CN117227483A

CN117227483A - Control method and device for pure electric vehicle, pure electric vehicle and storage medium

Info

Publication number: CN117227483A
Application number: CN202311517655.1A
Authority: CN
Inventors: 钟国翔; 陈广辉; 刘敏通
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2023-11-15
Filing date: 2023-11-15
Publication date: 2023-12-15
Anticipated expiration: 2043-11-15
Also published as: CN117227483B

Abstract

The invention belongs to the technical field of pure electric vehicles, and provides a control method and device of a pure electric vehicle, the pure electric vehicle and a storage medium, wherein the method comprises the following steps: the PDU is used for carrying out undervoltage detection on a high-voltage battery, carrying out adhesion detection before powering on each relay, carrying out pre-charging overtime detection on a pre-charging relay, carrying out closing abnormality detection on a main relay and carrying out closing abnormality detection on each auxiliary relay, so that the high-voltage power-on control of a relay module is realized; according to the bus voltage of the high-voltage battery, the PDU is enabled to carry out power failure detection on the high-voltage battery; after the relay module is electrified under high voltage, under the condition that the high-voltage battery is not powered down, the PDU is enabled to carry out power-down timeout detection on the main relay and power-down timeout detection on each auxiliary relay, and high-voltage power-down control on the relay module is achieved. According to the scheme, the PDU self-checking and the whole vehicle high-voltage power-on and power-off management functions in the all-in-one controller are optimized, and the reliability and safety of the whole vehicle high-voltage management are enhanced.

Description

Control method and device for pure electric vehicle, pure electric vehicle and storage medium

Technical Field

The invention belongs to the technical field of pure electric vehicles, and particularly relates to a control method and device of a pure electric vehicle, the pure electric vehicle and a storage medium, in particular to a high-voltage power distribution power on-off control method and device of a PDU (power distribution unit) in an all-in-one controller of the pure electric vehicle, the pure electric vehicle and the storage medium.

Background

With the increasing popularity of new energy electric vehicles (such as pure electric vehicles), products of pure electric vehicles are also being continuously upgraded and improved. Commercial buses and passenger cars in industry gradually push out all-in-one controller products integrating various control units such as a complete Vehicle Controller (VCU), a Motor Controller (MCU), an oil pump controller, an air pump controller, a high-voltage direct current to low-voltage direct current (DC-DC) controller, a high-voltage power distribution unit (Power Distribution Unit, PDU) and the like, and have been commonly known in industry development.

PDU in the all-in-one controller, namely the high-voltage distribution unit of the whole vehicle, which performs power-on and power-off control and management on the high voltage of the whole vehicle according to the control instruction of the whole vehicle controller, namely VCU; the reliability and the safety of the PDU in the all-in-one controller directly influence the safe operation of the whole vehicle. In the related scheme, protection measures of each relay are not considered in combination with practical application in the control logic of the PDU in the all-in-one controller, so that the reliability and safety of the whole vehicle high-voltage management are affected.

The foregoing is provided merely for the purpose of facilitating understanding of the technical solutions of the present invention and is not intended to represent an admission that the foregoing is prior art.

Disclosure of Invention

The invention aims to provide a control method and device for a pure electric vehicle, the pure electric vehicle and a storage medium, so as to solve the problems that the reliability and safety of the whole vehicle high-voltage management are affected by not considering the protection measures of each relay in combination with practical application in the control logic of a PDU in an all-in-one controller of the pure electric vehicle in a related scheme, and achieve the effect of enhancing the reliability and safety of the whole vehicle high-voltage management by optimizing the functions of PDU self-checking and whole vehicle high-voltage power-on and power-off management in the all-in-one controller.

The invention provides a control method of a pure electric vehicle, which comprises a high-voltage battery, an all-in-one controller and a relay module; the all-in-one controller comprises: MCU, VCU and PDU; the relay module includes: a main relay and an auxiliary relay; in the case that the power supply circuit of the pure electric vehicle has a pre-charging circuit, the relay module further includes: pre-charging a relay; the number of the auxiliary relays is more than one; the control method of the pure electric vehicle comprises the following steps: powering up and initializing the PDU at low voltage; obtaining the bus voltage of the high-voltage battery; the voltage of each relay in the relay module is obtained; according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, and in combination with a closing instruction sent by the VCU, the PDU performs under-voltage detection on the high-voltage battery, adhesion detection before power-on of each relay in the relay module, pre-charge timeout detection on the pre-charge relay, closing abnormality detection on the main relay and closing abnormality detection on each auxiliary relay according to set time sequence control logic, so that high-voltage power-on control on the relay module is realized; after the relay module is electrified at high voltage, according to the bus voltage of the high-voltage battery, the PDU is used for detecting the power failure of the high-voltage battery so as to realize the power supply control of the high-voltage battery; after the relay module is electrified under high voltage, under the condition that the high-voltage battery is not powered down, according to a disconnection instruction sent by the VCU, and in combination with the voltage of each relay in the relay module, the PDU is used for detecting the power-down timeout of each relay in the relay module so as to realize the high-voltage power-down control of the relay module; after the high voltage of the relay module is powered down, the PDU is powered down at a low voltage.

In some embodiments, the positive electrode of the high-voltage battery is connected to the first connection end of the normally open contact of the main relay, the first connection end of the normally open contact of the pre-charging relay, and the first connection end of the normally open contact of each of the one or more auxiliary relays, respectively; the second connecting end of the normally open contact of the main relay is connected with the MCU, and the second connecting end of the normally open contact of the pre-charging relay is connected with the second connecting end of the normally open contact of the main relay; the second connecting end of the normally open contact of each auxiliary relay is connected with a corresponding auxiliary electric device of the pure electric vehicle; obtaining the voltage of each relay in the relay module comprises the following steps: and acquiring the voltage of the second connection end of each relay in the relay module.

In some embodiments, according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, and in combination with a closing instruction sent by the VCU, the PDU performs under-voltage detection on the high-voltage battery, adhesion detection before powering on each relay in the relay module, precharge timeout detection on the precharge relay, closing anomaly detection on the main relay, and closing anomaly detection on each auxiliary relay according to a set sequential control logic, so as to implement high-voltage power-on control on the relay module, including: according to the bus voltage of the high-voltage battery, the PDU is enabled to carry out undervoltage detection on the bus voltage of the high-voltage battery; after the PDU performs undervoltage detection on the bus voltage of the high-voltage battery, if the bus voltage of the high-voltage battery is determined not to be undervoltage, the PDU performs adhesion detection before powering up each relay in the relay module according to the voltage of each relay in the relay module; after the PDU performs adhesion detection before powering on each relay in the relay module, if the power supply circuit of the pure electric vehicle is determined to have a pre-charging circuit and the pre-charging relay is not adhered, the PDU performs pre-charging timeout detection on the pre-charging relay according to a closing instruction sent by the VCU and the voltage of the pre-charging relay; after the PDU carries out the detection of the pre-charge overtime, if the pre-charge of the pre-charge relay is determined not to be overtime, the PDU carries out the detection of the abnormal closing of the main relay according to the closing instruction sent by the VCU and the voltage of the main relay; after the PDU detects adhesion before power-on of each relay in the relay module, if the power supply circuit of the pure electric vehicle is determined to have no pre-charging circuit and the main relay is not adhered, the PDU detects abnormal closing of the main relay according to a closing instruction sent by the VCU and the voltage of the main relay; after the PDU detects adhesion before power-on of each relay in the relay module, if the corresponding auxiliary relay is determined to be normally closed, the PDU detects abnormal closing of the corresponding auxiliary relay according to the closing instruction sent by the VCU according to the voltage of the corresponding auxiliary relay.

In some embodiments, the step of causing the PDU to perform undervoltage detection on the bus voltage of the high voltage battery according to the bus voltage of the high voltage battery includes: determining whether the bus voltage of the high-voltage battery is larger than a preset first undervoltage threshold value within a first set time; if yes, determining that the bus voltage of the high-voltage battery is not under-voltage; if the input voltage is not met, determining that the bus voltage of the high-voltage battery is under-voltage, and initiating a reminding message that the input under-voltage fault exists in the bus voltage of the high-voltage battery so as to inhibit subsequent high-voltage power-on; and/or, according to the voltage of each relay in the relay module, making the PDU perform adhesion detection before powering on each relay in the relay module, including: determining, for a voltage of each relay in the relay module, whether the voltage of the relay is equal to a bus voltage of the high voltage battery; if the voltage of the relay is equal to the bus voltage of the high-voltage battery, determining that the relay has a adhesion fault before power-on, and initiating a reminding message of the adhesion fault before power-on of the relay so as to inhibit subsequent high-voltage power-on; and if the voltage of the relay is determined to be unequal to the bus voltage of the high-voltage battery, determining that the relay has no adhesion fault before power-on.

In some embodiments, the detecting the precharge timeout of the precharge relay by the PDU according to the closing command sent by the VCU and the voltage of the precharge relay includes: if the PDU is determined to receive a closing instruction for closing the pre-charging relay sent by the VCU, the PDU is enabled to control the pre-charging relay to be closed; after the PDU controls the pre-charging relay to be closed, determining whether the voltage of the pre-charging relay is larger than a preset first high-voltage threshold value within a second set time; if yes, determining that the pre-charging relay is normal in pre-charging; if the pre-charging time-out fault is not met, determining that the pre-charging time-out of the pre-charging relay exists, and initiating a reminding message of the pre-charging time-out fault of the pre-charging relay so as to inhibit subsequent high-voltage power-on; and/or, according to the closing instruction sent by the VCU and the voltage of the main relay, the PDU detects the abnormal closing of the main relay, including: if the PDU is determined to receive a closing instruction for closing the main relay sent by the VCU, the PDU is enabled to control the main relay to be closed and the pre-charging relay to be opened; after the PDU controls the main relay to be closed, determining whether the voltage of the main relay is greater than a preset second high-voltage threshold; if the voltage of the main relay is determined to be larger than a preset second high-voltage threshold value, determining that the main relay is normally closed; if the voltage of the main relay is not larger than a preset second high-voltage threshold value, determining that the main relay is abnormal in closing, and initiating a reminding message of the main relay with abnormal closing faults so as to inhibit subsequent high-voltage power-on; and/or according to the voltage of the corresponding auxiliary relay, making the PDU perform abnormal closing detection on the corresponding auxiliary relay according to the closing instruction sent by the VCU, including: if the PDU is determined to receive a closing instruction for closing the corresponding auxiliary relay sent by the VCU, the PDU is enabled to control the corresponding auxiliary relay to be closed and the pre-charging relay to be opened; after the PDU controls the corresponding auxiliary relay to be closed, determining whether the voltage of the corresponding auxiliary relay is larger than a preset third high-voltage threshold value; if the voltage of the corresponding auxiliary relay is determined to be larger than a preset third high-voltage threshold value, determining that the corresponding auxiliary relay is normally closed; if the voltage of the corresponding auxiliary relay is not larger than the preset third high-voltage threshold value, determining that the corresponding auxiliary relay is abnormal in closing, and initiating a reminding message of abnormal closing faults of the corresponding auxiliary relay so as to inhibit subsequent high-voltage power-on.

