A control circuit and method for a vehicle-mounted power wall box

Abstract

The present invention provides a control circuit and method for a vehicle-mounted power wall box, which controls the on-off of a main power supply circuit of a load device through a high-power field effect transistor and uses a current sensor to collect the working current of the load device, thereby realizing a miniaturized design of the vehicle-mounted power wall box and reducing working noise, thereby improving user experience; in addition, firstly, the first current information of the load device is measured according to the first voltage information and the second voltage information; then, the second current information of the circuit is obtained according to the electrical characteristics of the vehicle-mounted power wall box circuit; finally, according to the size relationship between the first current information and the second current information, the supply current value of the circuit is adjusted through a current limiting management module or the on-off status of the main power supply circuit is switched through a contact switching module, thereby realizing intelligent management and control and improving the stability and safety of circuit operation.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle-mounted power wall boxes. More specifically, the present invention discloses a control circuit and method for a vehicle-mounted power wall box. Background Art

[0002] A power wall box, also known as a power box or power socket box, is an electrical device whose main function is to connect an external power source to the load input terminal through the wall box panel to provide power supply. A vehicle-mounted power wall box is a power distribution and management device designed specifically for vehicles. It is usually installed inside the vehicle to provide power support for various devices on the vehicle and to centrally distribute, monitor and manage them.

[0003] At present, the vehicle power wall box drives the external AC contactor through the onboard relay to control the on and off of the main power supply circuit of the load equipment, and measures the working current of the load equipment through the current transformer. Due to the large size of components such as AC contactors and current transformers, the size of the vehicle power wall box cannot be reduced; and the AC contactor makes a "clicking" sound when switching between attraction and disconnection, which affects the user experience.

[0004] Therefore, it is necessary to design a technology for a vehicle-mounted power wall box that can realize the miniaturization design of the vehicle-mounted power wall box, eliminate the noise generated when the device is working, and improve the user experience. Summary of the invention

[0005] In view of the above problems, the purpose of the present invention is to provide a control circuit and method for a vehicle-mounted power wall box, which adopts a high-power field effect transistor to control the on-off of the main power supply circuit of the load equipment, and adopts a current sensor to collect the working current of the load equipment, so as to realize the miniaturized design of the vehicle-mounted power wall box and reduce the working noise, thereby improving the user experience; in addition, according to the electrical characteristics of the vehicle-mounted power wall box circuit and the power supply requirements of the load equipment, the supply current value of the main power supply circuit is automatically adjusted or the on-off of the main power supply circuit is switched to ensure the stability and safety of the circuit operation.

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides a control circuit of a vehicle-mounted power wall box, wherein the control circuit of the vehicle-mounted power wall box:

[0007] A processor, used to control the current outputted by the vehicle power wall box to the load device according to the electrical characteristics of the vehicle power wall box circuit;

[0008] A contact switching module, used to switch on and off the load output power supply according to a control signal sent by the processor to the photocoupler;

[0009] A current acquisition module is used to be connected in series to a power supply circuit of a load device, and output first voltage information corresponding to the current value of the load device according to the current value of the load device;

[0010] The current limiting management module is used to adjust the maximum current value flowing through the load device.

[0011] In this solution, the contact switching module includes:

[0012] The contact switching circuit adjusts the on-off state of the photoelectric coupler according to the processor signal to control the conduction state of the field effect tube, and at least includes: a first photoelectric coupler (U2), a first triode (Q21), a first field effect tube (Q22), a first resistor (R21), a second resistor (R22), and a third resistor (R23);

[0013] The A level of the first photocoupler (U2) is connected to the power supply voltage VCC-1 of the photocoupler, the K level of the first photocoupler (U2) is connected to the control pin OPT_In of the processor, the C level of the first photocoupler (U2) is connected to the first end of the first resistor (R21), and the E level of the first photocoupler (U2) is connected to the source S of the first field effect transistor (Q22); the base B of the first transistor (Q21) is connected to the second end of the first resistor (R21), and the emitter E of the first transistor (Q21) is connected to The switching circuit is supplied with a power supply voltage VCC-2, the collector C of the first transistor (Q21) is connected to the first end of the second resistor (R22); the gate G of the first field effect transistor (Q22) is connected to the second end of the second resistor (R22) and the first end of the third resistor (R23); the source S of the first field effect transistor (Q22) is connected to the second end of the third resistor (R23) and the current output end V-2 of the contact switching circuit; and the drain D of the first field effect transistor (Q22) is connected to the current input end V-1 of the contact switching circuit.

