CN111381153A

CN111381153A - Relay contact state detection circuit and state detection method thereof, and electric automobile

Info

Publication number: CN111381153A
Application number: CN201811627813.8A
Authority: CN
Inventors: 张永安; 汪强
Original assignee: Shenzhen V&t Technologies Co ltd
Current assignee: Shenzhen V&t Technologies Co ltd
Priority date: 2018-12-28
Filing date: 2018-12-28
Publication date: 2020-07-07

Abstract

A relay contact state detection circuit of a high-voltage power distribution system, an electric automobile and a relay contact state detection method of the high-voltage power distribution system are provided, wherein the relay contact state detection circuit comprises: the device comprises a first direct current power supply, a power supply branch and a detection module; the first direct current power supply outputs first direct current electric energy; the power supply branch circuit is connected between the second ends of the contacts of the pre-charging relay and the main positive relay and the ground; the detection module generates a control signal for closing or switching off a contact of the pre-charging relay and/or a contact of the main positive relay, generates a detection result representing the on-off states of the contact of the pre-charging relay and the contact of the main positive relay according to the power-on or power-off state of the power supply branch circuit, and determines whether the contact of the pre-charging relay and the contact of the main positive relay are normal, adhered or invalid according to the detection result and the control signal; the relay contact state detection circuit can perform safety detection on the contact state of the relay.

Description

Relay contact state detection circuit and state detection method thereof, and electric automobile

Technical Field

The invention belongs to the technical field of high-voltage power distribution, and particularly relates to a relay contact state detection circuit of a high-voltage power distribution system, an electric automobile and a relay contact state detection method of the high-voltage power distribution system

Background

In the field of intelligent power supply of electronic equipment, high-voltage power distribution technology has been widely applied to a power supply system of the electronic equipment, and the high-voltage power distribution system can realize on-off control of a high-power supply and high-voltage components, wherein the high-voltage components comprise: the device comprises a main driving circuit, an oil pump, an air pump, a DC/DC conversion circuit, a charger and the like; in a high-voltage distribution system, a relay is generally used for realizing on-off control of high-voltage components, and due to the specific power on-off characteristics of the relay, the relay is used as a key component for realizing low voltage to control high voltage, and different power conversion functions of the high-voltage distribution system can be realized by switching on or off contacts of the relay; therefore, the on-off control performance of the contact of the relay has very important influence on the safe power supply performance of the high-voltage power distribution system.

When a contact of a relay in a high-voltage distribution system fails, the electric energy output by the high-voltage distribution system can lose effective control, so that the high-voltage distribution system has physical potential safety hazards, and electric equipment can be greatly damaged; therefore, when the high-voltage distribution system is applied to relevant electric equipment, fault removal and prevention must be carried out on occurrence of relays in the high-voltage distribution system in real time; taking an electric automobile as an example, according to the national standard GB/T18487.1-2015 part 1 of the conduction charging system of the electric automobile: 7.1 in the general requirements requires that the electric automobile should have functions of monitoring and warning adhesion of a charging loop contactor, and the power supply equipment should have functions of monitoring and warning adhesion of a power supply loop contactor; therefore, technical personnel need to detect the state of the relay contact in the high-voltage power distribution system and detect the state of the relay contact in real time so as to avoid potential safety hazards caused by relay contact faults.

However, when the relay contact of the high-voltage power distribution system is safely detected in the conventional technology, whether the contact of the relay is in a safe control state or not needs to be judged according to a comparison result between the voltage at the rear end of the relay contact and the voltage at the power supply side in the high-voltage power distribution system; then, the following problems exist in the conventional technical solutions: after a relay contact on the power supply side needs to be closed, the power supply side transmits power supply energy to a contact of a relay of a high-voltage distribution system so as to detect the voltage at the rear end of the contact of the relay and judge whether the contact of the relay is in fault operation or not; if before the relay contact of the power supply side is closed, the relay in the high-voltage distribution system has the adhesion problem, then after the relay contact of the power supply side is closed, the power supply side can output high-power electric energy to the contact of the relay in the high-voltage distribution system, larger impact current can be generated, even the relay contact on the power supply side can also have the adhesion phenomenon, secondary damage is caused to the high-voltage distribution system, the electric power safety of the high-voltage distribution system is influenced, and the fault occurrence rate of the relay contact in the high-voltage distribution system is higher.

Disclosure of Invention

In view of this, embodiments of the present invention provide a relay contact state detection circuit for a high voltage power distribution system, an electric vehicle, and a relay contact state detection method for a high voltage power distribution system, which are used to solve the problems that the conventional technical scheme cannot realize safety detection of a relay contact in a high voltage power distribution system, and the safety of the high voltage power distribution system is low.

A first aspect of an embodiment of the present invention provides a relay contact state detection circuit for a high-voltage power distribution system, where the high-voltage power distribution system includes: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then are connected with the positive relay or the negative relay; the relay contact state detection circuit includes:

the first direct-current power supply is connected with the first ends of the contacts of the pre-charging relay and the main positive relay and is used for outputting first direct-current energy;

the input end of the power supply branch circuit is connected with the second end of the contact of the pre-charging relay and the second end of the contact of the main positive relay, and the output end of the power supply branch circuit is grounded; and

the detection module is coupled with the power supply branch circuit and generates a control signal for closing or turning off the contact of the pre-charging relay and/or the contact of the main positive relay, the detection module generates a detection result representing the states of the contact of the pre-charging relay and the contact switch of the main positive relay according to the power-on or power-off state of the power supply branch circuit, and the detection module determines that the contact of the pre-charging relay and the contact of the main positive relay are normal, adhered or failed according to the detection result and the control signal.

In one embodiment, the power supply branch further comprises: the LED, the first diode and the first resistor;

the anode of the first diode is connected with the second end of the contact of the pre-charge relay and the second end of the contact of the main positive relay, the cathode of the first diode is connected with the first end of the first resistor, the second end of the first resistor is connected with the anode of the light-emitting diode, and the cathode of the light-emitting diode is grounded.

In one embodiment, the power supply branch further comprises: a second resistor;

the first end of the second resistor is connected with the second end of the contact of the pre-charging relay, and the second end of the second resistor is connected with the second end of the contact of the main positive relay and the anode of the first diode.