In some embodiments, according to the bus voltage of the high-voltage battery, the PDU performs power failure detection on the high-voltage battery to realize power supply control on the high-voltage battery, including: determining whether the bus voltage of the high-voltage battery is smaller than a preset second undervoltage threshold value; if the bus voltage of the high-voltage battery is determined to be smaller than a preset second undervoltage threshold value, determining that the bus voltage of the high-voltage battery is input under-voltage, and initiating a reminding message of input under-voltage faults of the bus voltage of the high-voltage battery to prohibit subsequent high-voltage on-voltage; and if the bus voltage of the high-voltage battery is not smaller than the preset second undervoltage threshold value, determining that the bus voltage of the high-voltage battery is normally input.

In some embodiments, according to the disconnection instruction sent by the VCU and in combination with the voltage of each relay in the relay module, the PDU performs power-down timeout detection on each relay in the relay module, so as to implement high-voltage power-down control on the relay module, including: for each relay in the relay module, if the PDU is determined to receive a disconnection instruction for disconnecting the relay sent by the VCU, the PDU is enabled to control the relay to be disconnected; after the PDU controls the relay to be disconnected, determining whether the voltage of the relay is smaller than a preset voltage threshold value within a third set time; if yes, determining that the relay is complete in high-voltage down-charging; if the relay is not satisfied, determining that the relay is stuck in a high-voltage overtime state, and initiating a reminding message of the relay with the fault of the relay in the high-voltage overtime state so as to inhibit the follow-up high-voltage power-up.

In the control device of the pure electric vehicle, the pure electric vehicle is provided with a high-voltage battery, an all-in-one controller and a relay module; the all-in-one controller comprises: MCU, VCU and PDU; the relay module includes: a main relay and an auxiliary relay; in the case that the power supply circuit of the pure electric vehicle has a pre-charging circuit, the relay module further includes: pre-charging a relay; the number of the auxiliary relays is more than one; the control device of the pure electric vehicle comprises: a control unit configured to power up and initialize the PDU at a low voltage; an acquisition unit configured to acquire a bus voltage of the high-voltage battery; the voltage of each relay in the relay module is obtained; the control unit is further configured to control logic according to a set time sequence by combining the voltage of the bus of the high-voltage battery and the voltage of each relay in the relay module and a closing instruction sent by the VCU, so that the PDU performs undervoltage detection on the high-voltage battery, adhesion detection before power-on of each relay in the relay module, pre-charge timeout detection on the pre-charge relay, closing anomaly detection on the main relay and closing anomaly detection on each auxiliary relay to realize high-voltage power-on control on the relay module; the control unit is further configured to enable the PDU to perform power-down detection on the high-voltage battery according to the bus voltage of the high-voltage battery after the relay module is powered on at high voltage so as to realize power supply control on the high-voltage battery; the control unit is further configured to, after the relay module is powered up at high voltage, enable the PDU to perform power-down timeout detection on each relay in the relay module according to a disconnection instruction sent by the VCU and combined with the voltage of each relay in the relay module under the condition that the high-voltage battery is not powered down, so as to realize high-voltage power-down control on the relay module; the control unit is further configured to low-voltage the PDU after the high-voltage of the relay module.

In some embodiments, the positive electrode of the high-voltage battery is connected to the first connection end of the normally open contact of the main relay, the first connection end of the normally open contact of the pre-charging relay, and the first connection end of the normally open contact of each of the one or more auxiliary relays, respectively; the second connecting end of the normally open contact of the main relay is connected with the MCU, and the second connecting end of the normally open contact of the pre-charging relay is connected with the second connecting end of the normally open contact of the main relay; the second connecting end of the normally open contact of each auxiliary relay is connected with a corresponding auxiliary electric device of the pure electric vehicle; the acquisition unit acquires the voltage of each relay in the relay module, including: and acquiring the voltage of the second connection end of each relay in the relay module.

In some embodiments, the control unit, according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, in combination with a closing instruction sent by the VCU, makes the PDU perform undervoltage detection on the high-voltage battery, perform adhesion detection before powering up each relay in the relay module, perform precharge timeout detection on the precharge relay, perform closing anomaly detection on the main relay, and perform closing anomaly detection on each auxiliary relay according to a set timing control logic, so as to implement high-voltage power-on control on the relay module, and includes: according to the bus voltage of the high-voltage battery, the PDU is enabled to carry out undervoltage detection on the bus voltage of the high-voltage battery; after the PDU performs undervoltage detection on the bus voltage of the high-voltage battery, if the bus voltage of the high-voltage battery is determined not to be undervoltage, the PDU performs adhesion detection before powering up each relay in the relay module according to the voltage of each relay in the relay module; after the PDU performs adhesion detection before powering on each relay in the relay module, if the power supply circuit of the pure electric vehicle is determined to have a pre-charging circuit and the pre-charging relay is not adhered, the PDU performs pre-charging timeout detection on the pre-charging relay according to a closing instruction sent by the VCU and the voltage of the pre-charging relay; after the PDU carries out the detection of the pre-charge overtime, if the pre-charge of the pre-charge relay is determined not to be overtime, the PDU carries out the detection of the abnormal closing of the main relay according to the closing instruction sent by the VCU and the voltage of the main relay; after the PDU detects adhesion before power-on of each relay in the relay module, if the power supply circuit of the pure electric vehicle is determined to have no pre-charging circuit and the main relay is not adhered, the PDU detects abnormal closing of the main relay according to a closing instruction sent by the VCU and the voltage of the main relay; after the PDU detects adhesion before power-on of each relay in the relay module, if the corresponding auxiliary relay is determined to be normally closed, the PDU detects abnormal closing of the corresponding auxiliary relay according to the closing instruction sent by the VCU according to the voltage of the corresponding auxiliary relay.

In some embodiments, the control unit, according to the bus voltage of the high-voltage battery, makes the PDU perform undervoltage detection on the bus voltage of the high-voltage battery, including: determining whether the bus voltage of the high-voltage battery is larger than a preset first undervoltage threshold value within a first set time; if yes, determining that the bus voltage of the high-voltage battery is not under-voltage; if the input voltage is not met, determining that the bus voltage of the high-voltage battery is under-voltage, and initiating a reminding message that the input under-voltage fault exists in the bus voltage of the high-voltage battery so as to inhibit subsequent high-voltage power-on; and/or, the control unit, according to the voltage of each relay in the relay module, makes the PDU perform adhesion detection before powering on to each relay in the relay module, including: determining, for a voltage of each relay in the relay module, whether the voltage of the relay is equal to a bus voltage of the high voltage battery; if the voltage of the relay is equal to the bus voltage of the high-voltage battery, determining that the relay has a adhesion fault before power-on, and initiating a reminding message of the adhesion fault before power-on of the relay so as to inhibit subsequent high-voltage power-on; and if the voltage of the relay is determined to be unequal to the bus voltage of the high-voltage battery, determining that the relay has no adhesion fault before power-on.

In some embodiments, the control unit, according to a closing instruction sent by the VCU and a voltage of the precharge relay, makes the PDU perform precharge timeout detection on the precharge relay, including: if the PDU is determined to receive a closing instruction for closing the pre-charging relay sent by the VCU, the PDU is enabled to control the pre-charging relay to be closed; after the PDU controls the pre-charging relay to be closed, determining whether the voltage of the pre-charging relay is larger than a preset first high-voltage threshold value within a second set time; if yes, determining that the pre-charging relay is normal in pre-charging; if the pre-charging time-out fault is not met, determining that the pre-charging time-out of the pre-charging relay exists, and initiating a reminding message of the pre-charging time-out fault of the pre-charging relay so as to inhibit subsequent high-voltage power-on; and/or, the control unit, according to the closing instruction sent by the VCU and the voltage of the main relay, makes the PDU perform abnormal closing detection on the main relay, including: if the PDU is determined to receive a closing instruction for closing the main relay sent by the VCU, the PDU is enabled to control the main relay to be closed and the pre-charging relay to be opened; after the PDU controls the main relay to be closed, determining whether the voltage of the main relay is greater than a preset second high-voltage threshold; if the voltage of the main relay is determined to be larger than a preset second high-voltage threshold value, determining that the main relay is normally closed; if the voltage of the main relay is not larger than a preset second high-voltage threshold value, determining that the main relay is abnormal in closing, and initiating a reminding message of the main relay with abnormal closing faults so as to inhibit subsequent high-voltage power-on; and/or, the control unit, according to the voltage of the corresponding auxiliary relay, makes the PDU perform abnormal closing detection on the corresponding auxiliary relay according to the closing instruction sent by the VCU, including: if the PDU is determined to receive a closing instruction for closing the corresponding auxiliary relay sent by the VCU, the PDU is enabled to control the corresponding auxiliary relay to be closed and the pre-charging relay to be opened; after the PDU controls the corresponding auxiliary relay to be closed, determining whether the voltage of the corresponding auxiliary relay is larger than a preset third high-voltage threshold value; if the voltage of the corresponding auxiliary relay is determined to be larger than a preset third high-voltage threshold value, determining that the corresponding auxiliary relay is normally closed; if the voltage of the corresponding auxiliary relay is not larger than the preset third high-voltage threshold value, determining that the corresponding auxiliary relay is abnormal in closing, and initiating a reminding message of abnormal closing faults of the corresponding auxiliary relay so as to inhibit subsequent high-voltage power-on.

In some embodiments, the control unit, according to the bus voltage of the high-voltage battery, makes the PDU perform power failure detection on the high-voltage battery to realize power supply control on the high-voltage battery, including: determining whether the bus voltage of the high-voltage battery is smaller than a preset second undervoltage threshold value; if the bus voltage of the high-voltage battery is determined to be smaller than a preset second undervoltage threshold value, determining that the bus voltage of the high-voltage battery is input under-voltage, and initiating a reminding message of input under-voltage faults of the bus voltage of the high-voltage battery to prohibit subsequent high-voltage on-voltage; and if the bus voltage of the high-voltage battery is not smaller than the preset second undervoltage threshold value, determining that the bus voltage of the high-voltage battery is normally input.

