Charger voltage safety output interface device based on multi-IO accurate control

Abstract

The invention discloses a charger voltage safety output interface device based on multi-IO accurate control, which comprises a power supply input module and a voltage output interface, and is characterized in that the output end of the power supply input module is connected with the source electrode of a PMOS1, the drain electrode of the PMOS1 is connected with the source electrode of a PMOS2, and the drain electrode of the PMOS2 is connected with the voltage output interface; the voltage output interface is connected with a voltage acquisition circuit and a current acquisition circuit, the voltage acquisition circuit and the current acquisition circuit are connected with the controller, and the controller is connected with the LCD driving chip; the voltage acquisition circuit and the current acquisition circuit are connected with a GND, a grid electrode of the PMOS1 and a grid electrode of the PMOS2 are respectively connected with an MOS unit, the MOS unit is connected with the GND, the MOS unit comprises at least two MOS units which are connected in series, and the MOS units are NMOS (N-channel Metal Oxide Semiconductor) or PMOS (P-channel Metal Oxide Semiconductor); the LCD driving chip is connected with grid electrodes of all levels of MOS of the two groups of MOS units; the device solves the technical problem that the output voltage of the existing electric vehicle charger is controlled by a single loop to control the MOS tube to directly output the voltage, so that the voltage is easily output by mistake, and uncontrollable potential safety hazards are caused.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle chargers, and in particular to a charger voltage safety output interface device based on multi-IO precise control. Background Art

[0002] As a convenient means of transportation, electric vehicles have been widely used around the world. Electric vehicle battery charging interfaces are usually used in home garages, public charging stations, commercial parking lots and other places. In these different use areas, the charging interface needs to adapt to various environmental conditions, such as temperature changes, humidity differences, electromagnetic interference, etc. The electric vehicle charging interface directly affects the safety of electric vehicles.

[0003] The existing electric vehicle battery charging interface usually consists of a plug, a socket, a charger and other parts. The charger contains a control circuit. When charging, the plug is connected to the socket, and the external power supply supplies power to the battery through the charger. The control circuit is used to monitor the voltage, current and other parameters during the charging process, and control the charging process according to the preset charging strategy.

[0004] In terms of the existing electric vehicle charger output voltage control method, the MOS tube is directly controlled to output voltage through a single loop. In the case of damaged control loop, poor contact, control program error, battery interference, etc., it is easy to cause incorrect output voltage, resulting in uncontrollable safety hazards.

[0005] Existing electric vehicle charging interfaces may have problems with the physical connection, such as loose plugs and poor contact, which may lead to increased resistance, heat, and even safety accidents such as fire.

[0006] The ability to detect and handle abnormal situations is insufficient. For example, when abnormal situations such as short circuit, overvoltage, overcurrent, etc. occur, the power supply cannot be cut off in time and effectively to protect the battery and equipment. Summary of the invention

[0007] In view of this, the purpose of the present invention is to provide a charger voltage safety output interface device based on multi-IO precise control, so as to at least solve the technical problem that the output voltage control of the existing electric vehicle charger directly controls the output voltage of the MOS tube through a single loop, which easily leads to erroneous output voltage and uncontrollable safety hazards.

[0008] The objective of the present invention is achieved through the following technical solutions: A charger voltage safety output interface device based on multi-IO precise control includes a power input module and a voltage output interface, wherein the output end of the power input module is connected to the source of PMOS1, the drain of PMOS1 is connected to the source of PMOS2, and the drain of PMOS2 is connected to the voltage output interface; the voltage output interface is connected to a voltage acquisition circuit and a current acquisition circuit, the voltage acquisition circuit and the current acquisition circuit are connected to a controller, and the controller is connected to an LCD driver chip; the voltage acquisition circuit and the current acquisition circuit are connected to GND, the gate of PMOS1 and the gate of PMOS2 are respectively connected to MOS units, the MOS units are connected to GND, the MOS units include at least two MOSs connected in series, and the MOS It is NMOS or PMOS. If the front-end MOS is NMOS, the drain of the NMOS is connected to PMOS1 or PMOS2. If the front-end MOS is PMOS, the source of the PMOS is connected to PMOS1 or PMOS2. If the rear-end MOS is NMOS, the source of the NMOS is connected to GND. If the rear-end MOS is PMOS, the drain of the PMOS is connected to GND. If the middle MOS is NMOS, the drain of the NMOS is connected to the front-stage MOS and the source is connected to the rear-stage MOS. If the middle MOS is PMOS, the source of the PMOS is connected to the front-stage MOS and the drain is connected to the rear-stage MOS. The LCD driver chip is connected to the gates of each level of MOS of the two groups of MOS units.

[0009] Furthermore, the MOS unit connected to the PMOS1 includes four NMOSs, and the MOS unit connected to the PMOS2 includes two NMOSs and two PMOSs, and the two PMOSs are respectively located at two sides of the two NMOSs.

