CN118544844A - A new energy vehicle battery charging control system - Google Patents

Abstract

The present invention relates to the technical field of new energy vehicles, and provides a new energy vehicle battery charging control system, comprising an input EMC module, a rectifier module, a drive output module, a drive control module and a power factor adjustment module, wherein the input end of the input EMC module is suitable for connecting an external AC power supply, and the output end is connected to the input end of the rectifier module, the input end of the power factor adjustment module is connected to the output end of the rectifier module, and the output end is connected to the input end of the drive output module to perform voltage boosting and improve the circuit power factor, the controlled end of the drive output module is connected to the drive control module, and the output end is connected to a vehicle battery to charge the vehicle battery under the control of the drive control module; the present invention can effectively improve the energy utilization efficiency of charging new energy vehicle batteries.

Description

A new energy vehicle battery charging control system

Technical Field

The present invention relates to the technical field of new energy vehicles, and in particular to a new energy vehicle battery charging control system.

Background Art

The new energy on-board charger is an energy conversion device fixedly installed on the electric vehicle to control and adjust the charging of the vehicle's power battery. The new energy on-board charger is equipped with a car battery charging control circuit, which has the ability to safely and automatically charge the electric vehicle's power battery. It dynamically adjusts the charging current and voltage parameters, converts civilian AC power into DC power, and charges the power battery. The existing car battery charging control circuit is generally composed of a power supply part and a charging drive control part. The power supply part converts AC power into DC power, and the charging drive control part controls the battery output charging. However, when the existing charging control circuit rectifies and converts the AC power to output, due to the load impedance in the circuit, the charging power factor is low and the energy utilization rate is poor.

Summary of the invention

The problem solved by the present invention is how to provide a new energy vehicle battery charging control system with higher electric energy utilization efficiency.

In order to solve the above problems, the present invention provides a new energy vehicle battery charging control system, comprising: an input EMC module, a rectifier module, a drive output module, a drive control module and a power factor adjustment module, wherein the input end of the input EMC module is suitable for connecting an external AC power supply, and the output end is connected to the input end of the rectifier module, the input end of the power factor adjustment module is connected to the output end of the rectifier module, and the output end is connected to the input end of the drive output module to boost the voltage and improve the circuit power factor, the controlled end of the drive output module is connected to the drive control module, and the output end is connected to the vehicle battery, so as to charge the vehicle battery under the control of the drive control module.

Furthermore, the rectifier module includes a first rectifier circuit, a second rectifier circuit and a conversion power supply circuit. The input ends of the first and second rectifier circuits are respectively connected to the output ends of the input EMC module, the output end of the first rectifier circuit is connected to the input end of the power factor adjustment module to supply power to the main charging circuit, the output end of the second rectifier circuit is connected to the input end of the conversion power supply circuit, and the output end of the conversion power supply circuit is respectively connected to the power supply ends of the drive control module and the power factor adjustment module to provide working power for the chips in the drive control module and the power factor adjustment module.

Further, the power factor adjustment module includes a first PFC driver chip, a first differential amplifier circuit, a first MOS tube, a first inductor, a first diode, a first charging capacitor group, a current feedback circuit and a voltage feedback circuit. The PWM output end of the first PFC driver chip is connected to the gate of the first MOS tube via the first differential amplifier circuit. The source of the first MOS tube is grounded, and the drain is connected to the second end of the first inductor. The first end of the first inductor is connected to the output end of the first rectifier circuit. The first end of the first diode is connected to the second end of the first inductor, and the second end is connected to the input end of the drive output module. The first end of the first charging capacitor group is connected to the second end of the first diode, and the second end is grounded. The input end of the current feedback circuit is connected to the source of the first MOS tube, and the output end is connected to the first PFC driver chip. The input end of the voltage feedback circuit is connected to the second end of the first diode, and the output end is connected to the first PFC driver chip.

Furthermore, the power factor adjustment module also includes a peak absorption circuit and a coil bypass circuit, the peak absorption circuit is connected to the gate of the first MOS tube, the first end of the coil bypass circuit is connected to the first end of the first inductor, and the second end is connected to the second end of the first diode.

Furthermore, the drive output module includes a drive circuit and a first transformer, the input end of the drive circuit is connected to the output end of the power factor adjustment module, the controlled end is connected to the drive control module, the output end is connected to the main winding of the first transformer, the secondary winding of the first transformer charges the vehicle battery via a first rectifier output circuit, and the auxiliary winding of the first transformer is connected to the drive control module via a second rectifier output circuit.

