CN210724567U

CN210724567U - Automobile DC-DC converter circuit

Info

Publication number: CN210724567U
Application number: CN201922027122.0U
Authority: CN
Inventors: 王西前; 黄学路; 桂春汛; 陈晓华
Original assignee: Shanghai Fengtian Electronics Co ltd
Current assignee: Shanghai Fengtian Electronics Co ltd
Priority date: 2019-11-20
Filing date: 2019-11-20
Publication date: 2020-06-09
Anticipated expiration: 2029-11-20

Abstract

The utility model discloses an automobile DC-DC converter circuit, which comprises a micro control unit, a passive crystal oscillator, a CAN chip, a first drive, a second drive, a 5v power supply circuit, a drive power supply circuit and a Buck-Boost bidirectional conversion topology circuit, wherein the micro control unit is connected with the passive crystal oscillator, the CAN chip, the first drive and the second drive; the input end of the 5v power supply circuit is connected with KL15 voltage signals and KL30 voltage signals, and the output end of the 5v power supply circuit is connected with the micro control unit and the CAN chip; the input end of the power supply of the driving power supply is connected with a KL30 voltage signal, and the output end of the power supply of the driving power supply is connected with the first driving unit and the second driving unit; the first drive and the second drive are both connected with a Buck-Boost bidirectional conversion topology circuit; the utility model provides a circuit structure is simple, and the voltage transformation ratio in the circuit can step up but the step-down, the in-service use of being convenient for.

Description

Automobile DC-DC converter circuit

Technical Field

The utility model relates to an automobile converter circuit technical field specifically is an automobile DC-DC converter circuit.

Background

The automobile 48V-12V DC/DC converter, the BSG motor and the 48V lithium battery form a 48V system. BSG energy recovery can be supplied to 12V loads such as ignition, air conditioning, lighting, information entertainment, audio and the like through a 48V-12V DC/DC converter. Meanwhile, when the automobile starts and accelerates, the 12V side drives the BSG motor to provide assistance for the engine through the 48V-12V DC/DC converter.

Under the current 12V system, the application of the start-stop technology reaches the limit (the power is 3kW), and other energy-saving technologies with high power consumption cannot be integrated. Under the condition of a 48V system, the oil-saving effect of 10-15 percent can be achieved along with the application of various advanced energy-saving technologies.

Because the 48V system is electrified with current level 1/4 of a 12V system, the power loss under the equal power is reduced considerably compared with the 12V system, and the power loss is 1/16 of the 12V system. The overall efficiency of the electric system is greatly improved due to lower power loss, the power limitation is removed, the vehicle electric appliance can be more finely controlled, and the performance of the vehicle electric appliance is improved.

On the other hand, the 48V system can provide more function integration such as an energy recovery system, an automatic start-stop system and the like, and meet the higher and higher demands of people. Meanwhile, the lithium battery has better charge and discharge performance, and the application effect of the start-stop system is better.

On the other hand, the lower current means that thinner wires can be applied, and the promotion effect on the light weight design of the whole vehicle is obvious.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide an automobile DC-DC converter circuit to solve the problem that proposes among the above-mentioned background art.

In order to achieve the above object, the utility model provides a following technical scheme: a DC-DC converter circuit for an automobile comprises a micro control unit, a passive crystal oscillator, a CAN chip, a first drive, a second drive, a 5v power supply circuit, a drive power supply circuit and a Buck-Boost two-way conversion topology circuit, wherein the micro control unit is connected with the passive crystal oscillator, the CAN chip, the first drive and the second drive; the input end of the 5v power supply circuit is connected with KL15 voltage signals and KL30 voltage signals, and the output end of the 5v power supply circuit is connected with the micro control unit and the CAN chip; the input end of the driving power supply circuit is connected with a KL30 voltage signal, and the output end of the driving power supply circuit is connected with the first driving unit and the second driving unit; the first drive and the second drive are both connected with a Buck-Boost bidirectional conversion topology circuit.

Preferably, the Buck-Boost bidirectional conversion topology circuit relationship is as follows: one end of the circuit is a 48V port, the 48V port is electrically connected with a 48V lithium battery, the 48V port is connected to a filter inductor L1, the filter inductor L1 is connected with a sub circuit, an energy storage capacitor C1 is connected between the filter inductor L1 and the sub circuit, and the other end of the energy storage capacitor C1 is connected with GND; the sub-circuit is connected with a filter capacitor C2, and the other end of the filter capacitor C2 is connected with GND; the node C2 of the filter capacitor is connected with a back-to-back protection Mosfet Q3 and a back-to-back protection Mosfet Q4, the back-to-back protection Mosfet Q3, the back-to-back protection Mosfet Q4 and a filter inductor L3 are connected, the filter inductor L3 is connected to a 12V port, and the 12V port is connected with a 12V lead-acid battery.

