CN219018526U

CN219018526U - Power supply circuit and electric automobile

Info

Publication number: CN219018526U
Application number: CN202223150003.2U
Authority: CN
Inventors: 刘文秀
Original assignee: Shanghai Jusheng Technology Co Ltd
Current assignee: Beijing Didi Infinity Technology and Development Co Ltd
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2023-05-12
Anticipated expiration: 2032-11-25

Abstract

The embodiment of the disclosure relates to a power supply circuit and an electric automobile. The power supply circuit includes: at least two power supply branches connected in parallel with each other; each power supply branch circuit comprises a power supply, an MOS tube and a driving circuit; the power supply is respectively connected with the MOS tube and the driving circuit, the MOS tube is also connected with the driving circuit, and the driving circuit controls the MOS tube to be conducted under the condition that the source voltage of the MOS tube is larger than the drain voltage. The power supply circuit provided by the embodiment of the disclosure can improve the available range of the voltage of the power supply.

Description

Power supply circuit and electric automobile

Technical Field

The application relates to the technical field of power supply, in particular to a power supply circuit and an electric automobile.

Background

For a high-reliability system, two independent power supplies are generally adopted to supply power to a load in parallel, and when one power supply fails, the other power supply can be switched to supply power to the load, so that uninterrupted power supply is realized.

In the prior art, a diode is adopted in the dual-power supply circuit to prevent reverse current from flowing into a power supply, so that the reverse connection prevention effect is realized. However, due to the forward voltage drop of the diode, the usable range of the voltage of the power supply decreases.

Disclosure of Invention

The embodiment of the disclosure provides a power supply circuit and an electric automobile, which can be used for improving the available range of the voltage of a power supply.

In a first aspect, embodiments of the present disclosure provide a power supply circuit, the power supply circuit comprising: at least two power supply branches connected in parallel with each other; each power supply branch circuit comprises a power supply, an MOS tube and a driving circuit; the power supply is respectively connected with the MOS tube and the driving circuit, and the MOS tube is also connected with the driving circuit;

and under the condition that the source voltage of the MOS tube is larger than the drain voltage, the driving circuit controls the MOS tube to be conducted.

In a second aspect, embodiments of the present disclosure provide an electric vehicle comprising a power supply circuit as described in the first aspect.

The power supply circuit comprises at least two power supply branches which are connected in parallel, wherein each power supply branch comprises a power supply, an MOS tube and a driving circuit; the power supply is respectively connected with the MOS tube and the driving circuit, the MOS tube is also connected with the driving circuit, the driving circuit controls the MOS tube to be conducted under the condition that the source voltage of the MOS tube is larger than the drain voltage, the driving circuit and the MOS tube are arranged in each power supply branch of the power supply circuit, the power supply is respectively connected with the MOS tube and the driving circuit, the MOS tube is also connected with the driving circuit, so that the driving circuit in each power supply branch can quickly determine whether to control the MOS tube to be conducted according to the source voltage and the drain voltage of the MOS tube, the power supply branch where the conducted MOS tube is located can be determined as the power supply branch for supplying power to a load, the problem of forward voltage drop does not exist, the usable range of the power supply voltage cannot be reduced, and in addition, for a load with constant power, the load with the smaller voltage loss provided by the power supply branch, the load cannot cause current rise due to the reduction of the input voltage, and the power consumption of the load is increased; in addition, after a certain power supply branch is determined to supply power to a load, the driving circuits in other power supply branches can control the MOS tubes of the branches to be non-conductive, so that the current of the power supply branch can be prevented from reversely flowing into a power supply, and the short circuit phenomenon in the power supply circuits is prevented.

Drawings

FIG. 1 is a schematic diagram of a dual power supply circuit in the prior art;

FIG. 2 is a schematic diagram of a power supply circuit in one embodiment;

FIG. 3 is a schematic diagram of a power supply circuit in another embodiment;

FIG. 4 is a schematic diagram of a power supply circuit in another embodiment;

FIG. 5 is a schematic diagram of a power supply circuit in another embodiment;

FIG. 6 is a schematic diagram of an electric vehicle in one embodiment;

reference numerals illustrate:

and (3) a power supply: 10; MOS tube: 20, a step of; and a driving circuit: 30;

and a comparison circuit: 301; a charge pump circuit: 302; capacitance: 40, a step of performing a;

resistance: 50; overvoltage protection circuit: 60; breakdown diode: 601.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application will be further described in detail with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly and implicitly understood by those of ordinary skill in the art that the embodiments described herein can be combined with other embodiments without conflict.

Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. Reference to "a," "an," "the," and similar terms herein do not denote a limitation of quantity, but rather denote the singular or plural. The terms "comprising," "including," "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, article, or apparatus that comprises a list of steps or modules (elements) is not limited to only those steps or elements but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus. The term "plurality" as used herein means greater than or equal to two. "and/or" describes an association relationship of an association object, meaning that there may be three relationships, e.g., "a and/or B" may mean: a exists alone, A and B exist together, and B exists alone. The terms "first," "second," and the like, as used herein, merely distinguish similar objects from each other and do not denote a particular order of the objects, but rather are not to be construed as indicating or implying a relative importance or implying a limitation in the number of technical features which are indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present application, the meaning of "plurality" is at least two, such as two, three, etc., unless explicitly defined otherwise.

First, before the technical solution of the embodiments of the present disclosure is specifically described, a description is given of a technical background or a technical evolution context on which the embodiments of the present disclosure are based. In general, in a dual-power supply circuit, the current technical background is: as shown in FIG. 1, two independent power supplies are adopted to supply power to a load in parallel, when one power supply fails, the other power supply can be switched to supply power to the load, so that uninterrupted power supply is realized, a diode is adopted in each branch to prevent reverse current from flowing into the power supply, and the reverse connection prevention function is realized, however, the forward voltage drop of the diode can cause the reduction of the available range of the voltage of the power supply, and meanwhile, for a constant power load, the load current is increased due to the reduction of the input voltage, so that the power consumption of the product is increased. Based on the background, the applicant finds that the problem of the reduction of the available range of the voltage of the power supply can be avoided by adopting the MOS tube to replace the diode through long-term model simulation research and development and collection, demonstration and verification of experimental data, however, under the dual-power supply scene, if the MOS tube is directly adopted to replace the diode, when one power supply branch is used for supplying power, the problem that the reverse current flows into the power supply exists in the other power supply branch, the short circuit phenomenon occurs in the power supply circuit, and the power supply and equipment can be damaged seriously. Therefore, how to increase the usable range of the voltage of the power supply and prevent the current from flowing reversely into the power supply, and avoid the problem of short circuit in the power supply circuit becomes a current urgent problem to be solved. In addition, the applicant has made a great deal of creative effort from determining to use MOS transistors instead of diodes and from the technical solutions described in the embodiments below.

The power supply circuit can be applied to various electronic equipment, electric automobiles or other high-reliability systems for power supply.

In one embodiment, as shown in fig. 2, a power supply circuit is provided, the power supply circuit comprising: at least two power supply branches connected in parallel with each other; each power supply branch circuit comprises a power supply 10, an MOS tube 20 and a driving circuit 30; the power supply 10 is respectively connected with the MOS tube 20 and the driving circuit 30, and the MOS tube 20 is also connected with the driving circuit 30; in the case that the source voltage of the MOS transistor 10 is greater than the drain voltage, the driving circuit 30 controls the MOS transistor 10 to be turned on.

Alternatively, the power source 10 may be a battery, typically, the maximum voltage of the battery does not exceed 12V, and the battery may be recycled through the process of charging and discharging. MOS transistor 20, also known as a field effect transistor, is a metal-oxide semiconductor field effect transistorThe MOS tube 20 is divided into PMOS tube and NMOS tube, in this embodiment, the MOS tube 20 may be NMOS tube, and the on-resistance inside the NMOS tube is R _DS(ON) If R is _DS(ON) Too large, too large voltage loss, if R _DS(ON) If the current is too small, the protection value of the reverse current is too large, so that the model selection of the NMOS tube can meet the following conditions:

wherein I is _D Is the operating current of the load.

In this embodiment, the positive electrode of the power supply 10 is connected to the source electrode of the MOS transistor 20, and provides voltage to the MOS transistor 20, and the driving circuit 30 is connected to the MOS transistor 20. Alternatively, in this embodiment, the driving circuit 30 may control the conduction of the MOS transistor 20 by providing the conduction voltage to the MOS transistor.

