CN218603368U - DC-DC conversion device and uninterruptible power supply system comprising same - Google Patents

Abstract

The utility model provides a DC-DC conversion device reaches uninterrupted power source system including it, wherein, DC-DC conversion device includes: a first dc terminal, a second dc terminal, a first current path, a second current path, a first switch assembly, an inductor, a second switch assembly, a first switch, a second switch, wherein the first switch assembly, the second switch assembly, the first switch and the second switch are configured to provide a boost circuit, a buck circuit or a bypass from the first dc terminal to the second dc terminal or from the second dc terminal to the first dc terminal. The uninterruptible power supply system comprises an uninterruptible power supply and the DC-DC conversion device, wherein the first direct current end of the DC-DC conversion device is connected with a rechargeable battery, and the second direct current end of the DC-DC conversion device is connected with the uninterruptible power supply.

Description

DC-DC conversion device and uninterruptible power supply system comprising same

Technical Field

The present invention relates to a DC power conversion field, and more particularly, to a DC-DC converter for converting battery voltage into different output voltages to meet different UPS voltage requirements.

Background

Online upss, which are capable of continuously supplying power to a load, have been widely used in various fields. On-line UPSs typically use mains power, which is supplied using an internal or external battery when the mains fails and the UPS is operating in standby mode. Different UPS models require different rated output powers, and in the prior art, different battery arrangement modes are used for UPSs with different rated output powers. Typically, SLA batteries are used in series or series-parallel to provide the required voltage and current for a UPS. Because different UPS models use different battery voltages, different UPS's may have different SLA battery arrangements. If the SLA battery pack is replaced by a lithium battery pack, a DC-DC conversion device is adopted to convert the battery voltage into the voltage required by the UPS. The DC-DC conversion device in the prior art generally adopts a multi-bridge arm topology, more components such as a switch tube and the like can be used in the multi-bridge arm topology, the size is large, the heating power consumption can be increased, different batteries are required to meet the requirements of different UPS voltages, different DC-DC conversion devices need to be designed, a large amount of battery stock and higher price and difficult maintenance can be caused, and the utilization rate of the batteries is not improved. Therefore, how to perform DC-DC conversion on the battery to output different voltages has important significance for improving the utilization rate of the battery and reducing the cost.

SUMMERY OF THE UTILITY MODEL

Therefore, an object of the present invention is to achieve the above object, and to provide a DC-DC converter and an uninterruptible power supply system including the same, which can realize different voltage conversion outputs using the same battery.

According to a first aspect of the present invention, there is provided a DC-DC conversion apparatus, the apparatus comprising: a first DC terminal for receiving a DC input or providing a DC output; a second dc terminal for receiving a dc input or providing a dc output; a first current path connected between the first and second DC terminals and having a first polarity; a second current path connected between the first and second DC terminals and having a second polarity; a first switching assembly disposed in a first current path, having a first control pole, a first pole, and a second pole, the first switching assembly being capable of conducting or breaking current from the first pole to the second pole via control of the first control pole, and the first switching assembly being further capable of conducting current from the second pole to the first pole; an inductor disposed in a first current path having a first end and a second end, the first end connected to the second pole of the first switching component; a second switching assembly connected between the first end of the inductance and the second current path, having a second control pole, a third pole, and a fourth pole, the second switching assembly being capable of conducting or breaking current from the third pole to the fourth pole via control of the second control pole, and the second switching assembly also being capable of conducting current from the fourth pole to the third pole; a first switch disposed in a first current path capable of selectively connecting the first direct current terminal to a first pole of the first switch assembly or a second terminal of the inductor; a second switch disposed in the first current path capable of selectively connecting the second direct current terminal to the first pole of the first switch assembly or the second terminal of the inductor; wherein the first switch assembly, the second switch assembly, the first switch and the second switch are arranged to provide a boost circuit, a buck circuit or a bypass from the first dc terminal to the second dc terminal or from the second dc terminal to the first dc terminal.

Preferably, the first switch assembly and the second switch assembly are both power switch tubes and anti-parallel diodes.

