Vehicle-mounted primary input voltage detection circuit and method

Abstract

The present invention provides a vehicle-mounted primary input voltage detection circuit and method, the circuit includes: a low voltage connector is connected to the first power supply input terminal and the second power supply input terminal of a MOS tube through a filter circuit, the signal output terminal of the MOS tube is connected to the input terminal of an isolation transformer, the first voltage output terminal of the isolation transformer is connected to the first terminal of a PWM chip, the second terminal of the PWM chip is connected to the signal input terminal of the MOS tube, and the first terminal of a control chip is connected to the second terminal of the PWM chip through a first isolator; a low voltage connector, a transceiver, a second isolator, and a control chip are connected in sequence. The present invention has the following advantages: 1. The circuit structure is simple and reliable, and the cost is low; 2. The control chip can quickly and accurately obtain the primary input voltage according to the duty cycle control parameters from the PWM chip, which can effectively improve the primary input voltage detection efficiency and detection accuracy.

Description

Technical Field

[0001] The present invention relates to the technical field of primary side information detection, and in particular to a vehicle-mounted primary side input voltage detection circuit and method. Background Art

[0002] With the continuous development of new energy technology, new energy electric vehicles have been used more and more widely. The on-board system of new energy electric vehicles is divided into two systems: high voltage and low voltage. The low voltage system is mainly used to power low voltage loads, and the high voltage system is mainly used to power high voltage components such as drive motors, compressors, and PTC (Positive Temperature Coefficient) heaters. Among them, PTC (Positive Temperature Coefficient) heaters are important components in the air conditioning system and battery thermal management system of new energy electric vehicles. Through suitable heating solutions, on the one hand, the battery pack can be heated to make it work in an ideal environment, extend its service life, shorten charging time, and increase driving range; on the other hand, it can also meet the heating needs in the car and improve the comfort of driving in winter.

[0003] Most compressor controllers and PTC controllers use a dual MCU architecture, and electrical isolation is achieved between high / low voltage areas through an isolated power supply. In order to improve the reliability of the operation of high-voltage components such as compressors and PTC heaters, and prevent damage to components due to over-voltage or under-voltage of the low-voltage power supply end, it is necessary to detect the voltage value of the low-voltage power supply end in real time / periodic manner, so as to control the opening or closing of high-voltage components such as compressors and PTC heaters according to the detected voltage value. However, the low-voltage power supply end is set in the low-voltage area, and the high-voltage components such as compressors and PTC heaters are set in the high-voltage area. Therefore, it is difficult to transmit the voltage value of the low-voltage area to the high-voltage area in a timely / real-time manner. In the prior art, a complex circuit is usually used to detect the voltage value of the low-voltage power supply end, so as to control the opening or closing of the high-voltage components in the high-voltage area according to the detected voltage value. Therefore, there are problems such as complex detection circuits, high detection costs, and low detection accuracy.

[0004] In summary, the existing on-board primary input voltage detection method has the problems of complex detection circuit and high detection cost. Summary of the invention

[0005] The embodiments of the present invention provide a vehicle-mounted primary input voltage detection circuit and method, aiming to solve the problems of complex detection circuit and high detection cost in the existing vehicle-mounted primary input voltage detection method.

[0006] In a first aspect, an embodiment of the present invention discloses a vehicle-mounted primary input voltage detection circuit, the circuit comprising a low-voltage connector, a filter circuit, a MOS tube, an isolation transformer, a PWM chip, a first voltage regulator, a second voltage regulator, a first isolator, a second isolator, a transceiver and a control chip; wherein the low-voltage connector is connected to a vehicle power supply terminal of a vehicle-mounted system;

[0007] The low-voltage connector, the filter circuit, the MOS tube, the PWM chip, the first voltage regulator and the transceiver are arranged on the low-voltage side of the circuit, the second voltage regulator and the control chip are arranged on the high-voltage side of the circuit, and the isolation transformer, the first isolator and the second isolator are arranged between the low-voltage side and the high-voltage side;

[0008] The low-voltage connector is connected to the first power supply input terminal and the second power supply input terminal of the MOS tube through the filter circuit, the signal output terminal of the MOS tube is connected to the input terminal of the isolation transformer, the first voltage output terminal of the isolation transformer is connected to the first terminal of the PWM chip, the second terminal of the PWM chip is connected to the signal input terminal of the MOS tube, and the first terminal of the control chip is connected to the second terminal of the PWM chip through the first isolator;

[0009] The low-voltage connector, the transceiver, the second isolator, and the control chip are connected in sequence.

[0010] Furthermore, the first voltage output end of the isolation transformer is connected to the power supply input end of the first isolator and the power supply input end of the second isolator respectively through the first voltage regulator, and the second voltage output end of the isolation transformer is connected to the power supply input end of the control chip through the second voltage regulator.