[0014] In this solution, the current acquisition module includes:

[0015] The current collection circuit comprises at least: a first current sensor (S3), a first diode (D3), a fourth voltage-dividing resistor (R34), and a fifth voltage-dividing resistor (R35);

[0016] The detection current input pin IP+ of the first current sensor (S3) is connected to the current input terminal V-3 of the current acquisition module, and the detection current output pin IP- of the first current sensor (S3) is connected to the current output terminal V-1 of the current acquisition module; the power supply pin VCC of the first current sensor (S3) is connected to the power supply voltage VCC-3 of the current sensor; the ground pin GND of the first current sensor (S3) is connected to the ground level and the second end of the fifth voltage-dividing resistor (R35); the output pin Iout of the first current sensor (S3) is connected to the first end of the fourth voltage-dividing resistor (R34); the positive electrode of the first diode (D3) is connected to the second end of the fourth voltage-dividing resistor (R34) and the first end of the fifth voltage-dividing resistor (R35); and the negative electrode of the first diode (D3) is connected to the analog-to-digital conversion input pin of the processor.

[0017] In this solution, the current limiting management module includes:

[0018] A first adjustable current limiting chip (U4), a sixth feedback resistor (R46);

[0019] The current input pin I_in of the first adjustable current limiting chip (U4) is connected to the current input terminal V-2 of the current limiting management module; the current output pin I_out of the first adjustable current limiting chip (U4) is connected to the current output terminal V-4 of the current limiting management module; the adjustment pin ADJ of the first adjustable current limiting chip (U4) is connected to the first end of the sixth feedback resistor (R46); and the ground pin GND of the first adjustable current limiting chip (U4) is connected to the second end of the sixth feedback resistor (R46) and to a low level.

[0020] The second aspect of the present invention further provides a control method for a vehicle-mounted power wall box, which is applied to the control circuit of any of the above-mentioned vehicle-mounted power wall boxes, and specifically includes:

[0021] Acquire first voltage information and second voltage information;

[0022] Calculating first current information according to the first voltage information and the second voltage information;

[0023] Acquiring first temperature information;

[0024] Obtaining second current information according to the first temperature information and the second voltage information;

[0025] determining whether the second current information exceeds the first current information;

[0026] If yes, adjusting the current limiting management module according to the first current information;

[0027] If not, sending a first communication instruction message;

[0028] Determining whether first feedback instruction information is received;

[0029] If so, the current limiting management module is set according to the second current information and the first feedback instruction information.

[0030] In this solution, the first current information is calculated based on the first voltage information and the second voltage information, specifically:

[0031] Setting a first current relationship according to the type of the second voltage information;

[0032] If the type of the second voltage information is alternating current, setting the first current relationship equation according to a preset alternating current relationship equation;

[0033] If the type of the second voltage information is direct current, setting the first current relationship equation according to a preset direct current current relationship equation;

[0034] The first voltage information and the second voltage information are substituted into the first current relationship equation to calculate and obtain the first current information.

[0035] In this solution, the second current information is obtained according to the first temperature information and the second voltage information, specifically:

[0036] Acquiring first temperature information;

[0037] Determining whether the first temperature information exceeds a preset first temperature threshold;

[0038] If yes, setting the second current information to a preset trickle value and sending a second communication instruction information;

[0039] If not, obtaining an allowable current correspondence table according to the type of the second voltage information;

[0040] The allowable current correspondence table is searched according to the first temperature information and the second voltage information to obtain the second current information.

[0041] In this solution, the current limiting management module is adjusted as follows:

[0042] Acquiring third current information;

[0043] Obtaining first resistance information according to the third current information;

[0044] Obtaining second resistance information;

[0045] Obtaining first resistance difference information according to a difference between the first resistance information and the second resistance information;

[0046] Determining whether the first resistance difference information exceeds a preset first resistance difference range;

[0047] If so, the resistance of the feedback resistor is adjusted according to the first resistance difference information and the preset first resistance adjustment instruction.

[0048] This plan also includes:

[0049] Adjust the feedback resistor value according to the preset calibration resistance value;

[0050] Collecting and recording the first analog-to-digital conversion value according to a preset time period;

[0051] After sorting the recorded first analog-to-digital conversion values ​​in ascending or descending order, a second analog-to-digital conversion value is calculated according to a preset mean value algorithm;

[0052] The first voltage information is obtained according to the preset voltage division ratio information, the reference voltage value and the second analog-to-digital conversion value.

[0053] This plan also includes:

[0054] When the level of the first pin is set to the first level, the load current loop is turned on;

[0055] When the level of the first pin is set to the second level, the load current loop is cut off.

[0056] The present invention provides a control circuit and method for a vehicle-mounted power wall box, which controls the on-off of a main power supply circuit of a load device through a high-power field effect transistor and uses a current sensor to collect the working current of the load device, thereby realizing a miniaturized design of the vehicle-mounted power wall box and reducing working noise, thereby improving user experience; in addition, firstly, the first current information of the load device is measured according to the first voltage information and the second voltage information; then, the second current information of the circuit is obtained according to the electrical characteristics of the vehicle-mounted power wall box circuit; finally, according to the size relationship between the first current information and the second current information, the supply current value of the circuit is adjusted through a current limiting management module or the on-off status of the main power supply circuit is switched through a contact switching module, thereby realizing intelligent management and control and improving the stability and safety of circuit operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and should not be regarded as limiting the scope.

