A high voltage power up and down control method and device

Abstract

The present invention discloses a high-voltage power-on and power-off control method and device, the control method includes a high-voltage power-on process and a high-voltage power-off process; wherein the high-voltage power-on process includes the following steps: performing a self-check of a motor controller in a low-voltage area; after the motor controller passes the self-check of the low-voltage area, the motor controller establishes CAN communication with a high-voltage battery; performing a self-check of the high-voltage battery; after the high-voltage battery passes the self-check, pre-charging the high-voltage battery and performing a high-voltage self-check of the motor controller are performed; after the high-voltage self-check of the motor controller passes, high-voltage power-on is completed. The present invention first performs a self-check of the low-voltage area of ​​the motor controller, and performs a high-voltage self-check of the motor controller during high-voltage power-on, ensuring that the vehicle is powered on with high-voltage electricity when power-on is allowed, reducing the possibility of danger to the vehicle, and improving the safety and reliability of the vehicle.

Description

Technical Field

[0001] The present invention belongs to the technical field of electric vehicles, and in particular relates to a high voltage up and down power control method and device. Background Art

[0002] The Chinese patent application number is 201611128624.7, and its name is "A method for controlling high-voltage power on and off by a vehicle controller of an electric vehicle". It discloses that the vehicle controller detects whether there is a reported main relay fault. If there is no fault, the pre-charging relay is closed and the pre-charging too fast or too slow fault is detected; when the pre-charging voltage is reached, the main relay is closed with a delay, the pre-charging relay is disconnected, and the pre-charging power-on process is completed, otherwise the pre-charging power-on process is stopped and a main relay fault signal is given; when the vehicle stops and the engine is turned off, the vehicle controller starts the first and second power-off delay timers respectively and detects the motor speed. If the conditions are met, the enable signal of the corresponding component is disconnected; then the lower voltage difference detection timer is started, and when the time is up and the lower voltage difference is greater than the set value, the motor control circuit contactor is disconnected to complete the high-voltage power-off process. The above method only solves the problem of relay contact adhesion.

[0003] In electric vehicle applications, it is necessary to effectively control the main relays and pre-charge relays used for high-voltage power on and off of the vehicle controller in the high-voltage distribution box. However, since the electrical life of the relay is much lower than the mechanical life, it is easier to damage the relay when switching under high current. In severe cases, the relay cannot be disconnected, affecting the safety of the vehicle. At present, there are still many shortcomings in the high and low voltage power on and off control methods. For example, high-voltage self-check is not performed when high-voltage power is on. If the vehicle is powered on without permission, high-voltage insulation failure, leakage, short circuit and other conditions may occur during the use of the vehicle, resulting in abnormal or even dangerous vehicle conditions, making the vehicle unable to be used normally, and in severe cases, endangering the driver's safety. Summary of the invention

[0004] In order to overcome the above technical defects, the present invention provides a high voltage power-on and power-off control method, including a high voltage power-on process and a high voltage power-off process; wherein the high voltage power-on process includes the following steps:

[0005] Perform a self-test of the motor controller's low voltage area;

[0006] The motor controller passes the low-voltage area self-test, and the motor controller establishes CAN communication with the high-voltage battery;

[0007] Perform high voltage battery self-test;

[0008] After the high-voltage battery self-test passes, the high-voltage battery pre-charge and motor controller high-voltage self-test are performed;

[0009] The motor controller high voltage self-test passed and high voltage power-on was completed.

[0010] Furthermore, before the step of performing the low-voltage area self-test of the motor controller, the steps include the following steps:

[0011] The low-voltage area of ​​the motor controller is powered on normally;

[0012] Initialize the motor controller low voltage area.

