Motor temperature detection device and detection method

Abstract

The application discloses a motor temperature detection device and a detection method. The device comprises a resistance measurement circuit and a voltage amplification circuit. The resistance measurement circuit is used for detecting the output voltage value of the resistance in the sensor to be detected. The voltage amplification circuit is used for amplifying the voltage value output by the resistance measurement circuit. The device further comprises a switching circuit. The application can be compatible with NTC temperature sensors and PTC temperature sensors. Two working states are switched through a switch, and the device has strong versatility. Moreover, most of the circuits of the two working states are shared, and the device has low cost.

Description

Technical Field

[0001] This application relates to the field of automotive motor temperature detection technology, and in particular to a motor temperature detection device and detection method. Background Technology

[0002] With the rapid development of technology, automation and process control technologies are being widely applied in fields such as automobiles, power plants, and water conservancy facilities. The requirements for automotive controllers in industrial applications are also becoming increasingly stringent. Motor temperature control, as a crucial component of automated control for electric actuators, is also facing increasingly demanding requirements.

[0003] Currently, motor temperature detection typically involves acquiring and processing signals from a thermistor sensor within the motor to obtain the motor's temperature. However, different motors are equipped with different thermistor sensors, meaning that the controller needs to be replaced along with the motor.

[0004] It should be noted that the statements herein provide only background information relevant to this application and do not necessarily constitute prior art. Summary of the Invention

[0005] In view of the above problems, this application proposes a motor temperature detection device and detection method that overcomes or at least partially solves the above problems.

[0006] The embodiments of this application adopt the following technical solutions:

[0007] In a first aspect, embodiments of this application provide a motor temperature detection device, the device comprising: a resistance measuring circuit and a voltage amplification circuit, the resistance measuring circuit being used to detect the output voltage value of the resistance in the sensor under test, the voltage amplification circuit being used to amplify the voltage value output by the resistance measuring circuit, and further comprising a switching circuit, wherein in a first operating state, the switching circuit uses the resistance measuring circuit as a resistance bridge circuit and switches the voltage amplification circuit as a differential amplifier; and in a second operating state, the switching circuit uses the resistance measuring circuit as a resistance voltage divider circuit and switches the voltage amplification circuit as a voltage follower circuit.

[0008] Optionally, the switching circuit includes a first switch and a second switch, and the first switch and the second switch are controlled by a microcontroller (MCU) to switch the circuit.

[0009] Optionally, the device further includes an EMC circuit, which includes a first EMC circuit and a second EMC circuit. The first EMC circuit is connected to the input terminal of the resistance measurement circuit, and the second EMC circuit is connected to the output terminal of the resistance measurement circuit.

[0010] Optionally, in the first operating state, the switching circuit uses the resistance measurement circuit as a resistance bridge circuit and switches the voltage amplification circuit to a differential amplifier so that the motor temperature detection device is configured to detect the temperature of the PTC sensor.

[0011] Optionally, in the second operating state, the switching circuit uses the resistance measurement circuit as a resistance voltage divider circuit and switches the voltage amplification circuit as a voltage follower, so that the motor temperature detection device is configured to detect the temperature of the NTC sensor.

[0012] Optionally, the input terminal of the motor temperature detection device is connected to the NTC temperature sensor.

[0013] Optionally, the input terminal of the motor temperature detection device is connected to the PTC temperature sensor.

[0014] Optionally, the resistance measurement circuit includes a power supply circuit as the power supply for the bridge in the resistance bridge circuit, and the power supply circuit includes an EMC power filter circuit and a voltage feedback regulation circuit.

[0015] Optionally, the motor temperature detection device further includes a short-circuit protection circuit to protect the input terminal of the motor temperature detection device from being short-circuited to a low-voltage power supply.

