A relay detection device, an energy storage system, and an electric vehicle
By replacing the voltage divider resistor with a device module that has unidirectional conduction function in the relay testing device, the safety problem of relay testing in high-voltage situations is solved, and the protection of circuit components and the accuracy of testing results are improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- HANGZHOU JIGAO INTELLIGENT ELECTRONIC TECH CO LTD
- Filing Date
- 2025-06-11
- Publication Date
- 2026-06-30
AI Technical Summary
Existing technologies for testing electric vehicle relays have safety issues, especially in high-voltage applications, where relay closure gaps can damage electronic components, and there is a lack of effective solutions.
Replace the voltage divider resistor with a device module that has unidirectional conduction function (such as a top-down MOSFET, diode, or high-voltage diode). The unidirectional conduction characteristic protects the circuit during the detection process and ensures the safety of the current path.
This improves the safety and reliability of relay testing, avoids damage to circuit components from high-voltage current, and enhances the accuracy and reliability of test results.
Smart Images
Figure CN224436530U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of new energy vehicle technology, and in particular to a relay detection device, an energy storage system, and an electric vehicle. Background Technology
[0002] Currently, the charging and discharging management of battery packs in electric vehicles is generally controlled by relays. Therefore, to ensure the safe and stable operation of electric vehicles and to avoid abnormal situations where relays fail to execute relevant control commands, it is necessary to monitor the status of the relays.
[0003] Please see Figure 1 , Figure 1 This is a schematic diagram illustrating the testing of a relay in the prior art. Figure 1 In the circuit diagram shown, K1 is the high-voltage negative terminal relay, K2 is the high-voltage positive terminal main relay, K3 is the high-voltage positive terminal pre-charge relay, and C is the DC bus capacitor located on the outer side of the battery pack at the vehicle end. In practical applications, it is usually necessary to focus on detecting the state of relay K1. When detecting the state of relay K1, a bias voltage U1 needs to be injected into the high-voltage negative terminal of the battery pack. When relay K1 is in the open state, U1 is divided by resistors R3 and R2. At this time, the voltage at AN can be detected through the AD (Analog-to-Digital) sampling port, resulting in the detection voltage U01. When relay K1 is in the closed state, U1 is divided by resistor R3 and the network connected in parallel with resistors R1 and R2. At this time, the voltage at AN can be detected through the AD sampling port, resulting in the detection voltage U02. Finally, by comparing the values of detection voltages U01 and U02, the connection state of relay K1 can be determined.
[0004] However, in certain situations where high voltage is applied to the circuit, relay K3 must be closed first before relay K1 can be closed. Because the voltage across the DC bus capacitor C cannot change abruptly, during the gap between closing relay K3 and not closing relay K1, the battery pack will experience voltage division by resistors R1 and R2 (e.g., Figure 1 (Path 1 in the circuit). Resistors R1 and R2 are typically surface-mount resistors. If R1 and R2 are not properly selected, the gap between closing relay K3 and not closing relay K1 can damage electronic components in the circuit. Currently, there is no effective solution to this technical problem.
[0005] Therefore, how to provide a safer and more reliable relay detection device is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content
[0006] In view of this, the purpose of this utility model is to provide a relay detection device, an energy storage system, and an electric vehicle, so as to solve the technical problem of low safety in the prior art when detecting relays. The specific solution is as follows:
[0007] To solve the above-mentioned technical problems, this utility model provides a relay detection device, characterized in that it includes: a battery pack, a first relay, a second relay, a third relay, a first resistor, a second resistor, a third resistor, a capacitor, and a device module with unidirectional conduction function;
[0008] The negative terminal of the battery pack is connected to the first end of the first resistor and the first end of the first relay, respectively. The first end of the first relay is grounded. The second end of the first relay is connected to the first end of the device module and the first end of the capacitor, respectively. The second end of the device module is connected to the second end of the first resistor and the first end of the second resistor, respectively. The second end of the second resistor is used to receive the target bias voltage. The positive terminal of the battery pack is connected to the first end of the second relay and the first end of the third relay, respectively. The second end of the third relay is connected to the first end of the third resistor. The second end of the third resistor and the second end of the second relay are both connected to the second end of the capacitor.