Preferably, the circuit relationship in the sub-circuit is: the converter upper tube Q1 is connected to a node of a filter inductor L1 and an energy storage capacitor C1, the drain electrode of the converter lower tube Q2 is connected with the source electrode of the converter upper tube Q1, and the source electrode of the converter lower tube Q2 is connected with GND; the connection node of the converter upper tube Q1 and the converter lower tube Q2 is connected to a conversion energy storage inductor L2, and the conversion energy storage inductor L2 is connected with a conversion sampling resistor R; the conversion sampling resistor R is connected with a filter capacitor C2.

Preferably, the plurality of sub-circuits (9) are connected in parallel.

Preferably, the inverter upper tube Q1 and the inverter lower tube Q2 in the first driving circuit, the second driving circuit and the sub-circuit are connected in parallel.

Preferably, the passive crystal oscillator is an 8m passive crystal oscillator.

Preferably, the data line connected with the CAN chip comprises CAN _ H, CAN _ L.

Compared with the prior art, the beneficial effects of the utility model are that: the circuit provided by the utility model has simple structure, the voltage transformation ratio in the circuit can be boosted and reduced, and the practical use is convenient; when the vehicle normally runs, the mode switching between Buck and Boost can be normally finished, the requirements for large load and acceleration can be met, and therefore the purposes of energy conservation and emission reduction are achieved.

Drawings

Fig. 1 is a schematic structural view of the present invention;

reference numbers in the figures: 1. a micro control unit; 2. a passive crystal oscillator; 3. a CAN chip; 4. driving one; 5. driving a second; 6. a 5v supply circuit; 7. a driving power supply circuit; 8. the Buck-Boost bidirectional conversion topology circuit; 9. a sub-circuit.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

Referring to fig. 1, the present invention provides a technical solution: a DC-DC converter circuit for an automobile comprises a micro control unit 1, a passive crystal oscillator 2, a CAN chip 3, a first drive 4, a second drive 5, a 5v power supply circuit 6, a drive power supply circuit 7 and a Buck-Boost bidirectional conversion topology circuit 8, wherein the micro control unit 1 is connected with the passive crystal oscillator 2, the CAN chip 3, the first drive 4 and the second drive 5; the input end of the 5v power supply circuit 6 is connected with KL15 voltage signals and KL30 voltage signals, and the output end of the 5v power supply circuit is connected with the micro control unit 1 and the CAN chip 3; the input end of the driving power supply circuit 7 is connected with KL30 voltage signals, and the output end of the driving power supply circuit is connected with a first driving circuit 4 and a second driving circuit 5; the first driver 4 and the second driver 5 are both connected with a Buck-Boost bidirectional conversion topology circuit 8.

Further, the Buck-Boost bidirectional conversion topology circuit 8 has the circuit relationship that: one end of the circuit is a 48V port, the 48V port is electrically connected with a 48V lithium battery, the 48V port is connected to a filter inductor L1, the filter inductor L1 is connected with a sub circuit 9, an energy storage capacitor C1 is connected between the filter inductor L1 and the sub circuit 9, and the other end of the energy storage capacitor C1 is connected with GND; the sub-circuit 9 is connected with a filter capacitor C2, and the other end of the filter capacitor C2 is connected with GND; the node C2 of the filter capacitor is connected with a back-to-back protection Mosfet Q3 and a back-to-back protection Mosfet Q4, the back-to-back protection Mosfet Q3, the back-to-back protection Mosfet Q4 and a filter inductor L3 are connected, the filter inductor L3 is connected to a 12V port, and the 12V port is connected with a 12V lead-acid battery.

Further, the circuit relationship in the sub-circuit 9 is: the converter upper tube Q1 is connected to a node of a filter inductor L1 and an energy storage capacitor C1, the drain electrode of the converter lower tube Q2 is connected with the source electrode of the converter upper tube Q1, and the source electrode of the converter lower tube Q2 is connected with GND; the connection node of the converter upper tube Q1 and the converter lower tube Q2 is connected to a conversion energy storage inductor L2, and the conversion energy storage inductor L2 is connected with a conversion sampling resistor R; the conversion sampling resistor R is connected with a filter capacitor C2.

Further, a plurality of sub-circuits 9 are provided, and the plurality of sub-circuits 9 are connected in parallel with each other.

Further, the first driver 4 and the second driver 5 are connected in parallel with the upper inverter tube Q1 and the lower inverter tube Q2 in the sub-circuit 9.

Further, the passive crystal oscillator is an 8m passive crystal oscillator.

Further, the data line connected with the CAN chip 3 includes CAN _ H, CAN _ L.

The working principle is as follows: the circuit works together with a 48V lithium ion battery unit and a 12V lead-acid battery unit; wherein the 12V bus will continue to power the ignition, lighting, information entertainment and audio systems. The 48V bus will power the active chassis system, air conditioning compressor, adjustable suspension, electronic supercapacitor/turbocharger and support regenerative braking. Additionally, the 48V bus can also support engine starting, which will make soft start operation smoother. Again, higher voltages mean that less cross-sectional area of the cable is required, which reduces cable size and weight.