[0011] Furthermore, the control chip is connected to the vehicle control end of the vehicle-mounted system through the first isolator, the transceiver and the low-voltage connector in sequence.

[0012] Further, the circuit further comprises a target high voltage component, and the target high voltage component is arranged on the high voltage side;

[0013] The third voltage output terminal of the isolation transformer is connected to one end of the target high-voltage component, and the other end of the target high-voltage component is connected to the control chip.

[0014] Further, the target high-voltage component includes a driver chip, an IGBT component and a target high-voltage component;

[0015] The first end of the driver chip is connected to the control output end of the control chip, the second end of the driver chip is connected to the third voltage output end of the isolation transformer, and the third end of the driver chip is connected to the target high-voltage component through the IGBT component.

[0016] Furthermore, the filtering circuit includes a common mode inductor, a filtering capacitor and a filtering coil;

[0017] The first pin of the low-voltage connector is connected to the first end of the common-mode inductor, the second pin of the low-voltage connector is connected to the second end of the common-mode inductor, the third end of the common-mode inductor is respectively connected to the first end of the filter capacitor and the first end of the filter coil, the second end of the filter coil is connected to the first input end of the MOS tube, and the fourth end of the common-mode inductor is respectively connected to the second end of the filter capacitor and the second input end of the MOS tube.

[0018] In a second aspect, an embodiment of the present invention further discloses a vehicle-mounted primary input voltage detection method, which is applied to the vehicle-mounted primary input voltage detection circuit in the first aspect. The method includes the following steps performed in the control chip:

[0019] Regularly acquiring the duty cycle control parameters from the PWM chip;

[0020] Acquire a primary input voltage corresponding to the duty cycle control parameter according to a preset voltage-duty cycle relationship table;

[0021] A corresponding control instruction is issued to a target high-voltage component according to the primary input voltage.

[0022] Furthermore, the step of sending a corresponding control instruction to a target high-voltage component according to the primary input voltage includes:

[0023] Determining whether the primary input voltage is within a preset range;

[0024] If not, a shutdown signal is sent to the driver chip to shut down the target high-voltage component.

[0025] Furthermore, the method further includes the steps performed in the control chip:

[0026] Obtain the power value of the target high-voltage component at regular intervals;

[0027] Determining whether the operating conditions are met according to the power value;

[0028] If not, a sleep signal is sent to the vehicle control terminal of the vehicle-mounted system, so that the vehicle control terminal stops supplying power to the circuit according to the received sleep signal.

[0029] Furthermore, the method further includes the steps of executing in the PWM chip:

[0030] Regularly detecting the primary input voltage from the isolation transformer;

[0031] Generate corresponding duty cycle control parameters according to a preset duty cycle adjustment strategy and the primary input voltage, and send the duty cycle control parameters to the control chip;

[0032] The duty cycle of the MOS tube is adjusted according to the duty cycle control parameter.

[0033] The present invention provides a vehicle-mounted primary input voltage detection circuit and method, the circuit comprising a low-voltage connector, a filter circuit, a MOS tube, an isolation transformer, a PWM chip, a first voltage regulator, a second voltage regulator, a first isolator, a second isolator, a transceiver and a control chip; wherein the low-voltage connector is connected to a vehicle power supply end of a vehicle-mounted system; the low-voltage connector, the filter circuit, the MOS tube, the PWM chip, the first voltage regulator and the transceiver are arranged on the low-voltage side of the circuit, the second voltage regulator and the control chip are arranged on the high-voltage side of the circuit, the isolation transformer, the first isolator and the The second isolator is arranged between the low-voltage side and the high-voltage side; the low-voltage connector is connected to the first power supply input terminal and the second power supply input terminal of the MOS tube through the filtering circuit, the signal output terminal of the MOS tube is connected to the input terminal of the isolation transformer, the first voltage output terminal of the isolation transformer is connected to the first terminal of the PWM chip, the second terminal of the PWM chip is connected to the signal input terminal of the MOS tube, and the first terminal of the control chip is connected to the second terminal of the PWM chip through the first isolator; the low-voltage connector, the transceiver, the second isolator, and the control chip are connected in sequence. The PWM chip in the embodiment of the present invention can regularly obtain the primary input voltage from the isolation transformer, and output a fixed-frequency driving signal according to the primary input voltage to control the duty cycle of the MOS tube, thereby accurately controlling the voltage value output by the isolation transformer, realizing closed-loop control of the primary input voltage, and improving the stability of the line operation; the PWM chip in the embodiment of the present invention can also send the duty cycle control parameter (driving signal) generated based on the primary input voltage to the control chip through the first isolator, and the control chip can obtain the primary input voltage corresponding to the duty cycle control parameter according to the preset voltage-duty cycle relationship table, and control the opening or closing of high-voltage components such as PTC heaters and compressors according to the primary input voltage, thereby further improving the stability and reliability of the line operation; in summary, compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The circuit structure is simple and reliable, and the cost is low; 2. The control chip can quickly and accurately obtain the primary input voltage according to the duty cycle control parameter from the PWM chip, which can effectively improve the primary input voltage detection efficiency and detection accuracy, and realize the secondary side (the control chip on the high-voltage side) to quickly and accurately detect the primary input voltage. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying any creative work.