[0016] Secondly, embodiments of this application also provide a method for detecting motor temperature, wherein the detection method includes: after the motor is powered on, if the type of sensor to be tested in the motor is a PTC temperature sensor, issuing a first control switching command to a switching circuit; according to the first control switching command, switching the resistance measurement circuit to a resistance bridge circuit and switching the voltage amplification circuit to a differential amplifier; if the type of sensor to be tested in the motor is an NTC sensor, issuing a second control switching command to the switching circuit, wherein the second control switching command and the first control switching command are obtained by being triggered by a switch signal; according to the second control switching command, switching the resistance measurement circuit to a resistance voltage divider circuit and switching the voltage amplification circuit to a voltage follower circuit.

[0017] The above-described technical solutions adopted in the embodiments of this application can achieve the following beneficial effects:

[0018] The motor temperature detection device of this application has good compatibility. The motor controller equipped with this detection device is compatible with most electric vehicle motors on the market. The device has a short circuit protection function. When the input is shorted to a low voltage power supply (0-36V), the circuit will not be damaged, and the reliability is good. The detection device is composed of ordinary operational amplifiers, resistors, diodes, switches, etc., and the cost is low.

[0019] As can be seen from the above, the technical solution of this application is described above only as an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0020] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0021] Figure 1 This is a schematic diagram of the motor temperature detection device of this application;

[0022] Figure 2 This is the circuit diagram of the motor temperature detection device of this application;

[0023] Figure 3 This is the equivalent circuit diagram of the motor temperature detection device in the first working state of this application;

[0024] Figure 4 This is the equivalent circuit diagram of the second working state of the motor temperature detection device of this application;

[0025] Figure 5 This is the high-precision power supply circuit diagram for the motor temperature detection device of this application. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application 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 application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0027] The concept of this application is that existing motor temperature detection devices are only applicable to automotive motors equipped with either negative temperature coefficient (NTC) thermistors or positive temperature coefficient (PTC) thermistors, and are not compatible with motors using either type of temperature sensor. Furthermore, general motor temperature detection devices have poor reliability and are easily damaged when the input is short-circuited. The motor temperature detection device of this application effectively solves these two problems. The input of the detection device can be connected to either an NTC or PTC temperature sensor; simultaneously, the detection device has a short-circuit protection function, ensuring that the circuit will not be damaged when the input is short-circuited to a low-voltage power supply (0-36V), thus demonstrating strong adaptability.

[0028] The technical solutions provided by the various embodiments of this application are described in detail below with reference to the accompanying drawings.

[0029] This application provides a motor temperature detection device and inspection method.

[0030] In motor engineering applications, temperature sensors (thermometers) are typically used to measure the temperature of motor windings, bearings, lubricating oil, and other components to understand the motor's operating status and provide necessary protection. Motor temperature detection circuits are used in motor controllers and generally come in two types: the first is suitable for NTC sensors (negative temperature coefficient sensors), whose resistance changes significantly with temperature; the second is suitable for PTC sensors (positive temperature coefficient sensors), whose resistance changes very little with temperature. These two detection circuits differ greatly, and once one type is used, it can only be applied to the corresponding temperature sensor type. That is, when replacing the motor, the motor controller compatible with the temperature sensor must also be replaced.

[0031] like Figure 1 The diagram shows a circuit structure of a motor temperature detection device 100 according to an embodiment of this application. The device includes a resistance measurement circuit 110 and a voltage amplification circuit 120. The resistance measurement circuit 110 is used to detect the output voltage value of the resistance in the sensor under test, and the voltage amplification circuit 120 is used to amplify the voltage value output by the resistance measurement circuit. The device also includes a switching circuit 130. In a first operating state, the switching circuit uses the resistance measurement circuit 110 as a resistance bridge circuit and switches the voltage amplification circuit 120 as a differential amplifier. In a second operating state, the switching circuit uses the resistance measurement circuit 110 as a resistance voltage divider circuit and switches the voltage amplification circuit 120 as a voltage follower circuit.

[0032] In this application, the motor temperature detection device includes at least two operating states: one operating state is suitable for an NTC sensor; the other operating state is suitable for a PTC sensor. Most of the circuit components are reused in both operating states. In the first operating state, the motor temperature detection device includes a resistor bridge circuit and a differential amplifier circuit, and is applied to a motor equipped with a PTC sensor.