[0013] Furthermore, the step wherein the motor controller passes the low-voltage area self-test, and the motor controller establishes CAN communication with the high-voltage battery, includes the following steps:

[0014] When the motor controller passes the low-voltage area self-test, the motor controller detects the key switch signal;

[0015] When the key switch signal is detected to be on, the motor controller sends a CAN message to the high-voltage battery;

[0016] The high-voltage battery receives the CAN message sent by the motor controller and establishes CAN communication with the motor controller;

[0017] The motor controller confirms the high-voltage battery connection status and high-voltage battery version number through CAN messages.

[0018] Furthermore, the high-voltage battery self-test is passed in the above step, and the high-voltage battery pre-charging and the motor controller high-voltage self-test are performed, including the following steps:

[0019] The high-voltage battery self-test passes, and the high-voltage battery is pre-charged;

[0020] After pre-charging is completed, discharge begins and a CAN message to start discharge is sent to the motor controller;

[0021] The motor controller receives the CAN message for starting discharge and performs a high-voltage self-test.

[0022] Furthermore, the step of the motor controller receiving the CAN message for starting discharge and performing a high voltage self-test includes the following steps:

[0023] The motor controller receives the CAN message that the high-voltage battery starts discharging and performs leakage detection;

[0024] Collect data and determine whether the first data meets the first condition;

[0025] When the first data meets the first condition, determine whether the second data meets the second condition, otherwise perform the first action;

[0026] determining whether the third data meets the third condition;

[0027] When the third data meets the third condition, PWM output is prohibited; otherwise, it is a second fault and PWM output is prohibited;

[0028] When the second data meets the second condition, determining whether the second data meets the fourth condition, otherwise it is a first fault and PWM output is prohibited;

[0029] When the second data meets the fourth condition, the second action is executed, otherwise it is a third fault and PWM output is prohibited;

[0030] determining whether the second data meets the fifth condition;

[0031] When the second data meets the fifth condition, the third action is executed, otherwise it is a fourth fault and PWM output is prohibited;

[0032] determining whether the second data meets the sixth condition;

[0033] When the second data meets the sixth condition, it is determined whether the fourth data meets the seventh condition, otherwise it is a fifth fault and PWM output is prohibited;

[0034] When the fourth data meets the seventh condition, the PWM output is restarted; otherwise, it is a sixth fault and the PWM output is prohibited.

[0035] Furthermore, the step of the motor controller receiving the CAN message for starting to discharge and performing a high voltage self-test further includes the following steps:

[0036] When the motor controller high voltage self-test fails, determine whether the fault condition found in the self-test requires the high voltage battery to stop discharging;

[0037] When the high-voltage battery needs to stop discharging, the motor controller sends a stop-discharging CAN message to the high-voltage battery;

[0038] The high-voltage battery receives the stop-discharge CAN message and stops discharging;

[0039] High voltage power-up is completed.

[0040] Furthermore, the high voltage power-off process includes:

[0041] The motor controller detects the key switch signal;

[0042] When the key switch signal is detected to be off, the motor controller sends a discharge stop CAN message to the high-voltage battery and starts timing;

[0043] The high-voltage battery receives the discharge stop CAN message and stops discharging, and feeds back the discharge stop completion CAN message to the motor controller;

[0044] The motor controller receives the feedback CAN message indicating that the discharge stops and is completed, and the motor controller disables the low-voltage power supply and enters a sleep state.

[0045] Furthermore, the high voltage power-off process also includes:

[0046] If the motor controller times out and does not receive the CAN message indicating that the discharge stop is complete, the motor controller will lose the low-voltage power supply and enter the sleep state.

[0047] Compared with the prior art, the present invention has the following beneficial effects:

[0048] The present invention discloses a high-voltage power-on and power-off control method, which firstly performs a low-voltage area self-check of a motor controller, and then performs a high-voltage self-check of the motor controller during high-voltage power-on, thereby ensuring that the whole vehicle is powered on with high-voltage electricity when power-on is allowed, thereby reducing the possibility of danger to the vehicle and improving the safety and reliability of the vehicle.