[0035] Figure 1 A schematic diagram of the overall structure of a vehicle-mounted primary input voltage detection circuit provided by an embodiment of the present invention;

[0036] Figure 2 A schematic diagram of a flow chart of a vehicle-mounted primary input voltage detection method provided by an embodiment of the present invention;

[0037] Figure Number:

[0038] 10. Circuit; 11. Low-voltage connector; 12. MOS tube; 13. Isolation transformer; 14. PWM chip; 151. First voltage regulator; 152. Second voltage regulator; 161. First isolator; 162. Second isolator; 17. Transceiver; 18. Control chip. DETAILED DESCRIPTION

[0039] 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 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.

[0040] It should be understood that when used in this specification and the appended claims, the terms "include" and "comprises" indicate the presence of described features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or combinations thereof.

[0041] It should also be understood that the terms used in the present specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an" and "the" are intended to include plural forms unless the context clearly indicates otherwise.

[0042] It should be further understood that the term "and / or" used in the present description and the appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0043] The embodiment of the present invention provides a vehicle-mounted primary input voltage detection circuit, such as Figure 1As shown, the circuit 10 includes a low-voltage connector 11, a filter circuit, a MOS tube 12, an isolation transformer 13, a PWM chip 14, a first voltage regulator 151, a second voltage regulator 152, a first isolator 161, a second isolator 162, a transceiver 17 and a control chip 18; wherein the low-voltage connector 11 is connected to the vehicle power supply end of the vehicle-mounted system; the low-voltage connector 11, the filter circuit, the MOS tube 12, the PWM chip 14, the first voltage regulator 151 and the transceiver 17 are arranged on the low-voltage side of the circuit 10, the second voltage regulator 152 and the control chip 18 are arranged on the high-voltage side of the circuit 10, the isolation transformer 13, the first isolator 161 and the second isolator 162 The second isolator 162 is arranged between the low-voltage side and the high-voltage side; the low-voltage connector 11 is connected to the first power supply input terminal and the second power supply input terminal of the MOS tube 12 through the filtering circuit, the signal output terminal of the MOS tube 12 is connected to the input terminal of the isolation transformer 13, the first voltage output terminal of the isolation transformer 13 is connected to the first terminal of the PWM chip 14, the second terminal of the PWM chip 14 is connected to the signal input terminal of the MOS tube 12, and the first terminal of the control chip 18 is connected to the second terminal of the PWM chip 14 through the first isolator 161; the low-voltage connector 11, the transceiver 17, the second isolator 162, and the control chip 18 are connected in sequence.

[0044] In this embodiment, the circuit 10 includes a low-voltage connector 11, a filter circuit, a MOS tube 12, an isolation transformer 13, a PWM chip 14, a first voltage regulator 151, a second voltage regulator 152, a first isolator 161, a second isolator 162, a transceiver 17 and a control chip 18; wherein, the low-voltage connector 11 is connected to the vehicle power supply end of the vehicle-mounted system, the vehicle power supply end is a low-voltage power supply end, and the vehicle power supply end supplies power to the circuit 10 through the low-voltage connector 11.

[0045] The low-voltage connector 11, the filter circuit, the MOS tube 12, the PWM chip 14, the first voltage regulator 151 and the transceiver 17 are arranged on the low-voltage side of the circuit 10, the second voltage regulator 152 and the control chip 18 are arranged on the high-voltage side of the circuit 10, and the isolation transformer 13, the first isolator 161 and the second isolator 162 are arranged between the low-voltage side and the high-voltage side; the low-voltage connector 11 is connected to the first power supply input terminal and the second power supply input terminal of the MOS tube 12 through the filter circuit; the vehicle power supply terminal provides input voltage to the circuit through the low-voltage connector 11; wherein, the use of the low-voltage connector 11 can reduce energy loss; the filter circuit performs a filtering operation on the input voltage, obtains the filtered input voltage and provides it to the MOS tube 12 and the transceiver 17 respectively to realize power supply, thereby ensuring the stable operation of the line.