Furthermore, the driving circuit includes a second differential amplifier circuit, a third differential amplifier circuit, a second MOS tube, a third MOS tube and a second inductor, the gate of the second MOS tube is connected to the first control end of the driving control module via the second differential amplifier circuit, the drain is connected to the output end of the power factor adjustment module, and the source is connected to the first end of the second inductor, the gate of the third MOS tube is connected to the second control end of the driving control module via the third differential amplifier circuit, the drain is connected to the first end of the second inductor, the source is grounded, the second end of the second inductor is connected to the first end of the main winding of the first transformer, and the second end of the main winding of the first transformer is grounded.

Furthermore, the drive control module includes a first output control chip, a voltage-stabilized power supply circuit, a control loop soft start circuit and a delay circuit. The input end of the voltage-stabilized power supply circuit is connected to the conversion power supply circuit, and the output end is connected to the first output control chip. The input end of the delay circuit is connected to the delay signal end of the first output control chip through a delay capacitor, and the delay capacitor is used to control the delay duration. The first input end of the control loop soft start circuit is connected to the voltage-stabilized power supply circuit, the second input end is connected to the second rectifier output circuit, and the output end is connected to the soft start end of the first output control chip.

Furthermore, the drive control module also includes a constant current loop control circuit and a constant voltage loop control circuit, the constant current loop control circuit includes a first current detection amplifier, a first comparator, a first transistor, a first optocoupler and a first operational amplifier, a current sampling resistor is connected between the two input ends of the first current detection amplifier, the sampling resistor is arranged between the negative output end of the first rectifier output circuit and the negative pole of the vehicle battery, the output end of the first current detection amplifier is respectively connected to the positive input end of the first operational amplifier and the first comparator, the negative pole of the first comparator is connected to the reference voltage, the output end is connected to the base of the first transistor, the emitter of the first transistor is connected to the first operational amplifier, the collector is connected to the transmitting end of the first optocoupler, and the receiving end of the first optocoupler is connected to the first output control chip.

Furthermore, the constant voltage ring control circuit includes a constant voltage control chip, a follower circuit, a comparison conversion circuit and a second optocoupler. The two input ends of the constant voltage control chip are respectively connected to the two ends of the second diode through a group of voltage divider circuits, the anode of the second diode is connected to the positive output end of the first rectifier output circuit, and the cathode is connected to the positive pole of the car battery. The output end of the constant voltage control chip is connected to the input end of the follower circuit, the output end of the follower circuit is connected to the input end of the comparison conversion circuit, the output end of the comparison conversion circuit is connected to the transmitting end of the second optocoupler, and the receiving end of the second optocoupler is connected to the first output control chip.

Furthermore, the automobile battery charging control circuit also includes a main soft start circuit and a first thermistor. The output end of the input EMC module is connected to the input end of the rectifier module through the first thermistor. The main soft start circuit includes a second transistor, a first relay and a third diode. The base of the second transistor is connected to the output end of the delay circuit, the emitter is grounded, and the base is connected to the working power supply through the coil of the first relay. The third diode is connected in parallel to the two ends of the coil of the first relay, and the normally open contacts of the first relay are connected in parallel to the two ends of the first thermistor.

Compared with the prior art, the present invention has the following beneficial effects:

When in use, the external AC power supply is input into the rectifier module through the input EMC module. The input EMC module can improve the anti-interference ability of the power supply. The power factor adjustment module can adjust the rectified power supply to make the power current output to the drive output module continuous, improve its voltage and current phase, and thus make the active power ratio of charging the car battery higher. When the drive output module charges the car battery under the control of the drive control module, the power factor is higher, which effectively improves the energy utilization efficiency of charging the new energy vehicle battery.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic diagram of the overall principle structure of an embodiment of the present invention;

FIG2 is a schematic diagram of the principle structure of a rectifier module according to an embodiment of the present invention;

FIG3 is a schematic diagram of the principle structure of a power factor adjustment module according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the principle structure of a drive control module according to an embodiment of the present invention.

Description of reference numerals:

1- input EMC module; 2- rectifier module; 21- first rectifier circuit; 22- second rectifier circuit; 23- conversion power supply circuit; 3- power factor adjustment module; 4- drive output module; 5- drive control module; 6- main soft start circuit; 51- first output control chip; 52- voltage stabilizing power supply circuit; 53- control loop soft start circuit; 54- delay circuit; 55- constant current loop control circuit; 56- constant voltage loop control circuit.