It can be understood that when the power supply 10 just starts to supply power, since the voltage between the gate and the source in the MOS transistor 20 does not reach the threshold voltage, the MOS transistor 20 is still in the off state, at this time, the body diode in the MOS transistor 20 is turned on first, and as the power supply continues to supply power, voltages will exist at both the source and the drain of the MOS transistor 20, and since the voltage provided by the power supply 10 passes through the source of the MOS transistor 20 and then passes through the drain of the MOS transistor 20, under the condition that the voltage of the source of the MOS transistor 20 is greater than the voltage of the drain, the driving circuit 30 can determine the output driving voltage, control the MOS transistor 20 to be turned on, and after the MOS transistor 20 is turned on, the load is supplied by the power supply branch where the MOS transistor 20 is located. Optionally, if the source voltage of the MOS transistor 20 is smaller than the drain voltage, the driving circuit 30 may not output the driving voltage, and continuously control the MOS transistor 20 to be turned off, so that the power supply branch where the MOS transistor 20 is located will not supply power to the load, and the non-conductive MOS transistor 20 ensures that the current in the power supply circuit supplying power to the load cannot flow into the power supply 10 reversely.

The power supply circuit comprises at least two power supply branches connected in parallel, wherein each power supply branch comprises a power supply, an MOS tube and a driving circuit; the power supply is respectively connected with the MOS tube and the driving circuit, the MOS tube is also connected with the driving circuit, the driving circuit controls the MOS tube to be conducted under the condition that the source voltage of the MOS tube is larger than the drain voltage, the driving circuit and the MOS tube are arranged in each power supply branch of the power supply circuit, the power supply is respectively connected with the MOS tube and the driving circuit, the MOS tube is also connected with the driving circuit, so that the driving circuit in each power supply branch can quickly determine whether to control the MOS tube to be conducted according to the source voltage and the drain voltage of the MOS tube, the power supply branch where the conducted MOS tube is located can be determined as the power supply branch for supplying power to a load, the problem of forward voltage drop does not exist, the usable range of the power supply voltage cannot be reduced, and in addition, for a load with constant power, the load with the smaller voltage loss provided by the power supply branch, the load cannot cause current rise due to the reduction of the input voltage, and the power consumption of the load is increased; in addition, after a certain power supply branch is determined to supply power to a load, the driving circuits in other power supply branches can control the MOS tubes of the branches to be non-conductive, so that the current of the power supply branch can be prevented from reversely flowing into a power supply, and the short circuit phenomenon in the power supply circuits is prevented.

In one embodiment, as shown in fig. 3, the drive circuit 30 includes a comparison circuit 301 and a charge pump circuit 302; the comparison circuit 301 is respectively connected with the MOS tube 20 and the charge pump circuit 302, and the charge pump circuit 302 is also connected with the MOS tube 20; when the source voltage of the MOS transistor 20 is greater than the drain voltage, the comparison circuit 301 outputs a control signal to the charge pump circuit 302; the charge pump circuit 302 provides a turn-on voltage to the MOS transistor 20 according to the control signal.

In this embodiment, the driving circuit 30 includes a comparison circuit 301 and a charge pump circuit 302, the comparison circuit 301 is connected to the MOS transistor 20 and the charge pump circuit 302, the charge pump circuit 302 is also connected to the MOS transistor 20, as an alternative implementation manner, a first end of the comparison circuit 301 may be connected to a source of the MOS transistor 20, a second end of the comparison circuit 301 may be connected to a drain of the MOS transistor 20, and a third end of the comparison circuit 301 is connected to one end of the charge pump circuit 302; the other end of the charge pump circuit 302 may be connected to the gate of the MOS transistor 20. As shown in fig. 3, the first end of the comparison circuit 301 may be an input end, the second end may be an output end, the comparison circuit 301 may obtain the source voltage of the MOS transistor 20 through the input end, obtain the drain voltage of the MOS transistor 20 through the output end, and output a control signal to the charge pump circuit 302 when the source voltage of the MOS transistor 20 is greater than the drain voltage, and after receiving the control signal, the charge pump circuit 302 provides the turn-on voltage to the MOS transistor 20 according to the control signal. Alternatively, in this embodiment, the turn-on voltage provided by the charge pump circuit 302 to the MOS transistor 20 may be 12V, or may be other voltages greater than 12V, which is not limited herein.