In some embodiments, the control unit, according to the disconnection instruction sent by the VCU and in combination with the voltage of each relay in the relay module, makes the PDU perform power-down timeout detection on each relay in the relay module, so as to implement high-voltage power-down control on the relay module, and includes: for each relay in the relay module, if the PDU is determined to receive a disconnection instruction for disconnecting the relay sent by the VCU, the PDU is enabled to control the relay to be disconnected; after the PDU controls the relay to be disconnected, determining whether the voltage of the relay is smaller than a preset voltage threshold value within a third set time; if yes, determining that the relay is complete in high-voltage down-charging; if the relay is not satisfied, determining that the relay is stuck in a high-voltage overtime state, and initiating a reminding message of the relay with the fault of the relay in the high-voltage overtime state so as to inhibit the follow-up high-voltage power-up.

In accordance with another aspect of the present invention, there is provided a pure electric vehicle comprising: the control device of the pure electric automobile.

In accordance with the above method, the present invention further provides a storage medium, where the storage medium includes a stored program, and when the program runs, the device where the storage medium is controlled to execute the above control method for the pure electric vehicle.

Therefore, according to the scheme of the invention, under-voltage detection, adhesion detection of each relay, pre-charge timeout detection and abnormal closing detection of each relay are added under the condition of reasonably controlling the power on and off of the high voltage of the whole vehicle by aiming at the PDU in the all-in-one controller of the pure electric vehicle, so that protection and fault detection of each relay can be effectively carried out while a VCU control instruction is responded, and the functions of PDU self-detection and power on and off management of the high voltage of the whole vehicle in the all-in-one controller are optimized; therefore, the PDU self-checking and the overall vehicle high-voltage power-on and power-off management functions in the all-in-one controller are optimized, and the reliability and safety of overall vehicle high-voltage management are enhanced.

Additional features and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention.

The technical scheme of the invention is further described in detail through the drawings and the embodiments.

Drawings

Fig. 1 is a schematic flow chart of an embodiment of a control method of a pure electric vehicle according to the present invention;

FIG. 2 is a schematic flow chart of an embodiment of the method of the present invention for high voltage power-on control of the relay module;

FIG. 3 is a flow chart of an embodiment of the method of the present invention for the PDU to detect the undervoltage of the bus voltage of the high voltage battery;

FIG. 4 is a flow chart of an embodiment of the method of the present invention for the PDU to detect adhesion before powering up each relay in the relay module;

FIG. 5 is a flow chart of an embodiment of the method of the present invention for the PDU to detect a precharge timeout of the precharge relay;

FIG. 6 is a flow chart of an embodiment of the method of the present invention for detecting the closing abnormality of the main relay by the PDU;

FIG. 7 is a flow chart of an embodiment of the method according to the present invention for detecting abnormal closing of the auxiliary relay by the PDU according to the closing command sent by the VCU;

FIG. 8 is a flow chart of an embodiment of the method of the present invention for detecting power loss of the high voltage battery by the PDU;

FIG. 9 is a flow chart of an embodiment of the method of the present invention for the PDU to detect a power-down timeout for each relay in the relay module;

fig. 10 is a schematic structural diagram of an embodiment of a control device for a pure electric vehicle according to the present invention;

FIG. 11 is a schematic electrical schematic of an all-in-one relay;

fig. 12 is a schematic diagram of an overall flow of PDU power-on and power-off control;

fig. 13 is a schematic flow chart of a PDU control relay.

In the embodiment of the present invention, reference numerals are as follows, in combination with the accompanying drawings:

102-an acquisition unit; 104-a control unit.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to specific embodiments of the present invention and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

In the related scheme, protection measures of each relay are not considered in combination with practical application in the control logic of the PDU in the all-in-one controller of the pure electric vehicle, so that the reliability and safety of the high-voltage management of the whole vehicle are affected. For example: the control logic of the PDU in the all-in-one controller can only control the on and off of each relay according to VCU instructions, and the protection measures of each relay are not considered in combination with practical application, so that the situation that each relay, a fuse in a power supply circuit of the whole vehicle and even a power utilization device at the rear end of the power supply circuit of the whole vehicle are damaged when the abnormality occurs in the process of carrying out power up and down on the high voltage of the whole vehicle, and the reliability and safety of the high voltage management of the whole vehicle are affected.

Therefore, the scheme of the invention provides a control method for the high-voltage power distribution power on and off of a PDU in an all-in-one controller of the pure electric vehicle, and the functions of PDU self-detection and overall vehicle high-voltage power on and off management in the all-in-one controller are optimized to reasonably control the power on and off of the overall vehicle high voltage, so that under-voltage detection, adhesion detection of each relay, precharge timeout detection and abnormal closing detection of each relay are increased, protection and fault detection of each relay can be effectively performed while a VCU control command is responded, and the reliability and safety of overall vehicle high-voltage management are enhanced.

According to an embodiment of the present invention, a control method of a pure electric vehicle is provided, and a flow chart of an embodiment of the method of the present invention is shown in fig. 1. The pure electric automobile is provided with a high-voltage battery, an all-in-one controller and a relay module; the all-in-one controller comprises: MCU, VCU and PDU; the relay module includes: a main relay and an auxiliary relay; in the case that the power supply circuit of the pure electric vehicle has a pre-charging circuit, the relay module further includes: pre-charging a relay; the number of the auxiliary relays is more than one. The positive electrode of the high-voltage battery is respectively connected with the first connecting end of the normally open contact of the main relay, the first connecting end of the normally open contact of the pre-charging relay and the first connecting end of the normally open contact of each auxiliary relay in more than one auxiliary relay; the second connecting end of the normally open contact of the main relay is connected with the MCU, and the second connecting end of the normally open contact of the pre-charging relay is connected with the second connecting end of the normally open contact of the main relay; and the second connecting end of the normally open contact of each auxiliary relay is connected with a corresponding auxiliary electric device of the pure electric vehicle.

Specifically, fig. 11 is a schematic electrical structure of an all-in-one relay, a main relay is shown as a main relay K1 in fig. 11, a pre-charge relay is shown as a pre-charge relay K2 in fig. 11, and one or more auxiliary relays are shown as an air conditioning relay K3, a heating relay K4, etc. in fig. 11. PDU in the all-in-one controller is used as the high-voltage power supply management system of the whole vehicle and is integrated in the all-in-one controller, and the PDU in the all-in-one controller generally controls a Motor Controller (MCU), an oil pump controller, an air pump controller, and a relay of high-voltage components such as an air conditioner, heating, defrosting, quick charging, slow charging and the like. Because the structural components of different high-voltage components are different, capacitive loads exist in part of the electric components, such as an MCU (micro control unit), a controller, an air pump controller and the like (a capacitive device C of the MCU shown in fig. 11), and the capacitive loads are in a conducting state at the moment of high-voltage electrification due to the component properties of the capacitive loads, and the positive and negative of the high-voltage are equivalent to direct short circuits, so that short-circuit high currents are caused, and the controller is damaged. Therefore, for the part of capacitive load high-voltage components, the circuit designs of the precharge resistor (the resistor R shown in fig. 11) and the precharge relay (the precharge relay K2 shown in fig. 11) are generally increased, so that the damage to the components at the moment of high-voltage charging is avoided. The non-capacitive load device can be powered by a main relay control (an air conditioner relay K3 and a heating relay K4 shown in fig. 11).

In the example shown in fig. 11, the high-voltage battery is capable of providing a bus voltage. The battery anode DC+ is connected to a first connection end of the power supply end of the MCU after passing through a normally open contact of the main relay K1; the voltage at the common end of the normally open contact of the main relay K1 and the first connecting end of the power supply end of the MCU is the voltage of the main relay K1; the first connecting end of the power supply end of the MCU is connected to the second connecting end of the power supply end of the MCU after passing through the capacitor C; and the second connecting end of the power supply end of the MCU is connected with the negative electrode DC-of the battery. The pre-charging resistor R is connected in series with a normally open contact of the pre-charging relay K2 and then connected in parallel with a normally open contact of the main relay K1. The battery anode DC+ is connected to a first connection end of a power supply end of the air conditioner after passing through a normally open contact of an air conditioner relay K3; the voltage at the common end of the normally open contact of the air conditioner relay K3 and the first connecting end of the power supply end of the air conditioner is the voltage of the air conditioner relay K3; and the second connecting end of the power supply end of the air conditioner is connected with the negative electrode DC-of the battery. The battery anode DC+ is connected to a first connection end of a power supply end of the heating element after passing through a normally open contact of the heating relay K4; the voltage at the common end of the normally open contact of the heating relay K4 and the first connecting end of the power supply end of the heating element is the voltage of the heating relay K4; the second connection of the supply end of the heating element is DC-connected to the battery cathode.

In the solution of the present invention, as shown in fig. 1, the control method of the pure electric vehicle, specifically, the method for controlling the relay module by using the PDU includes: step S110 to step S160.

At step S110, the PDU is low-voltage powered up and initialized.

At step S120, after the PDU is low-voltage-powered up and initialized, a bus voltage of the high-voltage battery is acquired; and obtaining the voltage of each relay in the relay module, in particular the voltage of the second connecting end of each relay in the relay module.

In some embodiments, obtaining the voltage of each relay in the relay module in step S120 includes: and acquiring the voltage of the second connection end of each relay in the relay module.

At step S130, according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, and in combination with the closing instruction sent by the VCU, the PDU performs under-voltage detection on the high-voltage battery, adhesion detection before powering on each relay in the relay module, precharge timeout detection on the precharge relay, closing anomaly detection on the main relay, and closing anomaly detection on each auxiliary relay according to a set sequential control logic, so as to implement high-voltage power on and off control on the relay module. The closing instruction sent by the VCU refers to a closing instruction for closing a corresponding relay sent by the VCU.

In some embodiments, in step S130, according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, in combination with the closing command sent by the VCU, the PDU performs, according to a set sequential control logic, undervoltage detection on the high-voltage battery, adhesion detection before powering up each relay in the relay module, precharge timeout detection on the precharge relay, closing anomaly detection on the main relay, and closing anomaly detection on each auxiliary relay, so as to implement a specific process of high-voltage power-up control on the relay module, which is described in the following exemplary embodiments.

The following is a schematic flow chart of an embodiment of the method of the present invention for performing high-voltage power-on control on the relay module in connection with fig. 2, which further describes a specific process for performing high-voltage power-on control on the relay module in step S130, including: step S210 to step S250.

And step S210, according to the bus voltage of the high-voltage battery, the PDU is used for carrying out undervoltage detection on the bus voltage of the high-voltage battery.

In some embodiments, step S210 is a specific process of making the PDU perform the undervoltage detection on the bus voltage of the high voltage battery according to the bus voltage of the high voltage battery, which is described in the following exemplary description.

The following is a schematic flow chart of an embodiment of the method of the present invention for making the PDU perform the undervoltage detection on the bus voltage of the high voltage battery in connection with the method of fig. 3, which further describes a specific process for making the PDU perform the undervoltage detection on the bus voltage of the high voltage battery in step S210, including: step S310 to step S330.