DETAILED DESCRIPTION

In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

In the description of this specification, the description with reference to the terms "embodiment", "one embodiment" and "one implementation" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or implementation are included in at least one embodiment or implementation of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or implementation. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or implementations in a suitable manner.

As shown in Figure 1, the present invention provides a new energy vehicle battery charging control system, including: an input EMC module 1, a rectifier module 2, a drive output module 4, a drive control module 5 and a power factor adjustment module 3, the input end of the input EMC module 1 is suitable for connecting an external AC power supply, and the output end is connected to the input end of the rectifier module 2, the input end of the power factor adjustment module 3 is connected to the output end of the rectifier module 2, and the output end is connected to the input end of the drive output module 4 to boost and improve the circuit power factor, the controlled end of the drive output module 4 is connected to the drive control module 5, and the output end is connected to the vehicle battery, so as to charge the vehicle battery under the control of the drive control module 5.

It should be noted that, when in use, the external AC power supply is input into the rectifier module 2 via the input EMC module 1. The input EMC module 1 can improve the anti-interference ability of the power supply. The power factor adjustment module 3 can adjust the rectified power supply to make the power supply current output to the drive output module 4 continuous, improve its voltage and current phase, and thus make the active power ratio of charging the car battery higher. When the drive output module 4 charges the car battery under the control of the drive control module 5, the power factor is higher, which effectively improves the energy utilization efficiency of charging the new energy vehicle battery. EMC refers to electromagnetic compatibility; the input EMC module 1 can improve the anti-electromagnetic interference ability. As shown in Figure 3, the input EMC module 1 is composed of capacitor C1, common mode inductor L1, capacitor C2 and common mode inductor L2, which can effectively ensure the stability of the input AC power supply.

In one embodiment of the present invention, the rectifier module 2 includes a first rectifier circuit 21, a second rectifier circuit 22 and a conversion power supply circuit 23. The input ends of the first and second rectifier circuits 22 are respectively connected to the output ends of the input EMC module 1. The output end of the first rectifier circuit 21 is connected to the input end of the power factor adjustment module 3 to supply power to the main charging circuit. The output end of the second rectifier circuit 22 is connected to the input end of the conversion power supply circuit 23. The output end of the conversion power supply circuit 23 is respectively connected to the power supply ends of the drive control module 5 and the power factor adjustment module 3 to provide working power for the chips in the drive control module 5 and the power factor adjustment module 3.

It should be noted that, as shown in FIG2 , when the system is connected to external AC mains, the AC input power is input to the rectifier module 2, and the first rectifier circuit 21 rectifies the AC input power and outputs it to the main charging circuit. At this time, the drive control module 5 and the power factor adjustment module 3 are not powered on, and the second rectifier circuit 22 and the conversion power supply circuit 23 are required to provide power for them. After the chips in the drive control module 5 and the power factor adjustment module 3 are powered on, the drive output module 4 is controlled to charge the car battery, thereby realizing orderly power supply and ensuring the stability and controllability of the charging process of the car battery. In FIG3 , the rectifier bridge BR1 is the first rectifier circuit 21, and the diodes D2 and D4 constitute the second rectifier circuit 22. After the rectified power supply is divided, a DC voltage of 13.7V is formed, which is used to provide the chips in the drive control module 5 and the power factor adjustment module 3 for use.

In the present invention, the connection relationship of each circuit node in Figures 3 and 4 is as follows: T4 and T8 in Figure 3 are connected to T14 in Figure 4, and T6 in Figure 3 is connected to T13 in Figure 4 to realize power supply of 13.7V voltage; in addition, T12 in Figure 3 is connected to T3 in Figure 4, both of which are ground terminals, T37 in Figure 3 is connected to T4 in Figure 4, T5 in Figure 3 is connected to T17 in Figure 4, T10 in Figure 3 is connected to T100 in Figure 4, T38 in Figure 3 is connected to T101 in Figure 4, T11 in Figure 3 is connected to T6 in Figure 4, T46 in Figure 3 is connected to T108 in Figure 4, T30 in Figure 3 is connected to T32 in Figure 4, T29 in Figure 3 is connected to T33 in Figure 4, T28 in Figure 3 is connected to T31 in Figure 4, T26 in Figure 3 is connected to T34 in Figure 4, and T27 in Figure 3 is connected to T24 in Figure 4.

