Relay contact state detection circuit and its state detection method, electric vehicle

Abstract

A relay contact state detection circuit for a high-voltage power distribution system, and a method for detecting the relay contact state in an electric vehicle and a high-voltage power distribution system are disclosed. The relay contact state detection circuit includes: a first DC power supply, a power supply branch, and a detection module; the first DC power supply outputs first DC power; the power supply branch is connected between the second terminal of the pre-charge relay contact and the second terminal of the main positive relay contact and ground; the detection module generates a control signal for closing or closing the contacts of the pre-charge relay and / or the main positive relay; the detection module generates a detection result indicating the switching state of the contacts of the pre-charge relay and the main positive relay based on the energized or de-energized state of the power supply branch; and the detection module determines whether the contacts of the pre-charge relay and the main positive relay are normal, stuck, or failed based on 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

Technical Field

[0001] This invention belongs to the field of high-voltage power distribution technology, and particularly relates to a relay contact status detection circuit for a high-voltage power distribution system, and a method for detecting the relay contact status in electric vehicles and high-voltage power distribution systems. Background Technology

[0002] Currently, in the field of intelligent power supply for electronic devices, high-voltage power distribution technology has been widely used in the power supply systems of electronic devices. High-voltage power distribution systems can realize the on / off control of high-power power supplies and high-voltage components, including main drive circuits, oil pumps, air pumps, DC / DC conversion circuits, and chargers. In high-voltage power distribution systems, relays are usually used to realize the on / off control of high-voltage components. Due to the specific power switching characteristics of relays, relays, as key components for controlling high voltage from low voltage, enable different power conversion functions of the high-voltage power distribution system by opening or closing the relay contacts. Therefore, the on / off control performance of the relay contacts themselves has a very important impact on the safe power supply performance of the high-voltage power distribution system.

[0003] When the contacts of a relay in a high-voltage power distribution system malfunction, the electrical energy output by the system loses effective control, leading to physical safety hazards and significant damage to electrical equipment. Therefore, when a high-voltage power distribution system is used in related electrical equipment, it is essential to conduct real-time troubleshooting and prevention of relay malfunctions. Taking electric vehicles as an example, according to section 7.1 of the national standard GB / T 18487.1-2015 "Electric Vehicle Conductive Charging System Part 1: General Requirements," electric vehicles should have contactor adhesion monitoring and alarm functions in the charging circuit, and power supply equipment should also have contactor adhesion monitoring and alarm functions in the power supply circuit. Therefore, technicians need to monitor the relay contact status in the high-voltage power distribution system in real time to avoid safety hazards caused by relay contact malfunctions.

[0004] However, traditional technologies for safety testing of relay contacts in high-voltage power distribution systems rely on comparing the voltage at the relay's contact terminals with the voltage on the power supply side to determine if the relay is in a safe control state. This traditional approach has several drawbacks: First, after the power supply side relay contacts close, the power supply transmits power to the relay contacts in the high-voltage power distribution system to detect the voltage at the relay's contact terminals and determine if the relay is malfunctioning. Second, if the relays in the high-voltage power distribution system have a sticking problem before the power supply side relay contacts close, the power supply will output high-power energy to the relay contacts after closing, generating a large inrush current. This could even cause the power supply side relay contacts to stick as well, resulting in secondary damage to the high-voltage power distribution system and affecting its electrical safety. The failure rate of relay contacts in high-voltage power distribution systems is relatively high. Summary of the Invention

[0005] In view of this, embodiments of the present invention provide a relay contact status detection circuit for a high-voltage power distribution system, and a relay contact status detection method for electric vehicles and high-voltage power distribution systems, aiming to solve the problems that traditional technical solutions cannot achieve safe detection of relay contacts in high-voltage power distribution systems and that the safety of high-voltage power distribution systems is low.

[0006] A first aspect of this invention provides a relay contact state detection circuit for a high-voltage power distribution system. The high-voltage power distribution system includes: a battery unit and a power distribution unit connected to the battery unit; wherein the battery unit includes: a battery, a positive relay connected to the positive terminal of the battery, and a negative relay connected to the negative terminal of the battery; the power distribution unit includes: a pre-charge relay and a main positive relay, wherein the contacts of the pre-charge relay and the contacts of the main positive relay are connected in parallel to either the positive relay or the negative relay; the relay contact state detection circuit includes:

[0007] A first DC power supply is connected to the first end of the contacts of the precharge relay and the first end of the contacts of the main positive relay. The first DC power supply is used to output first DC power.

[0008] A power supply branch, the input terminal of which is connected to the second terminal of the pre-charge relay contact and the second terminal of the main positive relay contact, and the output terminal of which is grounded; and

[0009] A detection module, coupled to the power supply branch, generates control signals to close or close the contacts of the pre-charge relay and / or the main positive relay. The detection module generates detection results indicating the switching state of the contacts of the pre-charge relay and the main positive relay based on the energized or de-energized state of the power supply branch. Furthermore, the detection module determines, based on the detection results and the control signals, whether the contacts of the pre-charge relay and the main positive relay are normal, stuck, or faulty.

[0010] In one embodiment, the power supply branch further includes: a light-emitting diode, a first diode, and a first resistor;

[0011] Wherein, the anode of the first diode is connected to the second end of the contact of the precharge relay and the second end of the contact of the main positive relay, the cathode of the first diode is connected to the first end of the first resistor, the second end of the first resistor is connected to the anode of the light-emitting diode, and the cathode of the light-emitting diode is grounded.

[0012] In one embodiment, the power supply branch further includes: a second resistor;

[0013] Wherein, the first end of the second resistor is connected to the second end of the contact of the precharge relay, and the second end of the second resistor is connected to the second end of the contact of the main positive relay and the anode of the first diode.

[0014] In one embodiment, the detection module includes:

[0015] A signal generation unit is coupled to the contacts of the precharge relay and the main positive relay, and the signal generation unit generates control signals for closing or closing the contacts of the precharge relay and / or the main positive relay.

[0016] A signal detection unit is coupled to the power supply branch and the signal generation unit. The signal detection unit generates a detection result indicating the switching state of the contacts of the precharge relay and the main positive relay based on the energized or de-energized state of the power supply branch. The signal detection unit determines whether the contacts of the precharge relay and the main positive relay are normal, stuck, or faulty based on the detection result and the control signal.

[0017] In one embodiment, the signal detection unit includes:

[0018] The second DC power supply is used to output a second DC power.

[0019] The third resistor, the first end of which is connected to the second DC power supply;

[0020] An optocoupler element, coupled to the light-emitting diode, wherein the first conducting terminal of the optocoupler element and the second terminal of the third resistor are jointly connected to form the signal output port of the signal detection unit, and the second conducting terminal of the optocoupler element is grounded; and

[0021] A status determination unit, the communication port of which is connected to the signal output port of the detection module, determines the switching status of the contacts of the precharge relay and the contacts of the main positive relay based on the level signal of the signal output port of the signal detection unit.

[0022] The state determination unit determines whether the contacts of the precharge relay and the main positive relay are normal, stuck, or faulty based on the correspondence between the control signal and the switch state.