[0009] Preferably, the device module is a top-down MOS transistor;
[0010] Accordingly, the common terminal formed by the drains of the two MOS transistors in the top-down MOS transistor is the first terminal of the device module, and the common terminal formed by the sources of the two MOS transistors in the top-down MOS transistor is the second terminal of the device module.
[0011] Preferably, the device module includes: a diode and a fourth resistor; the resistance value of the fourth resistor is set according to the target voltage division value, wherein the target voltage division value is the voltage division value at the connection between the second resistor and the first resistor when the first relay is in an open circuit state;
[0012] Wherein, the positive terminal of the diode is connected to the first end of the second resistor, the negative terminal of the diode is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the second end of the first relay;
[0013] Correspondingly, the second terminal of the fourth resistor and the positive terminal of the diode are the first and second terminals of the device module, respectively.
[0014] Preferably, the device module includes: A series of high-voltage diodes ,and The value is set according to the withstand voltage of the high voltage diode and the terminal voltage of the battery pack;
[0015] Correspondingly, The anode of the first high-voltage diode in the series-connected high-voltage diodes is the second terminal of the device module. Among the series of high-voltage diodes connected in series, the first one is... The negative terminal of a high-voltage diode is the first terminal of the device module.
[0016] Preferably, the number of high-voltage diodes is one, and when the first relay is in the open circuit state, the voltage drop at the connection between the second resistor and the first resistor is greater than or equal to twice the forward conduction voltage drop of the high-voltage diode;
[0017] Correspondingly, the positive and negative terminals of the high-voltage diode are the second and first terminals of the device module, respectively.
[0018] Preferably, the high-voltage diode is a silicon carbide diode.
[0019] Preferably, the capacitor is a thin-film capacitor or a ceramic capacitor.
[0020] Preferably, the first relay, the second relay, and the third relay are all high-voltage DC relays.
[0021] Accordingly, this utility model also provides an energy storage system, including a detection device for a relay as disclosed above.
[0022] Accordingly, this utility model also provides an electric vehicle, including an energy storage system as disclosed above.
[0023] Beneficial Effects: In the relay detection device provided by this utility model, when the first relay is in the open state, the target bias voltage is divided by the first resistor and the second resistor. At this time, the voltage value at the connection point of the first resistor and the second resistor can be collected to obtain the target detection voltage value. When the first relay is in the closed state, since the forward conduction voltage of the device module is necessarily lower than the voltage corresponding to the voltage divider module composed of the first resistor and the second resistor, the voltage value at the connection point of the first resistor and the second resistor will necessarily be less than the target detection voltage. In this case, by comparing the voltage values at the connection point of the first resistor and the second resistor when the first relay is in the open and closed states, the purpose of detecting the connection state of the first relay can be achieved. Furthermore, during the gap when the third relay is closed but the first relay is not closed, the voltage on the battery pack is almost entirely borne by the first resistor and the device module. At this time, by utilizing the unidirectional conduction characteristic of the device module, the high-voltage current conduction path in the circuit can be blocked, thus ensuring the safe and stable operation of each electronic component in the circuit and further improving the safety and reliability of the detection device in practical applications.
[0024] Correspondingly, the energy storage system and electric vehicle provided by this utility model also have the above-mentioned beneficial effects. Attached Figure Description
[0025] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, 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 embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.
[0026] Figure 1 This is a schematic diagram of the relay testing process in the prior art;
[0027] Figure 2 A structural diagram of a relay detection device provided in an embodiment of this utility model;
[0028] Figure 3 for Figure 2 A schematic diagram of the relay detection device when the second relay K2 in the circuit becomes stuck;
[0029] Figure 4 A structural diagram of another relay detection device provided in an embodiment of this utility model;
[0030] Figure 5 A structural diagram of another relay detection device provided in an embodiment of this utility model;
[0031] Figure 6for Figure 5 A schematic diagram of the first relay K1 in the closed state. Detailed Implementation
[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.
