Electric vehicle motor temperature measurement self-adaptive switching circuit

Abstract

The utility model discloses a self-adaptive switching circuit for temperature measurement of an electric vehicle motor. The self-adaptive switching circuit comprises a high-speed change-over switch, the acquisition module is electrically connected with the high-speed change-over switch, and the high-speed change-over switch is electrically connected with the motor temperature sensor and the controller temperature measurement circuit; wherein the motor temperature sensor is disconnected with the controller temperature measurement circuit, the acquisition module transmits an analog voltage signal to the controller temperature measurement circuit, acquires a voltage signal of the motor temperature sensor and analyzes the voltage signal into temperature, the high-speed change-over switch rapidly returns to a connection state, and the motor temperature sensor is disconnected with the controller temperature measurement circuit. The motor temperature sensor is reconnected with the controller temperature measuring circuit, and data measured by the motor temperature sensor are transmitted to the controller in real time. According to the utility model, limitation of the model of an original controller can be avoided, and characteristics of dynamic, reliable, rapid and lossless acquisition of temperature signals and the like can be realized.

Description

Technical Field

[0001] The utility model relates to an adaptive switching circuit for measuring the temperature of an electric vehicle motor. Background Art

[0002] Two-wheeled electric vehicles include electric bicycles and electric motorcycles. Both use batteries as auxiliary energy sources and electric motors as power sources. The batteries power the motors, which in turn drive the wheels, enabling the electric bicycles and motorcycles to move.

[0003] Typically, a motor has an integrated temperature sensor that monitors the motor's temperature in real time. Temperature transmission relies on a temperature line, and the controller uses logic to analyze the temperature sensor's signal to detect temperature. Traditional temperature acquisition assumes the controller's model and internal logic are known (such as the internal supply voltage and pull-up resistor value). The sampling logic is fixed: if the temperature line on the motor side is T1 and the controller side is T2, the controller samples T1's voltage signal and, based on a temperature sensor's characteristic table, converts its resistance value into a voltage. This is then converted to a corresponding temperature value using specialized logic. However, in real-world applications, the temperature acquisition logic varies significantly between controller models, controller protocols may be unknown, and power supply characteristics and pull-up resistors are not directly accessible. This creates a bottleneck in cross-controller compatibility for traditional sampling methods. Therefore, to address the shortcomings of existing technologies, an adaptive switching circuit for electric vehicle motor temperature measurement was developed. Summary of the Invention

[0004] The purpose of the utility model is to provide an electric vehicle motor temperature measurement adaptive switching circuit to address the defects of the existing technology.

[0005] In order to achieve the above-mentioned purpose of the utility model, the following technical solutions are adopted:

[0006] An adaptive switching circuit for measuring the temperature of an electric vehicle motor comprises a high-speed switching switch; and an acquisition module, wherein the acquisition module is electrically connected to the high-speed switching switch, and the high-speed switching switch is electrically connected to a motor temperature sensor and a controller temperature measurement circuit; wherein, when the motor temperature sensor is disconnected from the controller temperature measurement circuit, the acquisition module sends an analog voltage signal to the controller temperature measurement circuit while acquiring the voltage signal of the motor temperature sensor and analyzing it as temperature; the high-speed switching switch quickly returns to a connected state, the motor temperature sensor is reconnected to the controller temperature measurement circuit, and the data measured by the motor temperature sensor is transmitted to the controller in real time.

[0007] Furthermore, the electric vehicle motor temperature measurement adaptive switching circuit of the present invention further includes an on-board instrument, and the temperature collected by the collection module is displayed by the on-board instrument.

[0008] Furthermore, the high-speed switching switch includes two single-pole double-throw switches, the two single-pole double-throw switches are electrically connected to the controller temperature measurement circuit and the acquisition module, and one of the two single-pole double-throw switches is electrically connected to the motor temperature sensor and the acquisition module.

[0009] Furthermore, the acquisition module includes an analog switch; a single-chip microcomputer, the single-chip microcomputer is electrically connected to the analog switch, and the analog switch is used to control the switching of the high-speed switching switch; and a signal transmission circuit, the single-chip microcomputer is electrically connected to the high-speed switching switch through the signal transmission circuit.

[0010] Furthermore, the signal transmission circuit includes an operational amplifier follower circuit and a low-pass filter circuit, and the operational amplifier follower circuit and the low-pass filter circuit are electrically connected in series.

[0011] Furthermore, the operational amplifier follower circuit includes an operational amplifier.