It should be noted that, in this embodiment, the charge pump circuit 302 will superimpose the turn-on voltage provided to the MOS transistor 20 according to the control signal on the gate of the MOS transistor 20, and then the gate voltage of the MOS transistor 20 will be greater than the source voltage, and at this time, the voltage in the MOS transistor 20 satisfies the turn-on condition, and the MOS transistor 20 will be turned on.

In this embodiment, the driving circuit of the power supply branch circuit includes a comparison circuit and a charge pump circuit, the comparison circuit is connected with the MOS tube and the charge pump circuit respectively, the charge pump circuit is further connected with the MOS tube, under the condition that the source voltage of the MOS tube is greater than the drain voltage, the comparison circuit outputs a control signal to the charge pump circuit, so that the charge pump circuit can provide a conduction voltage to the MOS tube according to the control signal, and the MOS tube is controlled to be conducted.

In one embodiment, the comparison circuit 301 and the charge pump circuit 302 are integrated in a control chip.

Optionally, in this embodiment, an input end of the control chip may be connected to a source of the MOS transistor 20, an output end of the control chip may be connected to a drain of the MOS transistor 20, a voltage detection end of the control chip may be connected to the charge pump circuit 302, and based on the connection relationship, an input end voltage of the control chip is the same as a source voltage of the MOS transistor 20, and an output end voltage of the control chip is the same as a drain of the MOS transistor 20. Further, since the voltage detection terminal of the control chip is connected to the charge pump circuit 302, the voltage detection terminal of the control chip can supply power to the charge pump circuit 302.

In this embodiment, the comparison circuit 301 and the charge pump circuit 302 may be connected in a control chip, specifically, an output end of the comparison circuit 301 may be connected to an input end of the charge pump circuit 302, and a control signal output by the comparison circuit 301 is transmitted to the charge pump circuit 302, so that the charge pump circuit 302 may determine whether to output a driving voltage according to the control signal, thereby controlling on and off of the MOS transistor 20.

In this embodiment, since the comparison circuit and the charge pump circuit are integrally disposed in the control chip, the occupied volume is small, so that the volume occupied by the whole power supply circuit is small, and the volume occupied by the power supply circuit is saved.

In one embodiment, as shown in fig. 4, each power supply branch further includes a resistor 50 and a capacitor 40; the first end of the resistor 50 is connected with the drain electrode of the MOS tube 20, and the second end of the resistor 50 is respectively connected with the first end of the capacitor 40 and the voltage detection end; the second terminal of the capacitor 40 is grounded.

In this embodiment, the resistor 50 and the capacitor 40 are connected to form a low-pass filter, and the low-pass filter can allow signals lower than the cutoff frequency to pass, but signals higher than the cutoff frequency cannot pass, and the low-pass filter can effectively filter out frequency points with specific frequencies or frequencies outside the frequency points in the power supply branch circuit to obtain a power supply signal with specific frequencies, or obtain a power supply signal with specific frequencies eliminated.

In this embodiment, each power supply branch further includes a resistor and a capacitor, the first end of the resistor is connected with the drain electrode of the MOS transistor, the second end of the resistor is connected with the first end of the capacitor and the voltage detection end, and the second end of the capacitor is grounded.

In one embodiment, as shown in fig. 5, each power supply branch further includes an overvoltage protection circuit 60; one end of the overvoltage protection circuit 60 is connected with the negative electrode of the power supply 10, and the other end of the overvoltage protection circuit 60 is respectively connected with the positive electrode of the power supply 10 and the source electrode of the MOS tube 20.

Alternatively, the overvoltage protection circuit 60 in this embodiment may include two reverse-connected breakdown diodes 601. Wherein overvoltage protection refers to a protection mode in which the power supply 10 is turned off or the voltage of the controlled device is reduced when the protected line voltage exceeds a predetermined maximum value. If the voltage stabilizing circuit inside the power supply 10 fails or the output voltage exceeds the design threshold value due to improper operation of a user, the electric equipment can be protected from damage by the overvoltage protection circuit 60, and the output voltage is limited within a safe value range.