In one embodiment of the present invention, the power factor adjustment module 3 includes a first PFC driver chip, a first differential amplifier circuit, a first MOS transistor, a first inductor, a first diode, a first charging capacitor group, a current feedback circuit and a voltage feedback circuit. The PWM output end of the first PFC driver chip is connected to the gate of the first MOS transistor via the first differential amplifier circuit. The source of the first MOS transistor is grounded, and the drain is connected to the second end of the first inductor. The first end of the first inductor is connected to the output end of the first rectifier circuit 21. The first end of the first diode is connected to the second end of the first inductor, and the second end is connected to the input end of the drive output module 4. The first end of the first charging capacitor group is connected to the second end of the first diode, and the second end is grounded. The input end of the current feedback circuit is connected to the source of the first MOS transistor, and the output end is connected to the first PFC driver chip. The input end of the voltage feedback circuit is connected to the second end of the first diode, and the output end is connected to the first PFC driver chip.

It should be noted that PFC refers to power factor correction. As shown in FIG3 , chip U1 is a first PFC driver chip, and its model can be ICE3PCS01. After the first PFC driver chip is powered on at the power supply end, it will send out a PWM signal according to the internal setting. Transistors Q104 and Q110 form a differential amplifier circuit, which is used to amplify and isolate the above PWM signal, and reduce the influence of ambient temperature and the like on the signal, so as to ensure the accuracy of power factor correction. The first MOS tube Q6 switches under the control of the PWM signal to charge and discharge the first inductor L3, thereby solving the problem that in the process of AC power being rectified and output to the capacitor for energy storage, there is only voltage but no current in the circuit for a short time after the AC peak, resulting in inconsistent voltage and current phases. When in use, the first MOS tube Q6 is closed, and the rectified power supply is output to the first charging capacitor group through the first MOS tube D5 and the first inductor L3. The first charging capacitor group is composed of capacitors C6, C44, and C20 connected in parallel, and is used for energy storage. The terminal voltage of the first charging capacitor group is the output voltage of the drive output module 4. At the peak After the value is reached, the first MOS tube Q6 is turned on and the inductor is discharged, ensuring that there is always current in the loop, thereby increasing the effective power output; in the current feedback circuit, the resistor RD1 is the output current limiting resistor, and the output current information is transmitted to the first PFC driver chip through D13; in the voltage feedback circuit, the resistors R36, R35, R25, R44, and R46 form an output voltage adjustment circuit through voltage division collection, and transmit the output voltage information to the first PFC driver chip. The first PFC driver chip adjusts the output voltage according to the output voltage and current. The PWM signal of the first MOS tube Q6 is used to adjust the switching frequency and duration of the first MOS tube Q6, and the effective power output is continuously improved, so that the power factor is continuously corrected to reach the optimal point; in addition, in the voltage feedback circuit, resistors R22, R19, R13, R20, and R28 form a PFC output voltage protection loop. When the output is over-voltage, it will be transmitted to the first PFC driver chip. Resistors R43, R21, R32, R33, and R23 are output voltage protection circuits. When the output is over-voltage, it will be transmitted to the drive control module 5 to perform over-voltage protection in time when over-voltage occurs.

In one embodiment of the present invention, the power factor adjustment module 3 also includes a peak absorption circuit and a coil bypass circuit, the peak absorption circuit is connected to the gate of the first MOS tube, the first end of the coil bypass circuit is connected to the first end of the first inductor, and the second end is connected to the second end of the first diode.

It should be noted that, as shown in FIG3 , the resistor R8 is used for absorbing the peak value of the G pole of the first MOS tube Q6, and together with the diode D8, it can effectively protect the first MOS tube Q6 from the peak voltage during switching; when the system is just connected to the external power supply, at the moment of startup, the current of the first inductor L3 of the PFC loop is relatively large because the first charging capacitor group needs to be charged. If the moment when the power switch is turned on is at the maximum value of the sine wave, the PFC inductor L may be magnetically saturated during the charging process of the capacitor, thereby affecting the operation of the PFC circuit. The diodes D11 and D12 are connected in parallel and arranged at the first inductor L3 as a coil bypass circuit, which can make the current pass through the bypass when the power is turned on, and provide a charging path for the capacitor when the output voltage of the PFC loop is lower than the input voltage, thereby preventing the danger caused by the magnetic saturation of the first inductor L3 to the first MOS tube Q6, and at the same time reducing the burden of the first inductor L3, playing a protective role, and effectively ensuring the stable operation of the power factor adjustment module 3.