[0010] Furthermore, NMOS1 is connected between the PMOS1 and the MOS unit, the drain of the NMOS1 is connected to the gate of the PMOS1, and the source is connected to the MOS unit; NMOS2 is connected between the PMOS2 and the MOS unit, the drain of the NMOS2 is connected to the gate of the PMOS2, and the source is connected to the MOS unit; the voltage acquisition circuit includes a voltage-dividing sampling resistor composed of two resistors connected in series and a first operational amplifier, the voltage-dividing sampling resistor is connected to the first operational amplifier, and the first operational amplifier is connected to the gate of the NMOS1; the current acquisition circuit includes a current sampling resistor and a second operational amplifier connected to each other, and the second operational amplifier is connected to the gate of the NMOS2.

[0011] Furthermore, a pull-up resistor is connected between the gate and source of the PMOS1; and a pull-up resistor is connected between the gate and source of the PMOS2.

[0012] Furthermore, the controller is connected to a power input module.

[0013] The beneficial effects of the present invention are: In the charger voltage safety output interface device based on multi-IO precise control of the present invention, the voltage acquisition circuit acquires the voltage information of the voltage output interface in real time and transmits it to the controller, the current acquisition circuit acquires the current information of the voltage output interface in real time and transmits it to the controller, the controller receives the voltage information and the current information and calculates the actual charging power, and compares the actual charging power with the preset safe power range. If it exceeds the range, the controller controls the LCD driver chip to output the disconnection level to turn off each level of the two groups of MOS units, thereby disconnecting PMOS1 and PMOS2. In the case of damage to the control loop, poor contact, control program error, battery interference, etc., only the disconnection level is successfully output to part of the MOS in the two groups of MOS units, and PMOS1 and / or PMOS2 will also be disconnected, thereby disconnecting the charging to the battery, thereby solving the technical problem that the output voltage control of the existing electric vehicle charger directly outputs the voltage through a single loop to control the MOS tube to easily cause erroneous output voltage and uncontrollable safety hazards.

[0014] When the voltage acquisition circuit detects an abnormal increase in voltage, a low level 0 is input to NMOS1 to disconnect NMOS1, thereby disconnecting PMOS1 to ensure circuit safety. When the current acquisition circuit detects an abnormal increase in current, a low level 0 is input to NMOS2 to disconnect NMOS2, thereby disconnecting PMOS2 to ensure circuit safety. When the connection between the plug and the socket is loose or in poor contact, and the information collected by the voltage acquisition circuit and the current acquisition circuit exceeds the preset range, a low level 0 is input to NMOS1 and / or NMOS2 to disconnect them, thereby disconnecting PMOS1 and / or PMOS2 to ensure circuit safety.

[0015] When the gate MOS of PMOS1 is disconnected, the pull-up resistor pulls the gate (G pole) voltage of PMOS1 to the source (S pole) voltage, that is, VGS=0. Ensure that PMOS1 is in a stable disconnected state. Avoid false triggering caused by gate level floating. The same applies to the pull-up resistor between the gate and source of PMOS2.

[0016] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings, in which: Figure 1 This is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0018] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be understood that the preferred embodiments are only for illustrating the present invention, rather than for limiting the protection scope of the present invention.

[0019] like Figure 1As shown, a charger voltage safety output interface device based on multi-IO precise control includes a power input module, the output end of the power input module is connected to the source of PMOS1, the drain of PMOS1 is connected to the source of PMOS2, the drain of PMOS2 is connected to the voltage output interface, and PMOS1 and PMOS2 are both P-channel depletion-type insulated gate field effect transistors with a rated withstand voltage of 400V and a current of 30A. The voltage output interface is connected to a voltage acquisition circuit and a current acquisition circuit, the voltage acquisition circuit and the current acquisition circuit are connected to GND, and the voltage acquisition circuit and the current acquisition circuit are connected to a controller. The controller uses a high-performance microprocessor of automotive grade, which has powerful computing power and data processing capabilities. The controller has a PD control algorithm, and the controller is connected to an 8-segment 4-bit LCD driver chip. The voltage acquisition circuit includes a voltage-dividing sampling resistor, which is composed of two resistors connected in series, and the voltage-dividing sampling resistor is connected to a first operational amplifier. The current acquisition circuit includes a milliohm-level current sampling resistor, and the current sampling resistor is connected to a second operational amplifier. A pull-up resistor is connected between the source and gate of PMOS1, and a pull-up resistor is connected between the source and gate of PMOS2. The gate of PMOS1 is connected to the drain of NMOS1, the source of NMOS1 is connected to the MOS unit (group A MOS unit), and the gate is connected to the first operational amplifier. The gate of PMOS2 is connected to the drain of NMOS2, the source of NMOS2 is connected to the MOS unit (group B MOS unit), and the gate is connected to the second operational amplifier. Both NMOS1 and NMOS2 are 400V, 2A N-channel depletion-type insulated gate field effect transistors. Group A MOS unit consists of four NMOSs connected in sequence. The drain of the frontmost NMOS is connected to the source of NMOS1, and the source of the rearmost NMOS is connected to GND. The source of the front-stage NMOS in the two adjacent NMOSs is connected to the drain of the rear-stage NMOS. The MOS unit of group B consists of two PMOS and two NMOS. The two PMOS are located on both sides of the two NMOS. The source of the frontmost PMOS is connected to the source of NMOS2, and the drain is connected to the drain of the previous NMOS. The source of the previous NMOS is connected to the drain of the next NMOS, and the source of the next NMOS is connected to the source of the last PMOS. The drain of the last PMOS is connected to GND. The NMOS is turned on by a high level 1, and the PMOS is turned on by a low level 0. The LCD driver chip is connected to the gates of each MOS of the MOS units of group A and group B. The controller is connected to the power input module and is powered by the power input module.