[0058] Figure 1 A structural block diagram of the control circuit of the vehicle power wall box provided by an embodiment of the present invention is shown;

[0059] Figure 2A circuit connection structure diagram of the contact switching circuit provided by an embodiment of the present invention is shown;

[0060] Figure 3 A circuit connection structure diagram of the current acquisition circuit provided by an embodiment of the present invention is shown;

[0061] Figure 4 Another circuit connection structure diagram of the current limiting management module provided in an embodiment of the present invention is shown;

[0062] Figure 5 A schematic flow chart of a control method of the vehicle-mounted power wall box provided by an embodiment of the present invention is shown;

[0063] Figure 6 A calculation flow chart of the first current information provided by an embodiment of the present invention is shown;

[0064] Figure 7 A calculation flow chart of the second current information provided by an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0065] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0066] Unless otherwise defined, all terms (including technical and scientific terms) used in the embodiments of the present invention have the same meanings as commonly understood by those skilled in the art to which the present invention belongs. It should also be understood that terms such as those defined in common dictionaries should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless the embodiments of the present invention are explicitly defined in this way.

[0067] The words "first", "second" and similar words used in the embodiments of the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "one", "an" or "the" and similar words do not indicate a quantity limitation, but indicate the existence of at least one. Similarly, words such as "include" or "comprise" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. Words such as "connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The steps before or after the method of the embodiment of the present invention are not necessarily carried out in order. On the contrary, various steps can be processed in reverse order or simultaneously. At the same time, other operations can also be added to these processes, or a step or several steps can be removed from these processes.

[0068] Please refer to Figure 1 , Figure 1 A structural block diagram of the control circuit of the vehicle power wall box provided by an embodiment of the present invention is shown.

[0069] like Figure 1 As shown, the first aspect of the present invention discloses that the control circuit of the vehicle power wall box includes:

[0070] The processor 102 is used to control the current outputted by the vehicle power wall box to the load device according to the electrical characteristics of the vehicle power wall box circuit;

[0071] The contact switching module 104 is used to switch the on and off of the load output power supply according to the control signal sent by the processor to the photoelectric coupler;

[0072] The current acquisition module 106 is used to be connected in series to the power supply circuit of the load device and output the first voltage information corresponding to the current value of the load device according to the current value of the load device;

[0073] The current limiting management module 108 is used to adjust the maximum current value flowing through the load device.

[0074] It should be noted that the first voltage information is the amplitude value of the output voltage of the current acquisition module. The current of the input power source passes through the current acquisition module 106, the current limiting management module 108 and the contact switching module 104 in sequence, and then supplies power to the load device. First, the current acquisition module is connected in series to the power supply circuit of the load device to measure the current value of the power supply circuit, that is, the working current of the load device; wherein, the present invention adopts an onboard current sensor to replace the traditional external current transformer, which effectively reduces the volume of the current acquisition module; then, the current limiting management module is connected in series to the power supply circuit of the load device to adjust and limit the maximum current value that the load device can obtain, and to adjust the output current of the circuit in real time to avoid the situation where the circuit is burned due to excessive current or the load cannot work due to too small current, so as to improve the stability of the circuit operation; wherein, the current output port of the current acquisition module is connected to the input port of the current limiting management module; finally, the contact switching module is connected in series to the power supply circuit of the load device, and the present invention adopts a high-power field effect transistor to replace the traditional external AC contactor to realize the control of the conduction and disconnection of the power supply main circuit of the load device, which not only effectively reduces the space of the vehicle power wall box occupied by the switching module, but also eliminates the "click" sound emitted when the AC contactor is pulled in / out, thereby improving the user experience; wherein, the output port of the current limiting management module is connected to the input port of the contact switching module, and the output port of the contact switching module is connected to the power input port of the load device.

[0075] Please refer to Figure 2 , Figure 2 A circuit connection structure diagram of the contact switching circuit provided in an embodiment of the present invention is shown.

