Motor three-phase insulation detection method and device

Abstract

The invention discloses a motor three-phase insulation detection method and device. The detection method comprises the following steps: starting a motor control module according to a received motor control instruction of a vehicle control module; if the power-on signal of the whole vehicle control module is received, a negative electrode connection switch is controlled to be turned on; an insulation detection instruction is sent to the motor control module according to the obtained insulation detection request signal of the whole vehicle control module; the motor controller controls to turn on an anode connection switch according to the insulation detection instruction and generates a motor control module state signal, and the three-phase electric connection circuit is grounded; the insulation detection module carries out insulation impedance measurement according to the state signal of the motor control module and generates insulation impedance evaluation information. According to the method, through software functions of an insulation detection instrument and a motor control instrument in an electric new energy vehicle system, accurate detection and judgment of three-phase insulation of the motor can be realized under the limitation that the motor is only provided with a two-phase current sensor, and more comprehensive guarantee is provided for the safety of an electric vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of intelligent control, and in particular to a motor three-phase insulation detection method and device. Background Art

[0002] At present, the high-voltage power distribution related modules of new energy electric vehicles are usually equipped with insulation detection instruments, which can detect the insulation problem of the positive and negative electrodes of the battery to the ground. However, due to the existence of IGBT inside the motor controller, the three-phase line of the motor is not directly connected to the positive and negative electrodes of the battery, so the insulation of the three-phase line of the motor cannot be detected by this method. The current solution is to use the three-phase current sensor in the motor controller to detect the three-phase insulation fault of the motor. The basic principle is to determine whether the cumulative sum of the three-phase currents of Iu, Iv, and Iw is zero. If it exceeds a certain threshold, it indicates that there is a three-phase insulation fault. However, for cost-saving considerations, the current motor controller is usually only equipped with two-phase current sensors, which makes it impossible to detect the three-phase insulation fault. Therefore, the main problem of the existing new energy electric vehicle motor insulation detection technology is that the motor controller is only equipped with two-phase current sensors and the three-phase insulation fault of the motor cannot be directly detected. This may cause insufficient monitoring of the motor insulation state, and it is impossible to timely discover and prevent potential insulation fault problems, which has an adverse effect on the safety and reliability of the vehicle system. Summary of the invention

[0003] The embodiment of the present invention provides a method for detecting three-phase insulation of a motor, aiming to solve the problem of low accuracy in detecting insulation impedance of the motor existing in the prior art methods.

[0004] In the first aspect, an embodiment of the present invention discloses a three-phase insulation detection method for a motor, which is applied to a motor control module in a motor control system of a new energy vehicle. The motor control module is electrically connected to the motor module through an internal three-phase electrical connection circuit, and the three-phase electrical connection circuit is electrically connected to the positive pole of the battery module through a positive connection switch. The three-phase electrical connection circuit is electrically connected to the negative pole of the battery module through a negative connection switch. The battery module is connected in parallel with the insulation detection module, and the motor control module and the battery module are both controlled and connected to a vehicle control module and grounded. The method includes: if a power-on signal of the vehicle control module is received, the negative connection switch is controlled to be turned on; the motor control module is started according to the motor control instruction received from the vehicle control module; an insulation detection instruction is sent to the motor control module according to the insulation detection request signal of the vehicle control module; the motor controller controls the positive connection switch to be turned on according to the insulation detection instruction and generates a motor control module status signal, and the three-phase electrical connection circuit is grounded; the insulation detection module performs insulation impedance measurement according to the motor control module status signal and generates insulation impedance evaluation information.

[0005] Furthermore, a first voltage value from the motor module and a second voltage value from the battery module are obtained; it is determined whether the first voltage value and the second voltage value meet the preset starting conditions; if the starting conditions are met, it is determined that a power-on signal from the vehicle control module is received and the negative pole connection switch is controlled to be turned on.

[0006] Further, determine whether the first voltage value is greater than a preset voltage threshold; if the first voltage value is greater than the preset voltage threshold, the insulation detection condition is not met; if the first voltage value is not greater than the preset voltage threshold, determine whether the second voltage value is greater than the voltage threshold; if the second voltage value is greater than the preset voltage threshold, the insulation detection condition is not met; if the second voltage value is not greater than the preset voltage threshold, the insulation detection condition is met and an insulation detection instruction is sent to the motor control module.