In one embodiment thereof, the detection module comprises:

a signal generation unit coupled with contacts of the pre-charge relay and contacts of the main positive relay, the signal generation unit generating a control signal for closing or closing the contacts of the pre-charge relay and/or the contacts of the main positive relay;

the signal detection unit is coupled with the power supply branch circuit and the signal generation unit, generates a detection result representing the states of the contact of the pre-charging relay and the contact of the main positive relay according to the power-on or power-off state of the power supply branch circuit, and determines whether the contact of the pre-charging relay and the contact of the main positive relay are normal, adhered or invalid according to the detection result and the control signal.

In one embodiment, the signal detection unit includes:

the second direct current power supply is used for outputting second direct current electric energy;

a first end of the third resistor is connected with the second direct current power supply;

the optical coupling element is coupled with the light emitting diode, a first conducting end of the optical coupling element and a second end of the third resistor are connected in a common mode to form a signal output port of the signal detection unit, and a second conducting end of the optical coupling element is grounded; and

the communication port of the state judgment unit is connected with the signal output port of the detection module, and the state judgment unit confirms the switch states of the contact of the pre-charge relay and the contact of the main positive relay according to the level signal of the signal output port of the signal detection unit;

and the state judgment unit determines that the contact of the pre-charging relay and the contact of the main positive relay are normal, adhered or invalid according to the corresponding relation between the control signal and the switch state.

In one embodiment, the state determination unit includes: and the I/O pin of the control chip is connected with the signal output port of the signal detection unit.

In one embodiment, the signal output port of the signal detection unit outputs a first level signal when the light emitting diode does not emit a light source, and the signal output port of the signal detection unit outputs a second level signal when the light emitting diode emits a light source;

the first level signal is a high level signal or a low level signal, the second level signal is a high level signal or a low level signal, and the phases of the first level signal and the second level signal are staggered.

In one embodiment, the optical coupling element is a phototransistor or a photodiode.

A second aspect of an embodiment of the present invention provides an electric vehicle, including: the relay contact state detection circuit comprises a high-voltage distribution system and a relay contact state detection circuit of the high-voltage distribution system, wherein the relay contact state detection circuit is connected with the high-voltage distribution system; wherein the high voltage power distribution system comprises: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then connected with the positive relay or the negative relay.

A third aspect of an embodiment of the present invention provides a method for detecting a relay contact state of a high-voltage power distribution system, where the high-voltage power distribution system includes: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then are connected with the positive relay or the negative relay; the relay contact state detection method comprises the following steps:

generating a control instruction for closing or closing the contact of the pre-charging relay and/or the contact of the main positive relay;

connecting a contact of the pre-charging relay and a contact of the main positive relay in series between a first direct-current power supply and a power supply branch circuit, and generating a detection result representing the states of the contact of the pre-charging relay and the contact of the main positive relay according to the power-on or power-off state of the power supply branch circuit;

and determining whether the contact of the pre-charging relay and the contact of the main positive relay are normal, adhered or invalid according to the corresponding relation between the detection result and the control command.

The relay contact state detection circuit of the high-voltage power distribution system can independently provide a detection power supply for the contact detection process of the pre-charging relay and the contact detection process of the main positive relay through the first direct-current power supply, the power supply branch circuit feeds back the closed or off states of the contact of the pre-charging relay and the contact of the main positive relay according to the self power-on or power-off state, no matter whether the contact of the positive relay and the contact of the negative relay in the battery unit are closed or closed, the detection module can judge whether the contact of the pre-charging relay and/or the contact of the main positive relay are in a fault state according to the comparison relation between the switch states of the contact of the pre-charging relay and the contact of the main positive relay and the control signal, so that the control safety of the contact of the pre-charging relay and the contact of the main positive relay in the high-voltage power distribution system is improved; therefore, the relay contact state detection circuit in the embodiment of the invention realizes the safety detection of the contact of the pre-charging relay and the contact of the main positive relay, and avoids the damage of the positive relay and the negative relay caused by closing the contact of the positive relay and the contact of the negative relay in the battery unit under the condition that the pre-charging relay and/or the main positive relay are adhered in a high-voltage power distribution system; the relay contact state detection circuit in the embodiment has a wide application range, and greatly ensures the power distribution safety of a high-voltage power distribution system.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a relay contact state detection circuit of a high-voltage power distribution system according to an embodiment of the present invention;

fig. 2 is a system block diagram of a high voltage power distribution system in an electric vehicle according to an embodiment of the present invention;

fig. 3 is a schematic diagram of another structure of a relay contact state detection circuit of a high-voltage power distribution system according to an embodiment of the present invention;

fig. 4 is a schematic diagram of another structure of a relay contact state detection circuit of a high-voltage power distribution system according to an embodiment of the present invention;

fig. 5 is a schematic diagram of another structure of a relay contact state detection circuit of a high-voltage power distribution system according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an electric vehicle according to an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a relay contact state detection system of a high voltage power distribution system according to an embodiment of the present invention;

fig. 8 is a flowchart illustrating a method for detecting a relay contact state of a high-voltage power distribution system according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

Referring to fig. 1, a schematic structural diagram of a relay contact state detection circuit of a high-voltage power distribution system according to an embodiment of the present invention is provided, where the relay contact state detection circuit can detect a safety state of a contact of a relay in the high-voltage power distribution system, so as to ensure power supply safety of the high-voltage power distribution system; for convenience of explanation, only the parts related to the present embodiment are shown, and detailed as follows:

as shown in fig. 1, the relay contact state detection circuit in this embodiment is applied to a high-voltage power distribution system, where the high-voltage power distribution system in this embodiment is a broad concept, and the high-voltage power distribution system can implement various functions such as power transmission, on-off control of a circuit, and high-voltage power distribution; the high-voltage distribution system can realize the conversion and compatibility between electric energy with different amplitude values, so that various electronic components can be always connected with safe and stable electric energy, and therefore, the high-voltage distribution system is required to be adopted in certain industrial fields; taking an electric automobile as an example, fig. 2 shows a system block diagram of a high-voltage distribution system in the electric automobile, and referring to fig. 2, the high-voltage distribution system can output stable electric energy to each part in the electric automobile according to power requirements of different electronic components in the electric automobile, so as to guarantee power supply safety of the electric automobile.