[0020] The voltage acquisition circuit of the device acquires the voltage information of the voltage output interface in real time and transmits it to the controller. The current acquisition circuit acquires the current information of the voltage output interface in real time and transmits it to the controller. The controller receives the voltage information and the current information and calculates the actual charging power through the PD control algorithm, and compares the actual charging power with the preset safe power range. If it does not exceed the range, the controller controls the LCD driver chip to output 11110110 to turn on the MOS units of group A and group B, which are 8 MOS units in total. If it exceeds the range, the controller controls the LCD driver chip to output 00001001 to turn off the MOS units of group A and group B, which are 8 MOS units in total. In the case of damage to the control loop, poor contact, control program error, battery interference, etc., only the disconnection level is successfully output to part of the MOS units of group A and group B, which are 8 MOS units in total, and PMOS1 and / or PMOS2 are also disconnected, thereby disconnecting the battery power supply. When the voltage acquisition circuit detects that the voltage increases abnormally, a low level 0 is input to NMOS1 to disconnect NMOS1, and the overvoltage protection mechanism is started at the same time to ensure circuit safety. When the current acquisition circuit detects an abnormal increase in current, a low level 0 is input to NMOS2 to disconnect NMOS2, and the short-circuit protection mechanism is started, activating the fuse or circuit breaker to ensure circuit safety. When the connection between the plug and the socket is loose or the contact is poor, and the value collected by the voltage acquisition circuit and / or the current acquisition circuit exceeds the preset range, a low level 0 is input to NMOS1 and / or NMOS2 to disconnect it, and an alarm message is sent to the user through the controller control indicator light or communication module. There are a total of 8 MOSs in the A group MOS unit and the B group MOS unit. As long as one of NMOS1 and NMOS2 is disconnected, at least one of PMOS1 and PMOS2 is disconnected, and the power input module no longer charges the battery. If the power input module wants to charge the battery, all MOS tubes need to be turned on, thereby achieving precise control of the output voltage and current.

[0021] The device is no longer a single circuit, that is, it can output voltage and charge the battery only when PMOS1 and PMOS2 are turned on at the same time. The simultaneous turning on of PMOS1 and PMOS2 requires NMOS1, NMOS1, and MOS units of group A and group B, a total of 8 MOSs, to be turned on at the same time. In the case of damaged control circuit, poor contact, control program error, battery interference, etc., when the charging voltage increases abnormally, when the charging current increases abnormally, when the connection between the plug and the socket is loose or the contact is poor, it will inevitably cause at least one MOS to be disconnected and unable to charge the battery, thereby achieving precise control of the output voltage and current.

[0022] The technical effects of this device include: 1. Precise voltage output control Through the precise control of multiple IOs, especially the precise control of PMOS1 and PMOS2 by the 8-segment 4-bit LCD driver chip, highly precise control of the charger output voltage is achieved. Only under specific binary coding (11110110), PMOS1 and PMOS2 may conduct the output voltage, avoiding the wrong output voltage caused by a single circuit failure or abnormality, greatly improving the accuracy and stability of the voltage output, effectively eliminating safety hazards, and ensuring the safety and reliability of the battery charging process.

[0023] 2. The application of PD control algorithm can accurately calculate the actual charging power according to the feedback voltage and current information, and compare it with the preset safe power range. Once it exceeds the range, the conduction state of 8 MOS tubes of group A MOS unit and group B MOS unit can be adjusted in time to achieve dynamic and precise adjustment of output voltage and current, meet the charging needs of the battery, and extend the battery life.

[0024] 3. Enhanced abnormal situation detection and protection Overvoltage protection: NMOS1 is used for overvoltage protection. By setting a voltage acquisition circuit at the voltage output interface, abnormal voltage increases can be detected in time. Once overvoltage occurs, the conduction of NMOS1 is quickly cut off, the voltage output is stopped, and the overvoltage protection mechanism is activated to prevent the battery from being damaged due to excessive voltage, thus ensuring the safe operation of the battery and charger.