[0007] Furthermore, it is determined whether the current detection voltage value of the insulation detection module is greater than the safety voltage value; if the current detection voltage value of the insulation detection module is greater than the safety voltage value, an alarm message is issued; if the current detection voltage value of the insulation detection module is not greater than the safety voltage value, the positive connection switch is controlled to be turned on according to the obtained insulation detection instruction and a motor control module status signal is generated.

[0008] Furthermore, if a motor control module status signal is received, the current operating voltage value and the current operating current value of the three-phase electrical connection circuit are obtained; the insulation impedance value is calculated based on the current operating voltage value and the current operating current value; and it is determined whether the insulation impedance value is greater than a preset impedance threshold value. If so, the motor module is determined to be in an operable state and insulation impedance evaluation information is generated. If not, the motor module is determined to be in a fault state.

[0009] In the second aspect, an embodiment of the present invention discloses a three-phase insulation detection device for a motor, which applies the above-mentioned three-phase insulation detection method for a motor. The detection device includes a motor control module starting unit, which is used to start the motor control module according to the motor control instruction received from the vehicle control module; a first signal control unit, which is used to control the opening of the negative pole connection switch if a power-on signal from the vehicle control module is received; a second signal control unit, which is used to send an insulation detection instruction to the motor control module according to the insulation detection request signal obtained from the vehicle control module; a third signal control unit, which is used for the motor controller to control the opening of the positive pole connection switch according to the insulation detection instruction and generate a motor control module status signal, and the three-phase electrical connection circuit is grounded; and a bonding impedance measurement unit, which is used for the insulation detection module to perform insulation impedance measurement according to the motor control module status signal and generate insulation impedance evaluation information.

[0010] Furthermore, the device also includes a first measurement value acquisition unit, which is used to obtain a first voltage value from the motor module and a second voltage value from the battery module; a first judgment unit, which is used to judge whether the first voltage value and the second voltage value meet the preset starting conditions; a second judgment unit, which is used to judge whether the first voltage value is greater than a preset voltage threshold; and a third judgment unit, which is used to judge whether the current detection voltage value of the insulation detection module is greater than the safety voltage value.

[0011] Furthermore, the device also includes a second measurement value acquisition unit, which is used to obtain the current operating voltage value and the current operating current value of the three-phase electrical connection circuit if a motor control module status signal is received; and a calculation unit, which is used to calculate the insulation impedance value based on the current operating voltage value and the current operating current value.

[0012] The above-mentioned three-phase insulation detection method for a motor and the three-phase insulation detection device for a motor using the method determine the insulation status of the motor by judging and comparing multiple voltage values. Even if there are only two-phase current sensing modules, the voltage information of the three phases can be obtained from other circuits and a comprehensive judgment can be made. Through the above method, even if the motor control module only has two-phase current sensing modules, the three-phase insulation problem of the motor can still be detected and judged, which can improve the monitoring capability of the vehicle system on the insulation status of the motor, timely discover potential insulation problems, and avoid the resulting failures and safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0014] Figure 1 A schematic diagram of a flow chart of a motor three-phase insulation detection method provided by an embodiment of the present invention;

[0015] Figure 2 A schematic diagram of the structure of a three-phase insulation detection device for a motor provided in an embodiment of the present invention.

[0016] Figure Number:

[0017] 1. Motor control module; 2. Motor module; 3. Battery module; 4. Insulation detection module; 11. Three-phase electrical connection circuit; 12. Positive pole connection switch; 13. Negative pole connection switch. DETAILED DESCRIPTION

[0018] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0020] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include plural forms.

[0021] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0022] like Figure 1 and Figure 2 As shown, in the first aspect, an embodiment of the present invention discloses a three-phase insulation detection method for a motor, which is applied to a motor control module 1 in a motor control system of a new energy vehicle, wherein the motor control module 1 is electrically connected to the motor module 2 through a built-in three-phase electrical connection circuit 11, the three-phase electrical connection circuit 11 is electrically connected to the positive electrode of the battery module 3 through a positive connection switch 12, the three-phase electrical connection circuit 11 is electrically connected to the negative electrode of the battery module 3 through a negative connection switch 13, the battery module 3 is connected in parallel with the insulation detection module 4, the motor control module 1 and the battery module 3 are both connected to the vehicle control module and grounded, The method specifically includes: if a power-on signal of a vehicle control module is received, then controlling to open a negative pole connection switch 13; starting a motor control module 1 according to a motor control instruction received from the vehicle control module; sending an insulation detection instruction to the motor control module 1 according to an insulation detection request signal obtained from the vehicle control module; the motor controller controlling to open a positive pole connection switch 12 according to the insulation detection instruction and generating a motor control module 1 status signal, and the three-phase electrical connection circuit 11 is grounded; the insulation detection module 4 performs insulation impedance measurement according to the motor control module 1 status signal and generates insulation impedance evaluation information.