It should be noted that the high voltage distribution system in the electric vehicle shown in fig. 2 is only an embodiment, and does not constitute a limitation to the high voltage distribution system in the embodiment; the high-voltage power distribution system mentioned in each embodiment can be applied to different industrial products, has extremely strong compatibility so as to ensure the electric energy safety of different types of industrial products, and can be widely applied to various industrial fields; the high-voltage power distribution system is used as an application object of the relay contact state detection circuit, technicians can conduct fine adjustment on the structure of the high-voltage power distribution system on the basis of not violating the essential technical characteristics of the relay contact state detection circuit in the following embodiments, and the relay contact state detection circuit can be suitable for different types of high-voltage power distribution systems.

In order to better explain the working principle of the relay contact state detection circuit, the following embodiments all apply the relay contact state detection circuit to an electric vehicle, so as to explain the specific implementation of the relay contact state detection circuit; since this is merely an example, it is not intended that the relay contact state detection circuit in each embodiment can be applied only to an electric vehicle.

As shown in fig. 1, the high voltage power distribution system includes: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; the battery unit provides high-voltage electric energy, and all parts in the electric automobile can be provided with electric energy through the high-voltage electric energy; the conversion and on-off control of electric energy can be realized through the power distribution unit, so that the power on or power off of each part in the electric automobile is controlled, and corresponding electric energy is output according to the rated power requirement of each part, so that the operation safety of each part in the electric automobile is protected; specifically, the battery unit includes: the battery VDD, the positive relay connected with the positive pole of the battery VDD and the negative relay connected with the negative pole of the battery VDD are sequentially connected in series, the battery VDD is used for storing and outputting electric energy, and the electric energy can be continuously output outwards through the battery VDD so as to ensure the long-term operation of the electric automobile; the on-off of the circuit can be controlled through the contact K _ B + of the positive relay and the contact K _ B-of the negative relay, the battery unit can electrify the electric automobile only when the contact K _ B + of the positive relay and the contact K _ B-of the negative relay are closed simultaneously, for example, when the contact K _ B + of the positive relay and the contact K _ B-of the negative relay are closed simultaneously, the motor of the electric automobile can be electrified, and the electric automobile can be ignited to enter a running state; and the electric energy output by the battery unit has a great amplitude, and can simultaneously drive a plurality of parts in the electric automobile to be in a stable working state.

The power distribution unit includes: the power supply system comprises a pre-charging relay K1 and a main positive relay K2, wherein the power distribution unit can transmit the power of a battery unit to a plurality of parts in the electric automobile so that each part in the electric automobile can maintain a rated operation state, a contact K1-1 of the pre-charging relay and a contact K2-1 of the main positive relay are connected in parallel and then connected with the positive relay or the negative relay, when any one of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is closed, a power supply circuit of the parts in the electric automobile is conducted, the battery VDD outputs power outwards through a contact K _ B + of the positive relay and a contact K _ B-of the negative relay, and a main driving circuit of the electric automobile can be connected to maintain a normal working state; optionally, the main driving circuit includes an engine of an electric vehicle, and fig. 1 shows an equivalent circuit structure of the main driving circuit of the electric vehicle; if any one of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is closed, the resistor RL and the capacitor CL can be connected with electric energy; the pre-charging relay K1 is used for realizing pre-charging protection for the main driving circuit, and before the main driving circuit is formally connected with electric energy to keep a normal working state, a contact K1-1 of the pre-charging relay is closed firstly to prevent spike current generated at the moment of circuit conduction from causing physical damage to electronic components in the main driving circuit; when the current in the power supply loop of the electric automobile tends to be stable, the contact K2-1 of the main positive relay is closed so as to realize the rapid transition from the instant of circuit conduction to the stable operation stage of the electric energy in the main driving circuit; therefore, the power distribution unit can realize the function of low-voltage control of high-voltage parts through the on or off states of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay so as to realize the on or off of a power supply loop in the electric automobile, and each part in the electric automobile is in a power-on or power-off state; and the power distribution unit can realize the safe start of parts, has ensured electric automobile's operation safety, parts can be in safe, stable running state all the time among the electric automobile.

Referring to the relay contact state detection circuit shown in fig. 1, the relay contact state detection circuit includes: a first direct current power source VCC1, a power supply branch 101, and a detection module 102.

The first direct current power supply VCC1 with the first end of the contact K1-1 of the pre-charge relay and the first end of the contact K2-1 of the main positive relay are connected, the first direct current power supply VCC1 is used for outputting first direct current electric energy.

Illustratively, the first dc power source VCC1 is a +5V or +10V dc power source.

The first direct-current power supply VCC1 has an electric energy storage function, the first direct-current power supply serves as power supply power in the contact state detection process of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay in the embodiment, and when any one of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is closed, the first direct-current power supply VCC1 transmits the first direct-current power to the power supply branch 101; when the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay are both turned off, the first direct current power supply VCC1 cannot output first direct current electric energy; therefore, the relay contact state detection circuit in the embodiment utilizes the first direct-current power supply VCC1 as the power supply power in the detection process, and does not need to rely on the battery power in the battery unit as the power supply power in the relay contact state detection process; even if the contact K _ B + of the positive relay and the contact K _ B-of the negative relay in the battery unit are disconnected, the relay contact state detection circuit can still realize real-time detection on the relay contact state according to the first direct current energy output by the first direct current power supply VCC1, the safety of each relay contact in a high-voltage power distribution system is greatly guaranteed, and great physical damage to the battery unit caused by the fault states of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is avoided.

The input end of the power supply branch circuit 101 is connected with the second end of the contact K1-1 of the pre-charging relay and the second end of the contact K2-1 of the main positive relay, and the output end of the power supply branch circuit 101 is grounded GND, wherein the power supply branch circuit 101 can be used for realizing the transmission of electric energy; when any one of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is closed, the power supply branch circuit 101 can access first direct current power; the power supply branch 101 can be powered on or powered off by turning on or off the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay; the on or off states of the contacts K1-1 of the pre-charging relay and the contacts K2-1 of the main positive relay are in one-to-one correspondence with the power-on or power-off states of the power supply branch circuit 101; therefore, the electric energy transmission state of the power supply branch 101 has a sensitive control response speed, which is helpful for the relay contact state detection circuit to accurately detect the relay contact state.

