Battery system relay state detection circuit and circuit protection board thereof

Abstract

The utility model provides a battery system relay state detection circuit and a circuit protection board thereof, the battery system relay state detection circuit comprises a main loop and a negative terminal relay state detection circuit, and the main loop comprises a positive terminal relay, a negative terminal relay and a peripheral circuit; the negative terminal relay state detection circuit comprises a plurality of resistors, a plurality of diodes and a capacitor. According to the utility model, the state of the positive-end relay is detected through a voltage difference detection method, the state of the negative-end relay is indirectly detected through the negative-end relay state detection circuit, and the states of disconnection, connection, fault and the like of the negative-end relay in the battery system are detected in real time. When the relay has faults such as adhesion and incapability of closing, the control unit executes a corresponding protection strategy to ensure safe and reliable operation of the battery system.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of energy storage batteries, in particular to a battery system relay state detection circuit and a circuit protection board thereof. BACKGROUND

[0002] In a battery system, a relay in a high-voltage main circuit is responsible for controlling the power-on and power-off of the system. If the relay fails and its state cannot be determined, the entire battery system will have a safety hazard. In the prior art, common relay state detection methods include a relay auxiliary contact detection method and a differential pressure detection method. In the commonly used relay state detection method, the relay auxiliary contact detection method uses the auxiliary contact of the relay to determine the state of the relay. The auxiliary contact is usually closed or opened when the relay is powered on or powered off. However, the relay auxiliary contact detection method requires the relay to have an auxiliary contact feedback function, and has limitations in use. The differential pressure detection method determines the state of the relay by measuring the voltage differential across the relay. Under normal circumstances, when the relay is closed, the voltage across the relay should be zero; when the relay is open, there will be a voltage differential, but the differential pressure detection method cannot detect the state of the negative terminal relay of the battery system. CONTENT OF THE UTILITY MODEL

[0003] To solve the above technical problems, the utility model provides a battery system relay state detection circuit and a circuit protection board thereof. The utility model sets a negative terminal relay state detection circuit for the negative terminal relay, which can effectively determine the state of the negative terminal relay.

[0004] In a first aspect, the application provides a battery system relay state detection circuit, which comprises a main circuit and a negative terminal relay state detection circuit. The main circuit comprises a battery pack, a positive terminal relay and a negative terminal relay.

[0005] The positive terminal of the battery pack is connected to the positive terminal of the positive terminal relay, the positive terminal of the positive terminal relay is connected to the positive terminal of the negative terminal relay, and the negative terminal of the negative terminal relay is connected to the negative terminal of the battery pack.

[0006] The negative terminal relay state detection circuit is connected to the positive terminal of the negative terminal relay.

[0007] The negative terminal relay state detection circuit is connected to the negative terminal of the negative terminal relay, and the closing and opening states of the negative terminal relay can be indirectly obtained through the voltage change of the negative terminal relay state detection circuit.

[0008] Further, the main circuit is the main part of the battery system relay state detection circuit, which comprises a positive terminal relay and a negative terminal relay, and a peripheral circuit.

[0009] In one embodiment, the main circuit further comprises a protection resistor and an inductor.

[0010] In one embodiment, the main circuit further comprises: the protection resistor is arranged between the positive terminal relay and the negative terminal relay; and one end of the inductor is connected to the negative terminal of the battery pack, and the other end is grounded.

[0011] The protection resistor is used to limit the current in the main circuit, and the inductor is used to form a second circuit with the negative terminal relay state detection circuit.

[0012] Further, the negative terminal relay state detection circuit is a key part of the battery system relay state detection circuit, and is composed of a plurality of resistors, a plurality of diodes, and a capacitor, and includes a VAD_HVBus output port, which is used to measure the state of the negative terminal relay after voltage division.

[0013] In one embodiment, the negative terminal relay state detection circuit comprises: a power supply, a first voltage dividing resistor, a second voltage dividing resistor, a third voltage dividing resistor, a fourth voltage dividing resistor, a first diode, a second diode, and a capacitor.

[0014] In one embodiment, the negative terminal relay state detection circuit comprises: a VAD_HVBus output port.

[0015] In one embodiment, the negative terminal relay state detection circuit comprises: the power supply is connected to one end of the first voltage dividing resistor; the other end of the first voltage dividing resistor is connected to one end of the second voltage dividing resistor and one end of the third voltage dividing resistor; the other end of the second voltage dividing resistor is connected to one end of the fourth voltage dividing resistor; the other end of the third voltage dividing resistor is connected to one end of the capacitor and the VAD_HVBus output port; the other end of the capacitor is grounded; the other end of the fourth voltage dividing resistor is connected to the anode of the first diode; the cathode of the first diode is connected to the anode of the second diode; and the cathode of the second diode is connected to the negative terminal of the negative terminal relay.