Step S310, determining whether the bus voltage of the high-voltage battery is greater than a preset first undervoltage threshold value within a first set time.

Step S320, if yes, determining that the bus voltage of the high-voltage battery is not under-voltage, and allowing subsequent control.

Step S330, if not, determining that the bus voltage of the high-voltage battery is under-voltage, stopping subsequent control, and initiating a reminding message that the input under-voltage fault exists in the bus voltage of the high-voltage battery so as to inhibit subsequent high-voltage power-on.

Fig. 13 is a schematic flow chart of a PDU control relay. As shown in fig. 13, the flow of PDU controlling the relay may be divided into four phases, specifically including: the first stage is detection before high-voltage power-on, and mainly carries out all-in-one bus voltage detection to judge whether all-in-one high-voltage input is normal or not: if the input high voltage is not detected for a long time, reporting an input under-voltage fault.

Step S220, after the PDU performs the under-voltage detection on the bus voltage of the high-voltage battery, if it is determined that the bus voltage of the high-voltage battery is not under-voltage, according to the voltage of each relay in the relay module, the PDU performs the adhesion detection before powering on each relay in the relay module.

In some embodiments, step S220 includes a specific process of enabling the PDU to perform adhesion detection on each relay in the relay module before powering up according to the voltage of each relay in the relay module, which is described in the following exemplary description.

The following is a schematic flow chart of an embodiment of the method of the present invention for enabling the PDU to perform adhesion detection before powering up on each relay in the relay module in connection with the method of fig. 4, which further describes a specific process for enabling the PDU to perform adhesion detection before powering up on each relay in the relay module in step S220, including: step S410 to step S430.

Step S410, for each relay in the relay module, determines whether the voltage of the relay is equal to the bus voltage of the high-voltage battery.

And step S420, if the voltage of the relay is equal to the bus voltage of the high-voltage battery, determining that the relay has a pre-power-on adhesion fault, stopping subsequent control on the relay, and sending a reminding message of the relay having the pre-power-on adhesion fault to prohibit subsequent high-voltage power-on.

And step S430, if the voltage of the relay is determined not to be equal to the bus voltage of the high-voltage battery, determining that the relay has no adhesion fault before power-on, and allowing subsequent control of the relay.

Specifically, as shown in fig. 13, the flow of PDU controlling the relay specifically further includes: in the first stage, if the input high voltage is normal, the voltage of the relay (rear end) is detected before the relay executes the instruction action, and if the voltage of the relay (rear end) is equal to the bus voltage, the relay is judged to be stuck, and a fault is reported.

Step S230, after the PDU performs adhesion detection before powering on each relay in the relay module, if it is determined that the power supply circuit of the pure electric vehicle has a pre-charging circuit and the pre-charging relay is not adhered, the PDU performs pre-charging timeout detection on the pre-charging relay according to a closing instruction sent by the VCU and a voltage of the pre-charging relay; and after the PDU performs the detection of the pre-charge timeout on the pre-charge relay, if the pre-charge of the pre-charge relay is determined not to timeout, the PDU performs the detection of the abnormal closing of the main relay according to the closing instruction sent by the VCU and the voltage of the main relay.

In some embodiments, step S230 refers to a specific process of detecting the precharge timeout of the precharge relay by the PDU according to the closing command sent by the VCU and the voltage of the precharge relay, which is described in the following exemplary description.

The following is a schematic flow chart of an embodiment of the method of the present invention for enabling the PDU to perform the detection of the precharge timeout on the precharge relay in connection with fig. 5, which further describes a specific process for enabling the PDU to perform the detection of the precharge timeout on the precharge relay in step S230, including: step S510 to step S550.

Step S510, if it is determined that the PDU receives the closing instruction for closing the precharge relay sent by the VCU, the PDU is caused to control the precharge relay to be closed.

Step S520, after the PDU controls the pre-charging relay to be closed, determining whether the voltage of the pre-charging relay is greater than a preset first high voltage threshold value within a second set time.

Step S530, if yes, determining that the pre-charging relay is pre-charged normally, and allowing subsequent control to the pre-charging relay.

Step S540, if not, determining that the pre-charging time-out of the pre-charging relay is over, stopping performing subsequent control on the pre-charging relay, and initiating a warning message that the pre-charging relay has a pre-charging time-out fault, so as to inhibit subsequent high-voltage power-up.

Specifically, as shown in fig. 13, the flow of PDU controlling the relay specifically further includes: the second stage is a relay high-voltage power-on stage, and can be divided into two power-on modes of a pre-charging relay K2 and a non-pre-charging relay K2 according to hardware design:

when the pre-charge relay K2 exists, the PDU receives an instruction of the VCU to close the pre-charge relay K2 and then executes a closing action, at the moment, the main relay K1 is not closed, when the voltage of the pre-charge relay K2 does not reach a set high-voltage threshold value for a long time, the pre-charge relay K2 fails to be closed, a pre-charge overtime fault is reported, the situation can infer that the pre-charge relay K2 or the pre-charge resistor R in the pre-charge circuit is possibly damaged, and when the voltage of the pre-charge relay K2 reaches the set high-voltage threshold value, the executing action of the main relay K1 instruction can be executed.

For the power-on mode without the precharge relay K2, the instruction operation of the main relay K1 may be directly executed, the main relay K1 is closed, and the precharge relay K2 is opened.

Step S240, after the PDU performs adhesion detection before powering on each relay in the relay module, if it is determined that the power supply circuit of the pure electric vehicle has no pre-charging circuit and the main relay has no adhesion, the PDU performs abnormal closing detection on the main relay according to a closing instruction sent by the VCU and the voltage of the main relay.

In some embodiments, step S240 refers to a specific process of detecting the abnormal closing of the main relay by the PDU according to the closing command sent by the VCU and the voltage of the main relay, which is described in the following exemplary description.

An embodiment of the method of the present invention for detecting the abnormal closing of the main relay by the PDU in the method of the present invention as shown in fig. 6 is a flowchart, which further describes a specific process for detecting the abnormal closing of the main relay by the PDU in step S240, including: step S610 to step S640.

Step S610, if it is determined that the PDU receives the close command for closing the main relay sent by the VCU, the PDU is caused to control the main relay to be closed and the precharge relay to be opened.

Step S620, after the PDU controls the main relay to be turned on, determining whether the voltage of the main relay is greater than a preset second high voltage threshold.

Step S630, if it is determined that the voltage of the main relay is greater than the preset second high voltage threshold, it is determined that the main relay is normally closed, and subsequent control is allowed for the main relay.

Step S640, if it is determined that the voltage of the main relay is not greater than the preset second high voltage threshold, determining that the main relay is abnormal to be closed, stopping performing subsequent control on the main relay, and initiating a notification message that the main relay has an abnormal closing fault, so as to prohibit subsequent high voltage power-up.

Specifically, as shown in fig. 13, the flow of PDU controlling the relay specifically further includes: in the second stage, after the main relay K1 is closed and the precharge relay K2 is opened, the voltage of the main relay K1 is detected at this time, and if the voltage of the main relay K1 does not reach the set high voltage threshold, it can be inferred that the main relay K1 is powered up abnormally, the main relay K1 may be damaged, and a failure of "the main relay K1 is closed abnormally" is reported.

Step S250, after the PDU performs adhesion detection before powering on each relay in the relay module, if it is determined that the corresponding auxiliary relay is normally closed, according to the voltage of the corresponding auxiliary relay, the PDU performs abnormal closing detection on the corresponding auxiliary relay according to a closing instruction sent by the VCU.

According to the scheme, a set of PDU high-voltage power-on and power-off management control scheme is designed based on the characteristics of the electrical components of each relay, and the control logic functions of power-on self-detection, undervoltage detection, adhesion detection, pre-charge timeout protection, abnormal power-on of each relay and the like are provided, so that damage of each relay can be effectively protected, and meanwhile, real-time fault detection of each relay is increased.

In some embodiments, step S250 refers to a specific process of detecting abnormal closing of the auxiliary relay according to the closing command sent by the VCU by using the PDU according to the voltage of the auxiliary relay, which is described in the following exemplary description.

In the following, referring to fig. 7, a flowchart of an embodiment of the method of the present invention for causing the PDU to perform abnormal closing detection on the corresponding auxiliary relay according to the closing command sent by the VCU is further described, where the specific process for causing the PDU to perform abnormal closing detection on the corresponding auxiliary relay according to the closing command sent by the VCU in step S250 includes: step S710 to step S740.

Step S710, if it is determined that the PDU receives a closing instruction sent by the VCU to close the corresponding auxiliary relay, the PDU is caused to control the corresponding auxiliary relay to close and the precharge relay to open.

Step S720, after the PDU controls the corresponding auxiliary relay to be closed, determining whether the voltage of the corresponding auxiliary relay is greater than a preset third high voltage threshold.

Step S730, if it is determined that the voltage of the corresponding auxiliary relay is greater than the preset third high voltage threshold, it is determined that the corresponding auxiliary relay is normally closed, and subsequent control is allowed for the corresponding auxiliary relay.

And step 740, if the voltage of the corresponding auxiliary relay is not greater than the preset third high-voltage threshold, determining that the corresponding auxiliary relay is abnormal in closing, stopping subsequent control on the corresponding auxiliary relay, and sending a reminding message that the corresponding auxiliary relay has abnormal closing faults so as to inhibit subsequent high-voltage power-on.

The above function detection processes in the high-voltage power-on process of the relay module specifically comprise a function detection process for performing undervoltage detection on the high-voltage battery, a function detection process for performing adhesion detection before power-on each relay in the relay module, a function detection process for performing pre-charge timeout detection on the pre-charge relay, a function detection process for performing closing anomaly detection on the main relay, and a function detection process for performing closing anomaly detection on each auxiliary relay, wherein strict time sequence control logic is provided among the function detection processes, and the functions detection processes specifically comprise the following steps:

control logic for the first timing: before the high-voltage power-on of the relay module is executed, the PDU firstly performs undervoltage detection (namely, performs a function detection process of undervoltage detection on the high-voltage battery) so as to ensure that the subsequent power-on process is performed under the premise of normal high-voltage power supply and under the environment.

Control logic of the second timing: and (3) carrying out power-on adhesion detection (namely executing a functional detection process of adhesion detection before power-on of each relay in the relay module) under the condition that the high-voltage power supply is normal. The power-on adhesion detection is judged according to whether the relay voltage is equal to the bus voltage or not, so that the power-on adhesion detection is carried out on the premise that normal high-voltage power supply is required to be ensured, namely the bus voltage has high-voltage input; if the bus voltage input is 0V, the relay voltage is equal to the bus voltage at the moment, and whether the relay is adhered cannot be judged.

