of the motor to obtain the temperature sampling voltage of the motor; the temperature sampling voltage of the motor is as follows: Figure 2 The voltage output by the operational amplifier U1 before clamping or the voltage after clamping is Vc. The comparison unit is used to provide a preset voltage protection threshold, denoted as the current preset voltage protection threshold, based on the current operating condition of the motor, for characterizing a preset temperature protection threshold corresponding to the current operating condition of the motor; and to compare the temperature sampling voltage of the motor with the current preset voltage protection threshold, to determine if the motor temperature is over-temperature if the temperature sampling voltage is greater than or equal to the current preset voltage protection threshold, and to output an over-temperature protection signal for the motor. The protection unit is used to provide alerts and / or reduce the temperature based on the over-temperature protection signal of the motor, thereby achieving over-temperature protection for the motor.

[0061] In the solution of this invention, different operating states of the motor can be adapted (e.g., Figure 2 The motor shown can be configured to operate under various conditions such as low-temperature start-up, high-speed climbing, and continuous high load. The preset temperature protection thresholds for different operating conditions can be manually adjusted to achieve dynamic matching across all operating conditions. Furthermore, it is purely hardware controlled, requiring no program control, resulting in low cost and high reliability.

[0062] In some embodiments, the temperature sampling unit includes: an input resistor module, a sampling resistor module, a feedback resistor module, and an operational amplifier module, wherein the input resistor module is as follows: Figure 2 The resistor R4 shown is used in the sampling resistor module. Figure 2 The resistor R5 shown is the feedback resistor module as follows: Figure 2 The resistor R7 shown is used in the operational amplifier module. Figure 2The operational amplifier U1 is shown. A preset DC power supply is connected to the inverting input of the operational amplifier module via the input resistor module; the inverting input of the operational amplifier module is then connected to its output via the feedback resistor module. At this time, the input of the motor's temperature detection voltage is connected to the non-inverting input of the operational amplifier module via the sampling resistor module; the output of the operational amplifier module serves as the output of the sampling unit; the voltage output from the operational amplifier module is used as the motor's temperature sampling voltage. The motor's temperature sampling voltage is as follows: Figure 2 The voltage output of operational amplifier U1 before clamping is shown.

[0063] In this invention, an alarm circuit with an adjustable preset temperature protection threshold is added to the motor temperature detection circuit. When the motor temperature reaches the preset temperature protection threshold adjusted according to the current operating conditions, the alarm indicator light immediately illuminates, and the cooling fan is activated to protect the motor. The cooling fan is a separate component for heat dissipation; it can be independently installed on the side of the motor to accelerate the expulsion of hot air generated by the motor from the vehicle.

[0064] In some embodiments, the temperature sampling unit further includes at least one of the following: a first voltage divider module, a second voltage divider module, a first filter module, a second filter module, a third filter module, a fourth filter module, and a fifth filter module; the first voltage divider module includes a first voltage divider resistor module and a second voltage divider resistor module, and the second voltage divider module includes a third voltage divider resistor module and a fourth voltage divider resistor module; the first voltage divider resistor module is as follows: Figure 2 The resistor R2 shown, the second voltage divider resistor module as shown Figure 2 The resistor R3 shown is the third voltage divider resistor module as follows: Figure 2 The resistor R1 shown is the fourth voltage divider resistor module as follows: Figure 2 The resistor R6 shown is used in the first filter module. Figure 2 The capacitor C1 shown, the second filter module as shown Figure 2 The capacitor C2 shown, the third filter module as shown Figure 2 The capacitor C3 shown, the fourth filter module as... Figure 2 The capacitor C4 shown, the fifth filter module as... Figure 2The capacitor C5 is shown. Where the sampling unit also includes the first voltage divider module, the preset DC power supply is grounded after passing through the first and second voltage divider resistor modules; the common terminal of the first and second voltage divider resistor modules is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module. Where the sampling unit also includes the second voltage divider module, the preset DC power supply is connected to the input terminal of the motor's temperature detection voltage and the common terminal of the sampling resistor module after passing through the third voltage divider resistor module; the input terminal of the motor's temperature detection voltage is grounded after passing through the sampling resistor module and the fourth voltage divider resistor module; at this time, the common terminal of the sampling resistor module and the fourth voltage divider resistor module is connected to the non-inverting input terminal of the operational amplifier module. Where the sampling unit also includes the first filter module, the preset DC power supply is grounded after passing through the first filter module. Where the sampling unit also includes the second filter module, the input terminal of the motor's temperature detection voltage is grounded after passing through the second filter module. Where the sampling unit also includes the third filter module, the common terminal of the motor's temperature detection voltage and the sampling resistor module is grounded after passing through the third filter module. When the sampling unit further includes the fourth filtering module, the non-inverting input of the operational amplifier module is grounded after passing through the fourth filtering module. When the sampling unit further includes the fifth filtering module, the inverting input of the operational amplifier module is connected to the output of the operational amplifier module after passing through the fifth filtering module.