[0033] Please see Figure 2 , Figure 2 The present invention provides a structural diagram of a relay detection device, which includes: a battery pack, a first relay K1, a second relay K2, a third relay K3, a first resistor R1, a second resistor R2, a third resistor R3, a capacitor C, and a device module 10 with unidirectional conduction function.
[0034] The negative terminal of the battery pack is connected to the first terminal of the first resistor R1 and the first terminal of the first relay K1. The first terminal of the first relay K1 is grounded. The second terminal of the first relay K1 is connected to the first terminal of the device module 10 and the first terminal of the capacitor C. The second terminal of the device module 10 is connected to the second terminal of the first resistor R1 and the first terminal of the second resistor R2. The second terminal of the second resistor R2 is used to receive the target bias voltage U. The positive terminal of the battery pack is connected to the first terminal of the second relay K2 and the first terminal of the third relay K3. The second terminal of the third relay K3 is connected to the first terminal of the third resistor R3. The second terminals of the third resistor R3 and the second terminals of the second relay K2 are both connected to the second terminal of the capacitor C.
[0035] This embodiment provides a relay detection device. This circuit structure further ensures the safety and reliability of the relay detection device in practical applications. Compared to existing technologies, the voltage divider resistor in the original detection device is replaced with a device module 10 with unidirectional conduction function.
[0036] based on Figure 2 The circuit diagram shown in this embodiment will first be explained in detail regarding the principle of how this circuit detects the state of the relay. Figure 2In the diagram, BAT+ and BAT- represent the positive and negative terminals of the battery pack, respectively. When the first relay K1 is open, the target bias voltage U is divided by the first resistor R1 and the second resistor R2. By detecting the voltage at point AN, the voltage at the connection of the first resistor R1 and the second resistor R2 can be obtained, thus yielding the target detection voltage. When the first relay K1 is closed, since the unidirectional conduction voltage of the device module 10 is typically small, it will be lower than the voltage at which the first resistor R1 and the second resistor R2 divide the target bias voltage U. Therefore, when the first relay K1 is closed, the detected voltage value at point AN (i.e., the voltage at the connection of the first resistor R1 and the second resistor R2) will definitely be less than the target detection voltage. In this case, by comparing the detected voltage value at point AN, the connection state of the first relay K1 can be detected.
[0037] In some special scenarios, if the third relay K3 is to be closed first, and then the first relay K1 is closed to pre-charge capacitor C with high voltage, the voltage in capacitor C cannot change abruptly during the gap between closing the third relay K3 and not closing the first relay K1. This can be equivalent to a short circuit between P+ and P-, and the voltage on the battery pack is almost entirely borne by the first resistor R1 and device module 10. At this time, by utilizing the unidirectional conduction characteristic of device module 10, the high-voltage current conduction path in the circuit can be blocked (i.e.,...). Figure 2 Path 1 in the circuit ensures the safe and stable operation of each electronic component and further improves the safety and reliability of the detection device in practical applications.
[0038] Furthermore, in some abnormal scenarios, if the third relay K3 or the second relay K2 becomes abnormally stuck together, the voltage in capacitor C cannot change abruptly, which can be equivalent to a short circuit between P+ and P-. In this case, there is also the possibility of burning out various electronic components in the circuit. Please refer to [link to details] for more information. Figure 3 , Figure 3 for Figure 2 The diagram illustrates the operation of the relay detection device when the second relay K2 becomes stuck. When the second relay K2 abnormally sticks, the unidirectional conduction characteristic of the device module 10 can also be used to block the high-voltage current conduction path in the circuit (i.e.,...). Figure 3 Path 1 in the code avoids the spurious influence factor introduced by Path 1, which would cause disturbances in the detection voltage at AN (i.e., Figure 3 The path 2) in the detection results of the connection status of the first relay K1 can be misjudged, which can further improve the accuracy and reliability of the detection results when using the detection device to detect the connection status of the first relay K1.