In one embodiment of the present invention, the drive output module 4 includes a drive circuit and a first transformer, the input end of the drive circuit is connected to the output end of the power factor adjustment module 3, the controlled end is connected to the drive control module 5, and the output end is connected to the main winding of the first transformer. The secondary winding of the first transformer charges the automobile battery via a first rectifier output circuit, and the auxiliary winding of the first transformer is connected to the drive control module 5 via a second rectifier output circuit.

It should be noted that, as shown in FIG3 , the drive circuit, under the control of the drive control module 5, can adjust the charging voltage and current of the battery, and convert the regulated power supply through the first transformer L4, and then rectify it through the first rectifier output circuit to charge the vehicle battery. The output of the auxiliary winding of the first transformer is used to power the soft start of the drive control module 5 after the drive output module 4 works.

In one embodiment of the present invention, the driving circuit includes a second differential amplifier circuit, a third differential amplifier circuit, a second MOS transistor, a third MOS transistor and a second inductor. The gate of the second MOS transistor is connected to the first control end of the driving control module 5 via the second differential amplifier circuit, the drain is connected to the output end of the power factor adjustment module 3, and the source is connected to the first end of the second inductor. The gate of the third MOS transistor is connected to the second control end of the driving control module 5 via the third differential amplifier circuit, the drain is connected to the first end of the second inductor, the source is grounded, the second end of the second inductor is connected to the first end of the main winding of the first transformer, and the second end of the main winding of the first transformer is grounded.

It should be noted that, as shown in FIG3 , the gates of the second MOS tube Q3 and the third MOS tube Q4 are respectively connected to the drive control module 5. The second MOS tube Q3 and the third MOS tube Q4 switch the conduction state under the control of the PWM drive signal of the drive control module 5, and generate AC power for the main winding of the first transformer L4, and then the secondary winding of the first transformer L4 generates a charging power supply and charges the vehicle battery after rectification. The drive control module 5 changes the duty cycle of the PWM drive signal, and can adjust the conduction frequency and duration of the second MOS tube Q3 and the third MOS tube Q4, so that the input power supply on the main winding side of the first transformer L4 changes, thereby changing the vehicle battery. The charging voltage and current of the battery, the second inductor L4 has the function of storing energy and improving the power curve. In this way, the drive control module 5 can take different outputs according to the state of the battery to meet the battery charging needs. At the same time, during the output, the charging voltage and current of the car battery can be stabilized through adjustment; the transistors Q75 and Q77 form a second differential amplifier circuit, and the transistors Q76 and Q80 form a third differential amplifier circuit. The second differential amplifier circuit and the third differential amplifier circuit are used to improve the stability and accuracy of the PWM drive signal output by the drive control module 5 to the second MOS tube Q3 and the third MOS tube Q4, thereby ensuring the precise control of the battery charging power supply.

In one embodiment of the present invention, the drive control module 5 includes a first output control chip 51, a voltage-stabilized power supply circuit 52, a control loop soft start circuit 53 and a delay circuit 54. The input end of the voltage-stabilized power supply circuit 52 is connected to the conversion power supply circuit 23, and the output end is connected to the first output control chip 51. The input end of the delay circuit 54 is connected to the delay signal end of the first output control chip 51 through a delay capacitor, and the delay capacitor is used to control the delay duration. The first input end of the control loop soft start circuit 53 is connected to the voltage-stabilized power supply circuit 52, the second input end is connected to the second rectifier output circuit, and the output end is connected to the soft start end of the first output control chip 51.

It should be noted that, as shown in FIG. 4 , the chip U6 is the first output control chip 51, and its model can be L6599D. The voltage-stabilized power supply circuit 52 is arranged at the power supply end of the first output control chip 51, and its input end is connected to the conversion power supply circuit 23. The three transistors Q7, Q2, Q29 and the resistors R91, R120, R93, R120 and the capacitors C37, C18, C51, C1 in the voltage-stabilized power supply circuit 52 form a half-bridge power management circuit to provide a stable power supply for the chip U612 pin; in the delay circuit 54, the three transistors of the chip U6 The pin is a delay pin, which is connected to a capacitor C45. By adjusting the size of the capacitor C45, the delay duration of the output of the first output control chip 51 through the delay circuit 54 can be changed; when the control loop soft start circuit 53 is powered on, the 13.7V voltage of the conversion power supply circuit 23 is converted into a 5V voltage via the chip U2 as the voltage of the chip U6 soft start pin. During charging, the auxiliary winding of the first transformer generates a voltage which is compared and amplified by the amplifier U7B and output as the power supply for the control loop soft start circuit 53, thereby realizing orderly power supply to the soft start end of the chip U6.