[0065] See Figure 2 In the example shown, the "MOTORT+" signal at the motor's MOTORT+ terminal is the motor temperature signal collected by the temperature sensor, which is actually a voltage signal and serves as the sampling voltage for the motor temperature signal; the "MOTORT-" signal at the motor's MOTORT- terminal is the ground signal. The sampling voltage of the motor temperature signal is amplified by operational amplifier U1, and the output voltage at point c is Vc. Resistor R7 is the feedback resistor, and resistor R4 is the input resistor. The gain Av of operational amplifier U1 is: Av = 1 + R7 / R4, where R7 represents the resistance value of resistor R7, and R4 represents the resistance value of resistor R4. The voltage Vc, i.e., the signal M.TEM, is input to the main control chip to complete the motor temperature sampling.

[0066] In the solution of this invention, in order to address the problems that often exist in new energy vehicle systems, such as insufficient accuracy of motor temperature sampling, fixed temperature protection thresholds, and inability to dynamically adapt to various operating conditions, a signal amplification circuit and a temperature alarm circuit with adjustable preset temperature protection thresholds are designed. Preset temperature protection thresholds that match different operating conditions can be set. When the sampled temperature reaches the threshold, an alarm is immediately triggered and protection measures are activated, thereby achieving the effect of over-temperature warning and protection under all operating conditions.

[0067] In some embodiments, the sampling unit further includes at least one of a clamping module, a first current-limiting resistor module, and a sixth filtering module, wherein the clamping module is as follows: Figure 2 The clamping diode D1 shown, the first current-limiting resistor module as follows Figure 2 The resistor R8 shown is the sixth filter module as follows. Figure 2 The capacitor C7 is shown. Where the sampling unit also includes a clamping module, the output terminal of the operational amplifier module is connected to the clamping terminal of the clamping module; in this case, the clamping terminal of the clamping module serves as the output terminal of the sampling unit; the voltage output from the output terminal of the operational amplifier module, obtained from the clamping terminal of the clamping module, is used as the temperature sampling voltage of the motor. At this time, the temperature sampling voltage of the motor is as follows: Figure 2 The clamped voltage shown is Vc. When the sampling unit further includes a first current-limiting resistor module, the output of the operational amplifier module is connected to the input of the comparator unit via the first current-limiting resistor module; in this case, the common terminal of the first current-limiting resistor module and the input of the comparator unit serves as the output of the sampling unit. When the sampling unit further includes a sixth filter module, the common terminal of the first current-limiting resistor module and the input of the comparator unit is grounded via the sixth filter module.

[0068] Figure 2 In the circuit, clamping diode D1 controls the voltage Vc within the range of 0V to VCC to protect the main control chip from damage. When the voltage at point c (i.e., point d) is greater than VCC, the right diode (the first diode) of clamping diode D1 conducts, pulling the voltage at point d back to VCC. When the voltage at point d is less than 0V, the left diode (the second diode) of clamping diode D1 conducts, grounding point d and pulling the voltage at point d to 0V. Resistor R8 limits current to prevent excessive current from the input comparator U2 from burning out the comparator chip.