Control logic of the third timing sequence: under the condition that the relay is not adhered through the detection of the electrified adhesion, the control of the high-voltage electrification of the relay is allowed; that is, after the relay is electrified and stuck, the preparation work of the relay for high-voltage electrification is completed. After the preparation work of the high-voltage power-on of the relay is completed, the control of the high-voltage power-on of the relay is allowed. In the control of the high-voltage power-on of the relay, after the PDU performs an instruction to close the precharge relay (i.e., precharge relay K2), it is required to detect whether the voltage of the main relay (i.e., main relay K1) rises to a specified high-voltage threshold value, which is generally set to a value close to the bus voltage, for example, a value at which the voltage of the main relay K1 rises to a bus voltage up to 95% is set, so as to prevent the differential pressure across the main relay K1 at the closing instant of the main relay K1 from being excessively large in the next step, thereby reducing the lifetime of the main relay K1.

Therefore, it is necessary to perform the precharge timeout detection (i.e., perform the function control process of performing the precharge timeout detection on the precharge relay) during the precharge and power-up process of the precharge circuit to determine whether the precharge and power-up is normal, specifically: after the precharge relay K2 executes the closing instruction, in order to prevent the large current generated by the power consumption component at the rear end of the precharge relay K2 during operation, the precharge relay K2 and the precharge resistor R of the precharge circuit are damaged, so that the following is set: if the voltage of the main relay K1 exceeds the preset time and fails to reach the preset high-voltage threshold value in time, the pre-charging overtime fault alarm is carried out, and the pre-charging relay K2 is disconnected in time.

Control logic of the fourth timing sequence: after the precharge timeout detection, if it is determined that the precharge is powered on normally, the closing abnormality detection is performed (i.e., a function control process for performing the closing abnormality detection on the main relay is performed), specifically: after the pre-charge is powered on normally, an instruction of closing the main relay K1 is executed, the pre-charge relay K2 is usually required to be opened again, so that the working circuit is ensured to be the main relay K1, and if the voltage of the main relay K1 drops after the pre-charge relay K2 is opened at the moment, the abnormal closing of the main relay K1 is indicated, and a fault is reported.

Of course, after the closing of the main relay K1 is completed, the corresponding closing abnormality detection (i.e., the function control process of performing the closing abnormality detection for each of the auxiliary relays) is also performed for the closing of the corresponding auxiliary relay.

In the scheme of the invention, the power-on and power-off logic has universality for all relays of the all-in-one high-voltage power distribution unit, and is suitable for power-on and power-off management control of all relays. The method fully considers faults such as under-voltage of bus, up-and-down electric adhesion of the relay, protection of a pre-charging circuit, failure of the relay to close, overtime of power down and the like, has effective protection and fault detection functions on the PDU control relay, and has high practical application value. In the scheme of the invention, the detection of the upper and lower electric adhesion of the relay, the protection of the pre-charging circuit and the two power-on modes including the pre-charging relay and the non-pre-charging relay have universality, and are suitable for the upper and lower electric control logic of all high-voltage relays of the commercial vehicles and passenger vehicles with new energy sources.

In the scheme of the invention, after each function detection process in the high-voltage power-on process of the relay module is executed, further, after the main relay K1 is closed, the high-voltage power-on is determined to be completed, and meanwhile, whether the under-voltage fault exists in the bus voltage is monitored and detected in real time, so that the normal high-voltage power supply of a controller (such as the PDU) is ensured, and the power supply control of the high-voltage battery is realized. See in particular the description of step S140.

At step S140, after the relay module is powered up at high voltage, the PDU is caused to perform power failure detection on the high voltage battery according to the bus voltage of the high voltage battery, so as to implement power supply control on the high voltage battery.

In some embodiments, in step S140, the PDU performs power-down detection on the high-voltage battery according to the bus voltage of the high-voltage battery, so as to implement a specific process of power supply control on the high-voltage battery, which is described in the following exemplary description.

The following is a schematic flow chart of an embodiment of the method of the present invention for enabling the PDU to perform power failure detection on the high voltage battery in connection with the method of fig. 8, which further describes a specific process for enabling the PDU to perform power failure detection on the high voltage battery in step S140, including: step S810 to step S830.

Step S810, determining whether the bus voltage of the high-voltage battery is less than a preset second undervoltage threshold.

Step S820, if it is determined that the bus voltage of the high-voltage battery is less than the preset second undervoltage threshold, determining that the bus voltage of the high-voltage battery is input under-voltage, stopping performing subsequent control, and initiating a warning message that the bus voltage of the high-voltage battery has an input under-voltage fault, so as to prohibit subsequent high-voltage power-up.

Step S830, if it is determined that the bus voltage of the high-voltage battery is not less than the preset second under-voltage threshold, determining that the bus voltage of the high-voltage battery is input normally, and allowing the subsequent control.

Specifically, as shown in fig. 13, the flow of PDU controlling the relay further includes: the third stage is fault monitoring after the high-voltage power-on is completed, mainly monitoring whether the bus voltage is reduced or not in real time, if the bus voltage is smaller than a set undervoltage threshold value, indicating all-in-one input high-voltage undervoltage and reporting an input undervoltage fault.

In the scheme of the invention, after each function detection process in the high-voltage power-on process of the relay module is executed, further, in the power-off process, after the PDU executes the relay disconnection, the relay voltage can be theoretically reduced in time, at the moment, if the relay voltage fails to be reduced to the preset voltage threshold value within the preset time, the adhesion fault of the relay is indicated, the relay cannot be normally disconnected, and the fault is reported in time. The detection function highlights different fault detection from a plurality of different links of the high-voltage power-on process, the power-on completion process and the power-off process, and plays a role in protecting the power utilization safety of the controller and the power utilization components. See in particular the description of step S150 and step S160.

At step S150, after the relay module is powered up at high voltage, under the condition that the high-voltage battery is not powered down, according to the disconnection instruction sent by the VCU, and in combination with the voltage of each relay in the relay module, the PDU performs power-down timeout detection on each relay in the relay module, so as to realize high-voltage power-down control on the relay module. The disconnection instruction sent by the VCU refers to a disconnection instruction sent by the VCU for disconnecting the corresponding relay.

In some embodiments, step S150 is performed according to the turn-off command sent by the VCU, and in combination with the voltage of each relay in the relay module, the PDU performs power-down timeout detection on each relay in the relay module, so as to implement a specific process of high-voltage power-down control on the relay module, which is described in the following exemplary description.

The following is a schematic flow chart of an embodiment of the method of the present invention for enabling the PDU to perform the power-down timeout detection on each relay in the relay module in conjunction with fig. 9, which further describes a specific process for enabling the PDU to perform the power-down timeout detection on each relay in the relay module in step S150, including: step S910 to step S940.

Step S910, for each relay in the relay module, if it is determined that the PDU receives the switching-off instruction for switching off the relay sent by the VCU, the PDU is caused to control the switching-off of the relay.

Step S920, after the PDU controls the relay to be turned off, determining whether the voltage of the relay is less than a preset voltage threshold value within a third set time.

Step S930, if yes, determining that the relay is powered down at high voltage, and allowing subsequent control of the relay.

Step S940, if not, determining that the relay is stuck in a high-voltage overtime state, stopping subsequent control on the relay, and sending a reminding message that the relay is stuck in the high-voltage overtime state to prohibit subsequent high-voltage power-on.

Specifically, as shown in fig. 13, the flow of PDU controlling the relay further includes: the fourth stage is a high voltage down stage, when the VCU off relay command is executed, whether the relay voltage is reduced to a set voltage threshold is monitored (considering that the discharging condition of capacitive load exists in part of the power consumption components, the relay voltage can not be reduced to 0 for a long time at this time, therefore, the voltage threshold can not be set smaller generally), if the relay voltage is not reduced to the voltage threshold within the set time, the relay is judged to have adhesion fault, relay adhesion and power down timeout faults are reported, and if the relay voltage is reduced in time, the high voltage down is completed.

Referring to the examples shown in fig. 11, 12 and 13, the overall flow of PDU power-on and power-off control in the scheme of the present invention includes:

and step 11, firstly detecting high voltage and low voltage before high voltage power-on is executed, judging whether the front end input bus voltage of the all-in-one relay meets a set minimum low voltage threshold value, ensuring that the front end high voltage input to the all-in-one relay is normally supplied, which is a precondition of the follow-up step, and then executing step 12.

Step 12, firstly executing step 11, then detecting the adhesion function of each relay before each relay executes the closing action, judging whether the voltage at the rear end of each relay is equal to the bus voltage, ensuring that each relay has no adhesion fault, and then executing step 13. The two detection steps are preparation work before high-voltage power-on, and the problems of abnormal relay closing and device fault can be effectively avoided through undervoltage detection and adhesion detection.

And step 13, after the steps are finished, for the control of a pre-charging circuit (a pre-charging relay K2 and a pre-charging resistor R), after the pre-charging relay K2 is closed, pre-charging overtime detection is needed to prevent the pre-charging circuit from being damaged by high current generated by the work of a rear-end power utilization component, so that the effect of protecting the pre-charging circuit is achieved, and then step 14 is executed.

Step 14, further, after the main relay K1 is turned on, the voltage of the main relay K1 will be equal to the bus voltage at this time theoretically, if the voltage of the main relay K1 does not rise at this time, it indicates that the main relay K1 is abnormal in turn, and by detecting the voltage of the main relay K1 at this time, it can be determined whether the main relay K1 is abnormal in turn, and then step 15 is performed.

And 15, after the main relay K1 is powered on normally, detecting whether the bus voltage is reduced or not to achieve real-time monitoring of the bus input undervoltage fault, and then executing step 16.

And step 16, after each relay executes the power-down instruction, theoretically, the voltage of each relay can drop at the moment, whether the disconnection of each relay is abnormal or not can be judged by detecting the voltage of each relay, and if the voltage of the corresponding relay does not drop in time, the adhesion fault of the corresponding relay is indicated.

In the scheme of the invention, an input undervoltage detection function is added, and when the input high voltage of the PDU in the all-in-one controller is abnormal or reduced, the PDU in the all-in-one controller can timely detect and report faults; the adhesion detection function of each relay is added, whether the relay end has high voltage is detected before the relay is closed by power-up execution, and whether the voltage of the relay end is reduced is detected after the relay is opened by power-down execution, so that whether the relay has adhesion fault is judged; aiming at the power-on process of the pre-charging relay, the power-on pre-charging overtime detection is added, so that the function of protecting the pre-charging relay is achieved; after the corresponding relay closing instruction is executed, whether the voltage of the corresponding relay terminal follows the bus voltage change is detected, and accordingly whether the relay is damaged can be judged. The method comprises the steps of providing a plurality of functional detection modules, wherein the functional detection modules are provided with strict time sequence control logic, are a set of complete up-down current control method, each functional detection module is required to be completed in a specified power-on process, a cooperative cascade connection relation exists between the front and back processes, the next functional detection module can be accessed only on the premise that the previous functional detection module has no faults, and all detection functions are not simply overlapped, so that the method effectively manages the power-on and power-off of the whole vehicle, has universality for the power-on and power-off of all relays of the whole vehicle, can effectively protect the functions of all relays, increases the adhesion detection in the power-on and power-off processes of all relays, and improves the reliability and safety of the power-on and power-off control of the whole vehicle.