The detection module 102 is coupled to the power supply branch 101, the detection module 102 generates a control signal for closing or closing the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay; the detection module 102 has a function of controlling on-off of contacts of a relay, a control signal generated by the detection module 102 comprises different control instructions, and the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay can be driven to be in different on or off states through the different control instructions; optionally, the detection module 102 generates a corresponding control signal according to an operation instruction of a user, and the user can directly change the control instruction in the detection module 102, so that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are in corresponding on or off states, thereby improving the user experience; for example, the control command in the control signal has the following relationship with the closing or opening of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay:

1. the control signal comprises a first control command, the contact K1-1 of the pre-charge relay is closed, and the contact K2-1 of the main positive relay is closed.

2. The control signal comprises a second control command, the contact K1-1 of the pre-charge relay is closed, and the contact K2-1 of the main positive relay is closed.

3. The control signal contains a third control command, the contact K1-1 of the pre-charge relay is turned off, and the contact K2-1 of the main positive relay is turned off.

4. The control signal comprises a fourth control command, the contact K1-1 of the pre-charge relay is closed, and the contact K2-1 of the main positive relay is closed.

Therefore, in the embodiment, the on or off states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay can be directly changed through the control signal generated by the detection module 102, and the control response speed and the control sensitivity are extremely high.

The detection module 102 generates a detection result indicating the switch states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay according to the power-on or power-off of the power supply branch 101, and the detection module 102 determines that the contacts of the pre-charge relay and the main positive relay are normal, stuck or failed according to the detection result and the control signal.

The sticking phenomenon of the contacts of the relay is as follows: because the voltage/current that the relay flows through is too big, lead to the closure of the contact continuity of relay, even send the disconnection instruction to the relay, the contact of relay is still closed, and the adhesion phenomenon of the contact of relay will seriously influence power system's safety, can lead to the unusual power-on phenomenon of electronic components.

The detection module 102 can judge the on-off states of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay according to the power transmission state of the power supply branch 101, and the detection precision is extremely high; as described above, the state of the control signal has a one-to-one correspondence relationship with the switching states of both the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay, so whether the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay are in a fault state can be determined by the relationship between the detection result of the detection module 102 and the control signal.

The detection process of the detection module 102 for the state of the contact K1-1 of the pre-charge relay and the state of the contact K2-1 of the main positive relay is described below by a specific application scenario, which is as follows:

if the passing control signal contains a third control command, referring to the above, the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay respectively execute corresponding operations, and at this time, the detection module 102 determines the operation state of the relay contact according to the power transmission state of the power supply branch 101; the following two cases are distinguished:

if the power supply branch 101 is powered on, the detection module 102 detects that at least one of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay is closed, the detection result is not matched with the control information in the control signal, the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay are/is in an abnormal closed state, and then the detection module 102 can judge that the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay are/is in adhesion or failure.

If the power supply branch 101 is out of power, the detection module 102 detects that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are both turned off, the detection result is completely matched with the control information in the control signal, the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are in a normal turn-off state, and then the detection module 102 can judge that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are in a normal state according to the comparison relationship between the control signal and the switch states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay.

If the control signal includes the first control command, referring to the above, the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay respectively execute corresponding actions according to the fourth control command, at this time, the detection module 102 determines the closed state or the off state of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay according to the power-on or power-off state of the power supply branch 101, and the two cases are as follows:

if the power supply branch 101 is powered on, the detection module 102 detects that the contact K1-1 of the pre-charging relay is closed, and the power supply branch 101 has current, the closed state of the contact K1-1 of the pre-charging relay is completely matched with the control information in the control signal, and the control signal can implement normal operation on the contact K1-1 of the pre-charging relay, so that the detection module 102 can determine that the contact K1-1 of the pre-charging relay is normal.

If the power supply branch circuit 101 is power-off, the detection module 102 detects that the contact K1-1 of the pre-charging relay is turned off, the power supply branch circuit 101 cannot be connected with the first direct-current power, the off state of the contact K1-1 of the pre-charging relay is not matched with control information in the control signal, the contact K1-1 of the pre-charging relay is in a failure state, and the contact K1-1 of the pre-charging relay cannot be closed through the control signal; therefore, the detection module 102 can accurately identify the failure of the contact K1-1 of the pre-charging relay according to the power transmission state and the control signal of the power supply branch 101, the monitoring precision of the relay contact state detection circuit on the state of the contact K1-1 of the pre-charging relay is guaranteed, and the high-voltage power distribution system has higher power supply safety.

In combination with the above, the relay contact state detection circuit in the present embodiment can display the closing or opening information of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay through the power-on or power-off state of the power supply branch 101; because the control signal and the connection and disconnection of the contacts K1-1 of the pre-charging relay and the contacts K2-1 of the main positive relay have a one-to-one correspondence relationship, the detection module 102 can accurately judge whether the contacts K1-1 of the pre-charging relay and the contacts K2-1 of the main positive relay are in a normal working state or not according to the correspondence relationship between the detection results of the switch states of the contacts K1-1 of the pre-charging relay and the contacts K2-1 of the main positive relay and the control instruction, so that the accurate detection of the contacts of the relays is realized, and the power supply safety of the high-voltage distribution system is guaranteed; therefore, the relay contact state detection circuit in the embodiment can directly detect the abnormal state of the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay by using the electric energy output by the first direct-current power supply VCC1, and does not need to rely on the positive relay and the negative relay in the battery unit to provide power supply electric energy for the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay in the power distribution unit, thereby avoiding the secondary damage of the relay in the battery unit caused by the adhesion condition of the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay, and improving the safety performance of the high-voltage power distribution system; therefore, the relay contact state detection circuit can realize the accurate and safe detection function of the fault operation state of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay.

As an alternative implementation, fig. 3 shows another structural schematic of the relay contact state detection circuit of the high-voltage power distribution system provided in this embodiment, and as shown in fig. 3, the power supply branch 101 further includes: the circuit comprises a light emitting diode LED1, a first diode D1 and a first resistor R1.