[0069] In the solution of the present invention, the motor temperature sampling circuit can filter and amplify the motor temperature signal (i.e., the sampling voltage of the motor temperature signal) collected by the temperature sensor, and clamp the amplified signal (i.e. the signal output by the operational amplifier U1) within a safe range through the clamping diode D1 to obtain the voltage Vc at point c. Finally, the voltage Vc is input to the main control chip and input to the comparison circuit to be compared with the preset temperature protection threshold.

[0070] In this invention, under different operating conditions of the motor (such as low-temperature start-up, high-speed climbing, and continuous high load), the preset temperature protection threshold of the comparator circuit can be manually adjusted via a sliding rheostat without the need for program control. In this invention, when the motor temperature reaches the preset temperature protection threshold adjusted according to the current operating conditions, the alarm indicator light immediately illuminates and drives the cooling fan, serving both alarm and protection functions.

[0071] In some embodiments, the comparison unit includes: a comparison module, a reference resistor module, and a threshold adjustment module, wherein the comparison module is as follows: Figure 2 The comparator U2 shown, the reference resistor module as follows Figure 2 The resistor R9 shown is used in the threshold adjustment module. Figure 2 The adjustable resistor R10 is shown. The output of the sampling unit is connected to the non-inverting input of the comparison module. A preset reference power supply is grounded after passing through the reference resistor module and the threshold adjustment module; the common terminal of the reference resistor module and the threshold adjustment module is connected to the inverting input of the comparison module; the output of the comparison module serves as the output of the comparison unit. The threshold adjustment module adjusts its own resistance value based on the current operating condition of the motor. After adjustment, it, together with the reference resistor module, provides a preset temperature protection threshold corresponding to the current operating condition of the motor, denoted as the current preset voltage protection threshold of the motor.

[0072] In this invention, the comparator circuit compares the sampling signal (i.e., voltage Vc) transmitted from the motor temperature sampling circuit with a preset voltage threshold (i.e., a reference voltage determined by resistor R9 and adjustable resistor R10, corresponding to the preset temperature protection threshold under the current operating condition). The preset voltage threshold can be set by manually adjusting the adjustable resistor R10. When the received sampling signal (i.e., voltage Vc) is greater than or equal to the preset voltage threshold, comparator U2 outputs a high level, thereby activating the alarm circuit. When the received sampling signal is less than the preset voltage threshold, comparator U2 outputs a low level, and the alarm circuit is not activated. The comparator circuit employs an adjustable resistor R10, allowing manual adjustment of the preset temperature protection threshold for different operating conditions. This enables dynamic matching across all operating conditions; it is purely hardware-controlled, requiring no program control, resulting in low cost and high reliability.

[0073] In some embodiments, the protection unit includes: a switching transistor module, a second current-limiting resistor module, an alert module, and a heat dissipation module, wherein the switching transistor module is as follows: Figure 2 The transistor Q1 shown, and the second current-limiting resistor module as follows Figure 2 The resistor R11 shown is used in the reminder module. Figure 2 The alarm indicator D2 shown, the heat dissipation module as follows Figure 2 The cooling fan is shown. The output of the comparator unit is connected to the control terminal of the switching transistor module; a preset DC power supply is connected to the first connection terminal of the switching transistor module; the second connection terminal of the switching transistor module is connected to the drive terminal of the cooling module; the second connection terminal of the switching transistor module is also grounded via the second current-limiting resistor module and the reminder module. The control terminal of the switching transistor module is like the base of transistor Q1, the first connection terminal of the switching transistor module is like the collector of transistor Q1, and the second connection terminal of the switching transistor module is like the emitter of transistor Q1.

[0074] exist Figure 2 In the example shown, the voltage signal (i.e., voltage Vc) output by the motor temperature sampling circuit is transmitted to the main control chip and also input to the anode of comparator U2. When the voltage Ve at point e is greater than the voltage Vf at point f, comparator U2 outputs a high level, then transistor Q1 is turned on, alarm indicator D2 lights up, and the cooling fan is driven to run.