It should be noted that, when a short circuit occurs in the power supply circuit, an excessive current will occur in the power supply circuit instantaneously, and the excessive current will cause the power damage. In this embodiment, one end of the overvoltage protection circuit 60 is connected with the negative electrode of the power supply 10, the other end of the overvoltage protection circuit 60 is connected with the positive electrode of the power supply 10, which is equivalent to connecting the overvoltage protection circuit 60 in parallel with the power supply 10, the other end of the overvoltage protection circuit 60 is also connected with the source electrode of the MOS transistor 20, which is equivalent to connecting the overvoltage protection circuit 60 in series with the power supply 10, when the power supply circuit has a short circuit phenomenon, the breakdown diode 601 in the overvoltage protection circuit 60 is broken down first, and the power supply 10 is shorted, thereby protecting the power supply 10 from being damaged.

In this embodiment, each power supply branch further includes an overvoltage protection circuit, one end of the overvoltage protection circuit is connected with a negative electrode of the power supply, and the other end of the overvoltage protection circuit is connected with a positive electrode of the power supply and a source electrode of the MOS transistor respectively.

In one embodiment, an electric vehicle as shown in fig. 6 is provided, which includes the power supply circuit as described in all of the above embodiments.

Alternatively, the electric vehicle in this embodiment may be any one of a passenger car, a truck, a van, a commercial vehicle, a semitrailer, and the like. Alternatively, the electric vehicle in this embodiment may be a pure oil electric vehicle, or may be an electric vehicle with hybrid oil and electricity. The present embodiment does not limit the type of electric vehicle herein. In addition, the structure and the working principle of the power supply circuit included in the electric vehicle provided in the embodiment refer to the detailed description of the power supply circuit in the above embodiment, and the embodiment is not repeated herein.

The technical features of the above embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the present application. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.

Claims

1. A power supply circuit, the power supply circuit comprising: at least two power supply branches connected in parallel with each other; each power supply branch circuit comprises a power supply, an MOS tube and a driving circuit; the power supply is respectively connected with the MOS tube and the driving circuit, and the MOS tube is also connected with the driving circuit;

2. The power supply circuit of claim 1, wherein the drive circuit comprises a comparison circuit and a charge pump circuit; the comparison circuit is respectively connected with the MOS tube and the charge pump circuit, and the charge pump circuit is also connected with the MOS tube;

the comparison circuit outputs a control signal to the charge pump circuit in a case where the source voltage is greater than the drain voltage;

and the charge pump circuit provides a conduction voltage for the MOS tube according to the control signal.

3. The power supply circuit according to claim 2, wherein a first end of the comparison circuit is connected with a source electrode of the MOS transistor, a second end of the comparison circuit is connected with a drain electrode of the MOS transistor, and a third end of the comparison circuit is connected with one end of the charge pump circuit; the other end of the charge pump circuit is connected with the grid electrode of the MOS tube.

4. The power supply circuit of claim 2, wherein the comparison circuit and the charge pump circuit are integrally provided in a control chip.

5. The power supply circuit according to claim 4, wherein an input end of the control chip is connected with a source electrode of the MOS transistor, and an output end of the control chip is connected with a drain electrode of the MOS transistor; and a voltage detection end of the control chip is connected with the charge pump circuit.

6. The power supply circuit of claim 5, wherein each of the power supply branches further comprises a resistor and a capacitor; the first end of the resistor is connected with the drain electrode of the MOS tube, and the second end of the resistor is respectively connected with the first end of the capacitor and the voltage detection end; the second end of the capacitor is grounded.

7. The power supply circuit of claim 6, wherein each of the power supply branches further comprises an overvoltage protection circuit; one end of the overvoltage protection circuit is connected with the negative electrode of the power supply, and the other end of the overvoltage protection circuit is respectively connected with the positive electrode of the power supply and the source electrode of the MOS tube.

8. The power supply circuit of claim 7, wherein the overvoltage protection circuit comprises two reverse-connected breakdown diodes.

9. The power supply circuit according to any one of claims 1 to 8, wherein the MOS transistor is an NMOS transistor.

10. An electric vehicle, characterized in that it comprises a power supply circuit according to any one of claims 1-9.