[0023] In one embodiment, the state determination unit includes a control chip, wherein the I / O pins of the control chip are connected to the signal output port of the signal detection unit.

[0024] In one embodiment, when the light-emitting diode does not emit light, the signal output port of the signal detection unit outputs a first-level signal; when the light-emitting diode emits light, the signal output port of the signal detection unit outputs a second-level signal.

[0025] Wherein, 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 interleaved.

[0026] In one embodiment, the optocoupler is a phototransistor or a photodiode.

[0027] A second aspect of the present invention provides an electric vehicle, comprising: a high-voltage power distribution system and a relay contact state detection circuit of the high-voltage power distribution system as described above, connected to the high-voltage power distribution system; wherein the high-voltage power distribution system comprises: a battery unit and a power distribution unit connected to the battery unit; wherein the battery unit comprises: a battery, a positive relay connected to the positive terminal of the battery and a negative relay connected to the negative terminal of the battery, and the power distribution unit comprises: a pre-charge relay and a main positive relay, wherein the contacts of the pre-charge relay and the contacts of the main positive relay are connected in parallel to either the positive relay or the negative relay.

[0028] A third aspect of this invention provides a method for detecting the state of relay contacts in a high-voltage power distribution system. The high-voltage power distribution system includes a battery unit and a power distribution unit connected to the battery unit. The battery unit includes a battery, a positive relay connected to the positive terminal of the battery, and a negative relay connected to the negative terminal of the battery. The power distribution unit includes a pre-charge relay and a main positive relay. The contacts of the pre-charge relay and the main positive relay are connected in parallel to either the positive or negative relay. The method for detecting the state of relay contacts includes:

[0029] Generate control commands to close or close the contacts of the precharge relay and / or the contacts of the main positive relay;

[0030] The contacts of the precharge relay and the contacts of the main positive relay are connected in series between the first DC power supply and the power supply branch. A detection result representing the switching state of the contacts of the precharge relay and the main positive relay is generated based on the energized or de-energized state of the power supply branch.

[0031] Based on the correspondence between the test results and the control commands, it is determined whether the contacts of the precharge relay and the main positive relay are normal, stuck, or ineffective.

[0032] The relay contact status detection circuit of the aforementioned high-voltage power distribution system can provide separate detection power for the detection process of the pre-charge relay contacts and the main positive relay contacts through a first DC power supply. The power supply branch provides feedback on the closed or open state of the pre-charge relay contacts and the main positive relay contacts based on its own energized or de-energized state. Regardless of whether the contacts of the positive relay and the negative relay in the battery cell are closed or open, the detection module can determine the contact status of the pre-charge relay and / or the main positive relay based on the comparison between the switching state of the pre-charge relay contacts and the main positive relay contacts and the control signal. The detection of whether the contacts are in a faulty state improves the control safety of the contacts of the pre-charge relay and the main positive relay in the high-voltage power distribution system. Therefore, the relay contact state detection circuit in this embodiment of the invention achieves safety detection of both the contacts of the pre-charge relay and the main positive relay, preventing the contacts of the positive and negative relays in the battery cell from closing even when the pre-charge relay and / or the main positive relay are stuck together, thus avoiding damage to the positive and negative relays. The relay contact state detection circuit in this embodiment has a wide range of applications and greatly ensures the power distribution safety of the high-voltage power distribution system. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a schematic diagram of a relay contact status detection circuit for a high-voltage power distribution system according to an embodiment of the present invention.

[0035] Figure 2 This is a system block diagram of a high-voltage power distribution system for an electric vehicle provided in an embodiment of the present invention;

[0036] Figure 3 This is a schematic diagram of another structure of a relay contact status detection circuit for a high-voltage power distribution system provided in an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of another structure of a relay contact status detection circuit for a high-voltage power distribution system provided in an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of another structure of a relay contact status detection circuit for a high-voltage power distribution system provided in an embodiment of the present invention;

[0039] Figure 6 This is a schematic diagram of the structure of an electric vehicle provided in an embodiment of the present invention;

[0040] Figure 7 This is a schematic diagram of the structure of a relay contact status detection system for a high-voltage power distribution system according to an embodiment of the present invention;

[0041] Figure 8 The flowchart illustrates a specific method for detecting the status of relay contacts in a high-voltage power distribution system according to an embodiment of the present invention. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0043] Please see Figure 1The present invention provides a schematic diagram of the structure of a relay contact state detection circuit for a high-voltage power distribution system. This circuit can detect the safety status of the relay contacts in the high-voltage power distribution system to ensure the power supply safety of the system. For ease of explanation, only the parts relevant to this embodiment are shown, and are detailed below:

[0044] like Figure 1 As shown, the relay contact status detection circuit in this embodiment is applied to a high-voltage power distribution system. The high-voltage power distribution system referred to in this embodiment is a broad concept, capable of realizing various functions such as power transmission, circuit on / off control, and high-voltage power distribution. This high-voltage power distribution system enables the conversion and compatibility between power of different amplitudes, ensuring that various types of electronic components can always access safe and stable power. Therefore, high-voltage power distribution systems are necessary in certain industrial fields; for example, electric vehicles... Figure 2 A system block diagram of a high-voltage power distribution system in an electric vehicle is shown, with reference to... Figure 2 The high-voltage power distribution system can output stable power to various components in the electric vehicle according to the power requirements of different electronic components, thus ensuring the power supply safety of the electric vehicle.

[0045] It should be noted that, Figure 2 The high-voltage power distribution system shown in the electric vehicle is merely one embodiment and does not constitute a limitation on the high-voltage power distribution system in this embodiment. The high-voltage power distribution systems mentioned in the following embodiments can be applied to different industrial products, have strong compatibility, and can ensure the power safety of different types of industrial products. They are widely applicable in various industrial fields. As the application object of the relay contact state detection circuit, the high-voltage power distribution system can be fine-tuned by technicians without violating the essential technical features of the relay contact state detection circuit in the following embodiments. The relay contact state detection circuit can be applied to different types of high-voltage power distribution systems.

[0046] To better illustrate the working principle of the relay contact state detection circuit, the following embodiments all apply the relay contact state detection circuit to electric vehicles to illustrate the specific implementation of the relay contact state detection circuit; since this is only an example, it does not mean that the relay contact state detection circuit in each embodiment can only be applied to electric vehicles.