[0033] The circuit diagram of a resistor bridge circuit, such as... Figure 2 As shown, because the resistance of a PTC sensor changes very little with temperature variations, a resistor bridge circuit is needed to improve detection sensitivity in order to obtain a higher accuracy output voltage. The bridge circuit uses a high-precision 4.5V power supply. Figure 2 As shown, resistor RK1 is the first arm of the bridge, resistor RK2 is the second arm, resistor RK3 is the third arm, and resistors RP1 and RP2 are connected in parallel and then connected in series with the temperature sensor to form the fourth arm of the bridge. RP1 and RP2 are protective resistors. Their parallel connection can increase the rated power and ensure that the circuit will not be damaged when the sensor input line is short-circuited to the power supply.

[0034] For the aforementioned resistor bridge circuit, the voltage across each resistor can be calculated using Ohm's law. On the bridge arms RK2 and RK3, RK2 and RK3 divide the 4.5V voltage provided by the high-precision power supply circuit, allowing us to obtain the input voltage of the ferrite bead FB3. On the bridge arms RK1, RP1, RP2, and the PTC thermistor sensor, RP1, RP2, and the PTC thermistor sensor divide the 4.5V voltage provided by the high-precision power supply circuit, allowing us to obtain the input voltage of the ferrite bead FB2. If the resistances of all four bridge arms are equal, then the voltage difference ΔV between the input terminals of ferrite beads FB2 and FB3 is 0, meaning the bridge is in a balanced state. As the ambient temperature changes, the resistance of the PTC thermistor sensor changes, causing a change in ΔV. The differential voltage ΔV is amplified by a differential operational amplifier and then sampled by an AD converter. By referring to the resistance-temperature correspondence table of the PTC thermistor, the current ambient temperature can be determined.

[0035] One drawback of bridge circuits is that their output consists of differential signals and common-mode voltages. Typically, the differential signal must undergo level conversion before entering the ADC to become a ground-referenced signal. This necessitates an EMC filter circuit. The EMC filter in the detection circuit typically consists of two stages of filtering, see [link to EMC filter circuit]. Figure 2 The EMC filter circuit 1 and EMC filter circuit 2 are part of the system. The EMC filtering circuit is related to the EMC performance of the system and should be added or removed according to the actual situation.

[0036] Because the output voltage of the resistor bridge circuit is relatively small, it cannot be directly converted by ADC. It needs to be amplified by a differential amplifier circuit before being converted into a digital signal. For PTC100 or PTC1000 temperature sensors, the amplification factor of the amplifier circuit is more than 10 times.

[0037] like Figure 2 As shown, the switching circuit is the key part of the detection circuit, used to switch between two operating states. First operating state: First switch S1 is open, second switch S2 is closed. In this state, the detection circuit corresponds to the PTC temperature sensor; the resistance measurement circuit functions as a resistor bridge circuit, and the voltage amplification circuit functions as a differential amplification circuit. Second operating state: First switch S1 is closed, second switch S2 is open. In this state, the detection circuit corresponds to the NTC temperature sensor; closing switch S1 shorts the resistor RK3, switching the resistor bridge circuit to a resistor divider circuit; opening switch S2 switches the differential amplification circuit to a voltage follower. This circuit is specifically designed for NTC temperature sensors. Therefore, the detection circuits for the two types of temperature sensors can be freely switched, and the process is simple and effective.

[0038] In some embodiments of this application, the switching circuit includes a first switch and a second switch, and the first switch and the second switch are controlled by a microcontroller (MCU) to switch the circuit.

[0039] The motor temperature sensor detection circuit is simple and practical. Controlling the switching of the two switches only requires the output pin of an MCU (microprocessor). If there is no corresponding control interface, the first switch S1 and the second switch S2 can also be switched manually using DIP switches.