[0049] The present invention also discloses a high voltage power-on and power-off control device, which is used to implement any of the control methods described above, including:

[0050] High voltage battery;

[0051] The motor controller is divided into a high-voltage area and a low-voltage area. The positive and negative electrodes of the high-voltage area of ​​the motor controller are respectively connected to the positive and negative electrodes of the high-voltage battery through two high-voltage wires. The motor controller and the high-voltage battery are connected through CAN communication.

[0052] The low voltage area of ​​the motor controller is connected to the lead-acid battery;

[0053] The input end of the motor controller is connected to the key switch signal circuit.

[0054] Furthermore, the negative electrode in the high-voltage battery is connected to the MOS tube, the MOS tube is connected to the MOS tube driving circuit, the high-voltage battery MCU is connected to the MOS tube driving circuit, the CAN is connected to the high-voltage battery MCU, and the high-voltage battery MCU drives and controls the MOS tube through the MOS tube driving circuit. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] The specific embodiments of the present invention are further described in detail below in conjunction with the accompanying drawings, wherein:

[0056] Figure 1 A flowchart of the high voltage power-on process of the control method described in Example 1;

[0057] Figure 2 This is a flow chart of the high voltage self-test of the control method described in Example 1;

[0058] Figure 3 This is a flow chart of the high voltage power-down process of the control method described in Example 1;

[0059] Figure 4 is a schematic diagram of the control device described in Example 2;

[0060] Figure 5This is a schematic diagram of the internal connections of the high-voltage battery of the control device described in Example 2. DETAILED DESCRIPTION

[0061] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0062] Example 1

[0063] The present invention discloses a high voltage power-on and power-off control method, including a high voltage power-on process and a high voltage power-off process; wherein, Figure 1 ,The high voltage power-on process includes the following steps;

[0064] S1, the low voltage area of ​​the motor controller is powered on normally.

[0065] S2, initialize the motor controller low voltage area.

[0066] S3. Perform self-test of the motor controller low voltage area.

[0067] S4. The motor controller passes the low-voltage area self-test, and the motor controller establishes CAN communication with the high-voltage battery.

[0068] S5. Perform a high-voltage battery self-test.

[0069] S6. The high-voltage battery self-test passes, and the high-voltage battery pre-charging and motor controller high-voltage self-test are performed.

[0070] S7. The motor controller high voltage self-test passes and high voltage power-on is completed.

[0071] In the above embodiment, in step S3, when the low-voltage area self-test of the motor controller fails, the following steps are performed:

[0072] The motor controller takes corresponding measures according to the fault conditions that fail the self-test.

[0073] Specifically, step S4 includes the following steps:

[0074] When the motor controller passes the low voltage area self-test, the motor controller detects the key switch signal.

[0075] When the key switch signal is detected to be on, the motor controller sends a CAN message to the high-voltage battery.

[0076] The high-voltage battery receives the CAN message sent by the motor controller and establishes CAN communication with the motor controller.

[0077] The motor controller confirms the high-voltage battery connection status and high-voltage battery version number through CAN messages.

[0078] In the above embodiment, in step S5, when the high-voltage battery self-test fails, the following steps are performed;

[0079] End the high voltage power-on process.

[0080] Specifically, step S6 includes the following steps:

[0081] The high-voltage battery self-test passes and the high-voltage battery is pre-charged.

[0082] After the high-voltage battery is pre-charged, it starts discharging and sends a CAN message to the motor controller to start discharging.

[0083] The motor controller receives the CAN message for starting discharge and performs a high-voltage self-test.

[0084] In the above embodiment, if Figure 2 , the motor controller receives the CAN message for starting discharge and performs a high voltage self-test, including the following steps:

[0085] The motor controller receives the CAN message that the high-voltage battery starts discharging and performs leakage detection.

[0086] Collect the current vehicle speed and the reverse electromotive force of A / B / C, and determine whether the collected vehicle speed is less than or equal to the set value.