[0047] like Figure 1As shown, the high-voltage power distribution system includes: a battery unit and a power distribution unit connected to the battery unit; wherein the battery unit provides high-voltage electrical energy, which can power all components in the electric vehicle; the power distribution unit can realize the conversion and on / off control of electrical energy, thereby controlling the power supply or de-energization of various components in the electric vehicle, and outputting corresponding electrical energy according to the rated power requirement of each component to protect the operational safety of various components in the electric vehicle; specifically, the battery unit includes: a battery VDD, a positive relay connected to the positive terminal of the battery VDD, and a negative relay connected to the negative terminal of the battery VDD, wherein the contacts K_B+ of the positive relay, the battery VDD, and the contacts K_B- of the negative relay are connected in series. Next, the battery VDD is used for energy storage and output. Through the battery VDD, electrical energy can be continuously output to ensure the long-term operation of the electric vehicle. The on and off of the circuit can be controlled by the contacts K_B+ and K_B- of the positive relay and the negative relay. Only when the contacts K_B+ and K_B- of the positive relay and the negative relay are closed at the same time can the battery unit power the electric vehicle. For example, when the contacts K_B+ and K_B- of the positive relay and the negative relay are closed at the same time, the electric motor of the electric vehicle can be powered on, and the electric vehicle can be started to enter the driving state. Moreover, the electrical energy output by the battery unit has a large amplitude, which can simultaneously drive multiple components in the electric vehicle to a stable working state.

[0048] The power distribution unit includes a pre-charge relay K1 and a main positive relay K2. This unit can transmit electrical energy from the battery cell to multiple components in the electric vehicle, ensuring each component maintains its rated operating state. The contacts K1-1 of the pre-charge relay and K2-1 of the main positive relay are connected in parallel to either a positive or negative relay. When either contact K1-1 or K2-1 closes, the power supply circuit for the components in the electric vehicle is activated. The battery VDD outputs electrical energy through the contacts K_B+ and K_B- of the positive and negative relays, allowing the main drive circuit of the electric vehicle to be connected and maintain normal operation. Optionally, the main drive circuit includes the electric vehicle's engine. Figure 1The equivalent circuit structure of the main drive circuit of the electric vehicle is shown. If either the pre-charge relay contact K1-1 or the main positive relay contact K2-1 is closed, the resistor RL and capacitor CL can be connected to electrical energy. The pre-charge relay K1 is used to provide pre-charge protection for the main drive circuit. Before the main drive circuit is officially connected to electrical energy to maintain normal operation, the pre-charge relay contact K1-1 is closed to prevent the spike current generated at the moment of circuit conduction from causing physical damage to the electronic components in the main drive circuit. When the current in the power supply circuit of the electric vehicle tends to stabilize, then... By closing the contact K2-1 of the main positive relay, the electrical energy in the main drive circuit can be rapidly transitioned from the moment the circuit is turned on to the stable operation stage. Therefore, the power distribution unit can realize the function of low-voltage control of high-voltage components through the on or off states of the contacts K1-1 of the pre-charge relay and K2-1 of the main positive relay, so as to realize the on or off state of the power supply circuit in the electric vehicle, and the various components in the electric vehicle are in a energized or de-energized state. Moreover, the power distribution unit can realize the safe start-up of the components, ensuring the safe operation of the electric vehicle, and the components in the electric vehicle can always be in a safe and stable operating state.

[0049] Reference Figure 1 The relay contact state detection circuit shown includes: a first DC power supply VCC1, a power supply branch 101, and a detection module 102.

[0050] The first DC power supply VCC1 is connected to the first end of the contact K1-1 of the precharge relay and the first end of the contact K2-1 of the main positive relay. The first DC power supply VCC1 is used to output the first DC power.

[0051] For example, the first DC power supply VCC1 is a +5V or +10V DC power supply.

[0052] The first DC power supply VCC1 has an energy storage function. This first DC energy serves as the power supply for the contact status detection process of the pre-charge relay contact K1-1 and the main positive relay contact K2-1 in this embodiment. When either contact K1-1 of the pre-charge relay or contact K2-1 of the main positive relay is closed, the first DC power supply VCC1 transmits the first DC energy to the power supply branch 101. When both contact K1-1 of the pre-charge relay and contact K2-1 of the main positive relay are closed, the first DC power supply VCC1 cannot output the first DC energy. Therefore, the relay contact status detection circuit in this embodiment utilizes the first DC energy... Power supply VCC1 serves as the power source for the detection process, eliminating the need to rely on battery power from the battery cell for relay contact status detection. Even when the positive relay contact K_B+ and the negative relay contact K_B- in the battery cell are open, the relay contact status detection circuit can still perform real-time detection of the relay contact status based on the first DC power output from the first DC power supply VCC1. This greatly ensures the safety of each relay contact in the high-voltage power distribution system and avoids significant physical damage to the battery cell caused by faults in the pre-charge relay contact K1-1 and the main positive relay contact K2-1.

[0053] The input terminal of power supply branch 101 is connected to the second terminal of contact K1-1 of the precharge relay and the second terminal of contact K2-1 of the main positive relay. The output terminal of power supply branch 101 is grounded to GND. Power supply branch 101 can be used to realize the transmission of electrical energy. When either contact K1-1 of the precharge relay or contact K2-1 of the main positive relay is closed, power supply branch 101 can be connected to the first DC power. Therefore, the power supply branch 101 can be energized or de-energized by the conduction or de-energization of contact K1-1 of the precharge relay and contact K2-1 of the main positive relay. There is a one-to-one correspondence between the closed or closed state of contact K1-1 of the precharge relay and contact K2-1 of the main positive relay and the energized or de-energized state of power supply branch 101. Therefore, the power transmission state of power supply branch 101 has a relatively sensitive control response speed, which helps the relay contact state detection circuit to accurately detect the relay contact state.

[0054] The detection module 102 is coupled to the power supply branch 101. The detection module 102 generates control signals to close or close the contacts K1-1 of the pre-charge relay and / or the contacts K2-1 of the main positive relay. The detection module 102 has a relay contact on / off control function. The control signals generated by the detection module 102 contain different control commands. Different control commands can drive the contacts K1-1 of the pre-charge relay and / or the contacts K2-1 of the main positive relay to different on or off states. Optionally, the detection module 102 generates corresponding control signals according to the user's operation commands. The user can then directly change the control commands in the detection module 102 to make the contacts K1-1 of the pre-charge relay and the contacts K2-1 of the main positive relay in corresponding on or off states, improving the user experience. For example, the control commands in the control signals have the following relationship with the closing or closing of the contacts K1-1 of the pre-charge relay and the contacts K2-1 of the main positive relay:

[0055] 1. The control signal includes a first control command, in which the contact K1-1 of the precharge relay is closed and the contact K2-1 of the main positive relay is closed.

[0056] 2. The control signal includes a second control command, in which the contact K1-1 of the precharge relay is turned off and the contact K2-1 of the main positive relay is closed.

[0057] 3. The control signal includes a third control command, in which the contacts K1-1 of the precharge relay are turned off and the contacts K2-1 of the main positive relay are turned off.

[0058] 4. The control signal includes a fourth control command, in which the contacts K1-1 of the precharge relay are closed and the contacts K2-1 of the main positive relay are closed.

[0059] Therefore, in this embodiment, the control signal generated by the detection module 102 can directly change the on or off state of the precharge relay contact K1-1 and the main positive relay contact K2-1, which has extremely high control response speed and control sensitivity.

[0060] The detection module 102 generates a detection result indicating the switching state of the precharge relay contact K1-1 and the main positive relay contact K2-1 based on the energization or de-energization of the power supply branch 101. The detection module 102 then determines, based on the detection result and the control signal, whether the precharge relay contact and the main positive relay contact are in normal, stuck, or faulty condition.