[0012] Furthermore, one end of the low-pass filter circuit is electrically connected to the single-chip microcomputer, and the other end is electrically connected to the analog switch through the op amp follower circuit; the low-pass filter circuit includes R16, R17, C24 and C25, one end of R16 is electrically connected to the single-chip microcomputer, and the other end is connected to R17 and one end of C24, the other end of R17 is electrically connected to one end of C25 and the op amp follower circuit, and the other ends of C24 and C25 are both connected to the common ground line.

[0013] Furthermore, one end of the low-pass filter circuit is electrically connected to the analog switch, and the other end is connected to the op amp follower circuit, and the op amp follower circuit is electrically connected to the single-chip microcomputer; the low-pass filter circuit includes C23, one end of C23 and a pin of the analog switch are connected to a common ground line, and the other end is electrically connected to the op amp follower circuit.

[0014] Furthermore, the electric vehicle motor temperature measurement adaptive switching circuit of the present invention also includes a 3.3V power supply circuit, and the 3.3V power supply circuit is electrically connected to the analog switch.

[0015] Furthermore, the 3.3V power supply circuit includes a DC-DC circuit and an LDO circuit, and the DC-DC circuit and the LDO circuit are connected in parallel.

[0016] This high-speed switch utilizes a high-precision, fast-switching chip, achieving a total switching time of just 50ns. This effectively prevents signal interruptions caused by prolonged disconnections. Throughout the switching period, the analog voltage maintains a consistent controller signal, ensuring no significant jumps or anomalies in the output temperature. This allows the controller to maintain stable operation and prevent misjudgment of temperature changes.

[0017] 2. This new acquisition module collects temperature and analyzes data in less than 0.1 seconds, significantly faster than the actual temperature change, ensuring data accuracy. Designed to collect data once per second, the acquisition module significantly reduces interference with traditional controller logic, ensuring a stable controller output temperature signal during the acquisition cycle and eliminating the risk of data jumps and distortion.

[0018] 3. This utility model maintains the stability of the original circuit through analog voltage, and the entire acquisition process does not disrupt the controller logic or the original system functions. The independent analysis logic of the acquisition module makes it adaptable to different controller models on the market, eliminating the need for internal characteristic analysis. The modular design is suitable for various application scenarios, achieving plug-and-play operation without complex debugging. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly describes the drawings required for the specific embodiments or the description of the prior art. Similar elements or parts are generally identified by similar reference numerals throughout the drawings. Elements or parts in the drawings are not necessarily drawn to scale.

[0020] Figure 1 This is a circuit diagram of an electric vehicle motor temperature measurement adaptive switching circuit of the utility model;

[0021] Figure 2 This is a schematic diagram of the principle structure of the utility model;

[0022] Names and serial numbers of components in the figure:

[0023] In the circuit diagram: R represents resistance and C represents capacitance. DETAILED DESCRIPTION

[0024] In order to enable people skilled in the art to better understand the technical solutions in this application, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of this application. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of this application. Example

[0025] like Figure 1 、 2As shown, an electric vehicle motor temperature measurement adaptive switching circuit includes a high-speed switching switch and a collection module. The collection module is electrically connected with the high-speed switching switch, and the high-speed switching switch is electrically connected with a motor temperature sensor and a controller temperature measurement circuit; wherein the motor temperature sensor is disconnected with the controller temperature measurement circuit, the collection module sends an analog voltage signal to the controller temperature measurement circuit while collecting the voltage signal of the motor temperature sensor and analyzing the voltage signal into temperature, the high-speed switching switch quickly returns to the connection state, the motor temperature sensor is reconnected with the controller temperature measurement circuit, and the data measured by the motor temperature sensor is transmitted to the controller in real time.

[0026] In order to obtain temperature information in time, the temperature collected by the collection module is displayed through the vehicle-mounted instrument.

[0027] The temperature line motor end is T1, and the controller end is T2; the controller converts the resistance value into voltage by sampling the voltage signal of T1 in combination with the characteristic table of the temperature sensor, and further converts the voltage into the corresponding temperature value through specific logic.

[0028] The working mode of the collection is as follows:

[0029] The first step is the initial state.

[0030] In the normal working state, T1 (the motor temperature sensor end) is directly connected with T2 (the controller end), the controller reads the temperature signal through the set logic, and completes the normal temperature analysis. During this period, the collection module passively simulates the voltage signal of T1, and records the voltage value transmitted by the original line.

[0031] The second step is to switch the collection mode.