[0075] Since the processing and functions implemented by the motor controller in this embodiment are basically the same as those in the embodiments, principles and examples of the device, any details not covered in this embodiment can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0076] According to an embodiment of the present invention, a motor corresponding to a protection device for a motor is also provided. This motor may include: the motor protection device described above, or the motor controller described above.

[0077] Since the processing and functions implemented by the motor in this embodiment are basically the same as those in the embodiments, principles and examples of the device, any details not covered in this embodiment can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0078] According to an embodiment of the present invention, a vehicle corresponding to a motor protection device is also provided. The vehicle may include: the motor protection device described above, or the motor controller described above, or the vehicle described above.

[0079] Since the processing and functions implemented by the vehicle in this embodiment are basically the same as those in the embodiments, principles and examples of the device, any details not covered in this embodiment can be found in the relevant descriptions in the foregoing embodiments, and will not be repeated here.

[0080] According to embodiments of the present invention, a method for protecting a motor corresponding to a motor protection device is also provided, such as... Figure 4The diagram shows a flowchart of an embodiment of the method of the present invention. The motor protection method may include steps S110 to S150.

[0081] In step S110, the temperature of the motor is detected by the temperature detection unit to obtain a voltage characterizing the temperature of the motor, which is denoted as the motor temperature detection voltage; the motor temperature detection voltage is as follows: Figure 2 The MOTORT+ signal of the motor is shown.

[0082] In step S120, the temperature detection voltage of the motor is sampled by the temperature sampling unit, and the temperature detection voltage of the motor is at least amplified to obtain the temperature sampling voltage of the motor; the temperature sampling voltage of the motor, as shown... Figure 2 The voltage output of the operational amplifier U1 before clamping or the voltage after clamping is Vc.

[0083] In step S130, the comparison unit provides a preset voltage protection threshold, denoted as the current preset voltage protection threshold, based on the current operating condition of the motor, to characterize the preset temperature protection threshold corresponding to the current operating condition of the motor. The comparison unit then compares the temperature sampling voltage of the motor with the current preset voltage protection threshold to determine if the motor is overheating if the temperature sampling voltage is greater than or equal to the current preset voltage protection threshold. Finally, the comparison unit outputs an overheat protection signal for the motor.

[0084] In step S140, the protection unit provides an alert and / or reduces the temperature based on the motor's over-temperature protection signal to achieve over-temperature protection for the motor. And / or, In step S150, software protection is performed based on the temperature sampling voltage of the motor to achieve over-temperature protection for the motor.

[0085] Figure 3 This is a schematic diagram illustrating the logic function of a motor temperature detection and alarm circuit with an adjustable preset temperature protection threshold. Figure 3 As shown, the logic function of the motor temperature detection alarm circuit with adjustable preset temperature protection threshold includes: Step 1: The temperature sensor converts the motor temperature into a voltage signal (i.e., the sampling voltage of the motor temperature signal) and inputs it into the temperature sampling circuit. After the operational amplifier U1 amplifies the signal (i.e., the sampling voltage of the motor temperature signal), the sampling signal (i.e., the voltage is Vc) transmitted from the motor temperature sampling circuit is obtained. Then, steps 2 and 3 are executed.

[0086] Step 2: Input the motor temperature sampling signal (i.e., voltage Vc) into the main control chip. The main control chip then performs over-temperature protection control based on the motor temperature sampling signal (i.e., voltage Vc) and a preset temperature protection threshold. Over-temperature protection by the main control chip is a software-level control. A threshold value for the motor temperature sampling signal is preset in the program burned into the main control chip. If the actual sampled signal exceeds this threshold, the motor is considered overheated. For example, when the motor temperature is too high, the main control chip can use software to adjust the motor speed or stop it.