Preferably, the power switch tube is a MOS transistor.

In some embodiments of the present invention, the apparatus further comprises: a first capacitor connected between a first pole of the first switch assembly and the second current path; and/or a second capacitance connected between the second direct current terminal and the second current path; and/or a third capacitance connected between the first direct current terminal and the second current path; and/or a fourth capacitance connected between a second terminal of the inductance and the second current path.

Preferably, the first switch assembly, the second switch assembly and the inductor form a DC-DC conversion unit, and the apparatus includes a plurality of DC-DC conversion units connected in parallel.

In some embodiments of the present invention, the apparatus comprises two DC-DC conversion units connected in parallel.

In some embodiments of the invention, the apparatus is configured such that when the first dc terminal voltage is higher than the second dc terminal voltage, the first switch connects the first dc terminal to a first pole of the first switch assembly, and the second switch connects the second terminal of the inductor to the second dc terminal, wherein the first switch assembly repeatedly conducts and cuts off current from the first pole to the second pole via control of the first control pole, and the second switch assembly cuts off current from the third pole to the fourth pole via control of the second control pole, thereby enabling a step-down output from the first dc terminal to the second dc terminal, or wherein the first switch assembly cuts off current from the first pole to the second pole via control of the first control pole, and the second switch assembly repeatedly conducts and cuts off current from the third pole to the fourth pole via control of the second control pole, thereby enabling a step-up output from the second dc terminal to the third dc terminal.

In some embodiments of the invention, the apparatus is configured such that when the first dc voltage is lower than the second dc voltage, the first switch connects the first dc terminal to the second terminal of the inductor, and the second switch connects the second dc terminal to the first pole of the first switch assembly, wherein the first switch assembly cuts off current from the first pole to the second pole via control of the first control pole, the second switch assembly repeatedly conducts and cuts off current from the third pole to the fourth pole via control of the second control pole, thereby enabling boost output from the first dc terminal to the second dc terminal, or wherein the first switch assembly repeatedly conducts and cuts off current from the first pole to the second pole via control of the first control pole, and the second switch assembly cuts off current from the third pole to the fourth pole via control of the second control pole, thereby enabling buck output from the second dc terminal to the first dc terminal.

In some embodiments of the invention, the apparatus is configured such that when the first dc terminal voltage is equal to the second dc terminal voltage, the first switch connects the first dc terminal to the second terminal of the inductor, and the second switch connects the second dc terminal to the second terminal of the inductor to enable a bypass from the first dc terminal to the second dc terminal.

According to a second aspect of the present invention, there is provided an uninterruptible power supply system comprising an uninterruptible power supply and the DC-DC converter according to the first aspect of the present invention, wherein the first DC terminal of the DC-DC converter is connected to a rechargeable battery, and the second DC terminal is connected to the uninterruptible power supply.

Compared with the prior art, the utility model has the advantages of: the utility model discloses a components and parts that DC-DC conversion device used are few, and the device is whole small, and the low power dissipation that generates heat, and can realize adopting the same battery to realize different voltage conversion output, have greatly improved the utilization ratio of battery, have reduced the hardware cost.

Drawings

Embodiments of the invention are further described below with reference to the accompanying drawings, in which:

FIG. 1 is a schematic diagram of a basic buck chopper circuit in the prior art;

FIG. 2 is a schematic diagram of a basic circuit of a prior art buck DC-DC converter;

FIG. 3 is a schematic diagram of a basic circuit of a prior art boost DC-DC converter;

fig. 4 is a schematic diagram of a DC-DC conversion device according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a circuit connection of a DC-DC conversion apparatus connecting two DC-DC units in parallel for voltage reduction from a battery to a UPS and voltage increase from the UPS to the battery according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a circuit connection of a DC-DC conversion apparatus for connecting two DC-DC units in parallel according to an embodiment of the present invention for boosting voltage from a battery to a UPS and for stepping down voltage from the UPS to the battery;