[0061] It should be noted that the sticking phenomenon of the relay contacts refers to the following: due to excessive voltage / current flowing through the relay, the relay contacts remain continuously closed. Even if a disconnection command is issued to the relay, the relay contacts remain closed. The sticking phenomenon of the relay contacts will seriously affect the safety of the power system and may lead to abnormal power-on phenomena of electronic components.

[0062] The detection module 102 can determine the on / off state of the precharge relay contact K1-1 and the main positive relay contact K2-1 based on the power transmission status of the power supply branch 101, with extremely high detection accuracy. As mentioned above, there is a one-to-one correspondence between the state of the control signal and the on / off state of the precharge relay contact K1-1 and the main positive relay contact K2-1. Therefore, by comparing the detection result of the detection module 102 with the control signal, it is possible to determine whether the precharge relay contact K1-1 and / or the main positive relay contact K2-1 are in a fault state.

[0063] The following is a specific application scenario to illustrate the detection process of the detection module 102 for the state of contact K1-1 of the precharge relay and the state of contact K2-1 of the main positive relay:

[0064] If the control signal contains a third control command, then, referring to the above, the contacts K1-1 of the precharge relay and K2-1 of the main positive relay will perform their respective operations. At this time, the detection module 102 determines the working state of the relay contacts based on the power transmission status of the power supply branch 101; this can be divided into the following two cases:

[0065] If the power supply branch 101 is energized, the detection module 102 will detect that at least one of the contacts K1-1 of the precharge relay and K2-1 of the main positive relay is closed. This detection result does not match the control information in the control signal. The contacts K1-1 of the precharge relay and / or the contacts K2-1 of the main positive relay are in an abnormal closed state. At this time, the detection module 102 can determine that the contacts K1-1 of the precharge relay and / or the contacts K2-1 of the main positive relay are stuck or ineffective.

[0066] If the power supply branch 101 loses power, the detection module 102 detects that both the precharge relay contact K1-1 and the main positive relay contact K2-1 are closed. This detection result matches the control information in the control signal perfectly. The precharge relay contact K1-1 and the main positive relay contact K2-1 are in a normal closed state. Therefore, based on the comparison between the control signal and the switching states of the precharge relay contact K1-1 and the main positive relay contact K2-1, the detection module 102 can determine that the precharge relay contact K1-1 and the main positive relay contact K2-1 are in a normal state.

[0067] If the control signal contains the first control command, referring to the above, the contacts K1-1 of the precharge relay and K2-1 of the main positive relay execute corresponding actions according to the fourth control command. At this time, the detection module 102 determines the closed or closed state of the contacts K1-1 of the precharge relay and K2-1 of the main positive relay based on the energized or de-energized state of the power supply branch 101, which falls into the following two categories:

[0068] If the power supply branch 101 is energized, the detection module 102 detects that the precharge relay contact K1-1 is closed. Since there is current in the power supply branch 101, the closed state of the precharge relay contact K1-1 is completely matched with the control information in the control signal. The control signal can enable normal operation of the precharge relay contact K1-1. Therefore, the detection module 102 can determine that the precharge relay contact K1-1 is in normal condition.

[0069] If the power supply branch 101 loses power, the detection module 102 detects that the pre-charge relay contact K1-1 is closed. Since the power supply branch 101 cannot receive the first DC power, the closed state of the pre-charge relay contact K1-1 does not match the control information in the control signal. Therefore, the pre-charge relay contact K1-1 is in a failed state, and the control signal cannot close it. Thus, the detection module 102 can accurately identify the failure of the pre-charge relay contact K1-1 based on the power transmission status of the power supply branch 101 and the control signal, ensuring the monitoring accuracy of the relay contact status detection circuit for the state of the pre-charge relay contact K1-1. This provides higher power supply security for the high-voltage power distribution system.

[0070] In conjunction with the above, the relay contact status detection circuit in this embodiment can display the closing or closing information of the pre-charge relay contact K1-1 and the main positive relay contact K2-1 through the energization or de-energization status of the power supply branch 101. Since there is a one-to-one correspondence between the control signal and the on / off states of the pre-charge relay contact K1-1 and the main positive relay contact K2-1, the detection module 102 can accurately determine whether the pre-charge relay contact K1-1 and the main positive relay contact K2-1 are in normal working condition based on the detection results of the switching states of the pre-charge relay contact K1-1 and the main positive relay contact K2-1 and the correspondence with the control command, thus achieving accurate detection of the relay contacts and ensuring the power supply safety of the high-voltage power distribution system. In this embodiment, the relay contact status detection circuit can directly utilize the electrical energy output from the first DC power supply VCC1 to detect the abnormal state of the pre-charge relay contact K1-1 and / or the main positive relay contact K2-1. This eliminates the need for the positive and negative relays in the battery unit to supply power to the pre-charge relay contact K1-1 and the main positive relay contact K2-1 in the power distribution unit. This avoids secondary damage to the relays in the battery unit caused by the adhesion of the pre-charge relay contact K1-1 and / or the main positive relay contact K2-1, thus improving the safety performance of the high-voltage power distribution system. Therefore, the relay contact status detection circuit in this embodiment can achieve accurate and safe detection of the faulty operating states of the pre-charge relay contact K1-1 and the main positive relay contact K2-1.

[0071] As an optional implementation method, Figure 3 This embodiment illustrates another structural diagram of the relay contact status detection circuit for the high-voltage power distribution system provided, as shown below. Figure 3 As shown, the power supply branch 101 also includes: a light-emitting diode LED1, a first diode D1, and a first resistor R1.

[0072] Wherein, the anode of the first diode D1 is connected to the other end of the contact K1-1 of the precharge 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 to GND.

[0073] In this embodiment, the illumination state of LED1 can indicate the switching state of either contact K1-1 of the precharge relay or contact K2-1 of the main positive relay. Specifically, LED1 can achieve a corresponding light-emitting effect after being connected to the first DC power. If LED1 is not connected to the first DC power, it means that both contact K1-1 of the precharge relay and contact K2-1 of the main positive relay are closed, and LED1 does not emit the corresponding light source. Conversely, if either contact K1-1 of the precharge relay or contact K2-1 of the main positive relay is closed, LED1 is connected to the first DC power to emit the corresponding light source. Therefore, in this embodiment, the LED1 is made to light up or turn off according to the closed or closed state of contact K1-1 of the precharge relay and contact K2-1 of the main positive relay. The illumination state of LED1 can be used to intuitively monitor the switching state of contact K1-1 of the precharge relay and contact K2-1 of the main positive relay.

[0074] In this embodiment, the first resistor R1 can limit the current, preventing excessive current in the LED1 and thus protecting the LED1 from damage. The first diode D1 prevents reverse conduction of current in the power supply branch 101, ensuring the detection accuracy of the detection module 102 in detecting the on / off state of the precharge relay contact K1-1 and the main positive relay contact K2-1. This allows the relay contact state detection circuit in this embodiment to detect abnormal operating information of the precharge relay contact K1-1 and / or the main positive relay contact K2-1 more safely and accurately.