[0087] When the collected vehicle speed is less than or equal to the set value, determine whether the A / B / C back electromotive force is less than or equal to the bus voltage / 2, otherwise measure the average value of the A / B / C back electromotive force.

[0088] Determine whether the mean difference of the back EMF of A / B / C is greater than K*speed.

[0089] When the average difference of the back electromotive force of A / B / C is less than K*speed, it is considered that H-FET short circuit / L-FET short circuit / phase line break fault occurs, and PWM output is prohibited.

[0090] When the A / B / C back electromotive force is less than or equal to the bus voltage / 2, it is determined whether the A / B / C back electromotive force is greater than 2V. Otherwise, it is considered that the A / B / C phase H-FET is short-circuited and PWM output is prohibited.

[0091] When the A / B / C phase back electromotive force is greater than 2V, the A / B / C phase L-FET is turned on in sequence. Otherwise, the A / B / C phase L-FET is considered to be short-circuited and the PWM output is prohibited.

[0092] Determine whether the back electromotive force of A / B / C is less than or equal to 2V.

[0093] When the A / B / C phase back electromotive force is less than or equal to 2V, the A / B / C phase H-FET is turned on in sequence, otherwise the A / B / C phase L-FET is considered to be open-circuit fault and PWM output is prohibited.

[0094] Determine whether the A / B / C back electromotive force is greater than the bus voltage / 2.

[0095] When the A / B / C phase back electromotive force is greater than the bus voltage / 2, determine whether the A / B phase back electromotive force is greater than the bus voltage / 2 during the C phase opening process. Otherwise, it is considered that the A / B / C phase H-FET is open-circuit fault and PWM output is prohibited.

[0096] When the A / B back electromotive force is greater than the bus voltage / 2, the PWM output is restarted. Otherwise, it is considered that A / B / C is a phase failure and the PWM output is prohibited.

[0097] In the above embodiment, the A / B / C back electromotive force mean difference is calculated based on the measured average value of the A / B / C back electromotive force; the A / B / C phases are the three phases of the motor controller, the bus voltage is the positive electrode voltage of the high-voltage battery, and K is the coefficient.

[0098] In the above embodiment, after the motor controller receives the CAN message for starting to discharge and performs a high voltage self-test, the following steps are also included:

[0099] When the motor controller high voltage self-test fails, it is determined whether the high voltage battery needs to stop discharging based on the fault conditions found in the self-test.

[0100] When the high-voltage battery needs to stop discharging, the motor controller sends a stop-discharging CAN message to the high-voltage battery.

[0101] The high-voltage battery receives the stop-discharge CAN message and stops discharging.

[0102] High voltage power-up is completed.

[0103] Specifically, Figure 3 , the high voltage power-down process includes:

[0104] The motor controller detects the key switch signal.

[0105] When the key switch signal is detected to be off, the motor controller sends a discharge stop CAN message to the high-voltage battery and starts timing.

[0106] The high-voltage battery stops discharging after receiving the discharge stop CAN message, and feeds back the discharge stop completion CAN message to the motor controller.

[0107] The motor controller receives the feedback CAN message indicating that the discharge stops and is completed, and the motor controller disables the low-voltage power supply and enters a sleep state.

[0108] Specifically, the high voltage power-off process also includes:

[0109] If the motor controller times out and does not receive the CAN message indicating that the discharge stop is complete, the motor controller will lose the low-voltage power supply and enter the sleep state.

[0110] The present invention first performs a self-check of the low-voltage area of ​​the motor controller to detect whether there is a fault in the low-voltage area connecting components. After the self-check of the low-voltage area of ​​the motor controller passes, the next step is performed, and a self-check of the high-voltage area is performed to ensure that the whole vehicle is powered on with high voltage electricity when power-on is allowed, thereby improving vehicle safety.

[0111] The timing of high-voltage power on and off is controllable, and a self-check of the high-voltage area of ​​the motor controller is performed when the high voltage is powered on. When the self-check of the high-voltage area of ​​the motor controller fails, it can be determined whether the high-voltage battery needs to stop discharging based on the fault condition found in the self-check, or corresponding processing can be performed based on the fault condition, thereby reducing the possibility of danger to the vehicle and improving vehicle safety.