[0032] A high-speed switching switch is introduced to switch the temperature line to two states:

[0033] Connection state: T1 is directly connected with T2, and the controller works normally;

[0034] Collection state: disconnect T1 and T2, connect T1 to the collection module, and connect T2 to an analog voltage generator.

[0035] Third, the analog voltage keeps the controller stable. During the switching to the collection state, the controller receives the analog voltage signal from T2. The analog voltage signal is accurately generated by the collection module according to the original T1 voltage simulated before, and is completely consistent with the original voltage. The controller cannot perceive that the circuit is switched, continuously receives stable “pseudo signals”, the temperature display and control do not need to be corrected, and the original control logic is completely unaffected.

[0036] Fourth, the collection module completes temperature analysis.

[0037] At the moment when T1 is switched to the acquisition module, the acquisition module parses the motor temperature signal into actual temperature according to the acquired T1 actual voltage signal and combining with the conversion logic of the module itself. The acquisition module only needs 5-10 ms to complete the entire parsing process, and the time required for each ℃ temperature change is at least 1 second, so it is much shorter than the time of updating the temperature display of the controller.

[0038] Fifth, restore the initial state.

[0039] After the acquisition is completed, the switching switch quickly returns to the connection state, T1 and T2 are reconnected, and the original line returns to the initial state. The controller continues to complete its original parsing logic according to the signal of the temperature sensor.

[0040] The switching switch uses a high-precision fast switching chip, and the total time of switching on and off of the switching switch only needs 50 ns, which can effectively avoid signal interruption caused by long-time disconnection. During the entire switching period, the analog voltage remains consistent with the controller signal, ensuring that the output temperature does not appear obvious jump or abnormality, so that the controller continues to work in a stable state and does not misjudge the temperature change.

[0041] Temperature is not a rapidly changing physical quantity, and motor temperature is affected by heat dissipation, so its change is usually above seconds. Therefore, the acquisition time (within 0.1 seconds) of the acquisition module to acquire temperature and analyze data is much shorter than the actual temperature change time, ensuring data accuracy. The acquisition frequency of the acquisition module is 1 per second, which greatly reduces the interference to the traditional controller working logic, ensures the stability of the controller output temperature signal within the acquisition period, and eliminates the risk of data jump and distortion.

[0042] By keeping the original line stable through the analog voltage, the entire acquisition process does not damage the controller logic and the original system function. The independent parsing logic of the acquisition module makes it suitable for different models of controllers in the market without the need to analyze their internal characteristics. And the modular design is suitable for various application scenarios, realizing plug and play without complex debugging.

[0043] In some optional embodiments, a structure of a high-speed switching switch is given. The high-speed switching switch includes two single-pole double-throw switches, the two single-pole double-throw switches are electrically connected with the controller temperature measurement circuit and the acquisition module, and one of the two single-pole double-throw switches is electrically connected with the motor temperature sensor and the acquisition module.

[0044] As shown in Figure 1 , the two single-pole double-throw switches are SW1 and SW2 respectively.

[0045] In some optional embodiments, a data acquisition module structure is provided. The data acquisition module includes an analog switch, a single-chip microcomputer, and a signal transmission circuit. The single-chip microcomputer is electrically connected to the analog switch, and the analog switch is used to control the switching of a high-speed switching switch. The single-chip microcomputer and the high-speed switching switch are electrically connected via the signal transmission circuit.

[0046] like Figure 2 As shown, one structure of the analog switch may be GS3005-MR.

[0047] The signal transmission circuit includes an operational amplifier follower circuit and a low-pass filter circuit, and the operational amplifier follower circuit and the low-pass filter circuit are electrically connected in series.

[0048] The op amp follower circuit includes an operational amplifier. Figure 2 As shown, one structure of the operational amplifier may be GS358-MR.

[0049] like Figure 1 、 2 As shown, pin 3 of the GS3005-MR is connected to pins 1 and 2 of the GS358-MR. Pin 4 of the GS3005-MR is connected to pin 4 of the microcontroller to control the on / off switching of SW2. Pin 8 of the GS3005-MR is connected to pin 3 of the microcontroller to control the on / off switching of SW1. Pin 9 of the GS3005-MR is connected to the motor temperature sensor. Pin 10 of the GS3005-MR is connected to the temperature measurement circuit of the electric vehicle controller and is also connected to pin 2. Pin 7 of the GS3005-MR is connected to one end of R12, the other end of R12 is connected to the 3.3V power supply circuit. Pin 1 of the GS3005-MR is connected to the 3.3V power supply circuit and one end of C20, the other end of C20 is connected to the common ground.