The anode of the first diode D1 is connected to the other end of the contact K1-1 of the pre-charge relay and the other end of the contact K2-1 of the main positive relay, the cathode of the first diode D1 is connected to the first end of the first resistor R1, the second end of the first resistor R1 is connected to the anode of the light-emitting diode LED1, and the cathode of the light-emitting diode LED1 is grounded GND.

In the present embodiment, the switching state of either one of the contact K1-1 of the precharge relay and the contact K2-1 of the main-plus relay can be indicated by the lighting state of the light emitting diode LED 1; specifically, after the light emitting diode LED1 is connected to the first direct current power, a corresponding light emitting effect can be achieved, if the light emitting diode LED1 is not connected to the first direct current power, it indicates that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are both turned off, and the light emitting diode LED1 does not emit a corresponding light source; on the contrary, if any one of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay is closed, the light emitting diode LED1 is connected to the first direct current power to emit a corresponding light source; therefore, according to the closed or off state of the contacts K1-1 of the pre-charging relay and the contacts K2-1 of the main positive relay, the light-emitting diode LED1 is lighted or extinguished, and the switch states of the contacts K1-1 of the pre-charging relay and the contacts K2-1 of the main positive relay can be intuitively monitored through the lighting state of the light-emitting diode LED 1.

In this embodiment, the first resistor R1 can perform a current limiting function, and the first resistor R1 can prevent the current in the LED1 from being too large, thereby damaging the physical safety of the LED 1; the first diode D1 can prevent the current of the power supply branch 101 from being conducted reversely, and the detection accuracy of the detection module 102 for the conduction or the disconnection of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is guaranteed, so that the relay contact state detection circuit in the embodiment can detect the abnormal working information of the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay more safely and accurately.

As an alternative embodiment, as shown in fig. 3, the power supply branch 101 further includes: a second resistor R2; the first end of the second resistor R2 is connected with the second end of the contact K1-1 of the pre-charge relay, and the second end of the second resistor R2 is connected with the second end of the contact K2-1 of the main positive relay and the anode of the first diode D1.

The second resistor R2 can consume electric energy in the pre-charging protection process of the main driving circuit, so as to reduce the current impact on the electronic components caused by the peak current at the moment of circuit conduction; at the moment when the contact K1-1 of the pre-charging relay is conducted, the second resistor R2 has peak current, and electric energy can be consumed in time through the second resistor R2, so that the safe starting of the main driving circuit is guaranteed; therefore, the current limiting function is realized in the pre-charging protection process through the second resistor R2, and the electric energy stability and safety of the high-voltage distribution system are improved.

As an alternative implementation, fig. 4 shows another structural schematic of the relay contact state detection circuit of the high-voltage power distribution system provided in this embodiment, and as shown in fig. 4, the detection module 102 includes: a signal generation unit 1021, and a signal detection unit 1022.

Wherein the signal generating unit 1021 is coupled with the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay, and the signal generating unit 1021 generates a control signal for closing or opening the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay.

Referring to the above, the control signal generated by the signal generating unit 1021 has different control commands by which the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay can be respectively closed or closed, and further the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay have extremely high control response speed, and the detection rate of the relay contact state detection circuit for the relay contact state is improved.

The signal detection unit 1022 is coupled to the power supply branch 101 and the signal generation unit 1021, the signal detection unit 1022 generates a detection result indicating a switching state of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay according to the power-on or power-off of the power supply branch 101, and the signal detection unit 1022 determines that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are normal, stuck or failed according to the detection result and the control signal.

Specifically, the signal detection unit 1022 detects the switching state of any one of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay according to the light emitting state of the light emitting diode LED1, so that the detection accuracy of the contact state of the relay is improved; therefore, in the embodiment, the signal generating unit 1021 changes the closed or off state of any one of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay, the signal detecting unit 1022 can detect the actual closed or off state of the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay, and can accurately identify whether the state of the relay is in an abnormal state or not according to the corresponding relation between the control command in the control signal and the closing or off of the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay, and the detection accuracy is extremely high; therefore, in the embodiment, the detection module 102 controls the on or off state of the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay through the signal generation unit 1021, and determines the abnormal condition of the state of the relay contact through detecting the actual on or off state of the relay contact through the signal detection unit 1022, that is, the module structure of the detection module 102 is simplified, the determination rate of the relay contact state detection circuit on the state of the relay is increased, the detection error of the state of the relay contact caused by misoperation is avoided, and the normal and stable operation of the detection module 102 is ensured.

As an alternative implementation, fig. 5 shows another structural schematic of the relay contact state detection circuit of the high-voltage power distribution system provided in this embodiment, and as shown in fig. 5, the signal generation unit 1021 includes: a first signal generation unit 501 and a second signal generation unit 502.

Wherein the first signal generating unit 501 generates a first control signal for turning on or off a contact K1-1 of the pre-charge relay; the second signal generating unit 502 generates a second control signal for turning on or off the contact K2-1 of the main positive relay.

In the embodiment, the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay are respectively controlled to be switched on or switched off by the first control signal and the second control signal, so that the control accuracy and the control efficiency of the signal generation unit 1021 on the relay of the power distribution unit are improved; the control command in the first control signal has a one-to-one correspondence relationship with the switch state of the contact K1-1 of the pre-charging relay, and the control command in the second control signal has a one-to-one correspondence relationship with the switch state of the contact K2-1 of the main positive relay; therefore, the signal generating unit 1021 performs classification control on the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay by adopting the first control signal and the second control signal, so that the relay contact state detection circuit is favorable for the accurate precision of the working state of the contact K1-1 of the pre-charging relay and/or the contact K2-1 of the main positive relay, and the practical value is extremely high.