[0046] The signal output end of the MOS tube 12 is connected to the input end of the isolation transformer 13, the first voltage output end of the isolation transformer 13 is connected to the first end of the PWM chip 14 to power the PWM chip 14 to enable it to work normally, and the second end of the PWM chip 14 is connected to the signal input end of the MOS tube 12; the PWM chip 14 can regularly detect the primary input voltage from the isolation transformer 13, and output a fixed frequency driving signal according to the primary input voltage to control the duty cycle of the MOS tube, thereby accurately controlling the voltage value output by the isolation transformer, realizing closed-loop control of the primary input voltage, and improving the stability of the line operation; wherein, the primary input voltage is the low-voltage side voltage ; In an embodiment of the present invention, the PWM chip 14 can change the size of the output voltage of the isolation transformer 13 by changing the size of the duty cycle of the MOS tube 12; specifically, the PWM chip 14 determines whether the primary input voltage is greater than a preset voltage value; if greater than, the MOS tube is controlled to reduce its duty cycle; if less than, the MOS tube is controlled to increase its duty cycle; if equal, the duty cycle of the MOS tube is not adjusted; because the input voltage is often in a fluctuating state, the PWM chip 14 needs to dynamically adjust the duty cycle of the MOS tube according to the primary input voltage in a timely / real-time manner to achieve closed-loop control of the primary input voltage and improve the stability of the line operation.

[0047] The first end of the control chip 18 is connected to the second end of the PWM chip 14 through the first isolator 161; specifically, the second end of the PWM chip 14 is connected to the first end of the first isolator 161, and the second end of the first isolator 161 is connected to the first end of the control chip 18; the PWM chip 14 can send the duty cycle control parameter (drive signal) generated based on the primary input voltage to the control chip 18 through the first isolator 161, and the control chip 18 can obtain the primary input voltage corresponding to the duty cycle control parameter according to a preset voltage-duty cycle relationship table, and control the opening or closing of high-voltage components such as the compressor and the PTC heater according to the primary input voltage, which can effectively prevent device damage caused by over-voltage or under-voltage of the low-voltage power supply end, and further improve the stability and reliability of line operation.

[0048] When the high-voltage side load is stable, the duty cycle control parameter output by the PWM chip 14 is proportional to the change in the input voltage, that is, the lower the input voltage, the higher the output duty cycle control parameter, and vice versa; for example, when the primary input voltage is 10V and the primary input current is 30mA, if the input voltage provided by the vehicle power supply end is 6V, the duty cycle control parameter output by the PWM chip 14 is 80%; if the input voltage provided by the vehicle power supply end is 18V, the duty cycle control parameter output by the PWM chip 14 is 20%; therefore, the voltage-duty cycle relationship table can be obtained by continuous adjustment and optimization through experiments or simulations. The embodiment of the present invention can obtain the primary input voltage corresponding to the duty cycle control parameter according to the voltage-duty cycle relationship table, which can effectively improve the primary input voltage detection efficiency and detection accuracy, and realize the secondary side (the control chip on the high-voltage side) to quickly and accurately detect the primary input voltage.

[0049] The first isolator 161 is a capacitive coupling isolation chip, an inductive coupling isolation chip, etc. The first isolator 161 isolates the data line to ensure the safe transmission of data and realize the transmission of signals or energy between the low-voltage side and the high-voltage side.

[0050] The low-voltage connector 11, the transceiver 17, the second isolator 162, and the control chip 18 are connected in sequence; the vehicle control end of the vehicle-mounted system can be communicated with the control chip 18 through the low-voltage connector 11, the transceiver 17, and the second isolator 162 in sequence, and the vehicle control end can send heating control instructions to the control chip 18 through the low-voltage connector 11, the transceiver 17, and the second isolator 162 in sequence. The control chip 18 can accurately control the output power and / or output heat of high-voltage components such as the compressor and the PTC heater according to the received heating control instructions; the second isolator 162 is a capacitive coupling isolation chip, an inductive coupling isolation chip, etc. The second isolator 162 isolates the data line to ensure the safe transmission of data and realize the safe transmission of signals or energy between the low-voltage side and the high-voltage side.

[0051] In summary, compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The circuit structure is simple and reliable with low cost; 2. The control chip can quickly and accurately obtain the primary input voltage according to the duty cycle control parameters from the PWM chip, thereby improving the efficiency and accuracy of the secondary side (the control chip on the high-voltage side) in detecting the primary input voltage.

[0052] In one embodiment, if Figure 1 As shown, the first voltage output end of the isolation transformer 13 is connected to the power supply input end of the first isolator 161 and the power supply input end of the second isolator 162 respectively through the first voltage regulator 151, and the second voltage output end of the isolation transformer 13 is connected to the power supply input end of the control chip 18 through the second voltage regulator 152.