In one embodiment of the present invention, the drive control module 5 also includes a constant current loop control circuit 55 and a constant voltage loop control circuit 56, the constant current loop control circuit 55 includes a first current detection amplifier, a first comparator, a first transistor, a first optocoupler and a first operational amplifier, a current sampling resistor is connected between the two input ends of the first current detection amplifier, the sampling resistor is arranged between the negative output end of the first rectifier output circuit and the negative pole of the car battery, the output end of the first current detection amplifier is respectively connected to the positive input end of the first operational amplifier and the first comparator, the negative pole of the first comparator is connected to the reference voltage, the output end is connected to the base of the first transistor, the emitter of the first transistor is connected to the first operational amplifier, the collector is connected to the transmitting end of the first optocoupler, and the receiving end of the first optocoupler is connected to the first output control chip 51.

It should be noted that the constant current loop control circuit 55 and the constant voltage loop control circuit 56 are used for constant current or constant voltage control of the car battery to meet the needs of the car battery at various stages. The constant current loop control circuit 55 and the constant voltage loop control circuit 56 respectively collect the output current and voltage of the rechargeable battery, and perform a reference difference operation on them, and pass the voltage and current deviation values to the first output control chip 51. The first output control chip 51 adjusts the output PWM signal to change the charging power supply to achieve constant current or constant voltage control. As shown in Figure 3, the two ends of the sampling resistor R109 are respectively connected to the negative output end of the first rectifier output circuit and the negative electrode of the car battery. As shown in Figure 4, the first comparator is composed of the operational amplifier U9B and its The first current detection amplifier U3 is composed of connecting elements, and the current sampling resistor R109 is connected between the two input ends of the first current detection amplifier U3. The voltage across the current sampling resistor R109 is subjected to a difference operation. The first path of the difference signal is output to the first operational amplifier U141B, and the second path is compared with the reference voltage by the first comparator to generate a deviation voltage which is input to the base of the first transistor Q33. Under the action of the first transistor Q33, the first operational amplifier U141B and its loop elements, the deviation voltage generates a current signal on the collector-emitter of the first transistor Q33. The signal flows through the first optical coupler P8 and is isolated by photoelectric conversion. It is received by the first output control chip 51, and then the charging power supply is adjusted to change the current deviation value to achieve constant current charging.

In one embodiment of the present invention, the constant voltage ring control circuit 56 includes a constant voltage control chip, a follower circuit, a comparison conversion circuit and a second optocoupler. The two input ends of the constant voltage control chip are respectively connected to the two ends of the second diode through a group of voltage divider circuits, the anode of the second diode is connected to the positive output end of the first rectifier output circuit, and the cathode is connected to the positive electrode of the car battery. The output end of the constant voltage control chip is connected to the input end of the follower circuit, the output end of the follower circuit is connected to the input end of the comparison conversion circuit, the output end of the comparison conversion circuit is connected to the transmitting end of the second optocoupler, and the receiving end of the second optocoupler is connected to the first output control chip 51.

It should be noted that, as shown in Figure 4 and Figure 3, resistors R42, R56, R48, and R45 use a voltage division collection method to form a first group of voltage division circuits, and resistors R60, R61, R63, R57, and R62 use a voltage division collection method to form a second group of voltage division circuits. The constant voltage control chip calculates the output voltage signal, and the follower circuit is composed of an op amp U140A and its connected resistors and capacitors. The comparison conversion circuit is composed of an op amp U140B and its connected resistors and capacitors. The follower circuit can improve the accuracy of the output voltage signal, and the comparison conversion circuit compares and outputs a deviation signal, which is transmitted to the first output control chip 51 by the second optocoupler P2, thereby adjusting the charging power supply, changing the output voltage, and realizing a constant voltage charging control method when necessary.