[0040] In some embodiments of this application, the device further includes an EMC circuit, which includes a first EMC circuit and a second EMC circuit. The first EMC circuit is connected to the input terminal of the resistance measurement circuit, and the second EMC circuit is connected to the output terminal of the resistance measurement circuit.

[0041] In circuit design, critical signal filtering is essential. This application employs a two-stage EMC circuit to filter the circuitry in the temperature detection device: a first EMC circuit and a second EMC circuit, as follows: Figure 2As shown. The first EMC circuit (EMC filter circuit 1) is connected to the PTC / NTC thermistor sensor at the motor end, filtering out common-mode and differential-mode interference in the circuit. The second EMC circuit (EMC filter circuit 2) includes ferrite beads FB2 and FB3. The ferrite beads are used to suppress high-frequency noise and spike interference on the signal lines and have the ability to absorb electrostatic pulses. The ferrite beads are used to absorb ultra-high frequency signals and circuits containing ultra-high frequency storage devices. The ferrite beads have high resistivity and conductivity, comparable to resistors and inductors, but the resistance and conductivity values ​​vary with frequency. Capacitors C5 and C8 are used to filter out differential-mode interference from the two output signals; capacitors C6 and C7 are used to filter out common-mode interference from the two output signals. Common-mode inductor L1 is used to filter out common-mode interference from the two output signals.

[0042] In some embodiments of this application, when the switching circuit is in the first operating state, the resistance measurement circuit is used as a resistance bridge circuit and the voltage amplification circuit is switched to a differential amplifier so that the motor temperature detection device is configured to detect the temperature of the PTC sensor.

[0043] like Figure 3 The diagram shows the equivalent circuit of the motor temperature detection device in its first operating state. This first operating state is applicable to motors equipped with a PTC sensor. The circuit comprises four parts: an EMC filter circuit 1, a resistor bridge circuit, an EMC filter circuit 2, and a differential amplifier circuit.

[0044] EMC filter circuit 1 is connected to the PTC / NTC thermistor sensor at the motor end to filter out common-mode and differential-mode interference in the circuit. C2 and C3 are used to filter out common-mode interference signals, and C4 is used to filter out differential-mode interference signals.

[0045] Because the resistance of a PTC sensor varies very little, a resistor bridge circuit is needed to improve detection sensitivity and obtain a high-precision output voltage. The bridge circuit requires a high-precision 4.5V power supply. Figure 3 In the circuit, resistor RK1 is the first arm of the bridge, resistor RK2 is the second arm, resistor RK3 is the third arm, and resistors RP1 and RP2 are connected in parallel and then connected in series with the temperature sensor to form the fourth arm of the bridge. RP1 and RP2 are protective resistors. Their parallel connection can increase the rated power and ensure that the circuit will not be damaged when the sensor input line is short-circuited to the power supply.

[0046] For the aforementioned resistor bridge circuit, the voltage across each resistor can be calculated using Ohm's law. On the bridge arms RK2 and RK3, RK2 and RK3 divide the 4.5V voltage provided by the high-precision power supply circuit, allowing us to obtain the input voltage of the ferrite bead FB3. On the bridge arm RK1, RP1, RP2, and the PTC thermistor sensor, RP1, RP2, and the PTC thermistor sensor divide the 4.5V voltage provided by the high-precision power supply circuit, allowing us to obtain the input voltage of the ferrite bead FB2. If the resistances of all four bridge arms are equal, then the voltage difference ΔV between the input terminals of ferrite beads FB2 and FB3 is 0, meaning the bridge is in a balanced state. As the ambient temperature changes, the resistance of the PTC thermistor sensor changes, causing a change in ΔV. The differential voltage ΔV is amplified by a differential operational amplifier and then sampled by an AD converter. By referring to the resistance-temperature correspondence table of the PTC thermistor, we can determine the current ambient temperature.