[0053] In this embodiment, the first voltage output end of the isolation transformer 13 is respectively connected to the power supply input end of the first isolator 161 and the power supply input end of the second isolator 162 through the first voltage regulator 151, and the second voltage output end of the isolation transformer 13 is connected to the power supply input end of the control chip 18 through the second voltage regulator 152; the MOS tube 12 outputs the regulated voltage to the isolation transformer 13, and the isolation transformer 13 reduces or increases the regulated voltage according to the preset turns ratio of each coil, thereby meeting different circuit requirements and ensuring that the first isolator 161, the second isolator 162, and the control chip 18 are grounded, reducing interference and influence between different circuits, improving the stability and safety of the system, and preventing current leakage and electric shock risks.

[0054] In one embodiment, if Figure 1As shown, the control chip 18 is connected to the vehicle control end of the vehicle system through the first isolator 161, the transceiver 17 and the low-voltage connector 11 in sequence.

[0055] In this embodiment, the second end of the control chip 18 is connected to the third end of the first isolator 161, and the fourth end of the first isolator 161 is connected to the sleep signal input end of the transceiver 17. The transceiver 17 is connected to the vehicle control end of the vehicle-mounted system through the low-voltage connector 11, thereby realizing the safe transmission of signals or energy between the control chip 18 and the vehicle control end; the control chip 18 periodically obtains the power value of the target high-voltage component; determines whether the operating conditions are met according to the power value; for example, when the power value is greater than the preset power threshold in the operating condition, it is determined that the operating condition is not met; if not met, the control chip 18 sends a sleep signal to the vehicle control end of the vehicle-mounted system through the first isolator 161, the transceiver 17 and the low-voltage connector 11 in sequence, so that the vehicle control end stops supplying power to the circuit according to the received sleep signal, thereby improving the stability and reliability of the operation of the vehicle-mounted system.

[0056] In one embodiment, if Figure 1 As shown, the circuit 10 also includes a target high-voltage component, which is arranged on the high-voltage side; the third voltage output end of the isolation transformer 13 is connected to one end of the target high-voltage component, and the other end of the target high-voltage component is connected to the control chip 18.

[0057] In this embodiment, the circuit 10 also includes a target high-voltage component, which is arranged on the high-voltage side; wherein the target high-voltage component can be a high-voltage component such as a compressor component, a PTC heating component, etc.; the third voltage output end of the isolation transformer 13 is connected to one end of the target high-voltage component to power the target high-voltage component, and the other end of the target high-voltage component is connected to the control chip 18; the control chip 18 can accurately control the output power and / or output heat of the target high-voltage component according to the heating control instruction from the vehicle control end; the control chip 18 can also detect the actual operating power of the target high-voltage component in real time / periodic manner, and adjust the output power and / or output heat of the target high-voltage component according to the actual operating power to achieve power closed-loop control.

[0058] In one embodiment, if Figure 1As shown, the target high-voltage component includes a driver chip, an IGBT component and a target high-voltage component; the first end of the driver chip is connected to the control output end of the control chip 18, the second end of the driver chip is connected to the third voltage output end of the isolation transformer 13, and the third end of the driver chip is connected to the target high-voltage component through the IGBT component.

[0059] In this embodiment, the target high-voltage component includes a driver chip, an IGBT component and a target high-voltage component; wherein the target high-voltage component can be a high-voltage component such as a compressor, a PTC heater, etc.; the first end of the driver chip is connected to the control output end of the control chip 18, the second end of the driver chip is connected to the third voltage output end of the isolation transformer 13, and the third end of the driver chip is connected to the target high-voltage component through the IGBT component; the control chip 18 can generate corresponding duty cycle control parameters according to the heating control instruction and the actual operating power; the duty cycle control parameters are sent to the driver chip, so that the driver chip can accurately control the duty cycle of the IGBT component according to the duty cycle control parameters, thereby adjusting the output power value of the target high-voltage component to achieve power closed-loop control.

[0060] In one embodiment, if Figure 1 As shown, the filtering circuit includes a common-mode inductor, a filter capacitor and a filter coil; the first pin of the low-voltage connector 11 is connected to the first end of the common-mode inductor, the second pin of the low-voltage connector 11 is connected to the second end of the common-mode inductor, the third end of the common-mode inductor is respectively connected to the first end of the filter capacitor and the first end of the filter coil, the second end of the filter coil is connected to the first input end of the MOS tube 12, and the fourth end of the common-mode inductor is respectively connected to the second end of the filter capacitor and the second input end of the MOS tube 12.