[0075] As an optional implementation method, such as Figure 3 As shown, the power supply branch 101 further includes: a second resistor R2; wherein, the first end of the second resistor R2 is connected to the second end of the contact K1-1 of the precharge relay, and the second end of the second resistor R2 is connected to the second end of the contact K2-1 of the main positive relay and the anode of the first diode D1.

[0076] The second resistor R2 can consume electrical energy during the pre-charge protection process of the main drive circuit, thereby reducing the current surge caused to electronic components by the peak current at the moment the circuit is turned on. At the moment the contact K1-1 of the pre-charge relay is turned on, there is a peak current in the second resistor R2. The second resistor R2 can consume electrical energy in time, ensuring the safe start-up of the main drive circuit. Therefore, in this embodiment, the second resistor R2 plays a current-limiting role during the pre-charge protection process, thereby improving the power stability and safety of the high-voltage power distribution system.

[0077] As an optional implementation method, Figure 4 This embodiment illustrates another structural diagram of the relay contact status detection circuit for the high-voltage power distribution system provided, as shown below. Figure 4 As shown, the detection module 102 includes a signal generation unit 1021 and a signal detection unit 1022.

[0078] The signal generation unit 1021 is coupled to the contact K1-1 of the precharge relay and the contact K2-1 of the main positive relay. The signal generation unit 1021 generates control signals for closing or closing the contact K1-1 of the precharge relay and / or the contact K2-1 of the main positive relay.

[0079] Referring to the above, the control signals generated by the signal generation unit 1021 have different control commands. These control commands can respectively close or close the contacts K1-1 of the precharge relay and / or the contacts K2-1 of the main positive relay. As a result, the contacts K1-1 of the precharge relay and the contacts K2-1 of the main positive relay have extremely high control response speed, which improves the detection rate of the relay contact state detection circuit for the relay contact state.

[0080] 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 the switching state of the precharge relay contact K1-1 and the main positive relay contact K2-1 based on the power supply branch 101 being energized or de-energized. The signal detection unit 1022 determines, based on the detection result and the control signal, whether the precharge relay contact K1-1 and the main positive relay contact K2-1 are normal, stuck, or faulty.

[0081] Specifically, the signal detection unit 1022 detects the switching state of either the precharge relay contact K1-1 or the main positive relay contact K2-1 based on the illumination state of the light-emitting diode LED1, thereby improving the accuracy of relay contact state detection. Therefore, in this embodiment, by changing the closed or open state of either the precharge relay contact K1-1 or the main positive relay contact K2-1 through the signal generation unit 1021, the signal detection unit 1022 can detect the actual closed or open state of the precharge relay contact K1-1 and / or the main positive relay contact K2-1, and, based on the control command in the control signal and the contact state of the precharge relay contact K1-1 and / or the main positive relay contact K2-1, further determines the switching state. The correspondence between the closed and closed states of K1-1 and K2-1 is used to accurately identify whether the relay is in an abnormal state, with extremely high detection accuracy. Therefore, in this embodiment, the detection module 102 controls the on or off state of the precharge relay contact K1-1 and / or the main positive relay contact K2-1 through the signal generation unit 1021, and detects the actual on or off state of the relay contact through the signal detection unit 1022 to determine the abnormality of the relay contact state. This simplifies the module structure of the detection module 102, improves the judgment speed of the relay contact state detection circuit for the relay state, avoids relay contact state detection errors caused by misoperation, and ensures the normal and stable operation of the detection module 102.

[0082] As an optional implementation method, Figure 5 This embodiment illustrates another structural diagram of the relay contact status detection circuit for the high-voltage power distribution system provided, as shown below. Figure 5 As shown, the signal generation unit 1021 includes: a first signal generation unit 501 and a second signal generation unit 502.

[0083] The first signal generation unit 501 generates a first control signal to turn on or off the contact K1-1 of the precharge relay; the second signal generation unit 502 generates a second control signal to turn on or off the contact K2-1 of the main positive relay.

[0084] In this embodiment, the first control signal and the second control signal are used to control the on / off state of the precharge relay contact K1-1 and the main positive relay contact K2-1, respectively, which improves the control accuracy and efficiency of the signal generation unit 1021 for the relays in the power distribution unit. The control command in the first control signal corresponds one-to-one with the switching state of the precharge relay contact K1-1, and the control command in the second control signal corresponds one-to-one with the switching state of the main positive relay contact K2-1. Therefore, the signal generation unit 1021 uses the first and second control signals to classify and control the precharge relay contact K1-1 and the main positive relay contact K2-1, which is beneficial for the relay contact state detection circuit to accurately detect the working state of the precharge relay contact K1-1 and / or the main positive relay contact K2-1, and has extremely high practical value.

[0085] As an optional implementation, the first signal generation unit 501 and the second signal generation unit 502 can be implemented using a microcontroller or logic control circuit in conventional technology, which is not limited herein. For example, the first signal generation unit 501 can be implemented using a logic control circuit in conventional technology. The logic control circuit includes an array of switching transistors. By controlling the switching transistors to turn on or off, the logic control circuit outputs electrical energy during the on period to energize the coil K1-1 of the precharge relay and close the contact K1-1 of the precharge relay. During the off period, the logic control circuit cannot output electrical energy to de-energize the coil K1-1 of the precharge relay and close the contact K1-1 of the precharge relay. Therefore, the logic control circuit changes the energized or de-energized state of the coils of the relays (including the precharge relay and the main positive relay) to make the contacts of the relays close or close. The signal generation unit 1021 in this embodiment has a more flexible circuit structure, which improves the control response speed for the contacts K1-1 of the precharge relay and the contacts K2-1 of the main positive relay.

[0086] As an optional implementation method, such as Figure 5 As shown, the signal detection unit 1022 includes: a second DC power supply VCC2, a third resistor R3, an optocoupler Q1, and a state judgment unit 1031; wherein, the second DC power supply VCC2 is used to output second DC power, which 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 relay contacts.

[0087] The first end of the third resistor R3 is connected to the second DC power supply; wherein the third resistor R3 can limit current and convert between voltage signals and current signals.

[0088] The optocoupler Q1 is coupled to the light-emitting diode LED1. The first conducting terminal of the optocoupler Q1 and the second terminal of the third resistor R3 are connected together to form the signal output port of the signal detection unit 1022. The second conducting terminal of the optocoupler Q1 is grounded to GND. The light source change of the light-emitting diode LED1 is sensed through the optocoupler Q1.

[0089] Optionally, when the light-emitting diode LED1 does not emit light, the signal output port of the signal detection unit 1022 outputs a first level signal; when the light-emitting diode LED1 emits light, the signal output port of the signal detection unit 1022 outputs a second level signal.

[0090] As an optional implementation, the optocoupler element Q1 is a phototransistor or a photodiode.