As an optional implementation manner, the first signal generating unit 501 and the second signal generating unit 502 may be implemented by a single chip microcomputer or a logic control circuit in the conventional technology, which is not limited herein; for example, the first signal generating unit 501 is implemented by using a logic control circuit in the conventional technology, where the logic control circuit includes switching tubes distributed in an array, and by controlling the switching on or off of the switching tubes, the logic control circuit outputs electric energy in the on period, so as to charge the coil K1-1 of the pre-charge relay, and close the contact K1-1 of the pre-charge relay; the logic control circuit cannot output electric energy in the turn-off time period so that a coil K1-1 of the pre-charging relay is de-energized and a contact K1-1 of the pre-charging relay is turned off; therefore, the logic control circuit closes or closes the contact of the relay by changing the power-on or power-off state of the coil of the relay (comprising a pre-charging relay and a main positive relay); the signal generation unit 1021 in this embodiment has a flexible circuit structure, and improves the control response speed for the contact K1-1 of the precharge relay and the contact K2-1 of the main positive relay.

As an alternative embodiment, as shown in fig. 5, the signal detection unit 1022 includes: a second dc power supply VCC2, a third resistor R3, an opto-coupler element Q1, and a state determination unit 1031; the second dc power supply VCC2 is configured to output second dc power, and the second dc power can ensure that each electronic component in the signal detection unit 1022 is in a safe and stable operating state, and the signal detection unit 1022 has higher detection accuracy for the contact of the relay.

The first end of the third resistor R3 is connected with the second direct current power supply; wherein the third resistor R3 can function as a current limiting and a voltage signal and a current signal converting with each other.

The optical coupler element Q1 is coupled to the light emitting diode LED1, a first conducting terminal of the optical coupler element Q1 and a second terminal of the third resistor R3 are connected in common to form a signal output port of the signal detection unit 1022, and a second conducting terminal of the optical coupler element Q1 is connected to the GND; the light source change condition of the light emitting diode LED1 is sensed through a light coupling element Q1.

Optionally, the signal output port of the signal detection unit 1022 outputs a first level signal when the light emitting diode LED1 does not emit a light source, and the signal output port of the signal detection unit 1022 outputs a second level signal when the light emitting diode LED1 emits a light source.

As an alternative embodiment, the optical coupler Q1 is a photo transistor or a photo diode.

Since the optical coupler Q1 has the function of photoelectric signal conversion, when the optical signal received by the optical coupler Q1 changes, the electrical characteristics of the optical coupler Q1 itself also change, for example, taking a photodiode as an example, the photodiode is very sensitive to the intensity change of light; for example, when the incident light received by the photodiode is stronger, the higher the conductivity of the photodiode is, the larger the current passing through the photodiode is; when the incident illumination received by the photosensitive diode is weaker, the lower the conductivity of the photosensitive diode is, the smaller the current passing through the photosensitive diode is, and therefore, the one-to-one correspondence relationship exists between the current change in the photosensitive diode and the incident illumination of the photosensitive diode; in this embodiment, when the light source emitted by the light emitting diode LED1 can affect the power characteristics of the optical coupling element Q1, when the light emitting diode LED1 is in different light emitting states, the optical coupling element Q1 can output a first level signal or a second level signal; the light emitting diode LED1 can be determined to be in a light emitting or light-off state by the state of the level signal output from the signal output port of the signal detection unit 1022.

In combination with the above, when the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are both turned off, the light emitting diode LED1 cannot access the first direct current power, the light emitting diode LED1 cannot emit a light source, when the light coupling element Q1 senses the light source change state of the light emitting diode LED1, the signal output port of the signal detection unit 1022 outputs a first level signal, and then the non-light emitting state of the light emitting diode LED1 can be accurately obtained through the first level signal; on the contrary, when any one of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay is closed, the light emitting diode LED1 is connected with a first direct current power, the light emitting diode LED1 emits a light source, the light coupling element Q1 senses the illumination intensity of the light emitting diode LED1, the light coupling element Q1 adjusts the conductivity of the light coupling element, the signal output port of the signal detection unit 1022 outputs a second level signal, the closed or off states of the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay can be monitored in real time through the second level signal, and the monitoring accuracy is extremely high.

As an optional implementation, the first level signal is a high level signal or a low level signal, the second level signal is a high level signal or a low level signal, and phases of the first level signal and the second level signal are staggered; therefore, the circuit structure of the signal detection unit 1022 in this embodiment has higher flexibility.

Therefore, the signal detection unit 1022 can detect the light emitting state of the light emitting diode LED1 in real time through the optical coupling element Q1, and further output a first level signal or a second level signal according to the on or off states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay; the signal detection unit 1022 can accurately obtain the on-off state of the contact of the relay in the power distribution unit according to the first level signal or the second level signal, the operation is simple and convenient, and the detection step of the relay contact state detection circuit on the contact state of the relay is simplified.

A communication port of the state judgment unit 1031 is connected to a signal output port of the signal detection unit 1022, and the state judgment unit 1031 confirms the switching states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay according to the level signal of the signal output port of the signal detection unit 1022; optionally, the state determination unit 1031 confirms that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are both turned off by the first level signal, and the state determination unit 1031 confirms that the contact K1-1 of the pre-charge relay is closed and/or the contact K2-1 of the main positive relay is closed according to the second level signal.

Referring to the above, the first level signal corresponds to the turn-off of both the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay, and the second level signal corresponds to the closed state of any one of the contacts K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay; therefore, the state determination unit 1031 in this embodiment can accurately determine the on-off states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay according to the level signal of the signal output port, the detection rate is extremely fast, and the determination error of the state determination unit 1031 on the contact states of the relays is reduced.

The state judgment unit 1031 determines that the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay are normal, adhered or failed according to the corresponding relationship between the control signal and the switch state; further, the embodiment judges whether the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay are normal, adhered or failed according to the corresponding rule between the control signal and the contact K1-1 of the pre-charging relay and the contact K2-1 of the main positive relay; as described above, according to the matching result between the control command in the control signal and the switching state of any one of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main-plus relay, whether the relay performs the corresponding action according to the control command in the control signal can be quickly identified, and the detection accuracy of the relay contact state detection circuit for the relay contact state is improved.

Referring to the embodiment of fig. 5, wherein the control signal includes: a first control signal and a second control signal; the state judgment unit 1031 determines that the contact K1-1 of the pre-charging relay is normal, stuck or failed according to the corresponding relationship between the first control signal and the closing or turning-off of the contact K1-1 of the pre-charging relay; the state judgment unit 1031 determines that the contact K2-1 of the main positive relay is normal, stuck or failed according to the corresponding relationship between the second control signal and the closing or turning-off of the contact K2-1 of the main positive relay.