fig. 7 is a schematic diagram of a bypass connection of a DC-DC converter device connecting two DC-DC units in parallel from a battery to a UPS according to an embodiment of the present invention;

fig. 8 is a schematic diagram of a basic structure of a DC-DC conversion device according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a DC-DC converter with a voltage-stabilizing capacitor according to an embodiment of the present invention;

fig. 10 is a schematic diagram of a voltage step-down from a first dc terminal to a second dc terminal and a voltage step-up circuit from the second dc terminal to the first dc terminal according to an embodiment of the present invention;

fig. 11 is a schematic diagram of a voltage step-up circuit from a first dc terminal to a second dc terminal and a voltage step-down circuit from the second dc terminal to the first dc terminal according to an embodiment of the present invention;

fig. 12 is a schematic diagram of a bypass from a first dc terminal to a second dc terminal according to an embodiment of the present invention.

Detailed Description

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

In order to solve the problem in the UPS under the prior art, the utility model provides a new DC-DC conversion equipment for according to the big or small relation of battery and UPS demand voltage, carry out different conversions, carry out the different voltage of voltage conversion output with realizing that same battery. The utility model discloses a DC-DC conversion device carries out work according to following mode: when the battery voltage is greater than the UPS voltage requirement, the DC-DC conversion device adopts a voltage reduction mode to realize power supply from the battery to the UPS, when the battery voltage is greater than the UPS voltage requirement, the DC-DC conversion device adopts a voltage boosting mode to realize power supply from the battery to the UPS, and when the battery voltage is equal to the UPS voltage requirement, the DC-DC conversion device adopts a bypass mode to realize power supply from the battery to the UPS.

For a better understanding of the present invention, the basic principles of the buck and boost circuits are described below.

Fig. 1 (a) shows a basic step-down chopper circuit, where Ud is the input dc voltage, V is the switching tube, UR is the voltage across the load R, the switching tube V chops the input Ud into a square wave and outputs the square wave to R, fig. 1 (b) shows the chopped output waveform, the period of the square wave is T, the output voltage is equal to Ud when V is on, the on-time is ton, the output voltage is equal to 0 when V is off, the off-time is toff, the duty ratio d = ton/T, and the average value of the square wave voltage is proportional to the duty ratio. The square wave in fig. 1 (c) is a continuous output waveform, and the average voltage thereof is shown by the straight line in fig. 1 (c). The output voltage can be changed by changing the pulse width, the pulse is wider and narrower before the time t1, and the average voltage (UR 1) is higher; after time t1, the pulse narrows and the average voltage (UR 2) decreases. The fixed square wave period T is not changed, and the changing of the duty ratio to adjust the output voltage is a (PWM) method, also called a fixed frequency and width modulation method. The output voltage is lower than the input voltage, so that the Buck chopper circuit or the Buck converter is called.

Fig. 2 shows a basic buck DC-DC conversion circuit based on a basic chopper circuit, because square wave pulses cannot be used as a DC power supply, a filter circuit is added in practical use, fig. 2 is a circuit with LC filter, L is a filter inductor, C2 is a filter capacitor, and D is a freewheeling diode. When V is conducted, L and C2 store energy and transmit power to a load R; when the switch tube V is turned off, the capacitor C2 transmits power to the load R, and the inductor L transmits power to the load R through the diode D. The frequency of the output square wave is high, generally from thousands of hertz to dozens of kilohertz, so the inductance volume is very small and the output ripple is not large. In this circuit, the output voltage UR = d × Ud, d being the duty cycle, has a value of 0 to 1.

Based on the principle similar to buck chopping, a Boost chopper circuit can be further formed by an inductance element, which is not described herein again, and only a Boost DC-DC conversion circuit is briefly described, as shown in fig. 3, the Boost DC-DC conversion circuit is a Boost DC-DC conversion basic circuit or a Boost converter, when a switching tube V is turned on, energy is stored in an inductor L when current passes through the inductor L, and at this time, voltage on a load is provided by a capacitor C2, when the switching tube V is turned off, the inductor L releases energy, and output voltage is the sum of input voltage Ud and voltage generated by the inductor L, so that input voltage is increased, output voltage UR = Ud/(1-d), d is a duty ratio, and the value must be smaller than 1.