[0016] Further, the VAD_HVBus output port is collected by a chip.

[0017] In one embodiment, the negative terminal relay state detection circuit further comprises: an ADC chip.

[0018] In one embodiment, the negative terminal relay state detection circuit further comprises: the VAD_HVBus output port is connected to the ADC chip.

[0019] Further, the state of the positive terminal relay is detected by a differential pressure detection method.

[0020] In one embodiment, a voltage comparator is connected between the positive electrode and the negative electrode of the positive terminal relay, for detecting the voltage difference across the positive terminal relay, so as to determine the opening or closing state of the positive terminal relay.

[0021] In a second aspect, the utility model also provides a circuit protection board, the circuit protection board includes: the battery system relay state detection circuit and circuit substrate of first aspect, the battery system relay state detection circuit is integrated on the circuit substrate.

[0022] In conclusion, the battery system relay state detection circuit and the circuit protection board thereof are provided, the battery system relay state detection circuit includes a main loop and a negative terminal relay state detection circuit, the main loop includes a positive terminal relay, a negative terminal relay and a peripheral circuit; the negative terminal relay state detection circuit includes a plurality of resistors, a plurality of diodes and a capacitor. In the utility model, the state of the positive terminal relay is detected by the differential pressure detection method, the state of the negative terminal relay is indirectly detected by the negative terminal relay state detection circuit, and the states such as disconnection, closure and failure of the negative terminal relay in the battery system are detected in real time. When the relay has adhesion, closure failure and other failures, the control unit executes the corresponding protection strategy, and safe and reliable operation of the battery system is ensured.

[0023] Compared with the prior art, the present application has at least the following beneficial effects:

[0024] The utility model discloses a negative terminal relay state detection circuit, effectively overcome the limitation of relay auxiliary contact detection method and the shortcoming that the differential pressure detection method cannot detect the state of the negative terminal relay, and any kind of relay can use this method, reduces the complexity of system design, saves the cost. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 It is the battery system relay state detection circuit schematic diagram shown in the embodiment of the present application.

[0026] Figure 2 It is the relay state detection circuit schematic diagram shown in the embodiment of the present application. DETAILED DESCRIPTION

[0027] In order to make the personnel in the technical field better understand the scheme of the present application, the technical scheme in the embodiment of the present application will be clearly and completely described below in conjunction with the drawings in the embodiment of the present application. Obviously, the described embodiment is only a part of the embodiments of the present application, not all the embodiments of the present application.

[0028] The embodiments of the present application are not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by the person skilled in the art without creative labor should belong to the protection scope of the present application.

[0029] The following will be described in detail respectively.

[0030] The terms "first", "second", "third", and "fourth" and the like in the description and in the claims of the present application and the accompanying drawings are used for distinguishing between similar objects, not necessarily described in a particular order. Also, the terms "include" and "comprise" and their conjugates mean "including but not limited to" and "comprising but not limited to", respectively, and are intended to cover the respective stated elements or integers but not excluding other elements or integers. The terms "exemplary" and "example" are used to mean "an example of" and are not used in a restrictive sense.

[0031] The terms "include", "comprise" and "comprising" and other grammatical variations are used herein in a non-exclusive sense, such that a process, method, system, product, generation or facility that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such process, method, system, product, generation or facility.

[0032] Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the application. The appearances of the phrase "in an embodiment" in various places in the specification are not necessarily all referring to the same embodiment, nor are they necessarily all directed to the same embodiment, or to a common embodiment. It is expressly understood that any of the Embodiment one

[0033] The application provides a battery system relay state detection circuit, as shown in the accompanying drawings Figure 1 The battery system relay state detection circuit comprises a main loop and a negative terminal relay state detection circuit, the main loop comprises a positive terminal relay and a negative terminal relay, and the negative terminal relay state detection circuit is connected to the positive terminal of the negative terminal relay.

[0034] The negative terminal relay state detection circuit is connected to the negative terminal of the negative terminal relay, and the closing and opening states of the negative terminal relay can be indirectly obtained through the voltage change of the negative terminal relay state detection circuit.

[0035] Further, the main loop is the main part of the battery system relay state detection circuit, comprising the positive terminal relay and the negative terminal relay, and a peripheral circuit.

[0036] In one embodiment, the main loop further comprises a first power supply, a protection resistor R and an inductor L.

[0037] In one embodiment, the main loop further comprises that the positive terminal of the first power supply is connected to the positive terminal of the positive terminal relay, the negative terminal of the positive terminal relay is connected to one end of the protection resistor R, the other end of the protection resistor R is connected to the negative terminal of the negative terminal relay, and the positive terminal of the negative terminal relay is connected to the negative terminal of the first power supply; one end of the inductor L is connected to the negative terminal of the first power supply, and the other end is grounded.

[0038] The first power supply can be a direct current power supply, and can also be a direct current power supply formed by rectifying current generated by an alternator. The first power supply DC1 can be a power battery, and can also be a storage battery.

[0039] The protection resistor R is used for limiting the current in the main circuit, and its resistance value can be matched according to the size of the first power supply.

[0040] The inductor L is used for forming a second circuit with the negative-end relay state detection circuit.

[0041] Further, the negative-end relay state detection circuit is a key part of the battery system relay state detection circuit, and is composed of a plurality of resistors, a plurality of diodes and a capacitor, and includes a VAD_HVBus output port, which is used for measuring the state of the negative-end relay indirectly after voltage division.

[0042] In one embodiment, the negative-end relay state detection circuit includes a power supply, a first voltage division resistor Rb110, a second voltage division resistor Rb111, a third voltage division resistor Rb112, a fourth voltage division resistor Rb113, a first diode Db6, a second diode Db7 and a capacitor Cb108.

[0043] In one embodiment, the negative-end relay state detection circuit includes a VAD_HVBus output port.

[0044] In one embodiment, the negative-end relay state detection circuit includes that the power supply is connected to one end of the first voltage division resistor Rb110; the other end of the first voltage division resistor Rb110 is connected to one end of the second voltage division resistor Rb111 and one end of the third voltage division resistor Rb112; the other end of the third voltage division resistor Rb112 is connected to one end of the fourth voltage division resistor Rb113; the other end of the second voltage division resistor Rb111 is connected to one end of the capacitor Cb108 and the VAD_HVBus output port; the other end of the capacitor Cb108 is grounded; the other end of the fourth voltage division resistor Rb113 is connected to the anode of the first diode Db6; the cathode of the first diode Db6 is connected to the anode of the second diode Db7; and the cathode of the second diode Db7 is connected to the negative electrode of the negative-end relay.

[0045] The power supply can be a direct current power supply, and can also be a direct current power supply formed by rectifying current generated by an alternator. The power supply DC1 can be a power battery, and can also be a storage battery.

[0046] Further, the VAD_HVBus output port is collected by a chip.

[0047] In one embodiment, the negative end relay state detection circuit further comprises: an ADC chip.

[0048] In one embodiment, the negative end relay state detection circuit further comprises: the VAD_HVBus output port is connected to the ADC chip, and the ADC chip can detect the voltage value of the VAD_HVBus output port.

[0049] Further, the state of the positive end relay is detected by differential pressure detection method.

[0050] In one embodiment, a voltage comparator is connected between the positive electrode and the negative electrode of the positive end relay, for detecting the voltage difference between the two ends of the positive end relay, so as to determine the opening or closing state of the positive end relay.

[0051] As shown in the accompanying Figure 1 , the positive end relay can determine the closing or opening state of the relay by comparing the voltage values of Vint and Vout.

[0052] As shown in the accompanying Figure 1 and the accompanying Figure 2 , wherein NEG_rely is the negative end relay detection line, which needs to be connected to the positive electrode of the negative end relay. SUM_GND is connected to the negative electrode of the first power supply through an inductor L, and the reference voltage SUM_VCC = 5V. The voltage dividing resistors Rb110 = 220KΩ, Rb112 = 110KΩ, and Rb113 = 110KΩ. VAD_HVBus is connected to the ADC module of the control unit, which detects the voltage of VAD_HVBus in real time. When the negative end relay is closed or opened, the voltage of VAD_HVBus will change, and the state of the negative end relay can be determined according to the voltage of VAD_HVBus.

[0053] When the negative end relay is closed, a loop is formed: SUM_VCC à Rb110 à Rb112 à Rb113 à Db6 à Db7 à NEG_relay à the positive electrode of the negative end relay à the negative electrode of the negative end relay à inductor L à SUM_GND. At this time, the voltage VAD_HVBus = 2.5V. Therefore, the control unit can determine that the negative end relay is in the closed state by detecting VAD_HVBus = 2.5V. When the control unit does not enable the negative end relay to be closed, and still detects VAD_HVBus = 2.5V, it can be determined that the relay is stuck.

[0054] When the negative end relay is opened, the loop SUM_VCC à Rb110 à Rb112 à Rb113 à Db6 à Db7 à NEG_relay à positive pole of negative end relay à negative pole of negative end relay à inductance L à SUM_GND cannot be formed. At this time, the voltage VAD_HVBus = 5V. Therefore, the control unit can judge that the negative end relay is in an open state by detecting VAD_HVBus = 5V. When the control unit enables the negative end relay to be closed, and VAD_HVBus = 5V is still detected, it can be judged that the relay fails to be closed.