[0023] In the specific implementation process of the method, the three-phase insulation detection method of the motor of the new energy vehicle is intended to improve the safety and reliability of the motor system. In the weak current state of the whole vehicle, the circuit connection is completed by closing the switch contactor between the motor control module 1 and the negative and positive poles of the battery module 3. Then, the whole vehicle control module sends a request to the motor control module 1, requesting the motor module 2 to perform a detection based on the insulation performance of the three-phase circuit. The motor control module 1 controls the lower three-bridge IGBT (insulated gate bipolar transistor) to be continuously turned on to ensure that the three-phase line is in an energized state. At the same time, the whole vehicle control module receives the control signal based on the completion state of the motor control module 1 and sends a request signal for insulation detection to the insulation detector. The insulation detection module 4 detects the insulation impedance in the battery module 3, the motor control module 1 and the motor module 2. If the test result shows that the insulation impedance in the whole vehicle control module is low, it means that there is an insulation problem. The insulation detection module 4 will report a fault signal, and the whole vehicle control module will judge it as a three-phase line insulation problem, and take corresponding measures to handle the fault. If the test result shows that the insulation impedance of the whole vehicle is normal, it means that the three-phase insulation of the motor is good. The vehicle control module will enter the normal power-on process. The three-phase insulation detection method realizes the three-phase insulation detection of the motor in the weak current state of the vehicle. By controlling the conduction of the lower three-bridge I GBT, the three-phase circuit of the motor is ensured to be energized. With the help of the insulation detection module 4, the insulation impedance of the whole vehicle is detected to timely discover and deal with insulation problems. In this way, the safety of the motor system can be improved and the normal operation of the whole vehicle can be guaranteed. This method has important application value in the field of new energy vehicles and can meet the requirements for the safety and reliability of the motor system.

[0024] In the actual use scenario, according to the motor control instruction received from the vehicle control module, the motor control module 1 starts to run and prepares to perform insulation detection. If the power-on signal of the vehicle control module is received, the motor control module 1 controls to open the negative pole connection switch 13 to ensure that the circuit is normally powered. According to the insulation detection request signal received from the vehicle control module, the motor control module 1 sends an insulation detection instruction to the insulation detection module 4 to prepare for insulation detection. According to the insulation detection instruction, the motor control module 1 controls to open the positive pole connection switch 12 to ensure that the circuit is connected to the positive pole of the battery module 3. At the same time, the motor control module 1, the vehicle control module and the battery module 3 are all grounded to form a closed circuit. The insulation detection module 4 measures the insulation impedance of the motor according to the status signal of the motor control module 1. The measurement result will be used to generate insulation impedance evaluation information to determine the insulation condition of the motor. The method realizes the detection of the three-phase insulation state of the motor. By using the communication and control between the motor control module 1 and the vehicle control module and the insulation detection module 4, as well as the operation of the negative and positive connection switches 12, the circuit connection and the measurement and evaluation of the insulation impedance are realized. Such an approach helps to improve the safety and stability of the motor system.

[0025] In summary, with the help of the insulation detection module 4 in the whole vehicle system, combined with the software function of the motor control module 1, the technical effect of detecting the three-phase insulation of the motor is achieved when the motor has only a two-phase current sensing structure. Through the software function of the motor control module 1, the working state of the motor can be monitored and recorded, including parameters such as current and speed. During the detection process, the insulation detector in the whole vehicle system is used to convert the working state of the motor into feedback information of the insulation state through a specific circuit configuration and signal processing algorithm. In the case where the motor has only a two-phase current sensing structure, the approximate value of the third-phase current can be derived by analyzing and processing the existing two-phase current sensing module signal. Then, by comparing this approximate value with the preset threshold, it is judged to determine whether the motor has a three-phase insulation problem. If the detection result exceeds the threshold, the system can issue an alarm or take corresponding protective measures in time. The insulation detection method based on the two-phase current sensing structure can not only simplify the hardware structure of the motor system, reduce cost and complexity, but also realize reliable detection of the three-phase insulation of the motor in the weak current state of the whole vehicle. This technical effect has practicality and feasibility while improving the accuracy and sensitivity of insulation detection. The three-phase insulation detection method applied to the motor of new energy vehicles achieves the technical effect of detecting the three-phase insulation of the motor when the motor only has two-phase current sensing modules by using the insulation detector in the whole vehicle system and the software function of the motor control module 1, as well as the analysis and processing of the two-phase current sensing module signal. This method not only simplifies the hardware structure of the motor system, but also improves the accuracy and reliability of insulation detection, which has a positive role in promoting the development of the new energy vehicle industry.