[0025] Short circuit protection: NMOS2 is used for short circuit detection and protection. A current acquisition circuit is set at the voltage output interface to detect abnormal current increase in real time and accurately. When a short circuit occurs, the conduction of NMOS2 can be quickly cut off, the voltage output can be stopped, and the short circuit protection mechanism (such as a fuse or circuit breaker) can be activated to effectively prevent the short circuit current from causing serious damage to the circuit and battery, greatly improving the safety of the charger in the event of a short circuit.

[0026] 4. Optimize connection status monitoring The connection status between the plug and the socket is monitored in real time through NMOS1 and NMOS2. When a loose connection or poor contact is detected, the control circuit can respond quickly, immediately reduce the charging power or suspend charging, and send an alarm message to the user through the indicator light or communication module. This not only reduces the safety risks such as increased resistance and heat caused by connection problems, but also improves the user's right to know and safety of the charging process, making it easier for users to take timely measures to solve connection problems.

[0027] 5. Improve overall safety and reliability The invention adopts multiple technical means such as multi-IO precise control, abnormal situation detection and protection, and connection status monitoring to cooperate with each other to form a complete safety protection system. It ensures the safe operation of the charger from multiple dimensions, greatly reduces the probability of safety accidents, and improves the overall reliability and stability of the charger.

[0028] The application of automotive-grade high-performance microprocessors further enhances the performance and stability of the controller, ensuring that it can accurately and quickly process various signals and abnormal situations in complex working environments, providing solid core support for the safe and efficient operation of the charger.

[0029] Of course, the LCD driver chip can be other models, and the number and model of the corresponding group A MOS units and group B MOS units need to be adjusted.

[0030] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A charger voltage safety output interface device based on multi-IO precise control, which includes a power input module and a voltage output interface, and is characterized by: The output end of the power input module is connected to the source of PMOS1, the drain of PMOS1 is connected to the source of PMOS2, and the drain of PMOS2 is connected to the voltage output interface; the voltage output interface is connected to a voltage acquisition circuit and a current acquisition circuit, the voltage acquisition circuit and the current acquisition circuit are connected to a controller, and the controller is connected to an LCD driver chip; the voltage acquisition circuit and the current acquisition circuit are connected to GND, the gate of PMOS1 and the gate of PMOS2 are respectively connected to MOS units, the MOS units are connected to GND, the MOS units include at least two MOSs connected in series, the MOSs are NMOS or PMOS, if the frontmost MOS S is NMOS, the drain of the NMOS is connected to PMOS1 or PMOS2, if the front-end MOS is PMOS, the source of the PMOS is connected to PMOS1 or PMOS2, if the rear-end MOS is NMOS, the source of the NMOS is connected to GND, if the rear-end MOS is PMOS, the drain of the PMOS is connected to GND, if the middle MOS is NMOS, the drain of the NMOS is connected to the previous stage MOS and the source is connected to the next stage MOS, if the middle MOS is PMOS, the source of the PMOS is connected to the previous stage MOS and the drain is connected to the next stage MOS; the LCD driver chip is connected to the gates of each stage MOS of the two groups of MOS units.

2. The charger voltage safety output interface device based on multi-IO precise control according to claim 1, characterized in that: The MOS unit connected to the PMOS1 includes four NMOSs, and the MOS unit connected to the PMOS2 includes two NMOSs and two PMOSs, and the two PMOSs are respectively located at both sides of the two NMOSs.

3. The charger voltage safety output interface device based on multi-IO precise control according to claim 2, characterized in that: NMOS1 is connected between the PMOS1 and the MOS unit, the drain of the NMOS1 is connected to the gate of the PMOS1, and the source is connected to the MOS unit; NMOS2 is connected between the PMOS2 and the MOS unit, the drain of the NMOS2 is connected to the gate of the PMOS2, and the source is connected to the MOS unit; the voltage acquisition circuit includes a voltage-dividing sampling resistor composed of two resistors connected in series and a first operational amplifier, the voltage-dividing sampling resistor is connected to the first operational amplifier, and the first operational amplifier is connected to the gate of the NMOS1; the current acquisition circuit includes a current sampling resistor and a second operational amplifier connected to each other, and the second operational amplifier is connected to the gate of the NMOS2.

4. The charger voltage safety output interface device based on multi-IO precise control according to any one of claims 1 to 3, characterized in that: A pull-up resistor is connected between the gate and source of the PMOS1; and a pull-up resistor is connected between the gate and source of the PMOS2.

5. The charger voltage safety output interface device based on multi-IO precise control according to claim 1, characterized in that: The controller is connected to a power input module.

Images