[0061] In this embodiment, the filtering circuit includes a common-mode inductor, a filter capacitor and a filter coil; the first pin of the low-voltage connector 11 is connected to the first end of the common-mode inductor, the second pin of the low-voltage connector 11 is connected to the second end of the common-mode inductor, the third end of the common-mode inductor is respectively connected to the first end of the filter capacitor and the first end of the filter coil, the second end of the filter coil is connected to the first input end of the MOS tube 12, and the fourth end of the common-mode inductor is respectively connected to the second end of the filter capacitor and the second input end of the MOS tube 12; the common-mode inductor can suppress the common-mode current, and the filter capacitor and the filter coil can filter the input voltage to ensure the stable operation of the line.

[0062] The embodiment of the present invention also provides a vehicle-mounted primary input voltage detection method, which is applied to the above-mentioned vehicle-mounted primary input voltage detection circuit, such as Figure 1 and Figure 2 As shown, the method includes steps S110-S130 performed in the control chip:

[0063] S110, regularly acquiring a duty cycle control parameter from the PWM chip;

[0064] S120, acquiring a primary input voltage corresponding to the duty cycle control parameter according to a preset voltage-duty cycle relationship table;

[0065] S130, issuing corresponding control instructions to a target high-voltage component according to the primary input voltage.

[0066] In this embodiment, the circuit also includes a target high-voltage component, which is arranged on the high-voltage side; wherein the target high-voltage component can be a high-voltage component such as a compressor component, a PTC heating component, etc.; the third voltage output terminal of the isolation transformer is connected to one end of the target high-voltage component, and the other end of the target high-voltage component is connected to the control chip; the target high-voltage component includes a driver chip, an IGBT component and a target high-voltage component; wherein the target high-voltage component can be a high-voltage component such as a compressor, a PTC heater, etc.; the first end of the driver chip is connected to the control output end of the control chip, the second end of the driver chip is connected to the third voltage output end of the isolation transformer, and the third end of the driver chip is connected to the target high-voltage component through the IGBT component; the control chip can control the opening or closing of the target high-voltage component through the driver chip.

[0067] Obtain duty cycle control parameters from the PWM chip at regular intervals; wherein, the duty cycle control parameters from the PWM chip can be obtained every 100 microseconds; obtain the primary input voltage corresponding to the duty cycle control parameters according to a preset voltage-duty cycle relationship table; wherein, the voltage-duty cycle relationship table can be obtained by continuous adjustment and optimization through experiments or simulations; issue corresponding control instructions to the target high-voltage component according to the primary input voltage; for example, if the primary input voltage is not within a preset range, it indicates that the low-voltage power supply end is over-voltage or under-voltage. At this time, in order to prevent device damage, the target high-voltage component needs to be controlled to be turned off.

[0068] In one implementation, step S130 includes: determining whether the primary input voltage is within a preset range; if not, sending a shutdown signal to the driver chip to shut down the target high-voltage component.

[0069] In this embodiment, it is determined whether the primary input voltage is within a preset range; wherein the preset range can be set according to the actual application; if it is within the preset range, the step of periodically obtaining the duty cycle control parameters from the PWM chip is returned to be executed; if it is not within the preset range, a shutdown signal is sent to the driver chip to shut down the target high-voltage component.

[0070] Furthermore, the control chip can generate corresponding duty cycle control parameters according to the heating control instructions from the vehicle control end and the actual operating power of the target high-voltage component; and send the duty cycle control parameters to the driver chip, so that the driver chip can accurately control the duty cycle of the IGBT component according to the duty cycle control parameters, thereby adjusting the output power value of the target high-voltage component to achieve power closed-loop control.

[0071] In one implementation, the method also includes the steps performed in the control chip: regularly obtaining the power value of the target high-voltage component; judging whether the operating conditions are met based on the power value; if not, sending a sleep signal to the vehicle control end of the vehicle-mounted system so that the vehicle control end stops supplying power to the circuit based on the received sleep signal.

[0072] In this embodiment, the control chip is connected to the vehicle control end of the vehicle-mounted system through the first isolator, the transceiver and the low-voltage connector in sequence; the control chip can obtain the power value of the target high-voltage component at a regular interval; judge whether the operating conditions are met according to the power value; if the power value is greater than the preset power threshold in the operating conditions, it is determined that the operating conditions are not met; if not met, a sleep signal is sent to the vehicle control end of the vehicle-mounted system, so that the vehicle control end stops supplying power to the circuit according to the received sleep signal, thereby improving the stability and reliability of the operation of the vehicle-mounted system; if met, return to execute the step of regularly obtaining the power value of the target high-voltage component.