[0026] Furthermore, a first voltage value from the motor module 2 and a second voltage value from the battery module 3 are obtained; it is determined whether the first voltage value and the second voltage value meet the preset starting conditions; if the starting conditions are met, it is determined that a power-on signal from the vehicle control module is received and the negative pole connection switch 13 is controlled to be turned on.

[0027] Specifically, the voltage values ​​of the motor module 2 and the battery module 3 can be obtained through appropriate sensors. The voltage value of the motor module 2 represents the working state of the motor, while the voltage value of the battery module 3 represents the state of the entire battery system. These voltage values ​​can be read by the corresponding sensors and transmitted to the motor controller for processing. According to the preset start-up conditions, the first voltage value and the second voltage value are judged. These start-up conditions may include minimum voltage requirements, voltage difference ranges, etc. If the first voltage value and the second voltage value meet the preset start-up conditions, it means that the motor and the battery system are in normal working state and can continue to start. When the start-up conditions are met, after receiving the power-on signal of the vehicle control module, the battery module 3 is connected to the motor module 2 by controlling the negative pole connection switch 13. In this way, the power supply of the motor can be realized so that it can work normally. By obtaining the voltage values ​​of the motor module 2 and the battery module 3 and judging according to the preset start-up conditions, the start-up control of the motor system can be realized. After receiving the power-on signal of the vehicle control module, the power supply of the motor is realized by controlling the negative pole connection switch 13.

[0028] Further, determine whether the first voltage value is greater than a preset voltage threshold; if the first voltage value is greater than the preset voltage threshold, the insulation detection condition is not met; if the first voltage value is not greater than the preset voltage threshold, determine whether the second voltage value is greater than the voltage threshold; if the second voltage value is greater than the preset voltage threshold, the insulation detection condition is not met; if the second voltage value is not greater than the preset voltage threshold, the insulation detection condition is met and an insulation detection instruction is sent to the motor control module 1.

[0029] Specifically, after obtaining the first voltage value, it is compared with a preset voltage threshold. If the first voltage value is greater than the preset voltage threshold, it indicates that the insulation detection condition is not met. If the first voltage value is not greater than the preset voltage threshold, proceed to the next step. After obtaining the second voltage value, it is compared with the preset voltage threshold. If the second voltage value is greater than the preset voltage threshold, it indicates that the insulation detection condition is not met. If the second voltage value is not greater than the preset voltage threshold, it indicates that the insulation detection condition is met. When both the first voltage value and the second voltage value meet the insulation detection condition, an insulation detection instruction can be sent to the motor control module 1. The instruction can trigger the motor control module 1 to perform an insulation detection operation to ensure the safe operation of the motor system. The insulation detection condition is determined by judging the first voltage value and the second voltage value step by step. In this way, it can be ensured that an insulation detection instruction is sent to the motor control module 1 under the condition of meeting the preset voltage threshold requirement to further ensure the safety of the motor system.

[0030] Further, it is determined whether the current detection voltage value of the insulation detection module 4 is greater than the safety voltage value; if the current detection voltage value of the insulation detection module 4 is greater than the safety voltage value, an alarm message is issued; if the current detection voltage value of the insulation detection module 4 is not greater than the safety voltage value, the positive pole connection switch 12 is controlled to be turned on according to the obtained insulation detection instruction and a motor control module 1 status signal is generated.

[0031] Specifically, after obtaining the current detection voltage value of the insulation detection module 4, it is compared with the safety voltage value. If the current detection voltage value is greater than the safety voltage value, it indicates that there is an insulation fault and an alarm message needs to be issued. If the current detection voltage value is not greater than the safety voltage value, the next step can be continued. According to the insulation detection instruction obtained, the positive connection switch 12 is controlled to open. This ensures that the positive connection path is unobstructed. According to the comparison result of the current detection voltage value of the insulation detection module 4 and the safety voltage value, a corresponding motor control module 1 state signal is generated. This signal can be used to feedback the current insulation state to the motor control module 1 for further processing and control.