[0076] According to an embodiment of the present invention, the contact switching module includes:

[0077] The contact switching circuit adjusts the on-off state of the photoelectric coupler according to the processor signal to control the conduction state of the field effect tube, and at least includes: a first photoelectric coupler (U2), a first triode (Q21), a first field effect tube (Q22), a first resistor (R21), a second resistor (R22), and a third resistor (R23);

[0078] The A level of the first photocoupler (U2) is connected to the power supply voltage VCC-1 of the photocoupler, the K level of the first photocoupler (U2) is connected to the control pin OPT_In of the processor, the C level of the first photocoupler (U2) is connected to the first end of the first resistor (R21), and the E level of the first photocoupler (U2) is connected to the source S of the first field effect transistor (Q22); the base B of the first transistor (Q21) is connected to the second end of the first resistor (R21), and the emitter E of the first transistor (Q21) is connected to The switching circuit is supplied with a power supply voltage VCC-2, the collector C of the first transistor (Q21) is connected to the first end of the second resistor (R22); the gate G of the first field effect transistor (Q22) is connected to the second end of the second resistor (R22) and the first end of the third resistor (R23); the source S of the first field effect transistor (Q22) is connected to the second end of the third resistor (R23) and the current output end V-2 of the contact switching circuit; and the drain D of the first field effect transistor (Q22) is connected to the current input end V-1 of the contact switching circuit.

[0079] It should be noted that the contact switching module implements isolation control through the first photocoupler, so that the low-voltage control signal of the processor can control the high-voltage power supply signal of the load device connected to the first field effect tube. When the low-voltage control signal OPT_In of the processor is at a low level, the optical signal transmitting end (AK end) of the photocoupler is in a light emitting state, and the optical signal receiving end (CE end) is in a conducting state, and the first transistor is in a conducting state. At this time, the voltage between the gate G and the source S of the first field effect tube is greater than the conduction voltage of the field effect tube, so that the drain D and the source S of the first field effect tube are in a conducting state, that is, the power supply current of the load device flows from the V-1 port to the V-2 port. Similarly, when the low-voltage control signal OPT_In of the processor is at a high level, the optical signal receiving end (CE end) of the photocoupler is in a disconnected state, the first transistor is in a cut-off state, and the drain D and the source S of the first field effect tube are in a cut-off state, that is, the power supply current of the load device cannot flow from the V-1 port to the V-2 port. In summary, the processor can switch between the on state and the off state of the power supply current of the load device through the contact switching module.

[0080] Please refer to Figure 3 , Figure 3 A circuit connection structure diagram of the current acquisition circuit provided in an embodiment of the present invention is shown.

[0081] According to an embodiment of the present invention, the current acquisition module includes:

[0082] The current collection circuit comprises at least: a first current sensor (S3), a first diode (D3), a fourth voltage-dividing resistor (R34), and a fifth voltage-dividing resistor (R35);

[0083] The detection current input pin IP+ of the first current sensor (S3) is connected to the current input terminal V-3 of the current acquisition module, and the detection current output pin IP- of the first current sensor (S3) is connected to the current output terminal V-1 of the current acquisition module; the power supply pin VCC of the first current sensor (S3) is connected to the power supply voltage VCC-3 of the current sensor; the ground pin GND of the first current sensor (S3) is connected to the ground level and the second end of the fifth voltage-dividing resistor (R35); the output pin Iout of the first current sensor (S3) is connected to the first end of the fourth voltage-dividing resistor (R34); the positive electrode of the first diode (D3) is connected to the second end of the fourth voltage-dividing resistor (R34) and the first end of the fifth voltage-dividing resistor (R35); and the negative electrode of the first diode (D3) is connected to the analog-to-digital conversion input pin of the processor.

[0084] It should be noted that the current sensor chip is an electronic device for measuring current, which can convert the current signal into a voltage signal or a digital signal for subsequent processing and analysis. In the application of the present invention, the STK-600 series current sensor is used, and there is a strong electrical isolation level between the current conductor end and the signal detection end, which improves the accuracy of current detection. The present invention forms a voltage divider circuit through the fourth voltage divider resistor and the fifth voltage divider resistor to adapt to the working environment of different power supply voltage systems; in addition, the first diode effectively prevents the analog-to-digital conversion input end of the processor from having an electrical influence on the output signal of the first current sensor, thereby improving the stability of the measurement.

[0085] Please refer to Figure 4 , Figure 4 Another circuit connection structure diagram of the current limiting management module provided in an embodiment of the present invention is shown.

[0086] According to an embodiment of the present invention, the current limiting management module includes:

[0087] A first adjustable current limiting chip (U4), a sixth feedback resistor (R46);

[0088] The current input pin I_in of the first adjustable current limiting chip (U4) is connected to the current input terminal V-2 of the current limiting management module; the current output pin I_out of the first adjustable current limiting chip (U4) is connected to the current output terminal V-4 of the current limiting management module; the adjustment pin ADJ of the first adjustable current limiting chip (U4) is connected to the first end of the sixth feedback resistor (R46); and the ground pin GND of the first adjustable current limiting chip (U4) is connected to the second end of the sixth feedback resistor (R46) and to a low level.