[0047] One drawback of the resistor bridge circuit is that its output consists of a differential signal and a common-mode voltage. Typically, the differential signal must undergo level conversion before entering the ADC to become a ground-referenced signal. This necessitates an EMC filter circuit. The EMC filter circuit 2 includes ferrite beads FB2 and FB3. These beads suppress high-frequency noise and spike interference on the signal lines and have the ability to absorb electrostatic pulses. Ferrite beads are used to absorb ultra-high-frequency signals and circuits containing ultra-high-frequency storage devices. They possess high resistivity and conductivity, comparable to resistors and inductors, although these values ​​vary with frequency. Capacitors C5 and C8 filter differential-mode interference between the two output signals; capacitors C6 and C7 filter common-mode interference between the two output signals. A common-mode inductor L1 filters common-mode interference between the output signals.

[0048] Because the output voltage of the resistor bridge circuit is relatively small, it cannot be directly converted by an ADC. It needs to be amplified by a differential amplifier circuit before being converted into a digital signal. Figure 3 The intermediate differential amplifier circuit is a standard setup, its function is to amplify the input voltage for subsequent unit modules to capture and process, and will not be elaborated here.

[0049] In some embodiments of this application, when the switching circuit is in the second operating state, the resistance measurement circuit is used as a resistance voltage divider circuit, and the voltage amplification circuit is switched to a voltage follower, so that the motor temperature detection device is configured to detect the temperature of the NTC sensor.

[0050] like Figure 2As shown, closing the first switch S1 short-circuits the resistor RK3, switching the resistor bridge circuit operating in the first working state to a resistor voltage divider circuit; opening the switch S2 switches the differential amplifier circuit operating in the first working state to a voltage follower; at this time, the detection circuit operates in the second working state, and the equivalent circuit is as follows. Figure 4 As shown, Figure 4 The EMC filtering section is omitted, and this circuit is specifically designed for NTC temperature sensors. This demonstrates that the two types of temperature sensor detection circuits can be freely switched, and the circuit is simple and effective.

[0051] In the resistor divider circuit, RP1 and RP2 are protective resistors. Using them in parallel can increase the rated power and ensure that the circuit will not be damaged when the sensor input line is short-circuited to the power supply.

[0052] like Figure 4 As shown, the output voltage feedback of the voltage follower circuit is directly connected to the inverting input terminal, which is not grounded. Capacitors C9, C10, and C11 in the voltage follower circuit are all filter capacitors. The ambient temperature can be determined by referring to the resistance-temperature correspondence table of the NTC thermistor.

[0053] In the example of this application, the input terminal of the motor temperature detection device is connected to the NTC / PTC temperature sensor.

[0054] Since the motor temperature measurement device is compatible with NTC / PTC temperature sensors, and the NTC / PTC temperature sensors are installed on the motor, the NTC / PTC temperature sensor is used as the input terminal to the motor temperature detection device when replacing the motor. During motor replacement, a short circuit may occur; therefore, RP1 and RP2 are used in parallel to increase the rated power. This ensures that the circuit will not be damaged if the sensor input line is short-circuited to the power supply.

[0055] In some embodiments of this application, the resistance measurement circuit includes a power supply circuit as the power supply for the bridge in the resistance bridge circuit, and the power supply circuit includes an EMC power filter circuit and a voltage feedback regulation circuit.

[0056] like Figure 5 As shown, the power supply circuit is a 4.5V high-precision power supply circuit, which consists of EMC power filtering and voltage feedback regulation circuits. FB1 is a ferrite bead used to absorb ultra-high frequency signals. The ferrite bead has high resistivity and conductivity, comparable to resistors and inductors. Capacitor C1 mainly filters out differential-mode interference signals. The voltage feedback regulation circuit uses a TL431, a parallel voltage regulator integrated circuit. Due to its good performance and low price, it is widely used in various power supply circuits.