[0039] Obviously, in the relay detection device provided in this embodiment, when the first relay is in the open state, the target bias voltage is divided by the first resistor and the second resistor. At this time, the voltage value at the connection point of the first resistor and the second resistor can be collected to obtain the target detection voltage value. When the first relay is in the closed state, since the forward conduction voltage of the device module is necessarily lower than the voltage corresponding to the voltage divider module composed of the first resistor and the second resistor, the voltage value at the connection point of the first resistor and the second resistor will necessarily be less than the target detection voltage. In this case, by comparing the voltage values at the connection point of the first resistor and the second resistor when the first relay is in the open and closed states, the purpose of detecting the connection state of the first relay can be achieved. Furthermore, during the gap when the third relay is closed but the first relay is not closed, the voltage on the battery pack is almost entirely borne by the first resistor and the device module. At this time, by utilizing the unidirectional conduction characteristic of the device module, the high-voltage current conduction path in the circuit can be blocked. This ensures the safe and stable operation of each electronic component in the circuit and further improves the safety and reliability of the detection device in practical applications.
[0040] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. As a preferred implementation, the above device module is specifically a top-down MOS transistor.
[0041] Correspondingly, in a top-down MOSFET, the common terminal formed by the drains of the two MOSFETs is the first terminal of the device module, and in a top-down MOSFET, the common terminal formed by the sources of the two MOSFETs is the second terminal of the device module.
[0042] Specifically, in practical applications, device modules with unidirectional conduction function can be configured as top-down MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). This is because top-down MOSFETs not only possess fast switching characteristics and low on-resistance, but also, being composed of two MOSFETs connected back-to-back, allow for independent control or coordinated operation. This structure provides significant flexibility in the circuit design of the detection device, facilitating its control and management by operators.
[0043] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. Please refer to [link / reference]. Figure 4 , Figure 4This is a structural diagram of another relay detection device provided in an embodiment of the present invention. In a preferred embodiment, the device module 10 includes: a diode D0 and a fourth resistor R4; the resistance value of the fourth resistor R4 is set according to a target voltage division value, which is the voltage division value at the connection point of the second resistor R2 and the first resistor R1 when the first relay K1 is in an open-circuit state.
[0044] In this configuration, the positive terminal of diode D0 is connected to the first terminal of the second resistor R2, the negative terminal of diode D0 is connected to the first terminal of the fourth resistor R4, and the second terminal of the fourth resistor R4 is connected to the second terminal of the first relay K1.
[0045] Correspondingly, the second terminal of the fourth resistor R4 and the positive terminal of the diode D0 are the first and second terminals of the device module 10, respectively.
[0046] In practical applications, the device module 10 with unidirectional conduction function can also be configured as a diode plus resistor structure. Please refer to [link to relevant documentation] for details. Figure 4 When device module 10 is configured with diode D0 and a fourth resistor R4, adjusting the resistance value of the fourth resistor R4 allows for adjustment of the unidirectional conduction voltage of device module 10. In this case, adjusting the resistance value of the fourth resistor R4 according to the actual situation makes the voltage change at AN more obvious when the first relay K1 is in the open and closed states, thereby achieving the purpose of accurately detecting the connection state of the first relay K1.
[0047] Furthermore, compared to designing the device module 10 as a high-voltage diode, setting the device module 10 as a diode plus resistor structure can relatively reduce the cost required for the relay detection device provided in this application.
[0048] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. As a preferred implementation, the above-mentioned device module includes: A series of high-voltage diodes ,and The value is set based on the withstand voltage of the high voltage diode and the terminal voltage of the battery pack;
[0049] Correspondingly, The positive terminal of the first high-voltage diode in a series of interconnected high-voltage diodes is the second terminal of the device module. Among the series of high-voltage diodes connected in series, the first one is... The negative terminal of a high-voltage diode is the first terminal of the device module.