As described above, since there is a one-to-one correspondence relationship between the switch state of the contact K1-1 of the pre-charge relay and the control command of the first control signal, when the contact K1-1 of the pre-charge relay is closed or turned off by the first control signal, it can be accurately determined whether the contact K1-1 of the pre-charge relay is in an abnormal operation state according to matching information between the control command of the first control signal and the actual on or off state of the contact K1-1 of the pre-charge relay; similarly, because the on-off state of the contact K2-1 of the main positive relay and the control instruction of the second control signal have a one-to-one correspondence relationship, when the on-off state of the contact K2-1 of the main positive relay is changed through the second control signal, whether the contact K2-1 of the main positive relay is in a fault state can be judged in real time according to the matching result between the actual on-off state of the contact K2-1 of the main positive relay and the control instruction in the second control signal; therefore, the state determination unit 1031 in this embodiment can accurately determine the operation problem of the contacts of the relay in the power distribution unit according to the first level signal or the second level signal, and greatly improves the safety of the contacts of each relay in the high-voltage power distribution system.

As an optional implementation manner, the state determination unit 1031 includes: and an I/O pin of the control chip is connected to a signal output port of the signal detection unit 1022.

Optionally, the model of the control chip is AT91F40162 or LC67F 500.

Therefore, the state determination unit 1031 in this embodiment accesses the first control signal or the second control signal through the control chip, and the state determination unit 1031 has the functions of signal analysis and comprehensive processing, and the control chip can compare the control command in the control signals (the first control signal and the second control signal) with the contact switching states of the contact K1-1 of the pre-charge relay and the contact K2-1 of the main positive relay to determine whether the contact K1-1 of the pre-charge relay and/or the contact K2-1 of the main positive relay are normal, stuck or failed, so that the detection accuracy is extremely high; the control chip has high compatibility and expandability, can realize the function of quickly detecting the contact state of the relay in the power distribution unit, and greatly improves the compatibility and the practical value of the relay contact state detection circuit, so that the relay contact state detection circuit can be suitable for different industrial fields.

Fig. 6 shows a structural schematic of an electric vehicle 60 provided in the present embodiment, and as shown in fig. 6, the electric vehicle 60 includes: a high-voltage power distribution system 601 and a relay contact state detection circuit 602 of the high-voltage power distribution system as described above connected to the high-voltage power distribution system 601; wherein, the high voltage distribution system 601 includes: a battery unit 6011 and a power distribution unit 6012 connected to the battery unit 6011; wherein the battery cell 6011 includes: a battery VDD, a positive relay connected to a positive electrode of the battery VDD, and a negative relay connected to a negative electrode of the battery VDD, and the power distribution unit 6012 includes: the relay comprises a pre-charging relay K1 and a main positive relay K2, wherein a contact K1-1 of the pre-charging relay is connected with a contact K2-1 of the main positive relay in parallel and then connected with the positive relay or the negative relay.

Referring to the above-mentioned embodiments of fig. 1 to 5, in the present embodiment, the power output condition of the battery VDD can be controlled through the on or off states of the contact K _ B + of the positive relay and the contact K _ B-of the negative relay, so that the main driving circuit in the electric vehicle can be powered on or powered off, and the control efficiency and control accuracy of the electric vehicle 60 are ensured; the relay contact state detection circuit 602 can detect the normality, adhesion or failure of the contact K-1 of the pre-charging relay and the contact K1-1 of the main positive relay in real time so as to prevent the relay in the electric vehicle from generating control faults; in the process of detecting the contact state of the relay of the power distribution unit 6012, the relay contact state detection circuit 602 does not need to close the contact K _ B + of the positive relay and the contact K _ B of the negative relay in the battery unit, and the relay contact state detection circuit 602 detects the state of the contact K-1 of the pre-charge relay and/or the contact K1-1 of the main positive relay by means of the power supply of the relay, so that secondary damage to the physical safety of the positive relay and the negative relay in the relay contact state detection process is avoided; therefore, the high-voltage power distribution system of the electric vehicle 60 in the embodiment has higher safety, and the electric vehicle 60 has a wider application range; the problem that the relay contact in a high-voltage power distribution system in an electric automobile is detected by the conventional technology, so that the secondary damage of the relay on the power supply side in the electric automobile is caused, and the practical value of the electric automobile is reduced is effectively solved.

Fig. 7 shows a schematic configuration of a relay contact state detection system 70 of a high-voltage power distribution system provided in the present embodiment, the high-voltage power distribution system including: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected with the positive relay or the negative relay in parallel; as shown in fig. 7, the relay contact state detection system 70 includes: the relay contact state detection circuit 701 of the high voltage power distribution system described above.

Referring to the embodiments of fig. 1 to 5, the relay contact state detection circuit 701 of the present embodiment can implement a function of detecting a contact state of each relay in a power distribution unit, so as to determine whether a fault operation state occurs on a contact of each relay in the power distribution unit, and the detection precision is extremely high, and the operation is simple; in the process of detecting the contact state of the relay in the power distribution unit, the relay contact state detection circuit 701 only needs to feed back the contact state of the relay, and cannot control the relay state of the high-voltage power distribution system, so that the problems that the contact state of the relay in the battery unit is damaged and the detection accuracy is low due to the adhesion phenomenon of the relay contact in the power distribution unit are solved; when the relay contact state detection circuit 701 is applied to the relay contact state detection system 70, the relay contact state detection system 70 can ensure the electric power safety of a high-voltage power distribution system, the battery unit can always output safe and stable electric energy, and the relay contact state detection system 70 can be applied to different industrial fields, so that the safety performance of electric equipment is improved; the problem that the contact state detection system of the relay in the traditional technology cannot realize the safety detection of the contact state of the relay in the high-voltage distribution system and is difficult to universally apply is solved.

Fig. 8 shows a specific flow of a relay contact state detection method of a high-voltage power distribution system according to this embodiment, where the high-voltage power distribution system includes: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then are connected with the positive relay or the negative relay; the relay contact state detection method comprises the following steps:

s801: generating a control instruction for closing or closing the contact of the pre-charging relay and/or the contact of the main positive relay; the contact of the pre-charging relay and/or the contact of the main positive relay are controlled to be closed or turned off respectively, so that the physical safety performance of the contact of the pre-charging relay and/or the contact of the main positive relay is judged.