[0112] Example 2

[0113] like Figure 4 The present invention discloses a high-voltage power up and down control device, which is used to implement the control method described in Example 1. The control device includes a high-voltage battery and a motor controller. The motor controller is divided into a high-voltage area and a low-voltage area. The positive and negative electrodes of the high-voltage area of ​​the motor controller are respectively connected to the positive and negative electrodes of the high-voltage battery through two high-voltage wires. The motor controller and the high-voltage battery are communicated through CAN communication.

[0114] The low voltage area of ​​the motor controller is connected to the lead-acid battery, and the input end of the motor controller is connected to the key switch signal circuit.

[0115] Specifically, Figure 5 The negative pole of the high-voltage battery is connected to two MOS tubes, the two MOS tubes are connected to the MOS tube drive circuit, the high-voltage battery MCU is connected to the MOS tube drive circuit, the CAN is connected to the high-voltage battery MCU, and the high-voltage battery MCU drives and controls the two MOS tubes through the MOS tube drive circuit. When the high-voltage battery receives the CAN message sent by the motor controller to start discharging, the high-voltage battery MCU controls the MOS tube drive circuit to control the two MOS tubes to close, so that the high-voltage battery enters the discharge state.

[0116] The present invention realizes power on and off of the entire device by controlling the closing and opening of the MOS tube, and uses the MOS tube to replace the traditional relay switch. There is no need to use relays to power on and off the high voltage, which avoids the vehicle being unable to power on and off due to relay problems, improves the safety and reliability of the vehicle, and increases the life of the control device.

[0117] In addition, since the present invention adopts the CAN control mode to replace the traditional hard-wire control mode, the use of wiring harnesses is reduced and the cost is reduced.

[0118] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Therefore, any modification, equivalent change and modification made to the above embodiment based on the technical essence of the present invention without departing from the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A high voltage power on and off control method, characterized in that: It includes a high voltage power-on process and a high voltage power-off process; wherein, the high voltage power-on process includes the following steps: Perform a self-test of the motor controller's low voltage area; The motor controller passes the low-voltage area self-test, and the motor controller establishes CAN communication with the high-voltage battery; Perform high voltage battery self-test; After the high-voltage battery self-test passes, the high-voltage battery pre-charge and motor controller high-voltage self-test are performed; The motor controller high voltage self-test passed and high voltage power-on was completed; The steps of the high-voltage battery self-testing are as follows: The high-voltage battery self-test passes, and the high-voltage battery is pre-charged; After pre-charging is completed, discharge begins and a CAN message to start discharge is sent to the motor controller; The motor controller receives the CAN message for starting discharge and performs a high-voltage self-test; The step of the motor controller receiving the CAN message for starting discharge and performing a high voltage self-test includes the following steps: The motor controller receives the CAN message that the high-voltage battery starts discharging and performs leakage detection; Collect the current vehicle speed and the reverse electromotive force of A / B / C, and determine whether the collected vehicle speed is less than or equal to the set value; When the collected vehicle speed is less than or equal to the set value, determine whether the A / B / C back electromotive force is less than or equal to the bus voltage / 2, otherwise measure the average value of the A / B / C back electromotive force; Determine whether the difference in the mean values ​​of the back electromotive force of A / B / C is greater than K*speed; When the average difference of the back electromotive force of A / B / C is less than K*speed, it is an H-FET short circuit / L-FET short circuit / phase line disconnection fault, and PWM output is prohibited; When the A / B / C back electromotive force is less than or equal to the bus voltage / 2, determine whether the A / B / C back electromotive force is greater than 2V, otherwise it is an A / B / C phase H-FET short circuit fault, and PWM output is prohibited; When the A / B / C phase back electromotive force is greater than 2V, the A / B / C phase L-FET is turned on in sequence, otherwise the A / B / C phase L-FET is short-circuited and PWM output is prohibited; Determine whether the back electromotive force of A / B / C is less than or equal to 2V; When the A / B / C phase back electromotive force is less than or equal to 2V, the A / B / C phase H-FET is turned on in sequence, otherwise the A / B / C phase L-FET is open circuit fault and PWM output is prohibited; Determine whether the A / B / C back electromotive force is greater than the bus voltage / 2; When the A / B / C phase back electromotive force is greater than the bus voltage / 2, determine whether the A / B phase back electromotive force is greater than the bus voltage / 2 during the C phase opening process. Otherwise, it is an A / B / C phase H-FET open circuit fault, and PWM output is prohibited; When the A / B back electromotive force is greater than the bus voltage / 2, the PWM output is restarted, otherwise it is an A / B / C phase loss fault and the PWM output is prohibited. The A / B / C phases are the three phases of the motor controller, the bus voltage is the positive voltage of the high-voltage battery, and K is the coefficient.