[0089] It should be noted that the current limiting chip is an integrated circuit used to control the current output. Based on the principle of negative feedback, a feedback resistor is introduced into the feedback loop so that the output current and the input current maintain a constant ratio. The adjustable current limiting chip is to set an adjustable resistor as a feedback resistor in the feedback loop. By adjusting the resistance value of the feedback resistor, the ratio between the output current and the input current is adjusted to achieve the effect of adjusting the current output. As an implementation method, the sixth feedback resistor (R46) is a digital adjustable variable resistor, and the processor reads and adjusts the resistance value of the digital adjustable variable resistor through a preset communication instruction. The processor adjusts the resistance value of the sixth feedback resistor (R46) according to the target resistance value, thereby adjusting the output current of the current limiting management module, that is, limiting the maximum current of the power supply circuit of the load device.

[0090] It is worth mentioning that it also includes:

[0091] An isolation communication module, used to electrically disconnect the processor from an external communication device while maintaining data communication;

[0092] At least one CAN isolation chip is included, which connects the CAN high-voltage line of the processor, the CAN low-voltage line of the processor, the CAN high-voltage line of the external communication device, and the CAN low-voltage line of the external communication device.

[0093] It should be noted that the CAN isolation chip is a special chip used in the CAN (Controller Area Network) communication system. It can achieve electrical isolation of signals and improve the anti-interference ability and safety of the system. The signal of the CAN high-voltage line of the device at one end is transmitted to the CAN high-voltage line of the device at the other end through the CAN isolation chip, and the signal of the CAN low-voltage line of the device at one end is transmitted to the CAN low-voltage line of the device at the other end through the CAN isolation chip. By setting up the CAN isolation chip, the devices at both ends of the chip will not affect the working voltage of other devices due to the unstable level of a certain device, thereby improving the stability of data communication.

[0094] Please refer to Figure 5 , Figure 5A schematic flow chart of a method for controlling the vehicle-mounted power wall box provided in an embodiment of the present invention is shown.

[0095] like Figure 5 As shown, the second aspect of the present invention discloses a control method of the vehicle-mounted power wall box, which specifically includes:

[0096] S502, obtaining first voltage information and second voltage information;

[0097] S504, calculating and obtaining first current information according to the first voltage information and the second voltage information;

[0098] S506, obtaining first temperature information;

[0099] S508, obtaining second current information according to the first temperature information and the second voltage information;

[0100] S510, determining whether the second current information exceeds the first current information;

[0101] S512, if yes, adjusting the current limiting management module according to the first current information;

[0102] S514, if not, sending a first communication instruction message;

[0103] S516, determining whether the first feedback instruction information is received;

[0104] S518: If yes, set the current limiting management module according to the second current information and the first feedback instruction information.

[0105] It should be noted that the second voltage information is the power supply voltage of the load device; the first current information is the power supply current value required by the load device; the first temperature information is the temperature value of the vehicle power wall box circuit; the second current information is the maximum current value that the vehicle power wall box circuit can provide at the current working temperature; the first communication instruction information is the abnormal current value instruction sent to the external device; the first feedback instruction information is the abnormal current value processing instruction fed back by the external device. First, the power supply voltage of the load device and the output signal voltage of the current sensor, that is, the second voltage information and the first voltage information, are measured, and then due to the current calculation method stored in the working characteristics of the DC sensor, the first current information, that is, the power supply current value required by the load device, can be calculated based on the first voltage information and the second voltage information. Then, the temperature value of the vehicle power wall box circuit, that is, the first temperature information, is measured by a temperature sensor or a thermistor circuit; wherein, the first temperature information reflects the operating temperature of the circuit elements, and the operating characteristics of the circuit components will change at different temperatures; in order to ensure the stability of the operation of the vehicle power wall box circuit, the present invention calculates the second current information based on the first temperature information and the second voltage information, which is used to indicate the maximum value of the output current allowed by the vehicle power wall box circuit under the current operating temperature and the supply voltage value of the load device; the second current information serves as the upper limit of the operating current of the load device to avoid the vehicle power wall box circuit from over-current and causing heat and burning, thereby improving the stability of the circuit operation. Finally, compare the magnitude relationship between the operating current demand value of the load device and the current upper limit value that can be provided by the vehicle-mounted power wall box circuit, that is, compare the magnitude relationship between the first current information and the second current information; if the current upper limit value is not lower than the current demand value of the load device, it means that the output current of the vehicle-mounted power wall box circuit can meet the demand of the load device. Therefore, adjust the output current value of the current limiting management module of the power wall box circuit according to the current demand value of the load device; if the current upper limit value is lower than the current demand value of the load device, it means that the output current of the vehicle-mounted power wall box circuit cannot meet the demand of the load device. At this time, the vehicle-mounted power wall box circuit sends an abnormal current value instruction to the external device through the communication interface. After receiving the first feedback instruction information, the output current value of the current limiting management module is set or the power supply circuit of the load device is disconnected according to the analysis result of the first feedback instruction and the second current information, so as to protect the vehicle-mounted power wall box and avoid burning.