[0057] In some embodiments of this application, a short-circuit protection circuit is also included to protect the input terminal of the motor temperature detection device from being short-circuited to a low-voltage power supply. In this application, such as... Figure 2 As shown, two protection circuits are set up. One protection circuit consists of RP1 and RP2, which are used in parallel to increase the rated power and ensure that the circuit will not be damaged when the sensor input line is short-circuited to the power supply. The other protection circuit is diode D1. Figure 2 As shown, the circuit will not be damaged when diode D1 is shorted to a low-voltage power supply (0-36V), demonstrating good reliability.

[0058] The motor temperature detection device proposed in this solution is compatible with both NTC and PTC temperature sensors. Operating state 1 is adapted to PTC temperature sensors, and operating state 2 is adapted to NTC temperature sensors. The two operating states can be easily switched by a switch, making it highly versatile. Moreover, most of the circuits are shared between the two configurations, resulting in low cost.

[0059] In some embodiments of this application, a method for detecting motor temperature is also provided. The method includes: after the motor is powered on, if the sensor under test in the motor is a PTC temperature sensor, issuing a first control switching command to a switching circuit; according to the first control switching command, switching the resistance measurement circuit to a resistance bridge circuit and switching the voltage amplification circuit to a differential amplifier; if the sensor under test in the motor is an NTC sensor, issuing a second control switching command to the switching circuit, wherein the second control switching command and the first control switching command are triggered by a switch signal; according to the second control switching command, switching the resistance measurement circuit to a resistance voltage divider circuit and switching the voltage amplification circuit to a voltage follower circuit.

[0060] In this application, the motor temperature detection device includes at least two operating states: one operating state is suitable for an NTC sensor; the other operating state is suitable for a PTC sensor. Most of the circuit components are reused in both operating states. In the first operating state, the motor temperature detection device includes a resistor bridge circuit and a differential amplifier circuit, and is applied to a motor equipped with a PTC sensor.

[0061] The switching circuit in this application is a key part of the detection circuit, used to switch between two operating states. First operating state: First switch S1 is open, second switch S2 is closed. In this state, the detection circuit corresponds to a PTC temperature sensor; the resistance measurement circuit functions as a resistor bridge circuit, and the voltage amplification circuit functions as a differential amplification circuit. Second operating state: First switch S1 is closed, second switch S2 is open. In this state, the detection circuit corresponds to an NTC temperature sensor; closing switch S1 shorts the resistor RK3, switching the resistor bridge circuit to a resistor divider circuit; opening switch S2 switches the differential amplification circuit to a voltage follower. This circuit is specifically designed for NTC temperature sensors, demonstrating that the detection circuits for the two types of temperature sensors can be freely switched, and the process is simple and effective.

[0062] like Figure 3 The diagram shows the equivalent circuit of the motor temperature detection device in its first operating state. This first operating state is applicable to motors equipped with a PTC sensor. The circuit comprises four parts: an EMC filter circuit 1, a resistor bridge circuit, an EMC filter circuit 2, and a differential amplifier circuit.

[0063] like Figure 4 The diagram shows the equivalent circuit of the motor temperature detection device in the second operating state of this application. Figure 4 The EMC filtering section is omitted, and this circuit is specifically designed for NTC temperature sensors. This demonstrates that the two types of temperature sensor detection circuits can be freely switched, and the circuit is simple and effective.

[0064] At the hardware level, the vehicle controller includes a processor, and optionally also includes an internal bus, network interface, and memory. The memory may include main memory, such as high-speed random-access memory (RAM), or non-volatile memory, such as at least one disk drive. Of course, the vehicle controller may also include other hardware required for other business operations.

[0065] The processor, network interface, and memory can be interconnected via an internal bus, which can be an ISA (Industry Standard Architecture) bus, a PCI (Peripheral Component Interconnect) bus, or an EISA (Extended Industry Standard Architecture) bus, etc. This bus can be categorized into address bus, data bus, control bus, etc.

[0066] Memory is used to store programs. Specifically, programs may include program code, which includes computer operation instructions. Memory may include main memory and non-volatile memory, and provides instructions and data to the processor.

[0067] The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it. The processor executes the program stored in the memory and specifically uses it for the motor temperature detection method of this application.