[0087] Step 3: Input the motor temperature sampling signal (i.e., voltage Vc) into comparator U2 and compare it with the preset Vf value (i.e., voltage Vf at point f); if the motor temperature exceeds the preset temperature protection threshold, then Ve>Vf, and the alarm circuit will be activated.

[0088] In the present invention, a motor temperature detection and alarm circuit with an adjustable preset temperature protection threshold is designed, including a temperature sampling and voltage comparison circuit, an adjustable preset over-temperature protection threshold, and an alarm and drive heat dissipation circuit. This design can adapt to different working states, and the preset temperature protection threshold for different working conditions can be manually adjusted to achieve dynamic matching across all working conditions; moreover, it is purely hardware controlled, requiring no program control, and is low in cost and highly reliable.

[0089] Since the processing and functions implemented by the method in this embodiment are basically the same as the embodiments, principles and examples of the aforementioned motor controller, motor and vehicle, any details not covered in this embodiment can be found in the relevant descriptions in the aforementioned embodiments, and will not be repeated here.

[0090] In summary, it is readily understood by those skilled in the art that, without conflict, the aforementioned advantageous methods can be freely combined and superimposed.

[0091] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A protection device for an electric motor, characterized in that, The motor has a temperature detection unit; the motor's protection device includes: a temperature sampling unit, a comparison unit, and a protection unit; wherein, The temperature detection unit is used to detect the temperature of the motor and obtain a voltage characterizing the temperature of the motor, which is denoted as the temperature detection voltage of the motor. The temperature sampling unit is used to at least amplify the temperature detection voltage of the motor to obtain the temperature sampling voltage of the motor. The comparison unit is configured to provide a preset voltage protection threshold, denoted as the current preset voltage protection threshold of the motor, based on the current operating condition of the motor; and to compare the temperature sampling voltage of the motor with the current preset voltage protection threshold of the motor, so as to determine that the motor temperature has over-temperature when the temperature sampling voltage of the motor is greater than or equal to the current preset voltage protection threshold of the motor, and output the over-temperature protection signal of the motor. The protection unit is used to provide alerts and / or reduce the temperature based on the motor's over-temperature protection signal, thereby achieving over-temperature protection for the motor.

2. The motor protection device according to claim 1, characterized in that, The temperature sampling unit includes: an input resistor module, a sampling resistor module, a feedback resistor module, and an operational amplifier module; wherein, The preset DC power supply is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module; the inverting input terminal of the operational amplifier module is connected to the output terminal of the operational amplifier module after passing through the feedback resistor module. At this time, the input terminal of the temperature detection voltage of the motor is connected to the non-inverting input terminal of the operational amplifier module after passing through the sampling resistor module; the output terminal of the operational amplifier module serves as the output terminal of the sampling unit; and the voltage output by the output terminal of the operational amplifier module serves as the temperature sampling voltage of the motor.

3. The motor protection device according to claim 2, characterized in that, The temperature sampling unit further includes at least one of the following: a first voltage divider module, a second voltage divider module, a first filter module, a second filter module, a third filter module, a fourth filter module, and a fifth filter module; the first voltage divider module includes a first voltage divider resistor module and a second voltage divider resistor module, and the second voltage divider module includes a third voltage divider resistor module and a fourth voltage divider resistor module; wherein, The preset DC power supply is grounded after passing through the first voltage divider resistor module and the second voltage divider resistor module; the common terminal of the first voltage divider resistor module and the second voltage divider resistor module is connected to the inverting input terminal of the operational amplifier module after passing through the input resistor module. The preset DC power supply, after passing through the third voltage divider resistor module, is connected to the common terminal of the motor temperature detection voltage input terminal and the sampling resistor module; the motor temperature detection voltage input terminal is grounded after passing through the sampling resistor module and the fourth voltage divider resistor module; at this time, the common terminal of the sampling resistor module and the fourth voltage divider resistor module is connected to the non-inverting input terminal of the operational amplifier module. The preset DC power supply is grounded after passing through the first filter module; The input terminal of the temperature detection voltage of the motor is grounded after passing through the second filter module; The common terminal of the temperature detection voltage input of the motor and the sampling resistor module is grounded after passing through the third filter module; The non-inverting input terminal of the operational amplifier module is grounded after passing through the fourth filter module; The inverting input terminal of the operational amplifier module is connected to the output terminal of the operational amplifier module after passing through the fifth filter module.