[0106] Please refer to Figure 6 , Figure 6 A calculation flow chart of the first current information provided by an embodiment of the present invention is shown.

[0107] In the embodiment of the present invention, the first current information is calculated according to the first voltage information and the second voltage information, specifically:

[0108] S602, setting a first current relationship equation according to the type of the second voltage information;

[0109] S604: if the type of the second voltage information is alternating current, setting the first current relationship equation according to a preset alternating current relationship equation;

[0110] S606: if the type of the second voltage information is direct current, setting the first current relationship equation according to a preset direct current current relationship equation;

[0111] S608, substituting the first voltage information and the second voltage information into the first current relationship equation to calculate and obtain the first current information;

[0112] It should be noted that the first current relationship is a calculation relationship between the output voltage value and the current value preset according to the detection characteristics of the current sensor. The power supply voltage type of the load device is direct current or alternating current, and the first current relationship is determined according to the type of the power supply voltage; if it is alternating current, the first current relationship is set according to the preset alternating current relationship; if it is direct current, the first current relationship is set according to the preset direct current current relationship. Then, the output voltage value of the current sensor and the power supply voltage value of the load device are brought into the first current relationship to calculate the first current information, that is, the working current of the load device.

[0113] Please refer to Figure 7 , Figure 7 A calculation flow chart of the second current information provided by an embodiment of the present invention is shown.

[0114] In the embodiment of the present invention, obtaining the second current information according to the first temperature information and the second voltage information is specifically:

[0115] S702, obtaining first temperature information;

[0116] S704, determining whether the first temperature information exceeds a preset first temperature threshold;

[0117] S706: If yes, set the second current information to a preset trickle value and send a second communication instruction information;

[0118] S708, if not, obtaining an allowable current correspondence table according to the type of the second voltage information;

[0119] S710: Search the allowable current correspondence table according to the first temperature information and the second voltage information to obtain second current information.

[0120] It should be noted that the second communication instruction information is a temperature warning instruction sent to an external device. First, determine whether the temperature value of the vehicle-mounted power wall box circuit exceeds the preset first temperature threshold; if so, set the second current information to the preset trickle value, and send the temperature warning information to the external device through the communication interface; wherein, the trickle value is a preset smaller current value, which is used to ensure that the processor of the load device is in an activated state; if not, then according to the type of the second voltage information, that is, determine whether the power supply voltage of the load device is direct current or alternating current; when it is direct current, select the direct current correspondence table; when it is alternating current, select the alternating current correspondence table. Then, according to the temperature value and power supply voltage value of the power wall box circuit, the second current information is obtained by looking up the corresponding current correspondence table.

[0121] In the embodiment of the present invention, the adjusting the current limiting management module is specifically:

[0122] Acquiring third current information;

[0123] Obtaining first resistance information according to the third current information;

[0124] Obtaining second resistance information;

[0125] Obtaining first resistance difference information according to a difference between the first resistance information and the second resistance information;

[0126] Determining whether the first resistance difference information exceeds a preset first resistance difference range;

[0127] If so, the resistance of the feedback resistor is adjusted according to the first resistance difference information and the preset first resistance adjustment instruction.

[0128] It should be noted that the third current information is the target current value of the current limiting management module; the first resistance information is the target resistance value of the feedback resistor of the current limiting management module; the second resistance information is the current resistance value of the feedback resistor of the current limiting management module; the first resistance adjustment instruction is an instruction for adjusting the resistance value of the feedback resistor. When the current limiting management module needs to be adjusted, first, the first resistance information, that is, the target resistance value of the feedback resistor, is calculated according to the target current value and the feedback resistor calculation rule of the adjustable current limiting chip of the current limiting management module. Then, the processor reads the current resistance value of the feedback resistor of the current limiting management module by sending a communication instruction of a preset digital adjustable resistor. Finally, the difference between the current resistance value and the target resistance value of the feedback resistor is calculated and recorded as the first resistance difference information; it is determined whether the first resistance difference information exceeds the preset first resistance difference range; if so, it means that the current resistance value of the feedback resistor is significantly different from the target resistance value, and resistance adjustment is required. Therefore, according to the resistance difference, the processor sends a preset digital adjustable resistance adjustment instruction to adjust the resistance of the feedback resistor; wherein, in actual applications, the first resistance difference range is set according to the current limiting chip, for example, the range can be set to -10 ohms to 10 ohms.

[0129] In an embodiment of the present invention, it also includes:

[0130] Adjust the feedback resistor value according to the preset calibration resistance value;

[0131] Collecting and recording the first analog-to-digital conversion value according to a preset time period;

[0132] After sorting the recorded first analog-to-digital conversion values ​​in ascending or descending order, a second analog-to-digital conversion value is calculated according to a preset mean value algorithm;

[0133] The first voltage information is obtained according to the preset voltage division ratio information, the reference voltage value and the second analog-to-digital conversion value.