[0091] Since optocoupler Q1 has the function of photoelectric signal conversion, when the light signal received by optocoupler Q1 changes, the electrical characteristics of optocoupler Q1 itself will also change. For example, taking a photodiode as an example, the photodiode is very sensitive to changes in light intensity. For instance, the stronger the incident light received by the photodiode, the higher the conductivity of the photodiode, and the larger the current through the photodiode; the weaker the incident light received by the photodiode, the lower the conductivity of the photodiode, and the smaller the current through the photodiode. Therefore, there is a one-to-one correspondence between the change in current in the photodiode and the incident light. In this embodiment, when the light source emitted by the light-emitting diode LED1 can affect the electrical characteristics of optocoupler Q1, when the light-emitting diode LED1 is in different light-emitting states, optocoupler Q1 can output a first level signal or a second level signal. The level signal state output by the signal output port of the signal detection unit 1022 can determine whether the light-emitting diode LED1 is in a light-emitting or off state.

[0092] In conjunction with the above, when both the precharge relay contact K1-1 and the main positive relay contact K2-1 are closed, LED1 cannot receive the first DC power and therefore cannot emit light. When the optocoupler Q1 senses the change in the light source state of LED1, the signal output port of the signal detection unit 1022 outputs a first-level signal, thereby accurately determining the non-emitting state of LED1. Conversely, when either the precharge relay contact K1-1 or the main positive relay contact K2-1 is closed, LED1 receives the first DC power and emits light. The optocoupler Q1 senses the light intensity of LED1 and adjusts its conductivity, causing the signal output port of the signal detection unit 1022 to output a second-level signal. This second-level signal allows for real-time monitoring of the closed or closed states of both the precharge relay contact K1-1 and the main positive relay contact K2-1, resulting in extremely high monitoring accuracy.

[0093] 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 the phases of the first level signal and the second level signal are interleaved; therefore, the circuit structure of the signal detection unit 1022 in this embodiment has high flexibility.

[0094] Therefore, the signal detection unit 1022 can detect the light-emitting state of the LED1 in real time through the optocoupler element Q1, and then output a first level signal or a second level signal according to the on or off state of the precharge relay contact K1-1 and the main positive relay contact K2-1. The signal detection unit 1022 can accurately obtain the on / off state of the relay contacts in the power distribution unit according to the first level signal or the second level signal. The operation is simple and simplifies the detection steps of the relay contact state detection circuit for the relay contact state.

[0095] The communication port of the state determination unit 1031 is connected to the signal output port of the signal detection unit 1022. The state determination unit 1031 confirms the switching state of the precharge relay contact K1-1 and the main positive relay contact K2-1 based on the level signal of the signal output port of the signal detection unit 1022. Optionally, the state determination unit 1031 confirms with the first level signal that both the precharge relay contact K1-1 and the main positive relay contact K2-1 are closed, and the state determination unit 1031 confirms with the second level signal that the precharge relay contact K1-1 is closed and / or the main positive relay contact K2-1 is closed.

[0096] Referring to the above, the first level signal corresponds to the off state of both the precharge relay contact K1-1 and the main positive relay contact K2-1, and the second level signal corresponds to the closed state of either the precharge relay contact K1-1 or the main positive relay contact K2-1. Therefore, the state judgment unit 1031 in this embodiment can accurately determine the on / off state of the precharge relay contact K1-1 and the main positive relay contact K2-1 based on the level signal of the signal output port. The detection rate is extremely fast, reducing the error in the state judgment unit 1031's judgment of the relay contact state.

[0097] The state judgment unit 1031 determines whether the contacts K1-1 of the precharge relay and K2-1 of the main positive relay are normal, stuck, or ineffective based on the correspondence between the control signal and the switch state. Furthermore, this embodiment determines whether the contacts K1-1 of the precharge relay and K2-1 of the main positive relay are normal, stuck, or ineffective based on the correspondence between the control signal and the closed or closed state of the contacts K1-1 and K2-1 of the main positive relay. As shown above, based on the matching result between the control command in the control signal and the switch state of either the contacts K1-1 of the precharge relay or K2-1 of the main positive relay, it is possible to quickly identify whether the relay executes the corresponding action according to the control command in the control signal, thereby improving the detection accuracy of the relay contact state detection circuit for the relay contact state.

[0098] Reference Figure 5 In one embodiment, the control signal includes a first control signal and a second control signal; then the state determination unit 1031 determines whether the precharge relay contact K1-1 is in normal, stuck, or failed based on the correspondence between the first control signal and the closed or closed contact K1-1 of the precharge relay; the state determination unit 1031 determines whether the main positive relay contact K2-1 is in normal, stuck, or failed based on the correspondence between the second control signal and the closed or closed contact K2-1 of the main positive relay.

[0099] Referring to the above, since there is a one-to-one correspondence between the switching state of the precharge relay contact K1-1 and the control command of the first control signal, when the precharge relay contact K1-1 is closed or closed by the first control signal, the matching information between the control command of the first control signal and the actual on or off state of the precharge relay contact K1-1 can accurately determine whether the precharge relay contact K1-1 is in an abnormal operating state; similarly, since there is a one-to-one correspondence between the switching state of the main positive relay contact K2-1 and the control command of the second control signal, the precharge relay contact K1-1 can be closed or closed. In a one-to-one correspondence, when the on or off state of the main positive relay contact K2-1 is changed by the second control signal, the system can determine in real time whether the main positive relay contact K2-1 is in a fault state based on the matching result between the actual on / off state of the main positive relay contact K2-1 and the control command in the second control signal. Thus, the state judgment unit 1031 in this embodiment can accurately determine the operation problem of the relay contacts in the power distribution unit based on the first level signal or the second level signal, which greatly improves the safety of the contacts of each relay in the high-voltage power distribution system.

[0100] As an optional implementation, the state determination unit 1031 includes a control chip, the I / O pins of which are connected to the signal output port of the signal detection unit 1022.

[0101] Optionally, the control chip may be either AT91F40162 or LC67F500.

[0102] Therefore, in this embodiment, the state judgment unit 1031 is connected to the first control signal or the second control signal through a control chip. The state judgment unit 1031 has the function of signal analysis and comprehensive processing. The control chip can compare the control command in the control signal (first control signal and second control signal) with the contact switching state of the precharge relay contact K1-1 and the main positive relay contact K2-1 to determine whether the precharge relay contact K1-1 and / or the main positive relay contact K2-1 are normal, stuck, or failed. The detection accuracy is extremely high. The control chip has high compatibility and scalability, and can realize the function of rapid detection of the contact state of relays in the power distribution unit. This greatly improves the compatibility and practical value of the relay contact state detection circuit, so that the relay contact state detection circuit can be applied to different industrial fields.

[0103] Figure 6 This embodiment shows a schematic diagram of the structure of the electric vehicle 60 provided, as shown below. Figure 6As shown, the electric vehicle 60 includes: a high-voltage power distribution system 601 and a relay contact status 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 power distribution system 601 includes: a battery unit 6011 and a power distribution unit 6012 connected to the battery unit 6011; wherein the battery unit 6011 includes: a battery VDD, a positive relay connected to the positive terminal of the battery VDD and a negative relay connected to the negative terminal of the battery VDD, and the power distribution unit 6012 includes: a pre-charge relay K1 and a main positive relay K2, wherein the contacts K1-1 of the pre-charge relay and the contacts K2-1 of the main positive relay are connected in parallel to the positive relay or the negative relay.