In one embodiment of the present invention, the automobile battery charging control circuit further includes a main soft start circuit 6 and a first thermistor. The output end of the input EMC module 1 is connected to the input end of the rectifier module 2 through the first thermistor. The main soft start circuit 6 includes a second transistor, a first relay and a third diode. The base of the second transistor is connected to the output end of the delay circuit 54, the emitter is grounded, and the base is connected to the working power supply through the coil of the first relay. The third diode is connected in parallel to the two ends of the coil of the first relay, and the normally open contact of the first relay is connected in parallel to the two ends of the first thermistor.

It should be noted that, since a large current will be generated when the external AC power is first powered on and connected to the load, it may cause damage to the components in the circuit and the car battery. Therefore, as shown in Figure 3, the first thermistor RT1 is in a high resistance state when powered on, which can effectively reduce the current of the main charging circuit and achieve protection. After more than 10 seconds after power-on, when the circuit charging is stable, the first thermistor RT1 can be short-circuited to reduce losses and improve the stability of charging control. At this time, the first output control chip 51 turns on the second transistor Q1 through the delay signal of the delay circuit, and then the first relay K1 is attracted, and the first thermistor RT1 connected in parallel is connected to the open point switch, and the AC power is input to the rectifier module 2 through the first relay K1 to achieve soft starting of the main circuit, effectively protecting the stable operation of the circuit. The second transistor D6 can absorb the inductive current when the first relay K1 is switched on, protect the second transistor Q1, and achieve stable control.

Although the disclosure is disclosed as above, the protection scope of the disclosure is not limited thereto. Those skilled in the art may make various changes and modifications without departing from the spirit and scope of the disclosure, and these changes and modifications will fall within the protection scope of the present invention.

Claims (10)

1. A new energy automobile battery charge control system, characterized by comprising: input EMC module (1), rectifier module (2), drive output module (4), drive control module (5) and power factor adjustment module (3), the input of input EMC module (1) is suitable for connecting outside alternating current power supply, the output with the input of rectifier module (2) is connected, the input of power factor adjustment module (3) with the output of rectifier module (2) is connected, the output with the input of drive output module (4) is connected, in order to boost and improve circuit power factor, the controlled end of drive output module (4) with drive control module (5) are connected, the output is connected with car battery, in order to be in under the control of drive control module (5) charge car battery.

2. The battery charging control system of the new energy automobile according to claim 1, wherein the rectifying module (2) comprises a first rectifying circuit (21), a second rectifying circuit (22) and a conversion power supply circuit (23), the input ends of the first rectifying circuit (22) and the second rectifying circuit are respectively connected with the output ends of the input EMC module (1), the output end of the first rectifying circuit (21) is connected with the input end of the power factor adjusting module (3) to supply power for a charging main circuit, the output end of the second rectifying circuit (22) is connected with the input end of the conversion power supply circuit (23), and the output end of the conversion power supply circuit (23) is respectively connected with the power supply ends of the driving control module (5) and the power factor adjusting module (3) to provide working power for chips in the driving control module (5) and the power factor adjusting module (3).

3. The new energy automobile battery charging control system according to claim 2, wherein the power factor regulating module (3) comprises a first PFC driving chip, a first differential amplifying circuit, a first MOS transistor, a first inductor, a first diode, a first charging capacitor group, a current feedback circuit and a voltage feedback circuit, wherein a PWM output end of the first PFC driving chip is connected to a gate of the first MOS transistor through the first differential amplifying circuit, a source electrode of the first MOS transistor is grounded, a drain electrode of the first PFC driving chip is connected to a second end of the first inductor, a first end of the first inductor is connected to an output end of the first rectifying circuit (21), a first end of the first diode is connected to a second end of the first inductor, a second end of the first PFC diode is connected to an input end of the driving output module (4), a first end of the first charging capacitor group is connected to a second end of the first diode, a second end of the current feedback circuit is grounded, an input end of the current feedback circuit is connected to a gate of the first MOS transistor, a first end of the PFC diode is connected to a source electrode of the first PFC output end of the first PFC transistor, and a first diode is connected to an input end of the first diode.

4. The new energy automobile battery charging control system according to claim 3, wherein the power factor adjusting module (3) further comprises a peak value absorption circuit and a coil bypass circuit, the peak value absorption circuit is connected with the gate of the first MOS transistor, a first end of the coil bypass circuit is connected with a first end of the first inductor, and a second end of the coil bypass circuit is connected with a second end of the first diode.