At step S160, after the high voltage down of the relay module, the PDU is powered down low.

Specifically, fig. 12 is a schematic diagram of an overall flow of power-on and power-off control of the PDU. As shown in fig. 12, the overall power-on and power-off flow of PDU power-on and power-off control is low-voltage power-on, and the initialization self-test is performed, after the self-test is completed, the adhesion detection of each power-on relay before high-voltage power-on is performed, then the control operation of closing and opening the relay is performed, and finally the adhesion detection of each power-off relay is performed again by high-voltage power-off, so as to complete the low-voltage power-off.

Aiming at the problems of fault detection and relay abnormal protection mechanisms which are lack in the high-voltage power-on process of the all-in-one relay, the scheme of the invention provides an up-down current control scheme, in particular to a high-voltage power-on-off control scheme of PDU in the all-in-one controller of a pure electric automobile, and the functions of PDU self-detection and whole-automobile high-voltage power-on-off management in the all-in-one controller are optimized to reasonably control the power-on and power-off of the whole automobile high-voltage, and the functions of undervoltage detection, relay adhesion detection, pre-charging timeout detection, relay closing abnormality detection and the like are added to realize the real-time monitoring of the high-voltage power-on-off abnormal faults and the protection of all relays and rear-end power-on components by combining the function detection logic of undervoltage detection, relay adhesion detection, relay overtime detection, relay closing abnormality detection and the like in the power-on-off process; the protection and fault detection of each relay can be effectively performed while the VCU control instruction is matched and responded, and the reliability and safety of the whole vehicle high-voltage management are enhanced. In this way, the scheme of the invention combines different relay application working conditions, increases control logic functions such as undervoltage detection, adhesion detection, pre-charge overtime detection and protection of each relay, abnormal power-on detection of each relay and the like, can effectively protect each relay from damage, increases fault real-time detection of each relay, and improves reliability and safety of high-voltage control of the whole vehicle.

By adopting the technical scheme of the embodiment, under-voltage detection, adhesion detection of each relay, pre-charge timeout detection and abnormal closing detection of each relay are added under the condition of reasonably controlling the power on and off of the high voltage of the whole vehicle by aiming at the PDU in the all-in-one controller of the pure electric vehicle, so that protection and fault detection of each relay can be effectively carried out while a VCU control instruction is responded, and the functions of PDU self-detection and power on and off management of the high voltage of the whole vehicle in the all-in-one controller are optimized; therefore, the PDU self-checking and the overall vehicle high-voltage power-on and power-off management functions in the all-in-one controller are optimized, and the reliability and safety of overall vehicle high-voltage management are enhanced.

According to the embodiment of the invention, a control device of the pure electric vehicle corresponding to the control method of the pure electric vehicle is also provided. Referring to fig. 10, a schematic diagram of an embodiment of the apparatus of the present invention is shown. The pure electric automobile is provided with a high-voltage battery, an all-in-one controller and a relay module; the all-in-one controller comprises: MCU, VCU and PDU; the relay module includes: a main relay and an auxiliary relay; in the case that the power supply circuit of the pure electric vehicle has a pre-charging circuit, the relay module further includes: pre-charging a relay; the number of the auxiliary relays is more than one. The positive electrode of the high-voltage battery is respectively connected with the first connecting end of the normally open contact of the main relay, the first connecting end of the normally open contact of the pre-charging relay and the first connecting end of the normally open contact of each auxiliary relay in more than one auxiliary relay; the second connecting end of the normally open contact of the main relay is connected with the MCU, and the second connecting end of the normally open contact of the pre-charging relay is connected with the second connecting end of the normally open contact of the main relay; and the second connecting end of the normally open contact of each auxiliary relay is connected with a corresponding auxiliary electric device of the pure electric vehicle.

In the solution of the present invention, as shown in fig. 10, the control device of the pure electric vehicle, specifically, the device for controlling the relay module by using the PDU, includes: an acquisition unit 102 and a control unit 104.

Wherein the control unit 104 is configured to power up and initialize the PDU at low voltage. The specific function and process of the control unit 104 refer to step S110.

The acquiring unit 102 is configured to acquire a bus voltage of the high-voltage battery after the PDU is low-voltage powered on and initialized; and obtaining the voltage of each relay in the relay module, in particular the voltage of the second connecting end of each relay in the relay module. The specific function and process of the acquisition unit 102 refer to step S120.

In some embodiments, the acquiring unit 102 acquires a voltage of each relay in the relay module, including: the control unit 104 is in particular further configured to obtain the voltage of the second connection of each relay in the relay module.

The control unit 104 is further configured to, according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, combine the closing instruction sent by the VCU, make the PDU perform undervoltage detection on the high-voltage battery, perform adhesion detection before powering on each relay in the relay module, perform precharge timeout detection on the precharge relay, perform closing anomaly detection on the main relay, and perform closing anomaly detection on each auxiliary relay according to a set sequential control logic, so as to implement high-voltage power on control on the relay module. The specific function and processing of the control unit 104 is also referred to in step S130.

In some embodiments, the control unit 104, according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module and in combination with the closing command sent by the VCU, makes the PDU perform undervoltage detection on the high-voltage battery, adhesion detection before powering up each relay in the relay module, precharge timeout detection on the precharge relay, closing anomaly detection on the main relay, and closing anomaly detection on each auxiliary relay according to a set sequential control logic, so as to implement high-voltage power-on control on the relay module, including:

the control unit 104 is specifically further configured to make the PDU perform under-voltage detection on the bus voltage of the high-voltage battery according to the bus voltage of the high-voltage battery. The specific function and process of the control unit 104 also refer to step S210.

In some embodiments, the control unit 104, according to the bus voltage of the high-voltage battery, causes the PDU to perform undervoltage detection on the bus voltage of the high-voltage battery, including:

the control unit 104 is specifically further configured to determine whether the bus voltage of the high voltage battery is greater than a preset first under-voltage threshold value within a first set time. The specific function and process of the control unit 104 also refer to step S310.

The control unit 104 is specifically further configured to determine that the bus voltage of the high-voltage battery is not under-voltage, if satisfied, and allow subsequent control. The specific function and process of the control unit 104 also refer to step S320.

The control unit 104 is specifically further configured to determine that the bus voltage of the high-voltage battery is under-voltage if the input under-voltage fault is not met, stop performing subsequent control, and initiate a notification message that the input under-voltage fault exists in the bus voltage of the high-voltage battery to prohibit subsequent high-voltage power-up. The specific function and process of the control unit 104 also refer to step S330.

The control unit 104 is specifically further configured to, after the PDU performs the under-voltage detection on the bus voltage of the high-voltage battery, if it is determined that the bus voltage of the high-voltage battery is not under-voltage, make the PDU perform the adhesion detection before powering up each relay in the relay module according to the voltage of each relay in the relay module. The specific function and process of the control unit 104 is also referred to as step S220.

In some embodiments, the control unit 104, according to the voltage of each relay in the relay module, causes the PDU to perform adhesion detection before powering up each relay in the relay module, including:

the control unit 104 is in particular further configured to determine, for the voltage of each relay in the relay module, whether the voltage of that relay is equal to the bus voltage of the high voltage battery. The specific function and process of the control unit 104 also refer to step S410.

The control unit 104 is specifically further configured to determine that the relay has a pre-power-on adhesion fault if it is determined that the voltage of the relay is equal to the bus voltage of the high-voltage battery, stop performing subsequent control on the relay, and send a notification message that the relay has the pre-power-on adhesion fault to prohibit subsequent high-voltage power-on. The specific function and process of the control unit 104 also refer to step S420.

The control unit 104 is specifically further configured to determine that the relay has no adhesion fault before power-up, and allow subsequent control of the relay, if it is determined that the voltage of the relay is not equal to the bus voltage of the high-voltage battery. The specific function and process of the control unit 104 also refer to step S430.

The control unit 104 is specifically further configured to, after the PDU performs adhesion detection before powering on each relay in the relay module, if it is determined that the power supply circuit of the pure electric vehicle has a pre-charging circuit and the pre-charging relay is not adhered, enable the PDU to perform pre-charging timeout detection on the pre-charging relay according to a closing instruction sent by the VCU and a voltage of the pre-charging relay; and after the PDU performs the detection of the pre-charge timeout on the pre-charge relay, if the pre-charge of the pre-charge relay is determined not to timeout, the PDU performs the detection of the abnormal closing of the main relay according to the closing instruction sent by the VCU and the voltage of the main relay. The specific function and process of the control unit 104 is also referred to as step S230.

In some embodiments, the control unit 104, according to the closing instruction sent by the VCU and the voltage of the precharge relay, causes the PDU to perform precharge timeout detection on the precharge relay, including:

The control unit 104 is specifically further configured to, if it is determined that the PDU receives a closing instruction for closing the precharge relay sent by the VCU, cause the PDU to control the precharge relay to be closed. The specific function and process of the control unit 104 also refer to step S510.

The control unit 104 is specifically further configured to determine, after the PDU controls the closing of the pre-charge relay, whether the voltage of the pre-charge relay is greater than a preset first high voltage threshold value within a second set time. The specific function and process of the control unit 104 also refer to step S520.

The control unit 104 is specifically further configured to determine that the precharge relay is precharged normally if satisfied, allowing subsequent control of the precharge relay. The specific function and processing of the control unit 104 is also referred to in step S530.

The control unit 104 is specifically further configured to determine that the precharge relay is precharged out if the precharge timeout is not satisfied, stop performing subsequent control on the precharge relay, and initiate a notification message that the precharge relay has a precharge timeout fault, so as to prohibit subsequent high-voltage power-up. The specific function and process of the control unit 104 also refer to step S540.

The control unit 104 is specifically further configured to, after the PDU performs adhesion detection before powering on each relay in the relay module, if it is determined that the power supply circuit of the pure electric vehicle has no pre-charging circuit and the main relay has no adhesion, make the PDU perform abnormal closing detection on the main relay according to a closing instruction sent by the VCU and the voltage of the main relay. The specific function and process of the control unit 104 also refer to step S240.