The micro control unit 1 carries out data communication through a data line CAN _ H, CAN _ L connected with a CAN chip 3 and receives and transmits an external demand instruction; the matched duty ratio driving instruction is operated and output by acquiring input voltage such as +48V and output voltage such as +14V, the first driving unit 1 and the second driving unit 5 are driven to obtain the duty ratio driving instruction of the micro control unit 1, the corresponding driving signal is output to drive the upper tube Mosfet duty ratio to be 29.17%, the lower tube Mosfet duty ratio is adjusted and driven according to the size of an actual load, output verification is carried out through sampling feedback to obtain stable output, and when the load changes, matching output can be carried out in real time in a responding mode. Meanwhile, whether fault information such as overvoltage, undervoltage, overcurrent and short circuit exists or not is judged in real time, and real-time processing is carried out.

When the automobile starts to accelerate, an automobile motor needs to provide reverse power, similarly, an automobile engine control unit can issue a pre-charging command first, a micro control unit 1 receives the pre-charging command, electric barriers of back-to-back protection Mosfet Q4 are skipped through a pre-charging circuit, and the 12V battery side pre-charges the 48V side in two stages through an electric path of a filter inductor L3, the pre-charging circuit, the back-to-back protection Mosfet Q3, a conversion sampling resistor R, a conversion energy storage inductor L2, a converter upper tube Q1 and a filter inductor L1; when the 48V side is precharged to 48V, the lithium battery unit controls the relay to attract, and then the energy of the 12V battery side can be converted into the 48V lithium battery in a Boost mode to supply power required by the inversion of the BSG motor. When the vehicle starts and runs normally, the mode switching between Buck and Boost can be normally finished, the requirements for large load and acceleration can be met, and therefore the purposes of energy conservation and emission reduction are achieved.

It is worth noting that: the whole device realizes control over the device through the master control button, and the device matched with the control button is common equipment, belongs to the existing mature technology, and is not repeated for the electrical connection relation and the specific circuit structure.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.

Claims

1. An automotive DC-DC converter circuit, characterized in that: the system comprises a micro control unit (1), a passive crystal oscillator (2), a CAN chip (3), a first drive (4), a second drive (5), a 5v power supply circuit (6), a drive power supply circuit (7) and a Buck-Boost bidirectional conversion topology circuit (8), wherein the micro control unit (1) is connected with the passive crystal oscillator (2), the CAN chip (3), the first drive (4) and the second drive (5); the input end of the 5v power supply circuit (6) is connected with KL15 voltage signals and KL30 voltage signals, and the output end of the 5v power supply circuit is connected with the micro control unit (1) and the CAN chip (3); the input end of the driving power supply circuit (7) is connected with KL30 voltage signals, and the output end of the driving power supply circuit is connected with the first driving unit (4) and the second driving unit (5); the first drive (4) and the second drive (5) are both connected with a Buck-Boost bidirectional conversion topology circuit (8).

2. The automotive DC-DC converter circuit of claim 1, wherein: the Buck-Boost bidirectional conversion topological circuit (8) has the circuit relationship that: one end of the circuit is a 48V port, the 48V port is electrically connected with a 48V lithium battery, the 48V port is connected to the filter inductor L1, the filter inductor L1 is connected with the sub circuit (9), an energy storage capacitor C1 is connected between the filter inductor L1 and the sub circuit (9), and the other end of the energy storage capacitor C1 is connected with GND; the sub-circuit (9) is connected with a filter capacitor C2, and the other end of the filter capacitor C2 is connected with GND; the node C2 of the filter capacitor is connected with a back-to-back protection Mosfet Q3 and a back-to-back protection Mosfet Q4, the back-to-back protection Mosfet Q3, the back-to-back protection Mosfet Q4 and a filter inductor L3 are connected, the filter inductor L3 is connected to a 12V port, and the 12V port is connected with a 12V lead-acid battery.

3. The automotive DC-DC converter circuit of claim 2, wherein: the circuit relationship in the subcircuit (9) is as follows: the converter upper tube Q1 is connected to a node of a filter inductor L1 and an energy storage capacitor C1, the drain electrode of the converter lower tube Q2 is connected with the source electrode of the converter upper tube Q1, and the source electrode of the converter lower tube Q2 is connected with GND; the connection node of the converter upper tube Q1 and the converter lower tube Q2 is connected to a conversion energy storage inductor L2, and the conversion energy storage inductor L2 is connected with a conversion sampling resistor R; the conversion sampling resistor R is connected with a filter capacitor C2.

4. A DC-DC converter circuit for a vehicle according to claim 3, wherein: the plurality of sub-circuits (9) are arranged, and the plurality of sub-circuits (9) are connected in parallel.

5. A DC-DC converter circuit for a vehicle according to claim 3, wherein: the driving I (4) and the driving II (5) are mutually connected in parallel with an inverter upper tube Q1 and an inverter lower tube Q2 in the sub circuit (9).

6. The automotive DC-DC converter circuit of claim 1, wherein: the passive crystal oscillator is an 8MHz passive crystal oscillator.

7. The automotive DC-DC converter circuit of claim 1, wherein: the data line connected with the CAN chip (3) comprises CAN _ H, CAN _ L.