4. The motor protection device according to claim 2 or 3, characterized in that, The sampling unit further includes at least one of a clamping module, a first current-limiting resistor module, and a sixth filtering module; wherein... The output terminal of the operational amplifier module is connected to the clamping terminal of the clamping module; at this time, the clamping terminal of the clamping module serves as the output terminal of the sampling unit; the voltage output from the output terminal of the operational amplifier module obtained from the clamping terminal of the clamping module serves as the temperature sampling voltage of the motor. The output terminal of the operational amplifier module is connected to the input terminal of the comparator unit after passing through the first current-limiting resistor module; at this time, the common terminal of the first current-limiting resistor module and the input terminal of the comparator unit serves as the output terminal of the sampling unit; the common terminal of the first current-limiting resistor module and the input terminal of the comparator unit is grounded after passing through the sixth filter module.

5. The motor protection device according to any one of claims 1 to 4, characterized in that, The comparison unit includes: a comparison module, a reference resistor module, and a threshold adjustment module; wherein, The output terminal of the sampling unit is connected to the non-inverting input terminal of the comparison module; A preset reference power supply is grounded after passing through the reference resistor module and the threshold adjustment module; the common terminal of the reference resistor module and the threshold adjustment module is connected to the inverting input terminal of the comparison module; the output terminal of the comparison module serves as the output terminal of the comparison unit. The threshold adjustment module is used to adjust its own resistance value based on the current operating condition of the motor. After adjustment, it and the reference resistor module jointly provide a preset temperature protection threshold corresponding to the current operating condition of the motor, which is denoted as the current preset voltage protection threshold of the motor.

6. The motor protection device according to any one of claims 1 to 5, characterized in that, The protection unit includes: a switching transistor module, a second current-limiting resistor module, an alert module, and a heat dissipation module; wherein, The output terminal of the comparison unit is connected to the control terminal of the switching transistor module; the preset DC power supply is connected to the first connection terminal of the switching transistor module; the second connection terminal of the switching transistor module is connected to the drive terminal of the heat dissipation module; the second connection terminal of the switching transistor module is also grounded after passing through the second current limiting resistor module and the reminder module.

7. A motor controller, characterized in that, include: The motor protection device as described in any one of claims 1 to 6.

8. An electric motor, characterized in that, include: The motor protection device as described in any one of claims 1 to 6, or the motor controller as described in claim 7.

9. A vehicle, characterized in that, include: The motor protection device as described in any one of claims 1 to 6, or the motor controller as described in claim 7, or the motor as described in claim 8.

10. A method for protecting a motor using a motor protection device as described in any one of claims 1 to 6, characterized in that, include: The temperature of the motor is detected by the temperature detection unit, and a voltage characterizing the temperature of the motor is obtained, which is denoted as the temperature detection voltage of the motor. The temperature sampling unit amplifies the temperature detection voltage of the motor to obtain the temperature sampling voltage of the motor. The comparison unit provides a preset voltage protection threshold, based on the current operating condition of the motor, to characterize the preset temperature protection threshold corresponding to the current operating condition of the motor. This preset voltage protection threshold is denoted as the current preset voltage protection threshold of the motor. The temperature sampling voltage of the motor is compared with the current preset voltage protection threshold of the motor. If the temperature sampling voltage of the motor is greater than or equal to the current preset voltage protection threshold of the motor, it is determined that the motor temperature has exceeded the threshold, and the over-temperature protection signal of the motor is output. The protection unit provides alerts and / or reduces the temperature based on the motor's over-temperature protection signal, thereby protecting the motor from over-temperature. And / or, Software protection is implemented based on the temperature sampling voltage of the motor to achieve over-temperature protection for the motor.

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