[0032] Furthermore, if a status signal of the motor control module 1 is received, the current operating voltage value and the current operating current value of the three-phase electrical connection circuit 11 are obtained; the insulation impedance value is calculated based on the current operating voltage value and the current operating current value; and it is determined whether the insulation impedance value is greater than a preset impedance threshold value. If so, the motor module 2 is determined to be in an operable state and insulation impedance evaluation information is generated; if not, the motor module 2 is determined to be in a fault state.

[0033] Specifically, when the state signal of the motor control module 1 is received, subsequent operations can be triggered. The current operating voltage value and the current operating current value of the three-phase electrical connection circuit 11 are obtained by sensors or other means to calculate the insulation impedance. The insulation impedance is calculated according to the current operating voltage value and the current operating current value obtained. The specific calculation method depends on the specific needs and system characteristics. The calculated insulation impedance value is compared with the preset impedance threshold. If the insulation impedance value is greater than the preset impedance threshold, it means that the motor module 2 is in an operational state and insulation impedance evaluation information can be generated. In the case where the insulation impedance value is greater than the preset impedance threshold, insulation impedance evaluation information can be generated based on the insulation impedance value and other relevant information. This information can be used to judge the insulation state and performance evaluation of the motor module 2. If the insulation impedance value is not greater than the preset impedance threshold, it can be determined that the motor module 2 is in a fault state. Appropriate treatment measures can be taken, such as stopping the motor operation and generating fault alarm information.

[0034] In the second aspect, an embodiment of the present invention discloses a three-phase insulation detection device for a motor, which applies the above-mentioned three-phase insulation detection method for a motor. The detection device includes a motor control module 1 starting unit, which is used to start the motor control module 1 according to the motor control instruction received from the vehicle control module; a first signal control unit, which is used to control the opening of the negative pole connection switch 13 if a power-on signal from the vehicle control module is received; a second signal control unit, which is used to send an insulation detection instruction to the motor control module 1 according to the insulation detection request signal from the vehicle control module obtained; a third signal control unit, which is used for the motor controller to control the opening of the positive pole connection switch 12 according to the insulation detection instruction and generate a motor control module 1 status signal, and the three-phase electrical connection circuit 11 is grounded; and a bonding impedance measurement unit, which is used for the insulation detection module 4 to measure the insulation impedance according to the motor control module 1 status signal and generate insulation impedance evaluation information.

[0035] Specifically, in an actual usage scenario, the motor control module 1 is started by receiving the motor control instruction of the vehicle control module. When the power-on signal of the vehicle control module is received, the negative pole connection switch 13 is controlled to be turned on. When the insulation detection request signal of the vehicle control module is obtained, the insulation detection instruction is sent to the motor control module 1. The motor controller controls the positive pole connection switch 12 to be turned on according to the insulation detection instruction, and generates the motor control module 1 status signal. At the same time, the three-phase electrical connection circuit 11 is grounded. The insulation detection module 4 performs insulation impedance measurement according to the motor control module 1 status signal, and generates insulation impedance evaluation information. First, when the motor control instruction of the vehicle control module is received, the motor control module 1 is started. When the power-on signal of the vehicle control module is received, the first signal control unit controls the negative pole connection switch 13 to be turned on, so that the motor control module 1 is connected to the negative pole of the power supply. Then, when the insulation detection request signal of the vehicle control module is obtained, the second signal control unit sends the insulation detection instruction to the motor control module 1. According to the insulation detection instruction, the third signal control unit controls the opening of the positive connection switch 12, generates the motor control module 1 status signal, and grounds the three-phase electrical connection circuit 11. Finally, the insulation impedance measurement unit performs insulation impedance measurement according to the motor control module 1 status signal, and generates insulation impedance evaluation information. Through the motor three-phase insulation detection device, the insulation state of the motor can be quickly detected and evaluated to ensure the safe operation of the motor system.

[0036] Furthermore, the device also includes a first measurement value acquisition unit, which is used to obtain a first voltage value from the motor module 2 and a second voltage value from the battery module 3; a first judgment unit, which is used to judge whether the first voltage value and the second voltage value meet the preset starting conditions; a second judgment unit, which is used to judge whether the first voltage value is greater than a preset voltage threshold; and a third judgment unit, which is used to judge whether the current detection voltage value of the insulation detection module 4 is greater than the safety voltage value.