5. The new energy automobile battery charging control system according to claim 2, wherein the driving output module (4) comprises a driving circuit and a first transformer, the input end of the driving circuit is connected with the output end of the power factor adjusting module (3), the controlled end is connected with the driving control module (5), the output end is connected with the main winding of the first transformer, the secondary winding of the first transformer charges the automobile battery through the first rectifying output circuit, and the auxiliary winding of the first transformer is connected with the driving control module (5) through the second rectifying output circuit.

6. The new energy automobile battery charging control system according to claim 5, wherein the driving circuit comprises a second differential amplifying circuit, a third differential amplifying circuit, a second MOS tube, a third MOS tube and a second inductor, wherein a grid electrode of the second MOS tube is connected with a first control end of the driving control module (5) through the second differential amplifying circuit, a drain electrode of the second MOS tube is connected with an output end of the power factor adjusting module (3), a source electrode of the second MOS tube is connected with a first end of the second inductor, a grid electrode of the third MOS tube is connected with a second control end of the driving control module (5) through the third differential amplifying circuit, a drain electrode of the third MOS tube is connected with a first end of the second inductor, a source electrode of the second MOS tube is grounded, a second end of the second MOS tube is connected with a first end of a main winding of the first transformer, and a second end of the main winding of the first transformer is grounded.

7. The battery charging control system of a new energy automobile according to claim 5, wherein the driving control module (5) comprises a first output control chip (51), a voltage stabilizing power supply circuit (52), a control loop soft start circuit (53) and a delay circuit (54), wherein an input end of the voltage stabilizing power supply circuit (52) is connected with the switching power supply circuit (23), an output end of the voltage stabilizing power supply circuit is connected with the first output control chip (51), an input end of the delay circuit (54) is connected with a delay signal end of the first output control chip (51) through a delay capacitor, the delay capacitor is used for controlling delay time length, a first input end of the control loop soft start circuit (53) is connected with the voltage stabilizing power supply circuit (52), a second input end of the control loop soft start circuit is connected with the second rectifying output circuit, and an output end of the control loop soft start circuit is connected with the first output control chip (51).

8. The new energy automobile battery charging control system according to claim 7, wherein the driving control module (5) further comprises a constant current loop control circuit (55) and a constant voltage loop control circuit (56), the constant current loop control circuit (55) comprises a first current detection amplifier, a first comparator, a first triode, a first optocoupler and a first operational amplifier, a current sampling resistor is connected between two input ends of the first current detection amplifier, the sampling resistor is arranged between a negative output end of the first rectifying output circuit and a negative electrode of the automobile battery, an output end of the first current detection amplifier is connected with positive input ends of the first operational amplifier and the first comparator respectively, a negative electrode of the first comparator is connected with a reference voltage, an output end of the first comparator is connected with a base electrode of the first triode, an emitter electrode of the first triode is connected with the first operational amplifier, a collector electrode of the first optocoupler is connected with a transmitting end of the first optocoupler, and a receiving end of the first optocoupler is connected with the first output control chip (51).

9. The charging control system of a new energy automobile battery according to claim 8, wherein the constant voltage loop control circuit (56) comprises a constant voltage control chip, a follower circuit, a comparison and conversion circuit and a second optocoupler, two input ends of the constant voltage control chip are respectively connected with two ends of a second diode through a group of voltage dividing circuits, an anode of the second diode is connected with a positive output end of the first rectification output circuit, a cathode of the second diode is connected with an anode of the automobile battery, an output end of the constant voltage control chip is connected with an input end of the follower circuit, an output end of the follower circuit is connected with an input end of the comparison and conversion circuit, an output end of the comparison and conversion circuit is connected with a transmitting end of the second optocoupler, and a receiving end of the second optocoupler is connected with the first output control chip (51).

10. The new energy automobile battery charging control system according to claim 7, further comprising a main soft start circuit (6) and a first thermistor, wherein the output end of the input EMC module (1) is connected with the input end of the rectifying module (2) through the first thermistor, the main soft start circuit (6) comprises a second triode, a first relay and a third diode, the base electrode of the second triode is connected with the output end of the delay circuit (54), the emitter is grounded, the base electrode is connected with a working power supply through the coil of the first relay, the third diode is connected in parallel with two ends of the coil of the first relay, and the normally open contact of the first relay is connected in parallel with two ends of the first thermistor.