[0134] It should be noted that the first analog-to-digital conversion value is the analog-to-digital conversion value of the analog-to-digital converter of the processor; the second analog-to-digital conversion value is the average value of the first analog-to-digital conversion value; the voltage division ratio information is the voltage division ratio value of the voltage division circuit of the vehicle power wall box circuit. The output voltage of the DC sensor is divided by the voltage division circuit and input to the analog-to-digital converter pin of the processor. First, the feedback resistor of the current limiting management module is set according to the preset calibration resistance value, so that the current limiting management module does not limit the current of the power supply circuit. Secondly, according to the preset time period, such as 100ms, 200ms, the output current of the DC sensor is quantized into a digital signal in sequence through the analog-to-digital converter, that is, the first analog-to-digital conversion value, also called the AD value. Then, the collected and recorded AD values ​​are arranged in ascending or descending order, and the arranged AD values ​​are screened according to the preset mean algorithm, and the mean is calculated to obtain the second analog-to-digital conversion value; wherein, in the mean algorithm, when screening the AD value, at least one maximum value and one minimum value are excluded, and then the mean is calculated, so as to avoid affecting the calculated mean due to measurement mutation. Finally, the output voltage of the current sensor, that is, the first voltage information, is calculated based on the voltage division ratio of the voltage division circuit, the measurement reference voltage value of the current sensor, and the average value of the AD value.

[0135] In an embodiment of the present invention, it also includes:

[0136] When the level of the first pin is set to the first level, the load current loop is turned on;

[0137] When the level of the first pin is set to the second level, the load current loop is cut off.

[0138] It should be noted that the first pin level is the level value of the control pin of the contact switching module of the vehicle power wall box circuit controlled by the processor; the first level is a digital logic 0 level, that is, a low level; the second level is a digital logic 1 level, that is, a high level. The processor is provided with a control pin of the contact switching module for controlling the power wall box circuit, and the control pin is connected to the photoelectric coupler element in the contact switching module. By switching the level signal of the control pin, the effect of switching the photoelectric coupler on and off is achieved, thereby achieving the effect of controlling the contact switching module to turn on and off the current circuit of the load device. As an embodiment, when the first pin level is a low level, the contact switching module puts the current circuit of the load device in a conducting state; when the first pin level is a high level, the contact switching module puts the current circuit of the load device in a disconnected state.

[0139] It is worth mentioning that it also includes:

[0140] Acquiring first temperature information;

[0141] Determining whether the first temperature information exceeds a preset second temperature threshold;

[0142] If so, the load current loop is cut off.

[0143] It should be noted that the present invention is designed with an over-temperature protection function. When the operating temperature value of the vehicle power wall box circuit exceeds the preset second temperature threshold, it means that the temperature of the vehicle power wall box circuit has reached the over-temperature threshold, triggering the over-temperature protection function. The processor switches the control pin level so that the contact switching module disconnects the current loop of the load device and stops the power supply output.

[0144] It is worth mentioning that it also includes:

[0145] Obtaining third communication instruction information;

[0146] Determining whether the third communication instruction information is a remote control instruction;

[0147] If yes, parsing the third communication instruction information to obtain the first remote control information;

[0148] The contact switching module is controlled or the current limiting management module is adjusted according to the first remote control information.

[0149] It should be noted that the processor performs CAN communication with the wireless communication module through the CAN isolation chip. When the processor receives a communication instruction, that is, the third communication instruction, from the CAN communication process, first, it determines whether the third communication instruction is a remote control instruction from the wireless communication module according to the instruction code; if so, the first remote control information is obtained after parsing the third communication instruction information; wherein, the first remote control information is a preset control code and control parameter, which is used to control the contact switching module or adjust the current limiting management module. Through remote communication, the digital, intelligent and centralized management of the vehicle power wall box is realized, and the user experience is improved.

[0150] To sum up, the present invention provides a control circuit and method for a vehicle-mounted power wall box, which controls the on-off of the main power supply circuit of the load device through a high-power field effect transistor and uses a current sensor to collect the working current of the load device, thereby realizing the miniaturized design of the vehicle-mounted power wall box and reducing the working noise, thereby improving the user experience; in addition, first, the first current information of the load device is measured according to the first voltage information and the second voltage information; then, the second current information of the circuit is obtained according to the electrical characteristics of the vehicle-mounted power wall box circuit; finally, according to the size relationship between the first current information and the second current information, the supply current value of the circuit is adjusted through the current limiting management module or the on-off status of the main power supply circuit is switched through the contact switching module, thereby realizing intelligent management and control and improving the stability and safety of the circuit operation.

[0151] In addition, the functional modules in the various embodiments of the present invention may be integrated together to form an independent part, or each module may exist independently, or two or more modules may be integrated to form an independent part.