[0073] In one implementation, the method also includes the steps of being executed in the PWM chip: regularly detecting the primary input voltage from the isolation transformer; generating corresponding duty cycle control parameters according to a preset duty cycle adjustment strategy and the primary input voltage, and sending the duty cycle control parameters to the control chip; and adjusting the duty cycle of the MOS tube according to the duty cycle control parameters.

[0074] In this embodiment, the signal output end of the MOS tube is connected to the input end of the isolation transformer, the first voltage output end of the isolation transformer is connected to the first end of the PWM chip to power the PWM chip so that it works normally, and the second end of the PWM chip is connected to the signal input end of the MOS tube; the PWM chip can periodically detect the primary input voltage from the isolation transformer; generate corresponding duty cycle control parameters according to a preset duty cycle adjustment strategy and the primary input voltage, and send the duty cycle control parameters to the control chip; adjust the duty cycle of the MOS tube according to the duty cycle control parameters. The present invention can control the duty cycle of the MOS tube, thereby accurately controlling the voltage value output by the isolation transformer, thereby realizing closed-loop control of the primary input voltage and improving the stability of line operation.

[0075] The generation of the corresponding duty cycle control parameter according to the preset duty cycle adjustment strategy and the primary input voltage includes: obtaining a preset voltage value according to the duty cycle adjustment strategy; obtaining the difference between the preset voltage value and the primary input voltage; obtaining the duty cycle control parameter corresponding to the difference according to the difference-duty cycle relationship table in the duty cycle adjustment strategy; judging whether the primary input voltage is greater than the preset voltage value; if greater than, reducing the duty cycle of the MOS tube according to the difference; if not greater than, increasing the duty cycle of the MOS tube according to the difference. The embodiment of the present invention can adjust the voltage value output by the isolation transformer by adjusting the duty cycle of the MOS tube, realize the closed-loop control of the primary input voltage, and improve the stability of the line operation.

[0076] The present invention provides a vehicle-mounted primary input voltage detection circuit and method, the circuit comprising a low-voltage connector, a filter circuit, a MOS tube, an isolation transformer, a PWM chip, a first voltage regulator, a second voltage regulator, a first isolator, a second isolator, a transceiver and a control chip; wherein the low-voltage connector is connected to a vehicle power supply end of a vehicle-mounted system; the low-voltage connector, the filter circuit, the MOS tube, the PWM chip, the first voltage regulator and the transceiver are arranged on the low-voltage side of the circuit, the second voltage regulator and the control chip are arranged on the high-voltage side of the circuit, the isolation transformer, the first isolator and the The second isolator is arranged between the low-voltage side and the high-voltage side; the low-voltage connector is connected to the first power supply input terminal and the second power supply input terminal of the MOS tube through the filtering circuit, the signal output terminal of the MOS tube is connected to the input terminal of the isolation transformer, the first voltage output terminal of the isolation transformer is connected to the first terminal of the PWM chip, the second terminal of the PWM chip is connected to the signal input terminal of the MOS tube, and the first terminal of the control chip is connected to the second terminal of the PWM chip through the first isolator; the low-voltage connector, the transceiver, the second isolator, and the control chip are connected in sequence. The PWM chip in the embodiment of the present invention can regularly obtain the primary input voltage from the isolation transformer, and output a fixed-frequency driving signal according to the primary input voltage to control the duty cycle of the MOS tube, thereby accurately controlling the voltage value output by the isolation transformer, realizing closed-loop control of the primary input voltage, and improving the stability of the line operation; the PWM chip in the embodiment of the present invention can also send the duty cycle control parameter (driving signal) generated based on the primary input voltage to the control chip through the first isolator, and the control chip can obtain the primary input voltage corresponding to the duty cycle control parameter according to the preset voltage-duty cycle relationship table, and control the opening or closing of high-voltage components such as the compressor and the PTC heater according to the primary input voltage, so as to further improve the stability and reliability of the line operation; in summary, compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The circuit structure is simple and reliable, and the cost is low; 2. The control chip can quickly and accurately obtain the primary input voltage according to the duty cycle control parameter from the PWM chip, which can effectively improve the detection efficiency and detection accuracy of the primary input voltage.