[0050] In practical applications, device modules with unidirectional conduction function can also be set as... A series of high-voltage diodes connected in series, wherein... The value is set based on the withstand voltage of the high-voltage diode and the terminal voltage of the battery pack. That is, when the terminal voltage of the battery pack is high, the number of high-voltage diodes in the device module needs to be increased, while when the terminal voltage of the battery pack is low, the number of high-voltage diodes in the device module needs to be reduced.
[0051] Furthermore, because high-voltage diodes also possess advantages such as high withstand voltage, low leakage current, low forward voltage drop, and stable operation under high-temperature conditions, when a device module with unidirectional conduction function is set up... Using a series of high-voltage diodes can further improve the overall reliability of the relay detection device in practical applications.
[0052] In a preferred embodiment, the number of high-voltage diodes is one, and when the first relay is in the open circuit state, the voltage drop at the connection between the second resistor and the first resistor is greater than or equal to twice the forward conduction voltage drop of the high-voltage diode.
[0053] Correspondingly, the positive and negative terminals of the high-voltage diode are the second and first terminals of the device module, respectively.
[0054] Please see Figure 5 , Figure 5 This is a structural diagram of another relay detection device provided in an embodiment of the present utility model. Figure 5 In the relay detection device shown, D1 is a high-voltage diode. In this embodiment, in order to reduce the structural complexity of the relay detection device, the device module is set as a high-voltage diode D1, and when the first relay K1 is in the open circuit state, the voltage drop at the connection of the second resistor R2 and the first resistor R1 is greater than or equal to twice the forward conduction voltage drop of the high-voltage diode D1.
[0055] Assume that the resistance of both the first resistor R1 and the second resistor R2 is 10KΩ, the target bias voltage U is 5V, and the forward voltage drop of the high-voltage diode D1 is 0.7V. Please refer to [link / reference]. Figure 5 When the first relay K1 is in the open state, the target bias voltage U is divided by the first resistor R1 and the second resistor R2. At this time, the voltage detection value AN1 at AN is: ;in, Let R1 be the resistance value of the first resistor. Let R2 be the resistance value of the second resistor. The target bias voltage.
[0056] Please see Figure 6 , Figure 6 for Figure 5 This diagram illustrates the state when the first relay K1 is closed. When the first relay K1 is closed, the forward voltage of the high-voltage diode D1 is only 0.7V, which is lower than the voltage value when the first resistor R1 and the second resistor R2 divide the target bias voltage. Therefore, the voltage at AN is forcibly pulled down to 0.7V by the high-voltage diode D1. By comparing the voltage detection values at AN when the first relay K1 is open and closed, it can be seen that the voltage detection value at AN changes significantly when the first relay K1 is open and closed. Therefore, the technical solution provided in this embodiment can further improve the accuracy and reliability of the detection results when detecting the connection state of the first relay K1.
[0057] As a preferred embodiment, the high-voltage diode D1 is specifically a silicon carbide diode.
[0058] Specifically, in this embodiment, the high-voltage diode D1 can be set as a silicon carbide diode. Compared with conventional diodes, silicon carbide diodes not only have higher voltage withstand capability, but also maintain a lower leakage current under high voltage conditions. This not only improves the safety of the relay detection device provided in this application during use, but also relatively reduces the energy consumption of the relay detection device.
[0059] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. As a preferred implementation, the capacitor is specifically a film capacitor or a ceramic capacitor.
[0060] In practical applications, the capacitor can be set as a film capacitor. This is because film capacitors not only have a high withstand voltage, but are also non-polar and can be used in both directions. During installation, it is not necessary to distinguish between the positive and negative terminals of the film capacitor. Therefore, using a film capacitor can relatively reduce the difficulty of building the relay detection device provided in this application.
[0061] Alternatively, ceramic capacitors can be used. Because ceramic capacitors have a smaller footprint and charge / discharge very quickly, using ceramic capacitors not only reduces the space occupied by the relay detection device but also improves the efficiency of the battery pack when charging the capacitor.
[0062] Based on the above embodiments, this embodiment further explains and optimizes the technical solution. As a preferred implementation, the first relay, the second relay, and the third relay are all high-voltage DC relays.