In some embodiments, the control unit 104, according to the closing instruction sent by the VCU and the voltage of the main relay, causes the PDU to perform abnormal closing detection on the main relay, including:

the control unit 104 is specifically further configured to, if it is determined that the PDU receives a closing instruction sent by the VCU to close the main relay, cause the PDU to control the main relay to be closed and control the precharge relay to be opened. The specific function and process of the control unit 104 also refer to step S610.

The control unit 104 is specifically further configured to determine, after the PDU controls the main relay to be turned on, whether the voltage of the main relay is greater than a preset second high voltage threshold. The specific function and processing of the control unit 104 is also referred to in step S620.

The control unit 104 is specifically further configured to determine that the main relay is normally closed if it is determined that the voltage of the main relay is greater than a preset second high voltage threshold, and allow subsequent control of the main relay. The specific function and processing of the control unit 104 is also referred to in step S630.

The control unit 104 is specifically further configured to determine that the main relay is abnormal in closing if it is determined that the voltage of the main relay is not greater than a preset second high voltage threshold, stop performing subsequent control on the main relay, and initiate a notification message that the main relay has an abnormal closing fault, so as to prohibit subsequent high voltage power-up. The specific function and process of the control unit 104 also refer to step S640.

The control unit 104 is specifically further configured to, after performing adhesion detection before powering up each relay in the relay module by the PDU, if it is determined that the corresponding auxiliary relay is normally closed, enable the PDU to perform abnormal closing detection on the corresponding auxiliary relay according to a closing instruction sent by the VCU according to the voltage of the corresponding auxiliary relay. The specific function and processing of the control unit 104 is also referred to in step S250.

In some embodiments, the control unit 104, according to the voltage of the corresponding auxiliary relay, causes the PDU to perform abnormal closing detection on the corresponding auxiliary relay according to the closing instruction sent by the VCU, including:

the control unit 104 is specifically further configured to, if it is determined that the PDU receives a closing instruction sent by the VCU to close the auxiliary relay, cause the PDU to control the auxiliary relay to close and control the precharge relay to open. The specific function and process of the control unit 104 also refer to step S710.

The control unit 104 is specifically further configured to determine, after the PDU controls the respective auxiliary relay to be closed, whether the voltage of the respective auxiliary relay is greater than a preset third high voltage threshold. The specific function and process of the control unit 104 also refer to step S720.

The control unit 104 is specifically further configured to determine that the corresponding auxiliary relay is normally closed if it is determined that the voltage of the corresponding auxiliary relay is greater than a preset third high voltage threshold, and allow subsequent control to be performed on the corresponding auxiliary relay. The specific function and process of the control unit 104 also refer to step S730.

The control unit 104 is specifically further configured to determine that the corresponding auxiliary relay is abnormal in closing if it is determined that the voltage of the corresponding auxiliary relay is not greater than a preset third high voltage threshold, stop performing subsequent control on the corresponding auxiliary relay, and send a notification message that the corresponding auxiliary relay has abnormal closing faults, so as to prohibit subsequent high voltage power-up. The specific function and process of the control unit 104 also refer to step S740.

The control unit 104 is further configured to enable the PDU to perform power-down detection on the high-voltage battery according to the bus voltage of the high-voltage battery after the relay module is powered up at high voltage, so as to realize power supply control on the high-voltage battery. The specific function and process of the control unit 104 also refer to step S140.

In some embodiments, the control unit 104, according to the bus voltage of the high-voltage battery, makes the PDU perform power failure detection on the high-voltage battery to implement power supply control on the high-voltage battery, including:

the control unit 104 is in particular further configured to determine whether the bus voltage of the high voltage battery is smaller than a preset second under-voltage threshold. The specific function and process of the control unit 104 also refer to step S810.

The control unit 104 is specifically further configured to determine that the bus voltage of the high-voltage battery is input under-voltage if the bus voltage of the high-voltage battery is determined to be less than a preset second under-voltage threshold, stop performing subsequent control, and initiate a warning message that the bus voltage of the high-voltage battery has an input under-voltage fault, so as to prohibit subsequent high-voltage power-up. The specific function and process of the control unit 104 also refer to step S820.

The control unit 104 is specifically further configured to determine that the bus voltage of the high-voltage battery is input normally, and allow subsequent control, if it is determined that the bus voltage of the high-voltage battery is not less than a preset second undervoltage threshold. The specific function and processing of the control unit 104 also refer to step S830.

The control unit 104 is further configured to, after the relay module is powered up at high voltage, enable the PDU to perform power-down timeout detection on each relay in the relay module according to a disconnection instruction sent by the VCU and combined with a voltage of each relay in the relay module under a condition that the high-voltage battery is not powered down, so as to realize high-voltage power-down control of the relay module. The specific function and process of the control unit 104 also refer to step S150.

In some embodiments, the control unit 104, according to the disconnection instruction sent by the VCU and in combination with the voltage of each relay in the relay module, makes the PDU perform power-down timeout detection on each relay in the relay module, so as to implement high-voltage power-down control on the relay module, including:

The control unit 104 is specifically further configured to, for each relay in the relay module, if it is determined that the PDU receives a disconnection instruction for disconnecting the relay sent by the VCU, cause the PDU to control the relay to be disconnected. The specific function and process of the control unit 104 also refer to step S910.

The control unit 104 is specifically further configured to determine, after the PDU controls the relay to be turned off, whether the voltage of the relay is less than a preset voltage threshold value within a third set time. The specific function and processing of the control unit 104 is also referred to step S920.

The control unit 104 is specifically further configured to determine that the relay high voltage reduction is completed, if satisfied, allowing subsequent control of the relay. The specific function and processing of the control unit 104 is also referred to step S930.

The control unit 104 is specifically further configured to determine that the relay is stuck due to the high-voltage power-down timeout if the relay is not satisfied, stop performing subsequent control on the relay, and send a notification message that the relay has a fault due to the high-voltage power-down timeout adhesion so as to prohibit subsequent high-voltage power-up. The specific function and processing of the control unit 104 is also referred to in step S940.

The control unit 104 is further configured to power down the PDU low after the high voltage of the relay module. The specific function and process of the control unit 104 is also referred to as step S160.

Since the processes and functions implemented by the apparatus of the present embodiment substantially correspond to the embodiments, principles and examples of the foregoing methods, the descriptions of the embodiments are not exhaustive, and reference may be made to the descriptions of the foregoing embodiments and their descriptions are omitted herein.

By adopting the technical scheme of the invention, under-voltage detection, adhesion detection of each relay, pre-charge timeout detection and abnormal closing detection of each relay are added under the condition of reasonably controlling the power on and off of the high voltage of the whole vehicle by aiming at the PDU in the all-in-one controller of the pure electric vehicle, so that protection and fault detection of each relay can be effectively carried out while responding to a VCU control instruction, the functions of PDU self-checking and power on and off management of the high voltage of the whole vehicle in the all-in-one controller are optimized, the protection measures of each relay are considered in combination with practical application, and the situation that each relay and a fuse in a power supply circuit of the whole vehicle even the electric device at the rear end of the power supply circuit of the whole vehicle are damaged when the abnormality occurs in the power on and off process of the high voltage of the whole vehicle is avoided, thereby improving the reliability and safety of the high voltage management of the whole vehicle.

According to an embodiment of the present invention, there is also provided a pure electric vehicle corresponding to the control device of the pure electric vehicle. The pure electric vehicle may include: the control device of the pure electric automobile.

Since the processes and functions implemented by the pure electric vehicle of the present embodiment basically correspond to the embodiments, principles and examples of the foregoing apparatus, the descriptions of the present embodiment are not exhaustive, and reference may be made to the related descriptions of the foregoing embodiments, which are not repeated herein.

By adopting the technical scheme of the invention, under-voltage detection, adhesion detection of each relay, pre-charge timeout detection and abnormal closing detection of each relay are added under the condition of reasonably controlling the power on and off of the high voltage of the whole vehicle by aiming at the PDU in the all-in-one controller of the pure electric vehicle, so that protection and fault detection of each relay can be effectively carried out while responding to a VCU control instruction, the functions of PDU self-detection and power on and off management of the high voltage of the whole vehicle in the all-in-one controller are optimized, each relay can be effectively protected from damage, and meanwhile, the real-time fault detection of each relay is increased, thereby improving the reliability and safety of the high voltage control of the whole vehicle.

According to an embodiment of the present invention, there is further provided a storage medium corresponding to a control method of a pure electric vehicle, where the storage medium includes a stored program, and when the program runs, a device where the storage medium is controlled to execute the control method of the pure electric vehicle described above.

Since the processes and functions implemented by the storage medium of the present embodiment substantially correspond to the embodiments, principles and examples of the foregoing methods, the descriptions of the present embodiment are not exhaustive, and reference may be made to the related descriptions of the foregoing embodiments, which are not repeated herein.

By adopting the technical scheme of the invention, under-voltage detection, each relay adhesion detection, pre-charge timeout detection and each relay closing abnormality detection are added under the condition of reasonably controlling the power on and off of the high voltage of the whole electric vehicle by aiming at the PDU in the all-in-one controller of the pure electric vehicle, so that the protection and fault detection of each relay can be effectively carried out while responding to a VCU control instruction, the functions of PDU self-detection and power on and power off management of the whole vehicle in the all-in-one controller are optimized, the functions of effectively protecting each relay are realized, the adhesion detection in the power on and power off processes of each relay is increased, and the reliability and safety of the high voltage control of the whole vehicle are improved.

In summary, it is readily understood by those skilled in the art that the above-described advantageous ways can be freely combined and superimposed without conflict.

The above description is only an example of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of the claims of the present invention.

Claims

1. The control method of the pure electric vehicle is characterized by comprising a high-voltage battery, an all-in-one controller and a relay module; the all-in-one controller comprises: MCU, VCU and PDU; the relay module includes: a main relay and an auxiliary relay; in the case that the power supply circuit of the pure electric vehicle has a pre-charging circuit, the relay module further includes: pre-charging a relay; the number of the auxiliary relays is more than one; the control method of the pure electric vehicle comprises the following steps:

powering up and initializing the PDU at low voltage;

obtaining the bus voltage of the high-voltage battery; the voltage of each relay in the relay module is obtained;

according to the bus voltage of the high-voltage battery and the voltage of each relay in the relay module, and in combination with a closing instruction sent by the VCU, the PDU performs under-voltage detection on the high-voltage battery, adhesion detection before power-on of each relay in the relay module, pre-charge timeout detection on the pre-charge relay, closing abnormality detection on the main relay and closing abnormality detection on each auxiliary relay according to set time sequence control logic, so that high-voltage power-on control on the relay module is realized;

After the relay module is electrified at high voltage, according to the bus voltage of the high-voltage battery, the PDU is used for detecting the power failure of the high-voltage battery so as to realize the power supply control of the high-voltage battery;

after the relay module is electrified under high voltage, under the condition that the high-voltage battery is not powered down, according to a disconnection instruction sent by the VCU, and in combination with the voltage of each relay in the relay module, the PDU is used for detecting the power-down timeout of each relay in the relay module so as to realize the high-voltage power-down control of the relay module;

after the high voltage of the relay module is powered down, the PDU is powered down at a low voltage.