[0068] The aforementioned motor temperature detection method can be applied to a processor, or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. During implementation, each step of the above method can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the field, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0069] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0070] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0071] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0072] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0073] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0074] Memory may include non-persistent storage in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0075] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0076] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0077] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0078] The above description is merely an embodiment of this application and is not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A motor temperature detection device, characterized in that, The system includes a resistance measurement circuit and a voltage amplification circuit. The resistance measurement circuit detects the output voltage value of the resistance in the sensor under test, and the voltage amplification circuit amplifies the voltage value output by the resistance measurement circuit. It also includes a switching circuit, comprising a first switch S1 and a second switch S2. A microcontroller (MCU) controls the switching of the first switch S1 and the second switch S2. The first switch S1 is connected in parallel across the two ends of the bridge arm resistor RK3 in the resistor bridge circuit, and one end of the bridge arm resistor RK3 is directly electrically connected to the analog ground GND_T. The second switch S2 is connected in series in the lower differential signal transmission path between the EMC filter circuit 2 and the differential amplifier circuit. The input terminal of the second switch S2 is electrically connected to the lower signal output branch of the EMC filter circuit 2 via resistor R6. The output terminal of the second switch S2 is electrically connected to the inverting input terminal of the operational amplifier U2A built into the differential amplifier circuit. The I / O control pins of the microcontroller MCU are electrically connected to the control terminals of the first switch S1 and the second switch S2, respectively; in the first working state, the switching circuit uses the resistance measurement circuit as a resistance bridge circuit and switches the voltage amplification circuit to a differential amplifier. In the second operating state, the switching circuit uses the resistance measurement circuit as a resistance voltage divider circuit and switches the voltage amplification circuit to a voltage follower circuit.

2. The apparatus as described in claim 1, characterized in that, The device further includes an EMC circuit, which comprises a first EMC circuit and a second EMC circuit. The first EMC circuit is connected to the input terminal of the resistance measurement circuit, and the second EMC circuit is connected to the output terminal of the resistance measurement circuit.

3. The apparatus as described in claim 2, characterized in that, In the first operating state, the switching circuit uses the resistance measurement circuit as a resistance bridge circuit and switches the voltage amplification circuit to a differential amplifier so that the motor temperature detection device is configured to detect the temperature of the PTC sensor.

4. The apparatus as described in claim 2, characterized in that, In the second operating state, the switching circuit uses the resistance measurement circuit as a resistance voltage divider circuit and switches the voltage amplification circuit as a voltage follower, so that the motor temperature detection device is configured to detect the temperature of the NTC sensor.

5. The apparatus as described in claim 3, characterized in that, The input terminal of the motor temperature detection device is connected to the PTC temperature sensor.

6. The apparatus as described in claim 4, characterized in that, The input terminal of the motor temperature detection device is connected to the NTC temperature sensor.

7. The apparatus as claimed in claim 1, characterized in that, The resistance measurement circuit includes a power supply circuit as the power supply for the bridge in the resistance bridge circuit. The power supply circuit includes an EMC power filter circuit and a voltage feedback regulation circuit.

8. The apparatus as claimed in claim 1, characterized in that, It also includes a short-circuit protection circuit to protect the input terminal of the motor temperature detection device from being short-circuited to a low-voltage power supply.

9. A method for detecting motor temperature, using the motor temperature detection device as described in claim 1, characterized in that, The detection method includes: After the motor is powered on, if the type of sensor to be tested in the motor is a PTC temperature sensor, the first control switching command is sent to the switching circuit. According to the first control switching command, the resistance measurement circuit is switched to a resistance bridge circuit, and the voltage amplification circuit is switched to a differential amplifier. When the type of sensor to be tested in the motor is an NTC sensor, a second control switching command is sent to the switching circuit, wherein the second control switching command and the first control switching command are obtained by being triggered by a switch signal; According to the second control switching command, the resistance measurement circuit is switched to a resistance voltage divider circuit, and the voltage amplification circuit is switched to a voltage follower circuit.

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