[0152] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or the part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium, including several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, and other media that can store program codes.

[0153] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A control method for a vehicle-mounted power wall box, applied to a control circuit of a vehicle-mounted power wall box, the control circuit comprising: A processor, used to control the current outputted by the vehicle power wall box to the load device according to the electrical characteristics of the vehicle power wall box circuit; A contact switching module, used to switch on and off the load output power supply according to a control signal sent by the processor to the photocoupler; A current acquisition module is used to be connected in series to a power supply circuit of a load device, and output first voltage information corresponding to the current value of the load device according to the current value of the load device; A current limiting management module is used to adjust the maximum current value flowing through the load device; Characterized in that, the control method specifically includes: Acquire first voltage information and second voltage information; Calculating first current information according to the first voltage information and the second voltage information; Acquiring first temperature information; Obtaining second current information according to the first temperature information and the second voltage information; determining whether the second current information exceeds the first current information; If yes, adjusting the current limiting management module according to the first current information; If not, sending a first communication instruction message; Determining whether first feedback instruction information is received; If yes, setting the current limiting management module according to the second current information and the first feedback instruction information; The first voltage information is the amplitude value of the output voltage of the current acquisition module; The second voltage information is the power supply voltage of the load device; The first current information is the power supply current value required by the load device; The first temperature information is the temperature value of the vehicle power wall box circuit; The second current information is the maximum current value that can be provided by the vehicle power wall box circuit at the current operating temperature; The first communication instruction information is an instruction of abnormal current value sent to the external device; The first feedback instruction information is a current value abnormality processing instruction fed back by an external device.

2. The control method of a vehicle-mounted power wall box according to claim 1, characterized in that: The first current information is calculated according to the first voltage information and the second voltage information, specifically: Setting a first current relationship according to the type of the second voltage information; If the type of the second voltage information is alternating current, setting the first current relationship equation according to a preset alternating current relationship equation; If the type of the second voltage information is direct current, setting the first current relationship equation according to a preset direct current current relationship equation; Substituting the first voltage information and the second voltage information into the first current relationship equation to calculate and obtain the first current information; The first current relationship is a calculation relationship between an output voltage value and a current value preset according to detection characteristics of a current sensor.

3. The control method of a vehicle-mounted power wall box according to claim 1, characterized in that: The obtaining of the second current information according to the first temperature information and the second voltage information is specifically: Acquiring first temperature information; Determining whether the first temperature information exceeds a preset first temperature threshold; If yes, setting the second current information to a preset trickle value and sending a second communication instruction information; If not, obtaining an allowable current correspondence table according to the type of the second voltage information; According to the first temperature information and the second voltage information, searching the allowable current correspondence table to obtain second current information; The second communication instruction information is a temperature warning instruction sent to the external device.

4. The control method of a vehicle-mounted power wall box according to claim 1, characterized in that: The adjusting of the current limiting management module is specifically: Acquiring third current information; Obtaining first resistance information according to the third current information; Obtaining second resistance information; Obtaining first resistance difference information according to a difference between the first resistance information and the second resistance information; Determining whether the first resistance difference information exceeds a preset first resistance difference range; If yes, adjusting the resistance of the feedback resistor according to the first resistance difference information and the preset first resistance adjustment instruction; The third current information is the target current value of the current limiting management module; The first resistance information is a target resistance value of a feedback resistor of the current limiting management module; The second resistance information is the current resistance value of the feedback resistor of the current limiting management module; The first resistance adjustment instruction is an instruction for adjusting the resistance of the feedback resistor.

5. The control method of a vehicle-mounted power wall box according to claim 1, characterized in that: Also includes: Adjust the feedback resistor value according to the preset calibration resistance value; Collecting and recording the first analog-to-digital conversion value according to a preset time period; After sorting the recorded first analog-to-digital conversion values ​​in ascending or descending order, a second analog-to-digital conversion value is calculated according to a preset mean value algorithm; Obtaining first voltage information according to preset voltage division ratio information, a reference voltage value and the second analog-to-digital conversion value; The first analog-to-digital conversion value is an analog-to-digital conversion value of an analog-to-digital converter of a processor; The second analog-to-digital conversion value is an average value of the first analog-to-digital conversion value; The voltage division ratio information is the voltage division ratio value of the voltage division circuit of the vehicle-mounted power wall box circuit.

6. The control method of a vehicle-mounted power wall box according to claim 1, characterized in that: Also includes: When the level of the first pin is set to the first level, the load current loop is turned on; When the level of the first pin is set to the second level, the load current loop is cut off; The first pin level is the level value of the control pin of the contact switching module of the vehicle power wall box circuit controlled by the processor; The first level is a digital logic 0 level, i.e. a low level; The second level is a digital logic 1 level, ie, a high level.

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