[0104] Referring to the above Figures 1 to 5 In this embodiment, the on / off state of the positive relay contact K_B+ and the negative relay contact K_B- controls the power output of the battery VDD, enabling the main drive circuit in the electric vehicle to be energized or de-energized, thus ensuring the control efficiency and accuracy of the electric vehicle 60. Furthermore, the relay contact state detection circuit 602 can detect the normality, sticking, or failure of the pre-charge relay contact K-1 and the main positive relay contact K1-1 in real time, preventing control failures in the relays of the electric vehicle. Moreover, during the detection of the relay contact state in the power distribution unit 6012, the relay contact state detection circuit 602 does not require closing the battery switch. The relay contact state detection circuit 602 detects the state of the pre-charge relay contact K-1 and / or the main positive relay contact K1-1 using its own power supply. This avoids secondary damage to the physical safety of the positive and negative relays during the relay contact state detection process. Therefore, the high-voltage power distribution system of the electric vehicle 60 in this embodiment has high safety and the electric vehicle 60 has a wider range of applications. It effectively solves the problem that traditional technology, when detecting the relay contacts in the high-voltage power distribution system of an electric vehicle, will cause secondary damage to the relays on the power supply side of the electric vehicle, reducing the practical value of the electric vehicle.

[0105] Figure 7 This embodiment illustrates the structure of a relay contact status detection system 70 for a high-voltage power distribution system. The high-voltage power distribution system includes a battery unit and a power distribution unit connected to the battery unit. The battery unit includes a battery, a positive relay connected to the positive terminal of the battery, and a negative relay connected to the negative terminal of the battery. The power distribution unit includes a pre-charge relay and a main positive relay. The contacts of the pre-charge relay and the main positive relay are connected in parallel to either the positive relay or the negative relay. Figure 7As shown, the relay contact status detection system 70 includes: the relay contact status detection circuit 701 of the high-voltage power distribution system as described above.

[0106] Referring to the above Figures 1 to 5 In this embodiment, the relay contact state detection circuit 701 can detect the contact state of each relay in the power distribution unit to determine whether the contacts of each relay in the power distribution unit are in a faulty operating state. The detection accuracy is extremely high and the operation is simple. Furthermore, during the detection process of the relay contact state in the power distribution unit, the relay contact state detection circuit 701 only needs to feed back the relay contact state and cannot control the relay state of the high-voltage power distribution system. This avoids the problem of relay contacts sticking together in the power distribution unit, which could damage the contact state of the relays in the battery unit and result in low detection accuracy. Therefore, 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 power safety of the high-voltage power distribution system. The battery unit can always output safe and stable power. The relay contact state detection system 70 can be applied to different industrial fields, improving the safety performance of electrical equipment. It overcomes the problem that the relay contact state detection system in the traditional technology cannot realize the safety detection of the contact state of the relays in the high-voltage power distribution system and is difficult to be universally applied.

[0107] Figure 8 This embodiment illustrates the specific flow of a relay contact state detection method for a high-voltage power distribution system. The high-voltage power distribution system includes a battery unit and a power distribution unit connected to the battery unit. The battery unit includes a battery, a positive relay connected to the positive terminal of the battery, and a negative relay connected to the negative terminal of the battery. The power distribution unit includes a pre-charge relay and a main positive relay. The contacts of the pre-charge relay and the main positive relay are connected in parallel to either the positive or negative relay. The relay contact state detection method includes:

[0108] S801: Generate control commands to close or close the contacts of the precharge relay and / or the main positive relay; determine the physical safety performance of the contacts of the precharge relay and / or the main positive relay by controlling the contacts of the precharge relay and / or the main positive relay to close or close respectively.

[0109] S802: Connect the contacts of the pre-charge relay and the contacts of the main positive relay in series between the first DC power supply and the power supply branch. Generate a detection result indicating the switching state of the contacts of the pre-charge relay and the main positive relay based on the energized or de-energized state of the power supply branch. There is a one-to-one correspondence between the energized or de-energized state of the power supply branch and the closed or closed state of the contacts of the pre-charge relay and the main positive relay. Therefore, the on / off state of the contacts of the pre-charge relay and the main positive relay can be determined in real time and accurately by the power transmission state of the power supply branch, which is simple to operate.

[0110] S803: Based on the correspondence between the detection results and the control command, determine whether the contacts of the pre-charge relay and the main positive relay are normal, stuck, or faulty; the control command includes user request information on the relay contact status. Based on the matching result between the actual on / off state of the contacts of the pre-charge relay and the main positive relay and the control command, it can be determined whether the contacts of the pre-charge relay and the main positive relay are in an abnormal state.

[0111] It should be noted that, Figure 8 S801 to S803 and Figure 1 The relay contact status detection circuit in the medium and high voltage power distribution system corresponds accordingly; therefore, the specific implementation methods of S801 to S803 in this embodiment can be found by referring to... Figures 1 to 5 The specific implementation examples will not be described in detail here.

[0112] The relay contact state detection method for high-voltage power distribution systems provided in this embodiment can directly close or open the contacts of the pre-charge relay and the main positive relay through control commands. Since there is a one-to-one correspondence between the control commands and the on / off states of the pre-charge relay and the main positive relay, when the on / off state of the pre-charge relay and / or the main positive relay is detected by the energization or de-energization of the power supply branch, the physical state of the pre-charge relay and the main positive relay contacts can be accurately determined based on the detection results and the control commands, greatly ensuring the power supply safety of the high-voltage power distribution system. Therefore, the relay contact state detection method in this embodiment does not... However, it can accurately detect the contact status of relays in the power distribution unit, and avoids the inrush current caused by the adhesion of the contacts of the pre-charge relay and / or the main positive relay in the power distribution unit during the detection of the relay contact status, which could damage the relays in the battery unit. The relay contact status detection method realizes accurate and safe detection of the contacts of the pre-charge relay and the main positive relay in the power distribution unit, improving the applicability and practical value of the relay contact status detection method. It overcomes the problem that traditional technical methods cannot achieve safe detection of relay contacts in high-voltage power distribution systems, resulting in low safety of high-voltage power distribution systems.

[0113] Various embodiments of devices, circuits, apparatuses, systems, and / or methods are described herein. Numerous specific details are set forth 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, those skilled in the art will understand that embodiments may be practiced without such specific details. In other instances, well-known operations, components, and elements are described in detail to avoid obscuring the embodiments described in the specification. Those skilled in the art will understand that the embodiments described herein and illustrated are non-limiting examples, and therefore it will be appreciated that the specific structural and functional details disclosed herein may be representative and do not necessarily limit the scope of the embodiments.