[0050] Pin 8 of the GS358-MR is connected to the common ground of the GS3005-MR through C23. Pin 5 of the GS358-MR is connected to one end of R18. The other end of R18 and one end of C26 are connected to pin 9 of the GS3005-MR. The other end of C26 is connected to the common ground. Pins 6 and 7 of the GS358-MR are connected to MCU_ADC and pin 1 of the microcontroller. MCU_ADC can be an onboard instrument cluster in electric vehicles. Pin 4 of the GS358-MR is connected to the common ground.

[0051] In some optional embodiments, a low-pass filter circuit structure is provided for a single-chip microcomputer and an analog switch. One end of the low-pass filter circuit is electrically connected to the single-chip microcomputer, and the other end is electrically connected to the analog switch via an op amp follower circuit. The low-pass filter circuit includes R16, R17, C24, and C25. One end of R16 is electrically connected to the single-chip microcomputer, and the other end is connected to R17 and one end of C24. The other end of R17 is electrically connected to one end of C25 and the op amp follower circuit. The other ends of C24 and C25 are both connected to a common ground line.

[0052] In some optional embodiments, another low-pass filter circuit structure is provided for a single-chip microcomputer and an analog switch. One end of the low-pass filter circuit is electrically connected to the analog switch, and the other end is connected to an op amp follower circuit, which is electrically connected to the single-chip microcomputer. The low-pass filter circuit includes C23, one end of which and a pin of the analog switch are connected to a common ground line, and the other end is electrically connected to the op amp follower circuit.

[0053] In some optional embodiments, a power supply circuit structure is provided, wherein a 3.3V power supply circuit is additionally installed and electrically connected to an analog switch.

[0054] The 3.3V power supply circuit includes a DC-DC circuit and an LDO circuit, which are connected in parallel. Specifically, when the DC-DC and LDO are connected in parallel, the input voltage range is 4V to 18V, and the output voltage range is 3.3V to 3.4V. When the input voltage is greater than or equal to 4V and less than 5V, the DC-DC circuit's output voltage is less than 3.3V because it does not reach the DC-DC circuit's minimum input voltage. However, the LDO circuit operates normally and its output voltage is 3.3V, so it automatically switches to the LDO. When the input voltage is greater than or equal to 5V, the DC-DC circuit operates normally and its output voltage is 3.4V, which is greater than the LDO's output voltage of 3.3V. Based on the physical principle that "if two power sources provide current simultaneously, the current automatically flows from the power source with the higher voltage," the current will flow preferentially from the DC-DC circuit, automatically switching to the DC-DC circuit. This allows the Bluetooth chip to be powered by a weak power source.

[0055] According to the above embodiment, the utility model is used to intercept the motor temperature data of electric bicycles and electric motorcycles. Without affecting the normal operation of the electric vehicle controller, the motor temperature is obtained by means of the original motor temperature sensor circuit of the electric vehicle. The motor temperature intercepted by the circuit can be provided to the expansion device (which can be an on-board instrument) for use.

[0056] The working principle of this utility model:

[0057] ①When the circuit is powered on, the MCU's IO pin 3 outputs a level signal to the control pin of SW1, making SW1's pins 1 and 2 conductive (SW1's pins 1 and 3 disconnected). At this time, the electric vehicle controller can normally collect the motor temperature; at the same time, the MCU collects the motor temperature sensor and the electric vehicle controller's internal pull-up resistor through the ADC function. The intermediate nodes 1 and 2 (i.e. Figure 1 The microcontroller then outputs a PWM signal through PWM pin 2, which is filtered by the low-pass filter circuit to obtain a voltage V2 close to V1, making the voltage at node 3 V2.

[0058] ② The MCU's IO pin 4 outputs a level signal to the control pin of SW2, connecting SW2's pins 1 and 2. The voltages at nodes 1, 2, and 3 are all the same, V2. At this point, the MCU again uses its ADC function to collect the voltage V2 at node 1. After calculation, the MCU outputs a PWM signal through PWM pin 2. After filtering through the low-pass filter circuit, the resulting voltage is V1 at node 2. This closed-loop control ensures that V2 is approximately equal to V1. This process maintains the voltage at node 2 (the temperature measurement line at the electric vehicle controller) at V1.