[0037] Furthermore, the device also includes a second measurement value acquisition unit, which is used to obtain the current operating voltage value and the current operating current value of the three-phase electrical connection circuit 11 if a status signal of the motor control module 1 is received; and a calculation unit, which is used to calculate the insulation impedance value based on the current operating voltage value and the current operating current value.

[0038] The present invention discloses a three-phase insulation detection method and device for a motor, the method comprising the steps of step S1, if a power-on signal of a vehicle control module is received, then control to open a negative pole connection switch 13; step S2, start the motor control module 1 according to the motor control instruction received from the vehicle control module; step S3, according to the insulation detection request signal of the vehicle control module obtained, send an insulation detection instruction to the motor control module 1; step S4, the motor controller controls to open the positive pole connection switch 12 according to the insulation detection instruction and generates a motor control module 1 state signal. step S5, the insulation detection module 4 performs insulation impedance measurement according to the motor control module 1 state signal and generates insulation impedance evaluation information. The device includes a motor control module 1 starting unit, which is used to start the motor control module 1 according to the motor control instruction received from the vehicle control module; a first signal control unit, which is used to control the opening of the negative connection switch 13 if the power-on signal of the vehicle control module is received; a second signal control unit, which is used to send an insulation detection instruction to the motor control module 1 according to the insulation detection request signal of the vehicle control module; a third signal control unit, which is used for the motor controller to control the opening of the positive connection switch 12 according to the insulation detection instruction and generate the motor control module 1 state signal, and the three-phase electrical connection circuit 11 is grounded; and a junction impedance measurement unit, which is used for the insulation detection module 4 to measure the insulation impedance according to the motor control module 1 state signal and generate insulation impedance evaluation information. The above-mentioned motor three-phase insulation detection method and device are aimed at the problem that the whole vehicle system cannot detect the three-phase insulation problem of the motor when the motor control module 1 has only two-phase current sensing modules. The method measures the insulation impedance of the motor instead of directly relying on the current sensing structure. By measuring the change of the insulation impedance value, the insulation state between the phases of the motor can be judged, including whether there is insulation fault or damage. The method judges the insulation state of the motor by judging and comparing multiple voltage values. Even if there are only two-phase current sensing modules, the voltage information of the three phases can be obtained from other circuits and a comprehensive judgment can be made. Through the above method, even if the motor control module 1 only has two-phase current sensing modules, the three-phase insulation problem of the motor can still be detected and judged, which can improve the monitoring ability of the vehicle system on the insulation status of the motor, timely discover potential insulation problems, and avoid the resulting failures and safety risks.

[0039] In summary, in view of the fact that the vehicle system cannot detect the three-phase insulation problem of the motor when there are only two-phase current sensors, the above-mentioned motor three-phase insulation detection method can achieve the following technical effects: 1. Enhanced insulation status monitoring capability: By measuring the insulation impedance or other relevant parameters, the insulation status of the motor can be accurately monitored, including judging whether the insulation is normal and discovering potential insulation faults or damage. 2. Safe operation guarantee: By judging the voltage value and comprehensive voltage information, ensure that the motor starts and runs within the appropriate voltage range, prevent faults or safety risks caused by abnormal voltage, and improve the safety of the vehicle system. 3. Improved early warning and protection functions: Once the motor insulation status is abnormal or the voltage exceeds the safe range, the corresponding early warning and protection measures can be triggered in time, such as issuing an alarm, shutting down the power supply or automatically shutting down, to avoid further damage or danger. 4. Improved reliability and stability: This method provides a reliable insulation detection method for the motor system, which helps to achieve stable operation of the motor system, extend equipment life, and improve production efficiency and the reliability of the vehicle system.