S802: connecting a contact of the pre-charging relay and a contact of the main positive relay in series between a first direct-current power supply and a power supply branch circuit, and generating a detection result representing the states of the contact of the pre-charging relay and the contact of the main positive relay according to the power-on or power-off state of the power supply branch circuit; the power-on or power-off state of the power supply branch circuit and the on-off state of the contacts of the pre-charging relay and the contacts of the main positive relay are in one-to-one correspondence, so that the on-off state of the contacts of the pre-charging relay and the contacts of the main positive relay can be accurately judged in real time through the electric energy transmission state of the power supply branch circuit, and the operation is simple and convenient.

S803: determining whether the contact of the pre-charging relay and the contact of the main positive relay are normal, adhered or invalid according to the corresponding relation between the detection result and the control command; the control instruction comprises user request information of the state of the relay contact, and whether the contact of the pre-charging relay and the contact of the main positive relay are in abnormal states or not can be obtained according to the matching result between the actual on-off states of the contact of the pre-charging relay and the contact of the main positive relay and the control instruction.

It should be noted that S801 to S803 in fig. 8 correspond to a relay contact state detection circuit of the high voltage distribution system in fig. 1, and therefore, reference may be made to the embodiments in fig. 1 to 5 for specific implementation of S801 to S803 in this embodiment, and details will not be repeated here.

According to the relay contact state detection method for the high-voltage power distribution system, the contact of the pre-charging relay and the contact of the main positive relay can be directly closed or turned off through the control command, and due to the fact that the control command and the on-off states of the contact of the pre-charging relay and the contact of the main positive relay are in one-to-one correspondence, when the on-off states of the contact of the pre-charging relay and/or the contact of the main positive relay are detected through power-on or power-off of the power supply branch circuit, the physical states of the contact of the pre-charging relay and the contact of the main positive relay can be accurately judged according to the detection result and the control command, and power supply safety of the high-voltage power distribution system; therefore, the relay contact state detection method in the embodiment not only can accurately detect the contact state of the relay in the power distribution unit, but also avoids the damage to the relay in the battery unit caused by the impact current generated by the adhesion condition of the contact of the pre-charging relay and/or the contact of the main positive relay in the power distribution unit in the relay contact state detection process; the relay contact state detection method realizes accurate and safe detection of the contacts of the pre-charging relay and the contacts of the main positive relay in the power distribution unit, and improves the application range and the practical value of the relay contact state detection method; the problems that the safety detection of relay contacts in a high-voltage distribution system cannot be realized and the safety of the high-voltage distribution system is low in the traditional technical method are solved.

Various embodiments are described herein for various devices, circuits, apparatuses, systems, and/or methods. Numerous specific details are set forth in order to provide a thorough understanding of the overall structure, function, manufacture, and use of the embodiments as described in the specification and illustrated in the accompanying drawings. However, it will be understood by those skilled in the art that the embodiments may be practiced without such specific details. In other instances, well-known operations, components and elements have been described in detail so as not to obscure the embodiments in the description. It will be appreciated by those of ordinary skill in the art that the embodiments herein and shown are non-limiting examples, and thus, it can be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

Reference throughout the specification to "various embodiments," "in an embodiment," "one embodiment," or "an embodiment," etc., means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," or the like, in places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure, or characteristic illustrated or described in connection with one embodiment may be combined, in whole or in part, with features, structures, or characteristics of one or more other embodiments without presuming that such combination is not an illogical or functional limitation. Any directional references (e.g., plus, minus, upper, lower, upward, downward, left, right, leftward, rightward, top, bottom, above …, below …, vertical, horizontal, clockwise, and counterclockwise) are used for identification purposes to aid the reader's understanding of the present disclosure, and do not create limitations, particularly as to the position, orientation, or use of the embodiments.

Although certain embodiments have been described above with a certain degree of particularity, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this disclosure. Joinder references (e.g., attached, coupled, connected, and the like) are to be construed broadly and may include intermediate members between a connection of elements and relative movement between elements. Thus, connection references do not necessarily imply that two elements are directly connected/coupled and in a fixed relationship to each other. The use of "for example" throughout this specification should be interpreted broadly and used to provide non-limiting examples of embodiments of the disclosure, and the disclosure is not limited to such examples. It is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the disclosure.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A relay contact state detection circuit for a high voltage power distribution system, the high voltage power distribution system comprising: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then are connected with the positive relay or the negative relay; the relay contact state detection circuit includes:

2. The relay contact state detection circuit according to claim 1, wherein the power supply branch further comprises: the LED, the first diode and the first resistor;

3. The relay contact state detection circuit according to claim 2, wherein the power supply branch further comprises: a second resistor;

4. The relay contact state detection circuit according to claim 2, wherein the detection module comprises:

5. The relay contact state detection circuit according to claim 4, wherein the signal detection unit includes:

6. The relay contact state detection circuit according to claim 5, wherein the state judgment unit includes: and the I/O pin of the control chip is connected with the signal output port of the signal detection unit.

7. The relay contact state detection circuit according to claim 5, wherein a first level signal is output from the signal output port of the signal detection unit when the light emitting diode does not emit a light source, and a second level signal is output from the signal output port of the signal detection unit when the light emitting diode emits a light source;

8. The relay contact state detection circuit of claim 5, wherein the optocoupler is a phototransistor or a photodiode.

9. An electric vehicle, comprising: a relay contact state detection circuit of a high voltage power distribution system and the high voltage power distribution system according to any one of claims 1 to 8 connected to the high voltage power distribution system; wherein the high voltage power distribution system comprises: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then connected with the positive relay or the negative relay.

10. A method of detecting a relay contact state of a high voltage power distribution system, the high voltage power distribution system comprising: the battery pack comprises a battery unit and a power distribution unit connected with the battery unit; wherein the battery cell includes: battery, with the positive relay that battery positive pole is connected and with the negative relay that the battery negative pole is connected, the distribution unit includes: the contact of the pre-charging relay and the contact of the main positive relay are connected in parallel and then are connected with the positive relay or the negative relay; the relay contact state detection method comprises the following steps: