Battery charging control circuit, battery system, and electrical apparatus

Abstract

The present application relates to the technical field of batteries, and provides a battery charging control circuit, a battery system, and an electrical apparatus. The battery charging control circuit comprises: a main relay, configured to connect a battery and a charging apparatus; a charging negative relay, wherein a first terminal of the charging negative relay is configured to connect to a negative electrode of the battery, a second terminal of the charging negative relay is configured to connect to a negative electrode of the charging apparatus, and a reference point is further provided between the first terminal of the charging negative relay and the negative electrode of the battery; and a sampling circuit, connected to the first terminal and the second terminal of the charging negative relay, and configured to: when the main relay is closed and the charging negative relay is turned off, connect the first terminal and the second terminal of the charging negative relay to form a first sampling loop, and acquire, in the first sampling loop, a first voltage of the two terminals of the charging negative relay relative to the reference point. The charging control circuit of the present application can detect the actual output voltage of the charging apparatus when only a charging negative relay is provided, so as to satisfy charging standards.

Description

Battery charging control circuit, battery system and electrical device

[0001] Cross-references

[0002] This application incorporates Chinese Patent Application No. 202422730118.1, filed on November 8, 2024, entitled “Battery Charging Control Circuit, Battery System and Electrical Device”, which is incorporated herein by reference in its entirety. Technical Field

[0003] This application relates to the field of battery technology, and in particular to a battery charging control circuit, a battery system, and an electrical device. Background Technology

[0004] Batteries are used in applications involving high voltage and high current, and relays are typically used to control the connection between the battery and other components. For example, a main relay connects the positive and / or negative terminals of the battery, connecting them to other components so that the battery can power them. Charging relays control the on / off state of the charging circuit between the battery and the charging device; both the main relay and the charging relay are closed during battery charging. Charging relays typically include a positive charging relay and a negative charging relay, used to control the connection between the battery's positive and negative terminals and the charging device, respectively.

[0005] To reduce costs, the relevant technology only uses a single-sided negative charging relay to control the formation of the charging circuit.

[0006] However, some current charging devices (such as charging stations) require detecting the charging device's output voltage before determining whether to close the charging negative relay to form a charging circuit. In cases where only a single-sided charging negative relay is designed, the charging device's output voltage cannot be detected when the relay is turned off, thus failing to meet charging standards. Summary of the Invention

[0007] This application aims to at least solve one of the technical problems existing in the background art. Therefore, one object of this application is to provide a charging control circuit, a battery system, and an electrical device to solve the aforementioned problems.

[0008] An embodiment of the first aspect of this application provides a battery charging control circuit, including: a main relay, a first terminal of which is connected to a battery and a second terminal of which is connected to a charging device; a charging negative relay, a first terminal of which is connected to the negative terminal of the battery and a second terminal of which is connected to the negative terminal of the charging device, wherein the positive and negative terminals of the battery are connected to the positive and negative terminals of the charging device respectively through the main relay and the charging negative relay, and a reference point is further provided between the first terminal of the charging negative relay and the negative terminal of the battery; and a sampling circuit, which connects the first terminal and the second terminal of the charging negative relay and is configured to: during the period when the main relay is closed and the charging negative relay is closed, connect the first terminal and the second terminal of the charging negative relay to form a first sampling loop, and acquire a first voltage between the two terminals of the charging negative relay in the first sampling loop relative to the reference point.

[0009] In the technical solution of this application embodiment, a sampling circuit is set to connect the first and second terminals of the charging negative relay. During the period when the main relay is closed and the charging negative relay is closed, the sampling circuit can replace the charging negative relay to connect the negative terminal of the battery and the negative terminal of the charging device, so that the formed first sampling circuit can connect the positive and negative terminals of the battery to the positive and negative terminals of the charging device, respectively.

[0010] A reference point is set between the first terminal of the negative charging relay and the negative terminal of the battery. Thus, in the first sampling circuit, the negative terminal of the battery is connected to the reference point, and the first and second terminals of the negative charging relay are connected in series with the charging device between the positive terminal of the battery and the reference point. This is equivalent to the two terminals of the series-connected negative charging relay and the charging device being connected in parallel with the battery. Therefore, the total voltage between the two terminals of the series-connected negative charging relay and the charging device relative to the reference point is equal to the voltage between the two terminals of the battery relative to the reference point. Since the sampling circuit can also acquire the first voltage between the two terminals of the negative charging relay relative to the reference point, given that the voltage between the two terminals of the battery relative to the reference point is known, the output voltage of the charging device can be calculated by subtracting the first voltage from the voltage between the two terminals of the battery relative to the reference point, thereby meeting the charging standard.

[0011] In some embodiments, the sampling circuit includes: a first resistor module; and a first switch connected in series with the first resistor module. The first resistor module and the first switch are connected between a first terminal and a second terminal of the charging negative relay. The sampling circuit is configured to: control the first switch to close to form a first sampling loop during the period when the main relay is closed and the charging negative relay is off. When it is necessary to detect the output voltage of the charging device, the first switch is controlled to close, so that the first resistor module replaces the charging negative relay to connect the negative terminal of the battery and the negative terminal of the charging device. The voltage across the first resistor module is sampled to obtain a first voltage, and then the output voltage of the charging device is calculated. If the difference between the output voltage of the charging device and the voltage across the battery is less than a preset value, the charging negative relay is closed. This can, to a certain extent, avoid the problem of the charging negative relay sticking when the difference between the output voltage of the charging device and the voltage across the battery is too large. When the charging negative relay is closed to form a charging loop for the battery, the first switch is controlled to open, so as not to affect the charging of the battery.

[0012] In some embodiments, the first resistor module includes: a first resistor element and a second resistor element connected in series. The end of the first resistor element away from the second resistor element is connected to a first terminal of a charging negative relay, and the end of the second resistor element away from the first resistor element is connected to a second terminal of the charging negative relay. The node between the first resistor element and the second resistor element serves as a sampling point in the first sampling loop of the sampling circuit. By setting the first resistor element and the second resistor element in series and acquiring the voltage of the sampling point relative to a reference point, the voltage value of the first resistor element in the first sampling loop can be obtained. Furthermore, a first voltage can be obtained based on the voltage value of the first resistor element in the first sampling loop and the resistance values ​​of the first and second resistor elements, enabling the first resistor element to achieve a good voltage divider effect and improving the accuracy of the acquired first voltage.

[0013] In some embodiments, the sampling circuit further includes a second resistor module, a first end of which is connected to a node between the first and second resistor elements, and a second end of which is connected to a bias voltage. Since the first end of the second resistor module is connected to the node between the first and second resistor elements, according to Kirchhoff's laws, the sum of the current flowing through the node from the second resistor element and the current flowing through the node from the second resistor module is equal to the current flowing through the node from the first resistor element. Based on this, given the bias voltage, the second sampling voltage, the resistance values ​​of the first and second resistor elements, and the resistance values ​​of the second resistor module, the first voltage can be calculated using Ohm's law. Furthermore, this calculation method allows the first voltage to be acquired even if it is negative, thereby increasing the sampling range of the sampling circuit for the first voltage.

[0014] In some embodiments, the battery charging control circuit further includes a switching circuit, a first terminal of which is connected to the positive terminal of the charging device, and a second terminal of which is connected to the first terminal of the charging negative relay. The switching circuit is configured to connect the charging device and a sampling circuit during the period when both the main relay and the charging negative relay are off, to form a second sampling loop connected between the positive and negative terminals of the charging device together with the sampling circuit. The sampling circuit is further configured to acquire a second voltage relative to a reference point at both ends of the charging negative relay in the second sampling loop. During the charging process, the main relay is closed to connect the battery to external components to apply high voltage to the vehicle. When the main relay is open, the battery is disconnected from the first terminal of the charging negative relay, and the actual voltage at the first terminal of the charging negative relay is 0 volts (V). Since the second terminal of the charging negative relay is directly connected to the charging device, the actual voltage at the second terminal of the charging negative relay should be greater than 0V when the output voltage of the charging device is large. Therefore, when the charging negative relay is open, the voltage at the second terminal of the charging negative relay will be greater than the voltage at the first terminal of the charging negative relay. However, if the charging negative relay becomes stuck, the voltage at the first terminal and the voltage at the second terminal of the charging negative relay will be the same. Based on this, a second sampling circuit is formed by setting up a switching circuit and a sampling circuit, which can obtain the real voltage across the charging negative relay when both the main relay and the charging negative relay are off, and thus determine whether the charging negative relay has already stuck before the charging device charges the battery.

[0015] In some embodiments, the switching circuit includes: a third resistor module; and a second switch connected in series with the third resistor module. The series-connected third resistor module and second switch are connected to the positive terminal of the charging device and the first terminal of the charging negative relay. The switching circuit is configured to control the second switch to close when both the main relay and the charging negative relay are off. The sampling circuit is configured to connect the first and second terminals of the charging negative relay when both the main relay and the charging negative relay are off, so as to form a second sampling loop together with the switching circuit. The inclusion of the third resistor module in the switching circuit allows it to act as a voltage divider in the second sampling loop. Even if the charging negative relay sticks, a large current will not be generated in the second sampling loop, improving the safety of the detection and protecting the sampling circuit from damage by excessive current.

[0016] In some embodiments, the sampling circuit includes: a first resistor module comprising: a first resistor element and a second resistor element connected in series, wherein the first resistor element is connected to a first terminal of the charging negative relay, and the second resistor element is connected to a second terminal of the charging negative relay; a first switch connected in series with the first and second resistor elements; a second resistor module, wherein the first terminal of the second resistor module is connected to a node between the first and second resistor elements, and the second terminal of the second resistor module is connected to a bias voltage; the sampling circuit is configured to: close the first switch during the period when both the main relay and the charging negative relay are off to form a second sampling loop together with the switching circuit, wherein the node between the first and second resistor elements serves as a sampling point of the sampling circuit in the second sampling loop. By setting the first resistor module and the second resistor module, even if the actual voltage across the charging negative relay relative to a reference point is negative, it can still be acquired, thereby improving the accuracy of detecting whether the charging negative relay has stuck.

[0017] In some embodiments, the battery charging control circuit further includes a pre-charging capacitor, which is connected in parallel between the positive and negative terminals of the battery. The second terminal of the main relay is also connected to the pre-charging capacitor, and the first terminal of the negative charging relay is also connected to the pre-charging capacitor. The pre-charging capacitor stabilizes the charging voltage and protects the circuit from the impact of high voltage output from the charging device. In this embodiment, a sampling circuit is used to collect the first voltage across the negative charging relay in the first sampling circuit, and the output voltage of the charging pile is calculated using the first voltage. This allows for determination of whether to close the negative charging relay based on the difference between the output voltage of the charging pile and the voltage across the battery. This avoids, to some extent, the problem of the negative charging relay sticking due to the charging device instantly charging the pre-charging capacitor with a large current when the difference between the output voltage of the charging device and the voltage across the battery is too large.

[0018] In some embodiments, the battery charging control circuit further includes a pre-charge control circuit connected in parallel across the main relay. The pre-charge control circuit is configured to control the pre-charge capacitor to be connected in series with the battery to form a pre-charge loop while the main relay disconnects the battery from the pre-charge capacitor. Forming a pre-charge loop through the pre-charge control circuit enables pre-charging of the pre-charge capacitor, thus avoiding, to some extent, the problem of high-current charging of the pre-charge capacitor when the charging pile is connected to the battery, which could damage other components in the circuit.

[0019] In some embodiments, the first terminal of the pre-charge capacitor is connected to the positive terminal of the battery, and the second terminal is connected to the negative terminal of the battery. The first terminal of the negative charging relay is connected to the second terminal of the pre-charge capacitor. The main relay is a positive main relay, with its first terminal connected to the positive terminal of the battery and its second terminal connected to the first terminal of the pre-charge capacitor. Using only a single-sided positive main relay simplifies the circuit and reduces costs while controlling the positive and negative terminals of the battery to form a circuit with other components.

[0020] In some embodiments, the first terminal of the pre-charge capacitor is connected to the positive terminal of the battery, and the second terminal is connected to the negative terminal of the battery. The first terminal of the charging negative relay is connected to the second terminal of the pre-charge capacitor. The main relay is a main negative relay, with its first terminal connected to the negative terminal of the battery and its second terminal connected to the second terminal of the pre-charge capacitor. Using only a single-sided main negative relay simplifies the circuit and reduces costs while controlling the positive and negative terminals of the battery to form a circuit with other components.

[0021] In some embodiments, a first terminal of the pre-charge capacitor is connected to the positive terminal of the battery, and a second terminal is connected to the negative terminal of the battery. A first terminal of the charging negative relay is connected to the second terminal of the pre-charge capacitor. The main relay includes: a main positive relay, with its first terminal connected to the positive terminal of the battery and its second terminal connected to the first terminal of the pre-charge capacitor; and a main negative relay, with its first terminal connected to the negative terminal of the battery and its second terminal connected to the second terminal of the pre-charge capacitor. Using dual-sided main positive and main negative relays to control the connection between the positive and negative terminals of the battery and other components respectively improves the control capability for forming a circuit between the positive and negative terminals of the battery and other components.

[0022] An embodiment of the second aspect of this application provides a battery system including a battery; and the battery charging control circuit described in the above embodiment.

[0023] An embodiment of the third aspect of this application provides an electrical device that includes the battery system described in the above embodiments, the battery system being used to provide electrical energy.

[0024] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0025] In the accompanying drawings, unless otherwise specified, the same reference numerals throughout the various drawings denote the same or similar parts or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings depict only some embodiments disclosed in this application and should not be construed as limiting the scope of this application.

[0026] Figure 1 is a schematic diagram of the vehicle structure according to some embodiments of this application;

[0027] Figure 2 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0028] Figure 3 is an equivalent circuit diagram of the first sampling loop in some embodiments of this application;

[0029] Figure 4 is a second schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0030] Figure 5 is a third schematic diagram of the battery charging control circuit of some embodiments of this application;

[0031] Figure 6 is a fourth schematic diagram of the battery charging control circuit of some embodiments of this application;

[0032] Figure 7 is a fifth schematic diagram of the battery charging control circuit of some embodiments of this application;

[0033] Figure 8 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0034] Figure 9 is a schematic diagram of the battery charging control circuit of some embodiments of this application (the seventh one).

[0035] Figure 10 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0036] Figure 11 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0037] Figure 12 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0038] Figure 13 is an eleventh schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0039] Figure 14 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application;

[0040] Figure 15 is a schematic diagram of the battery charging control circuit of some embodiments of this application, number thirteen.

[0041] Figure 16 is a schematic diagram of the structure of a battery charging control circuit according to some embodiments of this application. Detailed Implementation

[0042] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0044] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0045] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0046] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0047] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0048] Currently, some charging devices (such as charging piles) require the charging device's output voltage to be detected first during the battery charging process. Only when the difference between the charging device's output voltage and the voltage across the battery terminals is less than a certain preset value will the charging relay be closed to form a charging circuit for the battery.

[0049] For example, in the European standard charging process, after the battery is physically connected to the European standard charging station, the positive and negative relays at the charging station will first close to form the DC power supply circuit of the charging station and output the voltage for charging.

[0050] Next, the vehicle's BMS (Battery Management System) interacts with the charging station, entering a handshake phase. After a successful handshake, the BMS controls the main relay to close, applying high voltage to the vehicle. During this high-voltage application process, the charging relay does not close.

[0051] After the high voltage is applied to the entire vehicle, the BMS needs to detect the output voltage of the charging pile and determine whether the difference between the output voltage of the charging pile and the voltage across the battery terminals is less than a preset value. If the difference between the output voltage of the charging pile and the voltage across the battery terminals is less than the preset value, the BMS controls the charging relay to close to form a charging circuit from the charging pile to the battery.

[0052] However, to reduce costs, the relevant technology omits the positive charging relay and only designs a single-sided negative charging relay to control the formation of the charging circuit. The negative charging relay connects the negative terminal of the battery and the negative terminal of the charging device. Understandably, since the negative charging relay is connected to the low-potential negative terminal of the battery and the low-potential negative terminal of the charging device, when it is disconnected, detecting the voltage across the negative charging relay cannot accurately characterize the output voltage of the charging device, thus making it difficult to obtain the output voltage of the charging device.

[0053] Based on the above considerations, a sampling circuit is set to connect the first and second terminals of the charging negative relay. During the period when the main relay is closed and the charging negative relay is closed, the sampling circuit can replace the charging negative relay to connect the negative terminal of the battery and the negative terminal of the charging device, so that the formed first sampling circuit can connect the positive and negative terminals of the battery to the positive and negative terminals of the charging device, respectively.

[0054] A reference point is set between the first terminal of the negative charging relay and the negative terminal of the battery. Thus, in the first sampling circuit, the negative terminal of the battery is connected to the reference point, and the first and second terminals of the negative charging relay are connected in series with the charging device between the positive terminal of the battery and the reference point. This is equivalent to the two terminals of the series-connected negative charging relay and the charging device being connected in parallel with the battery. Therefore, the total voltage between the two terminals of the series-connected negative charging relay and the charging device relative to the reference point is equal to the voltage between the two terminals of the battery relative to the reference point. Since the sampling circuit can also acquire the first voltage between the two terminals of the negative charging relay relative to the reference point, given that the voltage between the two terminals of the battery relative to the reference point is known, the output voltage of the charging device can be calculated by subtracting the first voltage from the voltage between the two terminals of the battery relative to the reference point, thereby meeting the charging standard.

[0055] The battery charging control circuit disclosed in this application can be used, but is not limited to, for charging batteries in electrical devices such as vehicles, ships, or aircraft.

[0056] Electrical devices can include, but are not limited to, mobile phones, tablets, laptops, electric toys, power tools, electric vehicles, electric cars, ships, spacecraft, etc. Among them, electric toys can include stationary or mobile electric toys, such as game consoles, electric car toys, electric ship toys, and electric airplane toys, etc. Spacecraft can include airplanes, rockets, space shuttles, and spacecraft, etc.

[0057] For ease of explanation, the following embodiments will be described using a vehicle 1000 as an example of an electrical device according to an embodiment of this application.

[0058] Please refer to Figure 1, which is a schematic diagram of the vehicle structure provided in some embodiments of this application. The vehicle 1000 can be a gasoline-powered vehicle, a natural gas-powered vehicle, or a new energy vehicle. The new energy vehicle can be a pure electric vehicle, a hybrid electric vehicle, or a range-extended electric vehicle, etc. A battery 100 is disposed inside the vehicle 1000, and the battery 100 can be located at the bottom, front, or rear of the vehicle 1000. The battery 100 can be used to power the vehicle 1000; for example, the battery 100 can serve as the operating power source for the vehicle 1000. The vehicle 1000 may also include a vehicle controller 200 and a motor 300. The vehicle controller 200 is used to control the battery 100 to supply power to the motor 300, for example, to meet the power needs of the vehicle 1000 during startup, navigation, and driving.

[0059] In some embodiments of this application, the battery 100 can not only serve as the operating power source for the vehicle 1000, but also as the driving power source for the vehicle 1000, replacing or partially replacing fuel or natural gas to provide driving power for the vehicle 1000.

[0060] Referring to Figure 2, this application embodiment provides a battery charging control circuit, including: a main relay 101, the first end of which is connected to a battery 100, and the second end of which is connected to a charging device 102; a charging negative relay 103, the first end P1 of which is connected to the negative terminal of the battery 100, and the second end P2 of which is connected to the negative terminal of the charging device 102; the positive and negative terminals of the battery 100 are connected to the positive and negative terminals of the charging device 102 respectively through the main relay 101 and the charging negative relay 103; a reference point G0 is also provided between the first end P1 of the charging negative relay and the negative terminal of the battery 100; and a sampling circuit 104, which is connected to the first end and the second end of the charging negative relay, and is configured to: during the period when the main relay 101 is closed and the charging negative relay 103 is closed, connect the first end and the second end of the charging negative relay to form a first sampling loop, and collect the first voltage of the two ends of the charging negative relay 103 in the first sampling loop relative to the reference point G0.

[0061] The charging device 102 may include, but is not limited to, devices capable of supplying power to the battery 100, such as charging piles. The charging device 102 may include a power module 1021, which converts alternating current (AC) to direct current (DC) to supply power to the battery 100 and regulates the output voltage and current. The positive terminal of the charging device 102 may be the positive terminal of the power module 1021, and the negative terminal of the charging device 102 may be the negative terminal of the power module 1021. The power module 1021 may be a structure well-known to those skilled in the art for providing voltage and current.

[0062] The charging device 102 may further include a positive relay 31 and a negative relay 32. The positive relay 31 is connected to the positive terminal of the power module 1021, and the negative relay 32 is connected to the negative terminal of the power module 1021. After the charging device 102 is physically connected to the battery 100, the positive relay 31 and the negative relay 32 will close first to form a DC power supply circuit for the charging device 102, outputting a voltage for charging. The main relay 101 can be connected to the positive relay 31 and / or the negative relay 32, and the charging negative relay 103 can be connected to the negative relay 32. When the positive relay 31 and the negative relay 32 of the charging device 102 are closed, the positive and negative terminals of the battery 100 can be connected to the positive and negative terminals of the charging device 102 respectively through the main relay 101 and the charging negative relay 103.

[0063] In some embodiments, the charging device 102 may include a pre-charge capacitor C1, which is connected in parallel between the positive and negative terminals of the power module 1021 to serve as a voltage regulator.

[0064] In some embodiments, the charging device 102 is a charging pile.

[0065] Reference point G0 refers to the potential reference point G0, which is defined as having a potential of zero.

[0066] Understandably, when the main relay 101 is closed, it can connect the battery 100 to external components to apply high voltage to the vehicle. During this period, to prevent the output voltage of the charging device 102 from differing too much from the voltage across the battery 100 and potentially damaging the charging negative relay 103, the charging negative relay 103 remains closed. Exemplarily, the main relay 101 may include at least one of a main positive relay and a main negative relay. The closure of the main relay 101 means that all relays included in the main relay 101 (the main positive relay and / or the main negative relay) are closed.

[0067] The main relay 101 may include at least one of a main positive relay K11 and a main negative relay. The first terminal of the main positive relay K11 is connected to the positive terminal of the battery 100, and the second terminal of the main positive relay K11 is connected to the positive terminal of the charging device 102. The first terminal of the main negative relay is connected to the negative terminal of the battery 100, and the second terminal of the main negative relay is connected to the negative terminal of the charging device 102. When the main relay 101 is the main positive relay K11, the first terminal P1 of the charging negative relay is directly connected to the negative terminal of the battery 100. When the main relay 101 is the main negative relay, the positive terminal of the battery 100 is directly connected to the positive terminal of the charging device 102. The first terminal P1 of the charging negative relay is connected to the second terminal of the main negative relay. As an example, Figure 2 shows the case where the main relay 101 is the main positive relay K11.

[0068] It is worth noting that in this embodiment, only one charging negative relay 103 is provided. When the main relay 101 includes a main positive relay K11, the first terminal of the main positive relay K11 is directly connected to the positive terminal of the battery 100, and the second terminal of the main positive relay K11 is directly connected to the positive terminal of the charging device 102. When the main relay 101 includes a main negative relay, the first terminal of the main negative relay is directly connected to the negative terminal of the battery 100, the second terminal of the main negative relay is connected to the first terminal P1 of the charging negative relay, and the second terminal P2 of the charging negative relay is directly connected to the negative terminal of the charging device 102.

[0069] The connection of the positive and negative terminals of battery 100 to the positive and negative terminals of charging device 102 via main relay 101 and charging negative relay 103 respectively means that when both main relay 101 and charging negative relay 103 are closed, the positive terminal of battery 100 is connected to the positive terminal of charging device 102, and the negative terminal of battery 100 is connected to the negative terminal of charging device 102.

[0070] The sampling circuit 104 is connected to the first and second terminals of the charging negative relay, which is connected to the negative terminal of the battery 100 and the negative terminal of the charging device 102, respectively. When the sampling circuit 104 is connected to the first and second terminals of the charging negative relay, it is equivalent to connecting the negative terminal of the battery 100 and the negative terminal of the charging device 102. Thus, during the period when the main relay 101 is closed and the charging negative relay 103 is closed, the sampling circuit 104 can replace the charging negative relay 103 in the first sampling circuit. Furthermore, through the first sampling circuit, the positive and negative terminals of the battery 100 can be connected to the positive and negative terminals of the charging device 102, respectively.

[0071] Reference point G0 is set between the first terminal P1 of the charging negative relay and the negative terminal of the battery 100. Thus, in the first sampling circuit, the negative terminal of the battery 100 is connected to reference point G0, the positive terminal of the charging device 102 is connected to the positive terminal of the battery 100, and the negative terminal of the charging device 102 is connected to reference point G0 through sampling circuit 104. Since sampling circuit 104 connects the first terminal P1 and the second terminal P2 of the charging negative relay, it is equivalent to the first terminal P1 and the second terminal P2 of the charging negative relay being connected in series with the charging device 102 and then connected between the positive terminal of the battery 100 and reference point G0. In other words, the first and second terminals of the charging negative relay are connected in series with the charging device 102 and then in parallel with the battery 100. Figure 3 shows the equivalent circuit diagram of the first sampling circuit.

[0072] Based on this, the sum of the voltage across the charging negative relay 103 relative to the reference point G0 and the output voltage of the charging device 102 relative to the reference point G0 is equal to the voltage across the battery 100 relative to the reference point G0. Since the sampling circuit 104 can also acquire the first voltage across the charging negative relay 103 relative to the reference point G0, the output voltage of the charging device 102 can be calculated by subtracting the first voltage from the voltage across the battery 100 relative to the reference point G0, given that the voltage across the battery 100 relative to the reference point G0 is known.

[0073] The voltage across the charging negative relay 103 can be the difference between the voltage of the second terminal P2 of the charging negative relay relative to the reference point G0 and the voltage of the first terminal P1 of the charging negative relay relative to the reference point G0.

[0074] In some embodiments, the voltage across the battery 100 can be obtained using a voltage sensor.

[0075] In other embodiments, the voltage across the battery 100 can be obtained by the battery management system (BMS) of the battery 100. The BMS may include an integrated chip for obtaining the voltage value of the battery 100, the pins of which are connected to the battery 100 to calculate the voltage value across the battery 100.

[0076] In the above technical solution, a reference point G0 is set between the first terminal P1 of the charging negative relay and the negative terminal of the battery 100. The sampling circuit 104 is connected to the first and second terminals of the charging negative relay, so that during the period when the main relay 101 is closed and the charging negative relay 103 is off, the sampling circuit 104 can replace the charging negative relay 103 in connecting the negative terminal of the battery 100 and the negative terminal of the charging device 102, forming a first sampling loop. Both the first and second terminals of the charging negative relay are connected in the first sampling loop. In the formed first sampling loop, the first and second terminals of the charging negative relay are connected in series with the charging device 102 between the positive terminal of the battery 100 and the reference point G0. The sampling circuit 104 is also used to collect the first voltage across the charging negative relay 103 in the first sampling loop. Given the voltage across the battery 100, the output voltage of the charging device 102 can be obtained by subtracting the first voltage from the voltage across the battery 100, thus meeting the charging standard.

[0077] Referring to FIG4, according to some embodiments of the present application, the sampling circuit 104 includes: a first resistor module 1041; a first switch S1 connected in series with the first resistor module 1041. The first resistor module 1041 and the first switch S1 connected in series are connected between the first terminal and the second terminal of the charging negative relay. The sampling circuit 104 is configured to control the first switch S1 to close to form a first sampling loop during the period when the main relay 101 is closed and the charging negative relay 103 is closed.

[0078] The sampling circuit can collect the first sampling voltage between the two ends of the first resistor module 1041 in the first sampling loop relative to the reference point G0, and use it as the first voltage.

[0079] In the first sampling circuit, the first resistor module 1041 and the first switch S1, which are connected in series, are connected to the reference point G0 and the negative terminal of the charging device 102. The positive terminal of the charging device 102 is connected to the positive terminal of the battery 100, and the negative terminal of the battery 100 is connected to the reference point G0. That is, the first resistor module 1041 and the charging device 102 are connected in series and then connected in parallel with the battery 100.

[0080] The two ends of the first resistor module 1041 are electrically connected to the first and second ends of the charging negative relay, respectively. Therefore, the first sampling voltage of the two ends of the first resistor module 1041 relative to the reference point G0 is the first voltage of the two ends of the charging negative relay 103 relative to the reference point G0.

[0081] Understandably, the sampling circuit 104 is also configured to control the first switch S1 to turn off while both the main relay 101 and the charging negative relay 103 are closed, so as not to affect the charging of the battery 100.

[0082] In some embodiments, the sampling circuit 104 can be controlled by the BMS of the battery 100, including controlling the turning off of the first switch S1 of the sampling circuit 104 and controlling the sampling of the sampling circuit 104.

[0083] In some embodiments, the first switch S1 may include, but is not limited to, switching elements such as relays.

[0084] In some embodiments, the first resistor module 1041 may include only one resistor element. In other embodiments, the first resistor module 1041 may also include a resistor string, which includes a plurality of resistor elements connected in series.

[0085] In some embodiments, the sampling circuit 104 further includes an ADC (Analog to Digital Converter) sampling device, which can be connected to the first resistor module 1041 to acquire a first sampling voltage across the first resistor module 1041 relative to a reference point G0. The ADC sampling device has the same meaning as commonly understood by those skilled in the art in the embodiments of this application, and its structure and principle will not be described in detail here.

[0086] In the above technical solution, when it is necessary to detect the output voltage of the charging device 102, the first switch S1 is closed, causing the first resistor module 1041 to replace the charging negative relay 103 in connecting the negative terminal of the battery 100 and the negative terminal of the charging device 102. The voltage across the first resistor module 1041 is sampled to obtain a first voltage, which is then used to calculate the output voltage of the charging device 102. If the difference between the output voltage of the charging device 102 and the voltage across the battery 100 is less than a preset value, the charging negative relay 103 is closed. This avoids, to some extent, the problem of the charging negative relay 103 sticking when the difference between the output voltage of the charging device 102 and the voltage across the battery 100 is too large. When the charging negative relay 103 is closed to form a charging circuit for the battery 100, the first switch S1 is opened, thus not affecting the charging of the battery 100.

[0087] Referring to Figure 5, according to some embodiments of this application, the first resistor module 1041 includes: a first resistor element R1 and a second resistor element R2 connected in series. The end of the first resistor element R1 away from the second resistor element R2 is connected to the first terminal P1 of the charging negative relay, and the end of the second resistor element R2 away from the first resistor element R1 is connected to the second terminal P2 of the charging negative relay. The node between the first resistor element R1 and the second resistor element R2 serves as a sampling point in the first sampling loop of the sampling circuit 104.

[0088] The sampling circuit 104 can acquire the voltage value of the sampling point relative to the reference point, so as to acquire the voltage value of the two ends of the first resistor element R1 in the first sampling loop relative to the reference point G0. In this way, the first sampling voltage can be obtained based on the voltage value of the two ends of the first resistor element R1 relative to the reference point G0, the resistance value of the first resistor element R1, and the resistance value of the second resistor element R2.

[0089] In some embodiments, the sampling circuit 104 includes an ADC sampling device (shown as ADC in FIG5), which can be connected to a node between the first resistive element R1 and the second resistive element R2, and use this node as a sampling point to acquire the voltage value of the two ends of the first resistive element R1 relative to the reference point G0.

[0090] By setting the first resistor element R1 and the second resistor element R2 in series, the voltage across the battery 100 can be further divided across the first resistor element R1 and the second resistor element R2, so that the voltage collected by the sampling circuit 104 falls within the sampling range and the sampling accuracy is improved.

[0091] In some embodiments, the resistance values ​​of the first resistive element R1 and the second resistive element R2 may be equal.

[0092] In other embodiments, the resistance value of the first resistive element R1 may be greater than the resistance value of the second resistive element R2.

[0093] In some embodiments, the first resistive element R1 may include a single resistive element. In other embodiments, the first resistive element R1 may also include a series of resistors.

[0094] In some embodiments, the second resistive element R2 may include a single resistive element. In other embodiments, the second resistive element R2 may also include a series of resistors.

[0095] The first switch S1 can be connected between the first resistive element R1 and the second resistive element R2, or the first switch S1 can be connected to the end of the first resistive element R1 that is away from the second resistive element R2, or the first switch S1 can be connected to the end of the second resistive element R2 that is away from the first resistive element R1.

[0096] Since the first resistor R1 and the second resistor R2 are connected in series, based on Ohm's law, the sum of the voltages across the first resistor R1 and the second resistor R2 relative to the reference point G0 is equal to the first sampling voltage across the first resistor module 1041 relative to the reference point G0. The voltage across the first resistor R1 is equal to the resistance value of the first resistor R1 multiplied by the current flowing through the first resistor R1, the voltage across the second resistor R2 is equal to the resistance value of the second resistor R2 multiplied by the current flowing through the second resistor R2, and the current flowing through the first resistor R1 is equal to the current flowing through the second resistor R2. Based on this, the following formula (1) can be obtained:

[0097] Wherein, U1 represents the first voltage, which is the first sampling voltage; Uad1 represents the voltage value across the two ends of the first resistor element R1 relative to the reference point G0; r1 represents the resistance value of the first resistor element R1; and r2 represents the resistance value of the second resistor element R2.

[0098] Substitute the voltage value of the two ends of the first resistor element R1 relative to the reference point G0, the resistance value of the first resistor element R1, and the resistance value of the second resistor element R2 into formula (1) to obtain the first voltage.

[0099] In some embodiments, the sampling circuit may include a calculation unit that has built-in mathematical functions and instructions, capable of performing the calculations of the above formula (1) to obtain the first voltage. The calculation unit may be any unit capable of performing calculations, including a computer program, that is well known to those skilled in the art.

[0100] In the above technical solution, by setting a first resistor element R1 and a second resistor element R2 in series, and collecting the voltage value of the first resistor element R1 in the first sampling circuit and the resistance values ​​of the first resistor element R1 and the second resistor element R2 to obtain the first sampling voltage, the first resistor element R1 can play a good voltage dividing effect, thereby improving the accuracy of the collected first sampling voltage.

[0101] Referring to FIG6, according to some embodiments of the present application, the sampling circuit 104 further includes: a second resistor module 1042, the first end of the second resistor module 1042 being connected to the node between the first resistor element R1 and the second resistor element R2, and the second end of the second resistor module 1042 being connected to the bias voltage U2.

[0102] When the second resistor module is included, the sampling circuit 104 can acquire the second sampling voltage of the sampling point relative to the reference point, thereby obtaining the first voltage based on the second sampling voltage, the bias voltage, the resistance value of the first resistor element R1, the resistance value of the second resistor element R2, and the resistance value of the second resistor module 1042.

[0103] In some embodiments, the sampling circuit 104 includes an ADC sampling device, which can acquire a second sampling voltage.

[0104] According to Kirchhoff's laws, the sum of the currents flowing into a node is equal to the sum of the currents flowing out of the node. For the node between the first resistive element R1 and the second resistive element R2, the second terminal of the second resistive module 1042 is connected to the bias voltage U2, and its first terminal is connected to the node between the first resistive element R1 and the second resistive element R2. Current flows into this node from the first terminal of the second resistive module 1042. The first terminal of the second resistive element R2 is connected to the charging device 102, and its second terminal is connected to the node between the first resistive element R1 and the second resistive element R2. Current flows into this node from the second terminal of the second resistive element R2. The first terminal of the first resistive element R1 is connected to the node between the first resistive element R1 and the second resistive element R2, and its second terminal is connected to the reference point G0. Current flows out of the node between the first resistive element R1 and the second resistive element R2 to the reference point G0.

[0105] Therefore, the sum of the current flowing through the node between the first resistor R1 and the second resistor R2 and the current flowing through the node between the first resistor R1 and the second resistor R2 in the second resistor module 1042 is equal to the current flowing through the node between the first resistor R1 and the second resistor R2 in the first resistor R1, resulting in the following formula (2):

[0106] Wherein, U1 represents the first voltage, U2 represents the bias voltage, Uad2 represents the second sampling voltage, r1 represents the resistance value of the first resistor element R1, r2 represents the resistance value of the second resistor element R2, and r3 represents the resistance value of the second resistor module 1042.

[0107] The above formula (2) can be transformed to obtain the following formula (3), and the first voltage can be calculated based on formula (3).

[0108] It is understandable that, due to the limitations of the sampling circuit 104 itself, the sampling voltage directly acquired by the sampling circuit 104 is usually a value greater than or equal to 0V. For example, the sampling value of the ADC sampling device is greater than or equal to 0V. That is to say, the second sampling voltage is greater than or equal to 0V, and the voltage value Uad1 across the first resistor element R1 relative to the reference point G0 acquired in the above formula (1) is also greater than or equal to 0V.

[0109] Therefore, even without the second resistor module 1042, the first voltage value obtained based on formula (1) is also a positive value greater than or equal to 0V.

[0110] With the second resistor module 1042 set, even if the second sampling voltage Uad2 is 0V, the first voltage U1 can still be calculated based on formula (3). That is, it is possible to obtain a negative first voltage, and the maximum negative voltage that can be sampled is

[0111] As can be seen from the above, by setting the second resistor module 1042 and inputting a bias voltage at the first terminal of the second resistor module 1042, a negative first voltage can be obtained, thereby increasing the acquisition range of the first voltage.

[0112] In some embodiments, the bias voltage can be 5V.

[0113] In some embodiments, the sampling circuit may include a calculation unit that has built-in mathematical functions and instructions, capable of performing the calculations of the above formula (3) to obtain the first voltage. The calculation unit may be any unit capable of performing calculations, including a computer program, that is well known to those skilled in the art.

[0114] In the above technical solution, by setting the second resistor module 1042, even if the first voltage is negative, it can still be collected, thereby increasing the sampling range of the sampling circuit 104 for the first voltage.

[0115] Referring to Figure 7, according to some embodiments of this application, the battery charging control circuit further includes: a switching circuit 105, a first terminal of which is connected to the positive terminal of the charging device 102, and a second terminal connected to the first terminal P1 of the charging negative relay; the switching circuit 105 is configured to connect the charging device 102 and the sampling circuit 104 during the period when both the main relay 101 and the charging negative relay 103 are off, so as to form a second sampling circuit connected between the positive and negative terminals of the charging device 102 together with the sampling circuit 104; the sampling circuit 104 is further configured to acquire a second voltage between the two terminals of the charging negative relay 103 in the second sampling circuit relative to the reference point G0.

[0116] During the charging process, the main relay 101 closes to connect the battery 100 to external components to apply high voltage to the vehicle. When the main relay 101 is open, the battery 100 is disconnected from the first terminal P1 of the negative charging relay, and the actual voltage of the first terminal P1 of the negative charging relay is 0V. Since the second terminal P2 of the negative charging relay is directly connected to the charging device 102, if the output voltage of the charging device 102 is high, the actual voltage of the second terminal P2 of the negative charging relay should be greater than 0V. Therefore, when the negative charging relay 103 is open, the voltage of the second terminal P2 of the negative charging relay will be greater than the voltage of the first terminal P1, meaning the voltage across the negative charging relay 103 will be either greater than 0V or less than 0V. If the negative charging relay 103 becomes stuck, the voltage at the first terminal and the voltage at the second terminal of the negative charging relay 103 will be the same, meaning the voltage across the negative charging relay 103 will be equal to 0V.

[0117] However, when the charging negative relay 103 is disconnected and no circuit is formed with the charging pile, the voltage at both the first and second terminals of the charging negative relay is low potential, and the voltage across the charging negative relay 103 is 0V when directly detected.

[0118] Based on this, this application embodiment includes a switching circuit 105. The switching circuit 105 connects the positive terminal of the charging device 102 to the first terminal P1 of the charging negative relay, allowing the charging device 102 to connect to the sampling circuit 104. When the sampling circuit 104 connects to the first and second terminals of the charging negative relay, the positive terminal of the charging device 102 can be connected to the negative terminal of the charging device 102 through the switching circuit 105 and the sampling circuit 104 to form a second sampling circuit. That is, the sampling circuit 104 replaces the charging negative relay 103 in connecting the first and second terminals of the charging negative relay, allowing the output voltage of the charging device 102 to be divided between the first and second terminals of the charging negative relay. This enables the acquisition of the second voltage across the charging negative relay 103 in the second sampling circuit relative to the reference point G0, which serves as the true voltage across the charging negative relay 103. If the second voltage is greater than 0V or less than 0V, it indicates that the charging negative relay 103 is not stuck; if the charging negative relay 103 is equal to 0V, it indicates that the charging negative relay 103 is stuck.

[0119] In the above technical solution, a second sampling circuit 104 is formed by setting a switching circuit 105 and a sampling circuit 104, which can obtain the real voltage across the charging negative relay 103 when both the main relay 101 and the charging negative relay 103 are turned off, and thus determine whether the charging negative relay 103 has already stuck before the charging device 102 charges the battery 100.

[0120] Referring to FIG8, according to some embodiments of the present application, the switching circuit 105 includes: a third resistor module; a second switch S2 connected in series with the third resistor module, wherein the third resistor module and the second switch S2 connected in series are connected to the positive terminal of the charging device 102 and the first terminal P1 of the charging negative relay; the switching circuit 105 is configured to control the second switch S2 to close during the period when both the main relay 101 and the charging negative relay 103 are off; the sampling circuit 104 is configured to connect the first terminal and the second terminal of the charging negative relay during the period when both the main relay 101 and the charging negative relay 103 are off, so as to form a second sampling loop together with the switching circuit 105.

[0121] Sampling circuit 104 connects the first and second terminals of the charging negative relay so that the negative terminal of charging device 102 is connected to the first terminal P1 of the charging negative relay. Second switch S2 is closed, connecting the third resistor module to the positive terminal of charging device 102 and the first terminal P1 of the charging negative relay. This connects charging device 102, the third resistor module, the first and second terminals of the charging negative relay, and sampling circuit 104 in series in the second sampling loop. In the second sampling loop, current flows from the positive terminal of charging device 102, sequentially through the third resistor module, the first terminal P1 of the charging negative relay, sampling circuit 104, and the second terminal P2 of the charging negative relay, before flowing into the negative terminal of charging device 102. With the second sampling loop formed, the output voltage of charging device 102 can be divided and sent to sampling circuit 104, allowing sampling circuit 104 to detect a potential difference between the first and second terminals of the charging negative relay, thereby acquiring the true voltage across the charging negative relay 103 relative to the reference point G0. As shown in Figure 7, the solid lines with arrows in Figure 7 illustrate the current path in the second sampling loop.

[0122] In some embodiments, the second switch S2 can be turned off by the BMS of the battery 100.

[0123] In some embodiments, the third resistor module may include a third resistor element R3 and a fourth resistor element R4 connected in series. The second switch S2 may be connected between the third resistor element R3 and the fourth resistor element R4, or it may be connected to the end of the third resistor element away from the fourth resistor element, or it may be connected to the end of the fourth resistor element away from the third resistor element.

[0124] In some embodiments, the resistance values ​​of the third resistive element R3 and the fourth resistive element R4 may be equal.

[0125] In some embodiments, the third resistive element R3 may include a single resistive element. In other embodiments, the third resistive element R3 may also include a series of resistors.

[0126] In some embodiments, the fourth resistive element R4 may include a single resistive element. In other embodiments, the fourth resistive element R4 may also include a series of resistors.

[0127] In the above technical solution, the switching circuit 105 includes a third resistor module, which enables the third resistor module to act as a voltage divider in the second sampling circuit. Even if the charging negative relay 103 sticks, a large current will not be generated in the second sampling circuit, thereby improving the safety of the detection and protecting the sampling circuit 104 from damage by excessive current.

[0128] Referring to FIG8, according to some embodiments of this application, the sampling circuit 104 includes: a first resistor module 1041, which includes: a first resistor element R1 and a second resistor element R2 connected in series, wherein the first resistor element R1 is connected to the first terminal P1 of the charging negative relay, and the second resistor element R2 is connected to the second terminal P2 of the charging negative relay; a first switch S1 connected in series with the first resistor element R1 and the second resistor element R2; a second resistor module 1042, the first terminal of which is connected to the node between the first resistor element R1 and the second resistor element R2, and the second terminal of which is connected to a bias voltage; the sampling circuit 104 is configured to: close the first switch S1 during the period when both the main relay 101 and the charging negative relay 103 are off, so as to form a second sampling loop together with the switch circuit 105, wherein the node between the first resistor element R1 and the second resistor element R2 serves as the sampling point of the sampling circuit 104 in the second sampling loop.

[0129] The sampling circuit can acquire the third sampling voltage of the node between the first resistor element R1 and the second resistor element R2 in the second sampling loop relative to the reference point G0, so that the second voltage can be obtained based on the third sampling voltage, the bias voltage, the resistance value of the first resistor element R1, the resistance value of the second resistor element R2, and the resistance value of the second resistor module 1042.

[0130] The structures of the first switch S1, the first resistor module 1041, and the second resistor module 1042 can be referred to the relevant descriptions in the above embodiments, and will not be repeated here. It is worth noting that during the period when the main relay 101 is closed and the charging negative relay 103 is off, the first switch S1 can be controlled to close to form a first sampling circuit, and the first switch S1, the first resistor module 1041, and the second resistor module 1042 can be used to acquire the first voltage.

[0131] During the period when both the main relay 101 and the charging negative relay 103 are off, the first switch S1 and the second switch S2 can be controlled to close to form a second sampling circuit. The first resistor R1 and the second resistor R2 are connected between the first and second terminals of the charging negative relay, replacing the charging negative relay 103 in series in the second sampling circuit. The second voltage is the sum of the voltages of the first resistor R1 and the second resistor R2 in the second sampling circuit.

[0132] According to Kirchhoff's laws, the sum of the current flowing through the node between the first and second resistive elements R1 and R2 in the second resistive element R2 and the current flowing through the node between the first and second resistive elements R1 and R2 in the second resistive module 1042 is equal to the current flowing through the node between the first and second resistive elements R1 and R2 in the first resistive element R1. Therefore, when the sampling circuit 104 acquires the third sampling voltage of the node between the first and second resistive elements R1 and R2, the second voltage can be obtained by the above formula (3). The relevant principles and methods can be referred to the relevant descriptions of the above embodiments, the only difference being that the third sampling voltage is obtained when a second sampling loop is formed, and the second sampling voltage is obtained when a first sampling loop is formed.

[0133] Understandably, in the second sampling circuit, the first resistor module 1041 and the third resistor module are connected in series, and the current flows from the positive terminal of the charging device 102 to the third resistor module, and then to the first resistor module 1041. Since the third resistor module is connected to the first terminal P1 of the charging negative relay, and the first terminal P1 of the charging negative relay is connected to the reference point G0, the current in the second sampling circuit flows from the reference point G0 to the first resistor module 1041. Therefore, the voltage across the charging negative relay 103 relative to the reference point G0 is negative. The theoretical voltage across the charging negative relay 103 relative to the reference point G0 should be -U0×A3 / A1, where U0 represents the output voltage of the charging pile, A1 represents the resistance value of the first resistor module 1041, and A3 represents the resistance value of the third resistor module.

[0134] This application sets up a first resistor module 1041 and a second resistor module 1042, and the first end of the second resistor module 1042 is input with a bias voltage, so that a negative second voltage can be obtained, thereby enabling the obtained second voltage to accurately represent the real voltage across the charging negative relay 103 relative to the reference point G0.

[0135] In some embodiments, the sampling circuit includes a calculation unit for calculating a second voltage based on a third sampling voltage and the above formula (3).

[0136] In the above technical solution, by setting the first resistor module 1041 and the second resistor module 1042, even if the actual voltage across the charging negative relay 103 relative to the reference point G0 is negative, it can still be collected, thereby improving the accuracy of detecting whether the charging negative relay 103 is stuck.

[0137] Referring to Figure 9, according to some embodiments of this application, the battery charging control circuit further includes: a pre-charging capacitor C2, which is connected in parallel between the positive and negative terminals of the battery 100. The second terminal of the main relay 101 is also connected to the pre-charging capacitor C2, and the first terminal P1 of the charging negative relay is also connected to the pre-charging capacitor C2.

[0138] Before closing the main relay 101, the pre-charge capacitor C2 can be charged. In some embodiments, the pre-charge capacitor C2 can be charged until the voltage across the pre-charge capacitor C2 is 80% of the voltage of the battery 100 or equal to the voltage of the battery 100. In this way, when the battery 100 and the charging device 102 form a charging circuit, large current surges can be avoided.

[0139] After charging the pre-charge capacitor C2, the main relay 101 is closed to initiate the high-voltage connection process for the entire vehicle. After the high-voltage connection is completed, the first voltage across the charging negative relay 103 relative to the reference point G0 can be measured to obtain the output voltage of the charging device 102.

[0140] In some embodiments, the pre-charge capacitor C2 can be pre-charged by a DC / DC (Direct Current / Direct Current) reverse pre-charge device. The DC / DC reverse pre-charge device has the same meaning as commonly understood by those skilled in the art in the present application, and the structure of the DC / DC reverse pre-charge device and the principle of charging the pre-charge capacitor C2 will not be described in detail here.

[0141] In the above technical solution, the pre-charge capacitor C2 plays a role in stabilizing the charging voltage and protecting the circuit from the impact of the high voltage output by the charging device 102. By setting up a sampling circuit 104 to collect the first voltage across the charging negative relay 103 in the first sampling circuit, and calculating the output voltage of the charging pile based on the first voltage, it is possible to determine whether to close the charging negative relay 103 based on the difference between the output voltage of the charging pile and the voltage across the battery 100. This can, to a certain extent, avoid the problem of the charging negative relay 103 sticking due to the charging device 102 instantly charging the pre-charge capacitor C2 with a large current when the difference between the output voltage of the charging device 102 and the voltage across the battery 100 is too large.

[0142] Referring to FIG10, according to some embodiments of the present application, the battery charging control circuit further includes: a pre-charge control circuit connected in parallel across the two ends of the main relay 101. The pre-charge control circuit is configured to control the pre-charge capacitor C2 to be connected in series with the battery 100 to form a pre-charge circuit during the period when the main relay 101 disconnects the battery 100 from the pre-charge capacitor C2.

[0143] The precharge control circuit is connected in parallel with the main relay 101, so that the precharge control circuit is connected to the battery 100 when the main relay 101 is disconnected from the battery 100.

[0144] For example, when the main relay 101 is the main positive relay K11, the precharge control circuit is connected in parallel across the two ends of the main positive relay K11. When the main relay 101 is the main negative relay, the precharge control circuit is connected in parallel across the two ends of the main negative relay. When the main relay 101 includes both the main positive relay K11 and the main negative relay, the precharge control circuit is connected in parallel across the two ends of the main positive relay K11. As an example, Figure 10 shows the case where the main relay 101 is the main positive relay K11, and the precharge control circuit is connected in parallel across the two ends of the main positive relay K11.

[0145] In some embodiments, the precharge control circuit may include a precharge relay K21 and a precharge resistor R5 connected in series. Taking the main relay 101 as a main positive relay K11 as an example, the first terminal of the main positive relay K11 is connected to the positive terminal of the battery 100, and the second terminal is connected to the first terminal of the precharge capacitor C2. The first terminal of the precharge relay K21 can be connected to the first terminal of the main positive relay K11, and the second terminal of the precharge relay K21 can be connected to the first terminal of the precharge resistor R5. The second terminal of the precharge resistor R5 can be connected to the second terminal of the main positive relay K11. The second terminal of the precharge capacitor C2 can be directly connected to the negative terminal of the battery 100.

[0146] While the main positive relay K11 is open, the pre-charge relay K21 is closed. Battery 100, pre-charge resistor R5, and pre-charge capacitor C2 are connected in series to form a pre-charge circuit, allowing battery 100 to charge pre-charge capacitor C2. When battery 100 is charging pre-charge capacitor C2, after the voltage across pre-charge capacitor C2 is charged to equal the voltage of battery 100, pre-charge relay K21 is opened and main positive relay K11 is closed.

[0147] In the above technical solution, a pre-charge circuit is formed by the pre-charge control circuit, which can pre-charge the pre-charge capacitor C2. This avoids, to a certain extent, the problem of high-current charging of the pre-charge capacitor C2 when the charging pile is connected to the battery 100, which would cause damage to other components in the circuit.

[0148] It is understood that in other embodiments, the battery charging control circuit may not include a pre-charge control circuit, but instead pre-charge the pre-charge capacitor C2 through a DC / DC reverse pre-charge device.

[0149] Referring to Figures 9 to 11, according to some embodiments of this application, the first end of the pre-charge capacitor C2 is used to connect to the positive terminal of the battery 100, and the second end is used to connect to the negative terminal of the battery 100. The first end P1 of the charging negative relay is connected to the second end of the pre-charge capacitor C2. The main relay 101 is the main positive relay K11. The first end of the main positive relay K11 is used to connect to the positive terminal of the battery 100, and the second end of the main positive relay K11 is connected to the first end of the pre-charge capacitor C2.

[0150] In other words, the main positive relay K11 is connected between the first terminal of the pre-charge capacitor C2 and the positive terminal of the battery 100, so that the first terminal of the pre-charge capacitor C2 is connected to the positive terminal of the battery 100 through the main positive relay K11. The second terminal of the pre-charge capacitor C2 is directly connected to the negative terminal of the battery 100, and the reference point G0 is located between the second terminal of the pre-charge capacitor C2 and the negative terminal of the battery 100. The charging negative relay 103 is connected between the second terminal of the pre-charge capacitor C2 and the negative terminal of the charging device 102.

[0151] Referring to Figure 11, in some embodiments, the battery charging control circuit further includes a switching circuit 105. The first terminal of the switching circuit 105 is directly connected to the second terminal of the main positive relay K11 and the first terminal of the pre-charge capacitor C2, and the second terminal of the switching circuit 105 is directly connected to the second terminal of the pre-charge capacitor C2. Thus, when the main positive relay K11 is off, the positive terminal of the charging device 102 and the first terminal P1 of the charging negative relay can be connected via the switching circuit 105.

[0152] As shown in Figures 10 and 11, in some embodiments, the battery charging control circuit further includes a pre-charge control circuit, which is connected in parallel across the main positive relay K11.

[0153] As shown in Figure 9, in some other embodiments, the two ends of the main positive relay K11 may not be connected in parallel with the precharge control circuit.

[0154] In the above technical solution, only a single-sided main positive relay K11 is set, which can simplify the circuit and reduce costs while controlling the positive and negative terminals of the battery 100 to form a circuit with other components.

[0155] Referring to Figures 12 and 13, according to some embodiments of this application, the first end of the pre-charge capacitor C2 is used to connect to the positive terminal of the battery 100, and the second end is used to connect to the negative terminal of the battery 100. The first end P1 of the charging negative relay is connected to the second end of the pre-charge capacitor C2. The main relay 101 is the main negative relay K12. The first end of the main negative relay K12 is used to connect to the negative terminal of the battery 100, and the second end of the main negative relay K12 is connected to the second end of the pre-charge capacitor C2.

[0156] In other words, the main negative relay K12 is connected between the second terminal of the pre-charge capacitor C2 and the negative terminal of the battery 100, so that the second terminal of the pre-charge capacitor C2 is connected to the negative terminal of the battery 100 through the main negative relay K12. The first terminal of the pre-charge capacitor C2 is directly connected to the positive terminal of the battery 100, and the reference point G0 is located between the first terminal of the main negative relay K12 and the negative terminal of the battery 100. The charging negative relay 103 is connected between the second terminal of the pre-charge capacitor C2 and the negative terminal of the charging device 102.

[0157] As shown in Figure 13, in some embodiments, the battery charging control circuit further includes a pre-charge control circuit, which is connected in parallel across the main negative relay K12.

[0158] As shown in Figure 12, in some other embodiments, the two ends of the main negative relay K12 may not be connected in parallel with the precharge control circuit.

[0159] In some embodiments, the battery charging control circuit further includes a switching circuit 105. The first terminal of the switching circuit 105 is directly connected to the first terminal of the pre-charge capacitor C2, and the second terminal of the switching circuit 105 is directly connected to the second terminal of the pre-charge capacitor C2 and the second terminal of the main negative relay K12. Thus, when the main negative relay K12 is off, the positive terminal of the charging device 102 and the first terminal P1 of the charging negative relay can be connected via the switching circuit 105.

[0160] In the above technical solution, only a single-sided main negative relay K12 is set, which can simplify the circuit and reduce costs while controlling the positive and negative terminals of the battery 100 to form a circuit with other components.

[0161] Referring to Figures 14 to 16, according to some embodiments of this application, the first terminal of the pre-charge capacitor C2 is used to connect to the positive terminal of the battery 100, and the second terminal is used to connect to the negative terminal of the battery 100. The first terminal P1 of the charging negative relay is connected to the second terminal of the pre-charge capacitor C2. The main relay 101 includes: a main positive relay K11, the first terminal of which is used to connect to the positive terminal of the battery 100, and the second terminal of which is connected to the first terminal of the pre-charge capacitor C2; and a main negative relay K12, the first terminal of which is used to connect to the negative terminal of the battery 100, and the second terminal of which is connected to the second terminal of the pre-charge capacitor C2.

[0162] In other words, the main positive relay K11 is connected between the first terminal of the pre-charge capacitor C2 and the positive terminal of the battery 100, so that the first terminal of the pre-charge capacitor C2 is connected to the positive terminal of the battery 100 through the main positive relay K11. The main negative relay K12 is connected between the second terminal of the pre-charge capacitor C2 and the negative terminal of the battery 100, so that the second terminal of the pre-charge capacitor C2 is connected to the negative terminal of the battery 100 through the main negative relay K12. The reference point G0 is located between the first terminal of the main negative relay K12 and the negative terminal of the battery 100. The charging negative relay 103 is connected between the second terminal of the pre-charge capacitor C2 and the negative terminal of the charging device 102.

[0163] In some embodiments, the battery charging control circuit further includes a pre-charge control circuit. As shown in Figure 14, the pre-charge control circuit can be connected in parallel across the two ends of the main positive relay K11. As shown in Figure 15, the pre-charge control circuit can also be connected in parallel across the two ends of the main negative relay K12.

[0164] As shown in Figure 16, in some embodiments, the battery charging control circuit further includes a switching circuit 105. The first terminal of the switching circuit 105 is directly connected to the second terminal of the main positive relay K11 and the first terminal of the pre-charge capacitor C2, and the second terminal of the switching circuit 105 is directly connected to the second terminal of the main negative relay K12 and the second terminal of the pre-charge capacitor C2. Thus, when the main positive relay K11 is off, the positive terminal of the charging device 102 and the first terminal P1 of the charging negative relay can be connected through the switching circuit 105.

[0165] In the above technical solution, the use of dual-sided main positive relay K11 and main negative relay K12 to control the connection between the positive and negative terminals of the battery 100 and other components can improve the control capability of the positive and negative terminals of the battery 100 forming a circuit with other components.

[0166] This application provides a battery 100 system, which includes a battery 100; and the battery charging control circuit in the above embodiment.

[0167] The battery 100 is connected to the battery charging control circuit and, through the battery charging control circuit, to the charging device 102. The battery 100 system has the beneficial effects of the battery charging control circuit provided in the embodiments of this application. Further details regarding the battery charging control circuit in the above embodiments can be found here, and will not be repeated here.

[0168] This application provides an electrical device that includes the battery 100 system described in the above embodiments, the battery 100 system being used to provide electrical energy.

[0169] The electrical devices can be referred to the relevant descriptions in the above embodiments, and will not be repeated below.

[0170] This application provides a battery charging control circuit. Referring to Figures 8 and 11, the battery charging control circuit includes: a main relay 101, with a first terminal for connecting to a battery 100 and a second terminal for connecting to a charging device 102; a charging negative relay 103, with a first terminal P1 for connecting to the negative terminal of the battery 100 and a second terminal for connecting to the negative terminal of the charging device 102; the positive and negative terminals of the battery 100 are connected to the positive and negative terminals of the charging device 102 respectively through the main relay 101 and the charging negative relay 103; a reference point G0 is also provided between the first terminal P1 of the charging negative relay and the negative terminal of the battery 100; and a sampling circuit 104, connected to the first and second terminals of the charging negative relay, configured to: during the period when the main relay 101 is closed and the charging negative relay 103 is closed, connect the first and second terminals of the charging negative relay to form a first sampling loop, and collect the first voltage of the two terminals of the charging negative relay 103 in the first sampling loop relative to the reference point G0.

[0171] Referring to FIG11, exemplarily, the sampling circuit 104 may include a first resistor module 1041 and a first switch S1. The first resistor module 1041 includes a first resistor element R1 and a second resistor element R2 connected in series. The first switch S1 is connected in series with the first resistor element R1 and the second resistor element R2. The sampling circuit 104 is configured to acquire the voltage value across the two ends of the first resistor element R1 in the first sampling loop relative to a reference point G0, and to obtain a first sampling voltage based on the voltage value across the two ends of the first resistor element R1 relative to the reference point G0, the resistance value of the first resistor element R1, and the resistance value of the second resistor element R2. The first sampling voltage is used as a first voltage.

[0172] Referring to Figure 8, by way of example, the sampling circuit 104 may further include a second resistor module 1042, the first end of which is connected to the node between the first resistor element R1 and the second resistor element R2, and the second end of which is connected to a bias voltage. The sampling circuit 104 is also configured to acquire a second sampling voltage of the node between the first resistor element R1 and the second resistor element R2 in the first sampling loop relative to a reference point G0, and to obtain a first voltage based on the second sampling voltage, the bias voltage, the resistance value of the first resistor element R1, the resistance value of the second resistor element R2, and the resistance value of the second resistor module 1042.

[0173] The battery charging control circuit also includes a switching circuit. The first terminal of the switching circuit is connected to the positive terminal of the charging device 102, and the second terminal is connected to the first terminal P1 of the charging negative relay. The switching circuit includes a third resistor module and a second switch S2. The third resistor module may include a third resistor element R3 and a fourth resistor element R4 connected in series. The second switch S2, the third resistor element R3, and the fourth resistor element R4 are connected in series. The switching circuit is configured to control the second switch S2 to close during the period when both the main relay 101 and the charging negative relay 103 are off. The sampling circuit 104 is configured to close the first switch S1 during the period when both the main relay 101 and the charging negative relay 103 are off to form a second sampling loop together with the switching circuit; and to acquire a third sampling voltage relative to a reference point G0 at the node between the first resistor element R1 and the second resistor element R2 in the second sampling loop, and to obtain a second voltage relative to the reference point G0 at both ends of the charging negative relay 103 based on the third sampling voltage, the bias voltage, the resistance value of the first resistor element R1, the resistance value of the second resistor element R2, and the resistance value of the second resistor module 1042.

[0174] The battery charging control circuit also includes: a pre-charge capacitor C2, which is connected in parallel between the positive and negative terminals of the battery 100; a first terminal of a switching circuit is connected to the first terminal of the pre-charge capacitor C2; a second terminal of the switching circuit is connected to the second terminal of the pre-charge capacitor C2; the first terminal of the pre-charge capacitor C2 is connected to the positive terminal of the battery 100; and the second terminal of the pre-charge capacitor C2 is connected to the negative terminal of the battery 100.

[0175] The main relay 101 can be a main positive relay, with its first terminal connected to the positive terminal of the battery 100 and its second terminal connected to the first terminal of the pre-charge capacitor C2. Alternatively, the main relay 101 can be a main negative relay, with its first terminal connected to the negative terminal of the battery 100 and its second terminal connected to the second terminal of the pre-charge capacitor C2. The main relay 101 can also include both a main positive relay and a main negative relay, with the first terminal of the main positive relay connected to the positive terminal of the battery 100 and its second terminal connected to the first terminal of the pre-charge capacitor C2, and the first terminal of the main negative relay connected to the negative terminal of the battery 100 and its second terminal connected to the second terminal of the pre-charge capacitor C2.

[0176] The battery charging control circuit also includes a pre-charge control circuit. When the main relay 101 is a main positive relay, the pre-charge control circuit is connected in parallel across the main positive relay. When the main relay 101 is a main negative relay, the pre-charge control circuit is connected in parallel across the main negative relay. When the main relay 101 includes both a main positive relay and a main negative relay, the pre-charge control circuit is connected in parallel across the main positive relay. The pre-charge control circuit includes a pre-charge relay K21 and a pre-charge resistor R5. The pre-charge relay K21 closes when the main relay 101 is off, connecting the battery 100 and the pre-charge capacitor C2, so that the battery 100 pre-charges the pre-charge capacitor C2.

[0177] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A battery charging control circuit, comprising: A main relay, wherein a first terminal of the main relay is used to connect to the battery and a second terminal is used to connect to a charging device; A charging negative relay, wherein the first end of the charging negative relay is used to connect to the negative terminal of the battery, and the second end is used to connect to the negative terminal of the charging device. The positive and negative terminals of the battery are connected to the positive and negative terminals of the charging device respectively through the main relay and the charging negative relay. A reference point is also provided between the first end of the charging negative relay and the negative terminal of the battery. A sampling circuit, connecting the first and second terminals of the charging negative relay, is configured to: during the period when the main relay is closed and the charging negative relay is turned off, connect the first and second terminals of the charging negative relay to form a first sampling loop, and acquire a first voltage between the two terminals of the charging negative relay in the first sampling loop relative to the reference point.

2. The battery charging control circuit according to claim 1, wherein, The sampling circuit includes: First resistor module; A first switch is connected in series with the first resistor module. The first resistor module and the first switch, after being connected in series, are connected between the first and second terminals of the charging negative relay. The sampling circuit is configured to control the first switch to close during the period when the main relay is closed and the charging negative relay is turned off, so as to form the first sampling loop.

3. The battery charging control circuit according to claim 2, wherein, The first resistor module includes: a first resistor element and a second resistor element connected in series, wherein the end of the first resistor element away from the second resistor element is connected to the first terminal of the charging negative relay, and the end of the second resistor element away from the first resistor element is connected to the second terminal of the charging negative relay; wherein the node between the first resistor element and the second resistor element serves as the sampling point of the sampling circuit in the first sampling loop.

4. The battery charging control circuit according to claim 3, wherein, The sampling circuit also includes: The second resistor module has a first end connected to the node between the first resistor element and the second resistor element, and a second end connected to the bias voltage.

5. The battery charging control circuit according to any one of claims 1-4, wherein, The battery charging control circuit further includes a switching circuit, wherein a first end of the switching circuit is used to connect to the positive terminal of the charging device, and a second end is connected to the first end of the charging negative relay. The switching circuit is configured to connect the charging device and the sampling circuit while both the main relay and the negative charging relay are off, so as to form a second sampling loop together with the sampling circuit between the positive and negative terminals of the charging device. The sampling circuit is further configured to acquire a second voltage across the terminals of the charging negative relay in the second sampling loop relative to the reference point.

6. The battery charging control circuit according to claim 5, wherein, The switching circuit includes: Third resistor module; The second switch is connected in series with the third resistor module. The third resistor module and the second switch are connected to the positive terminal of the charging device and the first terminal of the charging negative relay. The switching circuit is configured to control the second switch to close while both the main relay and the charging negative relay are off. The sampling circuit is configured to connect the first and second terminals of the charging negative relay during the period when both the main relay and the charging negative relay are off, so as to form the second sampling loop together with the switching circuit.

7. The battery charging control circuit according to claim 5 or 6, wherein, The sampling circuit includes: The first resistor module includes: a first resistor element and a second resistor element connected in series, wherein the first resistor element is connected to the first terminal of the charging negative relay, and the second resistor element is connected to the second terminal of the charging negative relay; The first switch is connected in series with the first resistive element and the second resistive element; The second resistor module has a first end connected to the node between the first resistor element and the second resistor element, and a second end connected to the bias voltage. The sampling circuit is configured to close the first switch during the period when both the main relay and the charging negative relay are off, so as to form the second sampling loop together with the switching circuit, wherein the node between the first resistive element and the second resistive element serves as the sampling point of the sampling circuit in the second sampling loop.

8. The battery charging control circuit according to any one of claims 1-7, wherein, The battery charging control circuit also includes: A pre-charge capacitor is provided, wherein the pre-charge capacitor is connected in parallel between the positive and negative terminals of the battery. The second terminal of the main relay is also connected to the pre-charge capacitor, and the first terminal of the charging negative relay is also connected to the pre-charge capacitor.

9. The battery charging control circuit according to claim 8, wherein, The battery charging control circuit also includes: A precharge control circuit is connected in parallel across the two ends of the main relay. The precharge control circuit is configured to control the precharge capacitor to be connected in series with the battery to form a precharge circuit while the main relay disconnects the battery from the precharge capacitor.

10. The battery charging control circuit according to claim 8 or 9, wherein, The first end of the pre-charge capacitor is used to connect to the positive terminal of the battery, and the second end is used to connect to the negative terminal of the battery. The first end of the charging negative relay is connected to the second end of the pre-charge capacitor. The main relay is a positive relay, the first end of which is connected to the positive terminal of the battery, and the second end of which is connected to the first end of the precharge capacitor.

11. The battery charging control circuit according to claim 8 or 9, wherein, The first end of the pre-charge capacitor is used to connect to the positive terminal of the battery, and the second end is used to connect to the negative terminal of the battery. The first end of the charging negative relay is connected to the second end of the pre-charge capacitor. The main relay is a main negative relay, the first end of the main negative relay is used to connect to the negative terminal of the battery, and the second end of the main negative relay is connected to the second end of the precharge capacitor.

12. The battery charging control circuit according to claim 8 or 9, wherein, The first end of the pre-charge capacitor is used to connect to the positive terminal of the battery, and the second end is used to connect to the negative terminal of the battery. The first end of the charging negative relay is connected to the second end of the pre-charge capacitor. The main relay includes: A main positive relay, wherein the first terminal of the main positive relay is connected to the positive terminal of the battery, and the second terminal is connected to the first terminal of the pre-charge capacitor; A main negative relay, wherein the first end of the main negative relay is used to connect to the negative terminal of the battery, and the second end is connected to the second terminal of the precharge capacitor.

13. A battery system, comprising: Battery; as well as The battery charging control circuit as described in any one of claims 1-12.

14. An electrical device comprising the battery system of claim 13, wherein the battery system supplies power to the electrical device.

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