[0063] High-voltage DC relays have advantages such as high voltage resistance, long service life, good insulation performance, and low maintenance cost. The relay detection device described in this application is commonly used in electric vehicles. Therefore, when the first, second, and third relays are all set as high-voltage DC relays, not only can the safety and reliability of the relay detection device be further improved during use, but the maintenance cost of the relay detection device can also be relatively reduced.
[0064] Accordingly, this utility model embodiment also provides an energy storage system, including a relay detection device as disclosed above.
[0065] The energy storage system provided in this embodiment of the present invention has the beneficial effects of the aforementioned relay detection device.
[0066] Accordingly, this utility model embodiment also provides an electric vehicle, including an energy storage system as disclosed above.
[0067] The electric vehicle provided in this embodiment of the present invention has the beneficial effects of the energy storage system disclosed above.
[0068] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A relay detection device, characterized in that, include: Battery pack, first relay, second relay, third relay, first resistor, second resistor, third resistor, capacitor, and device module with unidirectional conduction function; The negative terminal of the battery pack is connected to the first terminal of the first resistor and the first terminal of the first relay, respectively. The first terminal of the first relay is grounded. The second terminal of the first relay is connected to the first terminal of the device module and the first terminal of the capacitor, respectively. The second terminal of the device module is connected to the second terminal of the first resistor and the first terminal of the second resistor, respectively. The second terminal of the second resistor is used to receive the target bias voltage. The positive terminal of the battery pack is connected to the first terminal of the second relay and the first terminal of the third relay, respectively. The second terminal of the third relay is connected to the first terminal of the third resistor. The second terminal of the third resistor and the second terminal of the second relay are both connected to the second terminal of the capacitor.
2. The relay detection device according to claim 1, characterized in that, The device module is specifically a top-down MOS transistor; Accordingly, the common terminal formed by the drains of the two MOS transistors in the top-down MOS transistor is the first terminal of the device module, and the common terminal formed by the sources of the two MOS transistors in the top-down MOS transistor is the second terminal of the device module.
3. The relay detection device according to claim 1, characterized in that, The device module includes a diode and a fourth resistor; the resistance value of the fourth resistor is set according to the target voltage division value, which is the voltage division value at the connection between the second resistor and the first resistor when the first relay is in an open circuit state. Wherein, the positive terminal of the diode is connected to the first end of the second resistor, the negative terminal of the diode is connected to the first end of the fourth resistor, and the second end of the fourth resistor is connected to the second end of the first relay; Correspondingly, the second terminal of the fourth resistor and the positive terminal of the diode are the first and second terminals of the device module, respectively.
4. The relay detection device according to claim 1, characterized in that, The device module includes: A series of high-voltage diodes ,and The value is set based on the withstand voltage of the high-voltage diode and the terminal voltage of the battery pack; Correspondingly, The anode of the first high-voltage diode in the series-connected high-voltage diodes is the second terminal of the device module. Among the series of high-voltage diodes connected in series, the first one is... The negative terminal of a high-voltage diode is the first terminal of the device module.
5. The relay detection device according to claim 4, characterized in that, The number of high-voltage diodes is one, and when the first relay is in the open circuit state, the voltage drop at the connection between the second resistor and the first resistor is greater than or equal to twice the forward conduction voltage drop of the high-voltage diode; Correspondingly, the positive and negative terminals of the high-voltage diode are the second and first terminals of the device module, respectively.
6. The relay detection device according to claim 5, characterized in that, The high-voltage diode is specifically a silicon carbide diode.
7. The relay detection device according to claim 1, characterized in that, The capacitor is specifically a thin-film capacitor or a ceramic capacitor.
8. The relay detection device according to claim 1, characterized in that, The first relay, the second relay, and the third relay are all high-voltage DC relays.
9. An energy storage system, characterized in that, The detection device includes a relay as described in any one of claims 1 to 8.
10. An electric vehicle, characterized in that, Including an energy storage system as described in claim 9.