[0059] ③ After completing the above processes ① and ②, the MCU's IO pin 3 outputs a level signal to the SW1 control pin, making SW1's pins 1 and 3 conductive (SW1's pins 1 and 2 disconnected). The external 3.3V-10K pull-up resistor and the electric vehicle motor temperature sensor form the intermediate node 1 of the voltage divider measurement circuit. The MCU reads the voltage value of node 1 through the ADC pin and calculates the current temperature of the motor. The MCU can transmit the temperature data to the on-board instrument for use. At this time, the voltage on the temperature measurement line of the electric vehicle controller is maintained at V1. Although the temperature data obtained by the electric vehicle controller is not the real-time temperature of the current motor, the temperature data obtained by the electric vehicle controller will not jump or be abnormal.

[0060] ④ After completing the above processes ①, ②, and ③, the MCU's IO pin 3 outputs a level signal to the control pin of SW1, making SW1's pins 1 and 2 conductive (SW1's pins 1 and 3 disconnected). Then the MCU's IO pin 4 outputs a level signal to the control pin of SW2, making SW2's pins 1 and 2 disconnected. At this point, the electric vehicle controller can measure the real-time data of the motor temperature sensor normally.

[0061] ⑤ Repeat steps ①, ②, ③, and ④ in a reciprocating cycle to perfectly capture the temperature data of the electric vehicle motor temperature sensor circuit without affecting the normal operation of the electric vehicle controller.

[0062] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. An adaptive switching circuit for measuring temperature of an electric vehicle motor, characterized by: include High-speed switching; as well as An acquisition module, the acquisition module is electrically connected to the high-speed switch, and the high-speed switch is electrically connected to the motor temperature sensor and the controller temperature measurement circuit; Among them, the motor temperature sensor is disconnected from the controller temperature measurement circuit, and the acquisition module sends an analog voltage signal to the controller temperature measurement circuit while collecting the voltage signal of the motor temperature sensor and analyzing it as temperature. The high-speed switching switch quickly returns to the connection state, and the motor temperature sensor is reconnected to the controller temperature measurement circuit. The data measured by the motor temperature sensor is transmitted to the controller in real time.

2. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 1, characterized in that: It also includes an on-board instrument, and the temperature collected by the collection module is displayed by the on-board instrument.

3. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 1, characterized in that: The high-speed switching switch includes two single-pole double-throw switches, which are electrically connected to the controller temperature measurement circuit and the acquisition module, and one of the two single-pole double-throw switches is electrically connected to the motor temperature sensor and the acquisition module.

4. The electric vehicle motor temperature measurement adaptive switching circuit according to any one of claims 1 to 3, characterized in that: The acquisition module includes Analog switches; a single-chip microcomputer, the single-chip microcomputer being electrically connected to an analog switch, the analog switch being used to control switching of a high-speed switching switch; and A signal transmission circuit is provided, wherein the single chip microcomputer is electrically connected to the high-speed switching switch via the signal transmission circuit.

5. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 4, characterized in that: The signal transmission circuit includes an operational amplifier follower circuit and a low-pass filter circuit, and the operational amplifier follower circuit and the low-pass filter circuit are electrically connected in series.

6. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 5, characterized in that: The operational amplifier follower circuit includes an operational amplifier.

7. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 5, characterized in that: One end of the low-pass filter circuit is electrically connected to the single-chip microcomputer, and the other end is electrically connected to the analog switch through the operational amplifier follower circuit; The low-pass filter circuit includes R16, R17, C24 and C25. One end of R16 is electrically connected to the single-chip microcomputer, and the other end is connected to R17 and one end of C24. The other end of R17 is electrically connected to one end of C25 and the operational amplifier follower circuit. The other ends of C24 and C25 are both connected to a common ground line.

8. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 5, characterized in that: One end of the low-pass filter circuit is electrically connected to the analog switch, and the other end is connected to the operational amplifier follower circuit, and the operational amplifier follower circuit is electrically connected to the single-chip microcomputer; The low-pass filter circuit includes C23, one end of which is connected to a common ground line together with a pin of the analog switch, and the other end of which is electrically connected to the operational amplifier follower circuit.

9. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 4, characterized in that: It also includes a 3.3V power supply circuit, and the 3.3V power supply circuit is electrically connected to the analog switch.

10. The electric vehicle motor temperature measurement adaptive switching circuit according to claim 9, characterized in that: The 3.3V power supply circuit includes a DC-DC circuit and an LDO circuit, and the DC-DC circuit and the LDO circuit are connected in parallel.

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