[0040] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A motor three-phase insulation detection method, applied to a motor control module in a new energy vehicle motor control system, characterized in that: The motor control module is electrically connected to the motor module through a built-in three-phase electrical connection circuit, the three-phase electrical connection circuit is electrically connected to the positive electrode of the battery module through a positive connection switch, and the three-phase electrical connection circuit is electrically connected to the negative electrode of the battery module through a negative connection switch. The battery module is connected in parallel with the insulation detection module, and the motor control module and the battery module are both controlled and connected to the vehicle control module and grounded. The method includes: If a power-on signal from the vehicle control module is received, the negative electrode connection switch is controlled to be turned on; Starting the motor control module according to the motor control instruction received from the vehicle control module; Sending an insulation detection instruction to the motor control module according to the insulation detection request signal of the vehicle control module obtained; According to the insulation detection instruction, the positive connection switch is controlled to be turned on and a motor control module status signal is generated, and the three-phase electrical connection circuit is grounded; Insulation impedance measurement is performed according to the motor control module status signal and insulation impedance evaluation information is generated.

2. The motor three-phase insulation detection method according to claim 1, characterized in that: If a power-on signal from the vehicle control module is received, the negative electrode connection switch is controlled to be turned on, including: Acquire a first voltage value from the motor module and a second voltage value from the battery module; Determining whether the first voltage value and the second voltage value meet a preset start condition; If the start-up condition is met, it is determined that a power-on signal of the vehicle control module is received and the negative electrode connection switch is controlled to be turned on.

3. The motor three-phase insulation detection method according to claim 2 is characterized in that: Before sending the insulation detection instruction to the motor control module, the method includes: Determining whether the first voltage value is greater than a preset voltage threshold; If the first voltage value is greater than a preset voltage threshold, the insulation detection condition is not met; If the first voltage value is not greater than a preset voltage threshold, determining whether the second voltage value is greater than the voltage threshold; If the second voltage value is greater than the preset voltage threshold, the insulation detection condition is not met; If the second voltage value is not greater than a preset voltage threshold, the insulation detection condition is met and an insulation detection instruction is sent to the motor control module.

4. The motor three-phase insulation detection method according to claim 3 is characterized in that: Before controlling to open the positive connection switch according to the insulation detection instruction and generating a motor control module status signal, the method includes: Determine whether the current detection voltage value of the insulation detection module is greater than the safety voltage value; If the current detection voltage value of the insulation detection module is greater than the safety voltage value, an alarm message is issued; If the current detection voltage value of the insulation detection module is not greater than the safety voltage value, the positive pole connection switch is controlled to be turned on and a motor control module status signal is generated according to the obtained insulation detection instruction.

5. The motor three-phase insulation detection method according to claim 4, characterized in that: The step of measuring the insulation impedance according to the motor control module status signal and generating insulation impedance evaluation information comprises: If the motor control module status signal is received, the current operating voltage value and the current operating current value of the three-phase electrical connection circuit are obtained; Calculate the insulation resistance value according to the current operating voltage value and the current operating current value; Determine whether the insulation impedance value is greater than a preset impedance threshold value. If so, determine that the motor module is in an operable state and generate insulation impedance evaluation information. If not, determine that the motor module is in a fault state.

6. A motor three-phase insulation detection device, configured in a motor control system in a new energy vehicle, the detection device applies the motor three-phase insulation detection method according to any one of claims 1 to 5, characterized in that: The detection device comprises: A motor control module starting unit, used to start the motor control module according to the motor control instruction received from the vehicle control module; A first signal control unit, configured to control turning on the negative electrode connection switch upon receiving a power-on signal from the vehicle control module; A second signal control unit, configured to send an insulation detection instruction to the motor control module according to the insulation detection request signal of the vehicle control module obtained; A third signal control unit, used for the motor controller to control the opening of the positive connection switch and generate a motor control module state signal according to the insulation detection instruction, and the three-phase electrical connection circuit is grounded; The insulation impedance measurement unit is used for the insulation detection module to measure the insulation impedance according to the motor control module status signal and generate insulation impedance evaluation information.

7. The motor three-phase insulation detection device according to claim 6, characterized in that: Also includes: a first measurement value acquisition unit, configured to acquire a first voltage value from the motor module and a second voltage value from the battery module; A first judging unit, configured to judge whether the first voltage value and the second voltage value meet a preset starting condition; A second judging unit, used to judge whether the first voltage value is greater than a preset voltage threshold; The third judgment unit is used to judge whether the current detection voltage value of the insulation detection module is greater than the safety voltage value.

8. The motor three-phase insulation detection device according to claim 7, characterized in that: Also includes: a second measurement value acquisition unit, configured to acquire a current operating voltage value and a current operating current value of the three-phase electrical connection circuit if the motor control module status signal is received; A calculation unit is used to calculate the insulation resistance value according to the current operating voltage value and the current operating current value.

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