2. The control method according to claim 1, characterized in that: The steps include the following steps before the motor controller low voltage area self-test is performed: The low-voltage area of ​​the motor controller is powered on normally; Initialize the motor controller low voltage area.

3. The control method according to claim 1, characterized in that: The step of the motor controller low voltage area self-testing passes, and the motor controller establishes CAN communication with the high voltage battery, includes the following steps: When the motor controller passes the low-voltage area self-test, the motor controller detects the key switch signal; When the key switch signal is detected to be on, the motor controller sends a CAN message to the high-voltage battery; The high-voltage battery receives the CAN message sent by the motor controller and establishes CAN communication with the motor controller; The motor controller confirms the high-voltage battery connection status and high-voltage battery version number through CAN messages.

4. The control method according to claim 1, characterized in that: After the motor controller receives the CAN message for starting to discharge and performs a high-voltage self-test, the steps further include: When the motor controller high voltage self-test fails, determine whether the fault condition found in the self-test requires the high voltage battery to stop discharging; When the high-voltage battery needs to stop discharging, the motor controller sends a stop-discharging CAN message to the high-voltage battery; The high-voltage battery receives the stop-discharge CAN message and stops discharging; High voltage power-up is completed.

5. The control method according to claim 1, characterized in that: The high voltage power-off process includes: The motor controller detects the key switch signal; When the key switch signal is detected to be off, the motor controller sends a discharge stop CAN message to the high-voltage battery and starts timing; The high-voltage battery receives the discharge stop CAN message and stops discharging, and feeds back the discharge stop completion CAN message to the motor controller; The motor controller receives the feedback CAN message indicating that the discharge stops and is completed, and the motor controller disables the low-voltage power supply and enters a sleep state.

6. The control method according to claim 5, characterized in that: The high voltage power-off process also includes: If the motor controller times out and does not receive the CAN message indicating that the discharge stop is complete, the motor controller will lose the low-voltage power supply and enter the sleep state.

7. A high voltage power on and off control device, characterized in that: A control method for implementing any one of claims 1 to 6, comprising: High voltage battery; The motor controller is divided into a high-voltage area and a low-voltage area. The positive and negative electrodes of the high-voltage area of ​​the motor controller are respectively connected to the positive and negative electrodes of the high-voltage battery through two high-voltage wires. The motor controller and the high-voltage battery are connected through CAN communication. The low voltage area of ​​the motor controller is connected to the lead-acid battery; The input end of the motor controller is connected to the key switch signal circuit.

8. The control device according to claim 7, characterized in that: The negative electrode in the high-voltage battery is connected to the MOS tube, the MOS tube is connected to the MOS tube driving circuit, the high-voltage battery MCU is connected to the MOS tube driving circuit, the CAN is connected to the high-voltage battery MCU, and the high-voltage battery MCU drives and controls the MOS tube through the MOS tube driving circuit.

Images