The present invention will be described in detail with reference to the accompanying drawings and examples. Wherein, in order to simplify the circuit, the utility model discloses in the circuit in the embodiment all only draw positive pole return circuit, correspond the ground return circuit that relates and all omitted not drawing, but the skilled person in the art introduces through the basic principle of above buck-boost circuit, should know positive pole return circuit, ground return circuit's connection scheme, the embodiment of the utility model in do not do nothing and describe repeatedly.

The utility model discloses a theory of operation based on buck-boost circuit is used between battery and UPS, as shown in fig. 4, the utility model discloses a DC-DC conversion device, include: a first NMOS transistor Q1 and an antiparallel diode (Q1 can conduct or cut off current from drain to source under the control of a gate control signal, and based on the antiparallel diode, can conduct current from the direction of the source to the direction of the drain through the diode in the case of a drain-to-source cut-off current), an inductor L (for convenience of description, the two ends of the inductor are respectively referred to as a first end and a second end), a second NMOS transistor Q2 and an antiparallel diode (Q2 can conduct or cut off current from drain to source under the control of the gate control signal, and based on the antiparallel diode, in the case of a drain-to-source cut-off current, the relay comprises 5 terminal contacts, two control contacts, a movable contact, a normally closed contact and a normally open contact, wherein the movable contact can be controlled to be switched to the normally open contact or the normally closed contact to connect different paths when the two control contacts apply different control signals, for convenience of description, the two control contacts of the relay are collectively called as contacts 1 and 2, the normally closed contact is called as contact 3, the movable contact is called as contact 4, the normally open contact is called as contact 5), and the second relay RL2 (different control signals can be applied to the control contacts of the RL2 to realize the purpose of communicating different paths, for the sake of description, as with the relay RL1, the two control contacts of the relay RL2 are collectively referred to as contacts 1 and 2, the normally closed contact is referred to as contact 3, the moving contact is referred to as contact 4, and the normally open contact is referred to as contact 5), where: the source electrode of the transistor Q1 is connected with the drain electrode of the transistor Q2, and the drain electrode of the transistor Q1 is connected with the normally closed contact 3 of the relay RL1 and the normally open contact 5 of the relay RL 2; the source electrode of the transistor Q2 is connected with a ground circuit; a first end of the inductor L is connected with the source electrode of the transistor Q1 and the drain electrode of the transistor Q2, and a second end of the inductor L is connected with the normally open contact 5 of the relay RL1 and the normally closed contact 3 of the relay RL 2; the capacitor C1 is connected between the drain electrode of the transistor Q1 and the grounding loop; the capacitor C2 is connected between the UPS and the ground loop; the capacitor C3 is connected between the battery and the grounding loop; the capacitor C4 is connected between the second end of the inductor L and the ground return; the movable contact 4 of the relay RL1 is connected with a battery; the movable contact 4 of the relay RL2 is connected with the UPS. The connection mode of the relay is not fixed and unchanged, and the purpose of communicating different paths can be achieved, the connection mode of the normally open contact and the normally closed contact is not limited in the subsequent embodiment, and only the path communicated by the relay is described. To the technical personnel in this field, how to control different transistors, relays, etc. by applying different control signals is a known technique, and the utility model discloses do not do the repeated description, only describe the circuit structure of the utility model.

As can be seen from the foregoing description of the basic principle of the buck-boost circuit, by controlling the relay, NMOS transistor, etc. in the circuit shown in fig. 4, a boost or buck and bypass circuit from the battery to the UPS can be realized. Furthermore, the DC-DC converter of the present invention allows the UPS to turn on the UPS to provide a charging current for the battery under the condition of the utility voltage.