2. The control method of a pure electric vehicle according to claim 1, wherein the positive electrode of the high-voltage battery is connected to the first connection end of the normally open contact of the main relay, the first connection end of the normally open contact of the precharge relay, and the first connection end of the normally open contact of each of the one or more auxiliary relays, respectively; the second connecting end of the normally open contact of the main relay is connected with the MCU, and the second connecting end of the normally open contact of the pre-charging relay is connected with the second connecting end of the normally open contact of the main relay; the second connecting end of the normally open contact of each auxiliary relay is connected with a corresponding auxiliary electric device of the pure electric vehicle;

Obtaining the voltage of each relay in the relay module comprises the following steps:

and acquiring the voltage of the second connection end of each relay in the relay module.

3. The control method of a pure electric vehicle according to claim 1, wherein according to a bus voltage of the high-voltage battery and a voltage of each relay in the relay module, and in combination with a closing instruction sent by the VCU, the PDU is controlled according to a set time sequence, the high-voltage battery is subjected to undervoltage detection, each relay in the relay module is subjected to adhesion detection before power-up, the pre-charge relay is subjected to pre-charge timeout detection, the main relay is subjected to closing abnormality detection, and each auxiliary relay is subjected to closing abnormality detection, so that high-voltage power-up control of the relay module is realized, including:

according to the bus voltage of the high-voltage battery, the PDU is enabled to carry out undervoltage detection on the bus voltage of the high-voltage battery;

after the PDU performs undervoltage detection on the bus voltage of the high-voltage battery, if the bus voltage of the high-voltage battery is determined not to be undervoltage, the PDU performs adhesion detection before powering up each relay in the relay module according to the voltage of each relay in the relay module;

After the PDU performs adhesion detection before powering on each relay in the relay module, if the power supply circuit of the pure electric vehicle is determined to have a pre-charging circuit and the pre-charging relay is not adhered, the PDU performs pre-charging timeout detection on the pre-charging relay according to a closing instruction sent by the VCU and the voltage of the pre-charging relay; after the PDU carries out the detection of the pre-charge overtime, if the pre-charge of the pre-charge relay is determined not to be overtime, the PDU carries out the detection of the abnormal closing of the main relay according to the closing instruction sent by the VCU and the voltage of the main relay;

after the PDU detects adhesion before power-on of each relay in the relay module, if the power supply circuit of the pure electric vehicle is determined to have no pre-charging circuit and the main relay is not adhered, the PDU detects abnormal closing of the main relay according to a closing instruction sent by the VCU and the voltage of the main relay;

after the PDU detects adhesion before power-on of each relay in the relay module, if the corresponding auxiliary relay is determined to be normally closed, the PDU detects abnormal closing of the corresponding auxiliary relay according to the closing instruction sent by the VCU according to the voltage of the corresponding auxiliary relay.

4. The method for controlling a pure electric vehicle according to claim 3, wherein,

according to the bus voltage of the high-voltage battery, the PDU is enabled to carry out undervoltage detection on the bus voltage of the high-voltage battery, and the method comprises the following steps:

determining whether the bus voltage of the high-voltage battery is larger than a preset first undervoltage threshold value within a first set time;

if yes, determining that the bus voltage of the high-voltage battery is not under-voltage;

if the input voltage is not met, determining that the bus voltage of the high-voltage battery is under-voltage, and initiating a reminding message that the input under-voltage fault exists in the bus voltage of the high-voltage battery so as to inhibit subsequent high-voltage power-on;

and/or the number of the groups of groups,

according to the voltage of each relay in the relay module, the PDU is made to carry out adhesion detection before powering up of each relay in the relay module, and the method comprises the following steps:

determining, for a voltage of each relay in the relay module, whether the voltage of the relay is equal to a bus voltage of the high voltage battery;

if the voltage of the relay is equal to the bus voltage of the high-voltage battery, determining that the relay has a adhesion fault before power-on, and initiating a reminding message of the adhesion fault before power-on of the relay so as to inhibit subsequent high-voltage power-on;

And if the voltage of the relay is determined to be unequal to the bus voltage of the high-voltage battery, determining that the relay has no adhesion fault before power-on.

5. The method for controlling a pure electric vehicle according to claim 3, wherein,

according to the closing instruction sent by the VCU and the voltage of the pre-charging relay, the PDU is enabled to perform pre-charging overtime detection on the pre-charging relay, and the method comprises the following steps:

if the PDU is determined to receive a closing instruction for closing the pre-charging relay sent by the VCU, the PDU is enabled to control the pre-charging relay to be closed;

after the PDU controls the pre-charging relay to be closed, determining whether the voltage of the pre-charging relay is larger than a preset first high-voltage threshold value within a second set time;

if yes, determining that the pre-charging relay is normal in pre-charging;

if the pre-charging time-out fault is not met, determining that the pre-charging time-out of the pre-charging relay exists, and initiating a reminding message of the pre-charging time-out fault of the pre-charging relay so as to inhibit subsequent high-voltage power-on;

and/or the number of the groups of groups,

according to the closing instruction sent by the VCU and the voltage of the main relay, the PDU is used for detecting the abnormal closing of the main relay, and the method comprises the following steps:

If the PDU is determined to receive a closing instruction for closing the main relay sent by the VCU, the PDU is enabled to control the main relay to be closed and the pre-charging relay to be opened;

after the PDU controls the main relay to be closed, determining whether the voltage of the main relay is greater than a preset second high-voltage threshold;

if the voltage of the main relay is determined to be larger than a preset second high-voltage threshold value, determining that the main relay is normally closed;

if the voltage of the main relay is not larger than a preset second high-voltage threshold value, determining that the main relay is abnormal in closing, and initiating a reminding message of the main relay with abnormal closing faults so as to inhibit subsequent high-voltage power-on;

and/or the number of the groups of groups,

according to the voltage of the corresponding auxiliary relay, the PDU is enabled to conduct abnormal closing detection on the corresponding auxiliary relay according to a closing instruction sent by the VCU, and the method comprises the following steps:

if the PDU is determined to receive a closing instruction for closing the corresponding auxiliary relay sent by the VCU, the PDU is enabled to control the corresponding auxiliary relay to be closed and the pre-charging relay to be opened;

after the PDU controls the corresponding auxiliary relay to be closed, determining whether the voltage of the corresponding auxiliary relay is larger than a preset third high-voltage threshold value;

If the voltage of the corresponding auxiliary relay is determined to be larger than a preset third high-voltage threshold value, determining that the corresponding auxiliary relay is normally closed;

if the voltage of the corresponding auxiliary relay is not larger than the preset third high-voltage threshold value, determining that the corresponding auxiliary relay is abnormal in closing, and initiating a reminding message of abnormal closing faults of the corresponding auxiliary relay so as to inhibit subsequent high-voltage power-on.

6. The control method of a pure electric vehicle according to claim 1, wherein the step of detecting the PDU to power down the high-voltage battery according to the bus voltage of the high-voltage battery to realize power supply control of the high-voltage battery includes:

determining whether the bus voltage of the high-voltage battery is smaller than a preset second undervoltage threshold value;

if the bus voltage of the high-voltage battery is determined to be smaller than a preset second undervoltage threshold value, determining that the bus voltage of the high-voltage battery is input under-voltage, and initiating a reminding message of input under-voltage faults of the bus voltage of the high-voltage battery to prohibit subsequent high-voltage on-voltage;

and if the bus voltage of the high-voltage battery is not smaller than the preset second undervoltage threshold value, determining that the bus voltage of the high-voltage battery is normally input.

7. The control method of a pure electric vehicle according to any one of claims 1 to 6, wherein the step of enabling the PDU to perform power-down timeout detection on each relay in the relay module according to a disconnection instruction issued by the VCU and in combination with a voltage of each relay in the relay module, to implement high-voltage power-down control of the relay module, includes:

for each relay in the relay module, if the PDU is determined to receive a disconnection instruction for disconnecting the relay sent by the VCU, the PDU is enabled to control the relay to be disconnected;

after the PDU controls the relay to be disconnected, determining whether the voltage of the relay is smaller than a preset voltage threshold value within a third set time;

if yes, determining that the relay is complete in high-voltage down-charging;

if the relay is not satisfied, determining that the relay is stuck in a high-voltage overtime state, and initiating a reminding message of the relay with the fault of the relay in the high-voltage overtime state so as to inhibit the follow-up high-voltage power-up.

8. The control device of the pure electric automobile is characterized by comprising a high-voltage battery, an all-in-one controller and a relay module; the all-in-one controller comprises: MCU, VCU and PDU; the relay module includes: a main relay and an auxiliary relay; in the case that the power supply circuit of the pure electric vehicle has a pre-charging circuit, the relay module further includes: pre-charging a relay; the number of the auxiliary relays is more than one; the control device of the pure electric vehicle comprises:

A control unit configured to power up and initialize the PDU at a low voltage;

an acquisition unit configured to acquire a bus voltage of the high-voltage battery; the voltage of each relay in the relay module is obtained;

the control unit is further configured to control logic according to a set time sequence by combining the voltage of the bus of the high-voltage battery and the voltage of each relay in the relay module and a closing instruction sent by the VCU, so that the PDU performs undervoltage detection on the high-voltage battery, adhesion detection before power-on of each relay in the relay module, pre-charge timeout detection on the pre-charge relay, closing anomaly detection on the main relay and closing anomaly detection on each auxiliary relay to realize high-voltage power-on control on the relay module;

the control unit is further configured to enable the PDU to perform power-down detection on the high-voltage battery according to the bus voltage of the high-voltage battery after the relay module is powered on at high voltage so as to realize power supply control on the high-voltage battery;

the control unit is further configured to, after the relay module is powered up at high voltage, enable the PDU to perform power-down timeout detection on each relay in the relay module according to a disconnection instruction sent by the VCU and combined with the voltage of each relay in the relay module under the condition that the high-voltage battery is not powered down, so as to realize high-voltage power-down control on the relay module;

The control unit is further configured to low-voltage the PDU after the high-voltage of the relay module.

9. A pure electric vehicle, comprising: the control device of a pure electric vehicle according to claim 8.

10. A storage medium, characterized in that the storage medium comprises a stored program, wherein the device in which the storage medium is controlled to execute the control method of the pure electric vehicle according to any one of claims 1 to 7 when the program is run.