[0077] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed by the present invention, and these modifications or replacements should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A vehicle-mounted primary input voltage detection circuit, characterized in that: The circuit includes a low-voltage connector, a filter circuit, a MOS tube, an isolation transformer, a PWM chip, a first voltage regulator, a second voltage regulator, a first isolator, a second isolator, a transceiver and a control chip; wherein the low-voltage connector is connected to the vehicle power supply terminal of the vehicle system; The low-voltage connector, the filter circuit, the MOS tube, the PWM chip, the first voltage regulator and the transceiver are arranged on the low-voltage side of the circuit, the second voltage regulator and the control chip are arranged on the high-voltage side of the circuit, and the isolation transformer, the first isolator and the second isolator are arranged between the low-voltage side and the high-voltage side; The low-voltage connector is connected to the first power supply input terminal and the second power supply input terminal of the MOS tube through the filter circuit, the signal output terminal of the MOS tube is connected to the input terminal of the isolation transformer, the first voltage output terminal of the isolation transformer is connected to the first terminal of the PWM chip, the second terminal of the PWM chip is connected to the signal input terminal of the MOS tube, and the first terminal of the control chip is connected to the second terminal of the PWM chip through the first isolator; wherein the PWM chip is used to periodically detect the primary input voltage from the isolation transformer, and send the duty cycle control parameter generated based on the primary input voltage to the control chip through the first isolator, so that the control chip obtains the primary input voltage corresponding to the duty cycle control parameter according to a preset voltage-duty cycle relationship table; The low-voltage connector, the transceiver, the second isolator, and the control chip are connected in sequence.

2. The vehicle-mounted primary input voltage detection circuit according to claim 1, characterized in that: The first voltage output end of the isolation transformer is connected to the power supply input end of the first isolator and the power supply input end of the second isolator through the first voltage regulator, and the second voltage output end of the isolation transformer is connected to the power supply input end of the control chip through the second voltage regulator.

3. The vehicle-mounted primary input voltage detection circuit according to claim 1, characterized in that: The control chip is connected to the vehicle control end of the vehicle-mounted system through the first isolator, the transceiver and the low-voltage connector in sequence.

4. The vehicle-mounted primary input voltage detection circuit according to claim 1, characterized in that: The circuit further includes a target high voltage component, the target high voltage component being disposed on the high voltage side; The third voltage output terminal of the isolation transformer is connected to one end of the target high-voltage component, and the other end of the target high-voltage component is connected to the control chip.

5. The vehicle-mounted primary input voltage detection circuit according to claim 4, characterized in that: The target high-voltage component includes a driver chip, an IGBT component and a target high-voltage component; The first end of the driver chip is connected to the control output end of the control chip, the second end of the driver chip is connected to the third voltage output end of the isolation transformer, and the third end of the driver chip is connected to the target high-voltage component through the IGBT component.

6. The vehicle-mounted primary input voltage detection circuit according to claim 1, characterized in that: The filter circuit includes a common mode inductor, a filter capacitor and a filter coil; The first pin of the low-voltage connector is connected to the first end of the common-mode inductor, the second pin of the low-voltage connector is connected to the second end of the common-mode inductor, the third end of the common-mode inductor is respectively connected to the first end of the filter capacitor and the first end of the filter coil, the second end of the filter coil is connected to the first input end of the MOS tube, and the fourth end of the common-mode inductor is respectively connected to the second end of the filter capacitor and the second input end of the MOS tube.

7. A vehicle-mounted primary input voltage detection method, applied to the vehicle-mounted primary input voltage detection circuit described in any one of claims 1 to 6, characterized in that: The method comprises the steps performed in the control chip: Regularly acquiring the duty cycle control parameters from the PWM chip; Acquire a primary input voltage corresponding to the duty cycle control parameter according to a preset voltage-duty cycle relationship table; A corresponding control instruction is issued to a target high-voltage component according to the primary input voltage; wherein the circuit also includes a target high-voltage component, and the target high-voltage component is arranged on the high-voltage side; the target high-voltage component includes a driver chip, an IGBT component and a target high-voltage component; the first end of the driver chip is connected to the control output end of the control chip, the second end of the driver chip is connected to the third voltage output end of the isolation transformer, and the third end of the driver chip is connected to the target high-voltage component through the IGBT component.

8. The vehicle-mounted primary input voltage detection method according to claim 7, characterized in that: The step of sending a corresponding control instruction to a target high-voltage component according to the primary input voltage includes: Determining whether the primary input voltage is within a preset range; If not, a shutdown signal is sent to the driver chip to shut down the target high-voltage component.

9. The vehicle-mounted primary input voltage detection method according to claim 7, characterized in that: The method further comprises the steps of: Obtain the power value of the target high-voltage component at regular intervals; Determining whether the operating conditions are met according to the power value; If not, a sleep signal is sent to the vehicle control terminal of the vehicle-mounted system, so that the vehicle control terminal stops supplying power to the circuit according to the received sleep signal.

10. The vehicle-mounted primary input voltage detection method according to claim 7, characterized in that: The method further comprises the steps of performing in the PWM chip: Regularly detecting the primary input voltage from the isolation transformer; Generate corresponding duty cycle control parameters according to a preset duty cycle adjustment strategy and the primary input voltage, and send the duty cycle control parameters to the control chip; The duty cycle of the MOS tube is adjusted according to the duty cycle control parameter.

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