When the battery voltage is higher than the UPS voltage, the DC-DC conversion apparatus shown in fig. 4 may be selectively configured, by appropriate control of transistors Q1 and Q2, as either 1) a buck circuit to power the UPS from the battery, or 2) a boost circuit to charge the battery from the mains voltage associated with the UPS. At this time, as shown in fig. 4, the relay RL1 connects the battery to the drain of the transistor Q1 by the control of the control signal, and the relay RL2 connects the UPS to the second end of the inductor by the control of the control signal. When configured as a buck circuit, a PWM signal is applied to transistor Q1 that controls the drain of transistor Q1 to repeatedly conduct and shut off current to the source, and a signal is applied to transistor Q2 that controls the drain of transistor Q2 to shut off the source (freewheeling via a diode connected in anti-parallel with transistor Q2 at this time), thereby enabling the battery to provide a buck supply for the UPS. Accordingly, when configured as a boost circuit, a signal is applied to transistor Q1 to control the turn-off of the drain to source of transistor Q1 (freewheeling is achieved by a diode connected in anti-parallel with transistor Q1 at this time), and a PWM signal is applied to transistor Q2 to control the drain to source of transistor Q2 to repeatedly conduct and cut off current, thereby enabling boost charging of the battery from the UPS.

Similarly, when the battery voltage is lower than the UPS voltage, the DC-DC conversion apparatus shown in fig. 4 may also be selectively configured, by appropriate control of transistors Q1 and Q2, as 1) a buck circuit to charge the battery with the mains voltage associated with the UPS, or 2) a boost circuit to power the UPS with the battery. At this time, unlike the connection relationship shown in fig. 4, the relay RL1 connects the battery to the second terminal of the inductor L by the control of the control signal, and the relay RL2 connects the UPS to the drain of the transistor Q1 by the control of the control signal. When the UPS is configured as a voltage reduction circuit, a PWM signal for controlling the drain electrode of the transistor Q1 to conduct and cut off current repeatedly is applied to the transistor Q1, and a signal for controlling the drain electrode of the transistor Q2 to cut off the source electrode is applied to the transistor Q2 (freewheeling is realized through a diode which is connected with the transistor Q2 in an anti-parallel mode), so that the UPS can realize the voltage reduction charging of the battery. Accordingly, when configured as a boost circuit, a signal is applied to transistor Q1 that controls the turn off of the drain to source of transistor Q1 (freewheeling is achieved by a diode connected in anti-parallel with transistor Q1 at this time), and a PWM signal is applied to transistor Q2 that controls the drain to source of transistor Q2 to repeatedly conduct and shut off current, thereby enabling boost power for the UPS from the battery.

When the battery voltage is equal to the UPS voltage, the DC-DC converter shown in fig. 4 is operated in bypass both during the time when the battery is in the discharge mode to power the UPS and when the battery is charged by the mains voltage associated with the UPS, and at this time, the relays RL1 and RL2 directly connect the UPS to the battery through control of the control signal to achieve bypass power supply from the battery to the UPS and bypass charging of the battery from the UPS.

In addition, in order to satisfy the high-power load demand of second direct current end, the utility model discloses still provide a scheme of parallelly connected DC-DC unit, wherein, with the same first transistor of transistor Q1, with the same second transistor of transistor Q2, constitute DC-DC conversion unit with the inductance that inductance L is the same, satisfy high-power load demand through the mode of parallelly connected a plurality of DC-DC units.

Still taking the embodiment shown in fig. 4 as an example, as shown in fig. 5, two DC-DC units consisting of a first transistor, a second transistor and an inductor L are connected in parallel. Wherein, can see that the normal open contact of relay and the connected mode of normally closed contact are different with in figure 4, this is because the normal open contact of relay and the connected mode of normally closed contact are not only fixed, no matter which kind of connected mode, only need guarantee under the applied scene of difference, can adopt the route that control signal intercommunication needs can, for example can exchange the connected mode of the normal open contact and the normally closed contact in above-mentioned embodiment, corresponding control signal adjust can. The control method of the relay is known to those skilled in the art and will not be described herein. The battery to UPS boost or buck and bypass circuits may be implemented by controlling the relays, NMOS transistors, etc. in the circuit shown in fig. 5 based on the same principles as the embodiment described in fig. 4.