[0114] Throughout this specification, references to “various embodiments,” “in embodiments,” “one embodiment,” or “implementation,” etc., are intended to mean that a particular feature, structure, or characteristic described with respect to an embodiment is included in at least one embodiment. Therefore, the appearance of the phrases “in various embodiments,” “in some embodiments,” “in one embodiment,” or “in embodiments,” etc., in appropriate places throughout this specification does not necessarily refer to the same embodiment. Furthermore, a particular feature, structure, or characteristic may be combined in any suitable manner in one or more embodiments. Thus, a particular feature, structure, or characteristic shown or described with respect to 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 illogical or a functional limitation. Any directional references (e.g., plus, subtract, upper, lower, up, down, left, right, to the left, to the right, top, bottom, above, below, vertical, horizontal, clockwise, and counterclockwise) are used for identification purposes to aid the reader’s understanding of this disclosure and do not create limitation, particularly regarding the location, orientation, or use of embodiments.

[0115] While some embodiments have been described above in a certain level of detail, those skilled in the art can make many changes to the disclosed embodiments without departing from the scope of this disclosure. Connection references (e.g., attachment, coupling, connection, etc.) should be interpreted broadly and may include intermediate members between connections of elements and relative movement between elements. Therefore, a connection reference does not necessarily imply that two elements are directly connected / coupled and in a fixed relationship with each other. The use of “e.g.” throughout the specification should be interpreted broadly and is intended to provide non-limiting examples of embodiments of this disclosure, and this disclosure is not limited to such examples. It is intended that all matters contained in the foregoing description or shown in the drawings should be interpreted as illustrative rather than limiting. Changes in detail or structure may be made without departing from this disclosure.

[0116] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A relay contact status detection circuit for a high-voltage power distribution system, characterized in that, The high-voltage power distribution system includes: a battery unit and a power distribution unit connected to the battery unit; wherein the battery unit includes: a battery, a positive relay connected to the positive terminal of the battery, and a negative relay connected to the negative terminal of the battery; during the process of the relay contact state detection circuit detecting the contact state of the relays in the power distribution unit, the contacts of the positive relay and the negative relay are open; the power distribution unit includes: a pre-charge relay and a main positive relay, wherein the contacts of the pre-charge relay and the contacts of the main positive relay are connected in parallel to either the positive relay or the negative relay; the relay contact state detection circuit includes: A first DC power supply is connected to the first end of the contacts of the precharge relay and the first end of the contacts of the main positive relay. The first DC power supply is used to output first DC power. A power supply branch, the input terminal of which is connected to the second terminal of the pre-charge relay contact and the second terminal of the main positive relay contact, and the output terminal of which is grounded; and A detection module, coupled to the power supply branch, generates a control signal to close or close the contacts of the precharge relay and / or the main positive relay. The detection module generates a detection result indicating the switching state of the contacts of the precharge relay and the main positive relay based on the energized or de-energized state of the power supply branch. Furthermore, the detection module determines, based on the detection result and the control signal, whether the contacts of the precharge relay and the main positive relay are normal, stuck, or faulty. The power supply branch also includes: a light-emitting diode, a first diode, and a first resistor; The detection module includes: A signal generation unit is coupled to the contacts of the precharge relay and the main positive relay, and the signal generation unit generates control signals for closing or closing the contacts of the precharge relay and / or the main positive relay. A signal detection unit is coupled to the power supply branch and the signal generation unit. The signal detection unit generates a detection result indicating the switching state of the contacts of the precharge relay and the main positive relay based on the energized or de-energized state of the power supply branch. The signal detection unit determines whether the contacts of the precharge relay and the main positive relay are normal, stuck, or ineffective based on the detection result and the control signal. The signal detection unit includes: The second DC power supply is used to output a second DC power. The third resistor, the first end of which is connected to the second DC power supply; An optocoupler element, coupled to the light-emitting diode, wherein the first conducting terminal of the optocoupler element and the second terminal of the third resistor are jointly connected to form the signal output port of the signal detection unit, and the second conducting terminal of the optocoupler element is grounded; and A status determination unit, the communication port of which is connected to the signal output port of the detection module, determines the switching status of the contacts of the precharge relay and the contacts of the main positive relay based on the level signal of the signal output port of the signal detection unit. The state determination unit determines whether the contacts of the precharge relay and the main positive relay are normal, stuck, or faulty based on the correspondence between the control signal and the switch state.

2. The relay contact state detection circuit according to claim 1, characterized in that, The anode of the first diode is connected to the second terminal of the precharge relay contact and the second terminal of the main positive relay contact. The cathode of the first diode is connected to the first terminal of the first resistor. The second terminal of the first resistor is connected to the anode of the light-emitting diode. The cathode of the light-emitting diode is grounded.

3. The relay contact state detection circuit according to claim 2, characterized in that, The power supply branch also includes: a second resistor; The first end of the second resistor is connected to the second end of the contact of the precharge relay, and the second end of the second resistor is connected to the second end of the contact of the main positive relay and the anode of the first diode.

4. The relay contact state detection circuit according to claim 2, characterized in that, The status determination unit includes a control chip, whose I / O pins are connected to the signal output port of the signal detection unit.

5. The relay contact state detection circuit according to claim 1, characterized in that, When the light-emitting diode does not emit light, the signal output port of the signal detection unit outputs a first-level signal; when the light-emitting diode emits light, the signal output port of the signal detection unit outputs a second-level signal. Wherein, 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 interleaved.

6. The relay contact state detection circuit according to claim 1, characterized in that, The optocoupler is a phototransistor or a photodiode.

7. An electric vehicle, characterized in that, include: A high-voltage power distribution system and a relay contact status detection circuit for the high-voltage power distribution system as described in any one of claims 1-6 connected to the high-voltage power distribution system; wherein the high-voltage power distribution system includes: a battery unit and a power distribution unit connected to the battery unit; wherein the battery unit includes: a battery, a positive relay connected to the positive terminal of the battery and a negative relay connected to the negative terminal of the battery, and the power distribution unit includes: a pre-charge relay and a main positive relay, wherein the contacts of the pre-charge relay and the contacts of the main positive relay are connected in parallel to either the positive relay or the negative relay.

8. A method for detecting the state of relay contacts in a high-voltage power distribution system, applied to the relay contact state detection circuit of the high-voltage power distribution system as described in any one of claims 1-6, characterized in that, The high-voltage power distribution system includes: a battery unit and a power distribution unit connected to the battery unit; wherein the battery unit includes: a battery, a positive relay connected to the positive terminal of the battery, and a negative relay connected to the negative terminal of the battery; the power distribution unit includes: a pre-charge relay and a main positive relay, wherein the contacts of the pre-charge relay and the contacts of the main positive relay are connected in parallel to the positive relay or the negative relay; the relay contact status detection method includes: Generate control commands to close or close the contacts of the precharge relay and / or the contacts of the main positive relay; The contacts of the precharge relay and the contacts of the main positive relay are connected in series between the first DC power supply and the power supply branch. A detection result representing the switching state of the contacts of the precharge relay and the main positive relay is generated based on the energized or de-energized state of the power supply branch. Based on the correspondence between the test results and the control commands, it is determined whether the contacts of the precharge relay and the main positive relay are normal, stuck, or ineffective.

Images