[0055] wherein the voltage is calculated according to a resistance voltage division method ; Embodiment two

[0056] The utility model further provides a circuit protection board, the circuit protection board includes: the battery system relay state detection circuit and circuit substrate of first aspect, the battery system relay state detection circuit is integrated on the circuit substrate.

[0057] In conclusion, the application provides a battery system relay state detection circuit and a circuit protection board thereof, the battery system relay state detection circuit comprises a main loop and a negative end relay state detection circuit, the main loop comprises a positive end relay, a negative end relay and a peripheral circuit; the negative end relay state detection circuit comprises a plurality of resistors, a plurality of diodes and a capacitor. In the utility model, the state of the positive end relay is detected by the differential pressure detection method, and the state of the negative end relay is indirectly detected by the negative end relay state detection circuit, so that the open, closed and fault states of the negative end relay in the battery system can be detected in real time. When the relay fails to be closed or adhered, the control unit executes the corresponding protection strategy, so that the battery system can be safely and reliably operated.

[0058] The utility model discloses a negative end relay state detection circuit, which effectively overcomes the limitations of the relay auxiliary contact detection method and the shortcomings that the differential pressure detection method cannot detect the state of the negative end relay, and any kind of relay can use this method, so that the complexity of system design is reduced, and the cost is saved.

[0059] In several embodiments provided in the present application, it can be understood that each block in the flowchart or block diagram can represent a module, a segment or a portion of code which includes one or more executable instructions for implementing the specified logic function. It should also be noted that in some alternative implementations, the functions noted in the blocks can occur out of the order noted in the figure. For example, two blocks noted in succession can in fact be executed substantially concurrently or in the reverse order, depending on the functionality involved.

[0060] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on such understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, and includes a number of instructions for causing an electronic device to perform all or part of the steps of the methods described in the various embodiments of the present application. The foregoing storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk or an optical disk, and various media that can store program codes.

[0061] The specific embodiments described above further illustrate the purposes, technical solutions and beneficial effects of the present application. It should be understood that the above description is only for specific embodiments of the present application and is not intended to limit the protection scope of the present application. It is particularly pointed out that any modification, equivalent replacement, improvement, etc. made by those skilled in the art within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A battery system relay state detection circuit, characterized by, The battery system relay state detection circuit comprises a main circuit and a negative relay state detection circuit, the main circuit comprises a battery pack, a positive relay and a negative relay; The positive electrode of the battery pack is connected to the positive electrode of the positive relay, the positive electrode of the positive relay is connected to the positive electrode of the negative relay, and the negative electrode of the negative relay is connected to the negative electrode of the battery pack; The negative relay state detection circuit is connected to the positive electrode of the negative relay; The main circuit further comprises a protection resistor and an inductor; The protection resistor is arranged between the positive relay and the negative relay, one end of the inductor is connected to the negative electrode of the battery pack, and the other end is grounded.

2. The battery system relay state detection circuit according to claim 1, characterized by, The negative relay state detection circuit comprises a power supply, a first voltage dividing resistor, a second voltage dividing resistor, a third voltage dividing resistor, a fourth voltage dividing resistor, a first diode, a second diode and a capacitor.

3. The battery system relay state detection circuit according to claim 2, characterized by, The negative relay state detection circuit comprises a VAD_HVBus output port.

4. The battery system relay state detection circuit according to claim 3, characterized by, The negative relay state detection circuit comprises that the power supply is connected to one end of the first voltage dividing resistor; the other end of the first voltage dividing resistor is connected to one end of the second voltage dividing resistor and one end of the third voltage dividing resistor; the other end of the second voltage dividing resistor is connected to one end of the fourth voltage dividing resistor; the other end of the third voltage dividing resistor is connected to one end of the capacitor and the VAD_HVBus output port; the other end of the capacitor is grounded; the other end of the fourth voltage dividing resistor is connected to the anode of the first diode; the cathode of the first diode is connected to the anode of the second diode; the cathode of the second diode is connected to the negative electrode of the negative relay.

5. The battery system relay state detection circuit according to claim 4, characterized by, The negative relay state detection circuit further comprises an ADC chip.

6. The battery system relay state detection circuit according to claim 5, characterized by, The negative relay state detection circuit further comprises that the VAD_HVBus output port is connected to the ADC chip.

7. The battery system relay state detection circuit according to claim 1, characterized by, A voltage comparator is connected between the positive electrode and the negative electrode of the positive relay.

8. A circuit protection board, characterized by The circuit protection board comprises the battery system relay state detection circuit and a circuit substrate, the battery system relay state detection circuit is integrated on the circuit substrate.

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