When the battery voltage is higher than the UPS load demand voltage, the DC-DC converter shown in fig. 5 will operate with a buck circuit (the battery supplying the UPS with buck) during the discharge mode and with a boost circuit during the battery charge mode. As shown in fig. 5, the battery voltage is applied to the drains of the first NMOS transistors of the two parallel DC-DC units through the normally open contact 5 of RL1, and the UPS is connected to the second ends of the inductors of the two parallel DC-DC units through the normally open contact 5 of the relay RL 2. In this configuration, the battery is connected to the drains of the two first transistors and the UPS is connected to the lower voltage node via a relay RL2, which makes the system inherently safe because the DC-DC conversion module does not provide an output voltage when energized, and the upper switching tube must be opened to enable current flow from the battery to the load. Furthermore, the utility model discloses a DC-DC conversion equipment allows UPS can provide charging current for the battery when opening UPS under the circumstances of using mains voltage, because UPS voltage is less than battery voltage, consequently when charging, through DC-DC's configuration, realizes being charged for the battery by UPS under the mode of stepping up.

When the battery voltage is lower than the UPS voltage, the DC-DC conversion apparatus shown in fig. 5 will operate in boost mode (the battery will boost the UPS) during the discharge mode and in buck mode during the battery charge mode. As shown in fig. 6, the battery voltage is applied to the inductors of the two parallel DC-DC units through the normally closed contact 3 of the relay RL1, and the UPS is connected to the drains of the first NMOS transistors of the two DC-DC units through the normally closed contact 3 of the relay RL 2. In this configuration, the battery voltage is only applied to the UPS when the DC-DC conversion module is open, because both relays must be switched to the corresponding positions to create a path for current to flow through, enabling current to flow from the battery to the load. During operation of the DC-DC converter, the output voltage will always be higher than the battery voltage to enable normal powering of the UPS. The UPS can provide charging current for the battery when the UPS is started under the condition of applying the mains supply voltage, and the UPS voltage is higher than the battery voltage, so that the battery can be charged by the UPS in a voltage reduction mode through the configuration of the DC-DC when the battery is charged.

When the battery voltage matches the UPS voltage, the DC-DC converter apparatus described in fig. 5 will operate in bypass mode in both discharge mode and charge mode, controlling the relay switching via the control signal, effectively connecting the UPS directly to the battery. As shown in fig. 7, the movable contact 4 of relay RL1 switches to the position of normally closed contact 3 and the movable contact of relay RL2 switches to the position of normally open contact 5, allowing current to flow directly between the battery and the UPS.

To reduce input and output current ripple, a common voltage conversion module implements high power stage DC-DC conversion using an interleaved topology, the DC-DC of two or more identical power stages operating in series with a phase shift of 360 °/n, where n is the number of active stages, each additional phase allowing ripple current to be reduced by n. The power switches and inductors per phase can be much smaller than those used in single stage circuits. Furthermore, at high output powers, the multi-phase circuit may achieve better sharing of dissipated power. The staggered topology is a common hardware topology technology in the field, and the present invention is not described in detail.

As can be seen from the above description of the embodiments, by configuring the operation modes of the switching tubes (the transistor Q1, the transistor Q2) and the switches (the relay RL1, the relay RL 2) between the two dc terminals (the battery and the UPS), the step-up or step-down and the bypass modes between the two dc terminals can be realized. Therefore, the DC-DC conversion device capable of realizing conversion of different output voltages can be flexibly configured to adapt to different UPS voltage requirements under the condition of not replacing batteries. According to an embodiment of the present invention, as shown in fig. 8, a DC-DC conversion apparatus of the present invention includes: a first DC terminal for receiving a DC input or providing a DC output; a second dc terminal for receiving a dc input or providing a dc output; a first current path connected between the first and second DC terminals and having a first polarity; a second current path connected between the first and second DC terminals and having a second polarity; a first switching assembly disposed in a first current path, having a first control pole, a first pole, and a second pole, the first switching assembly being capable of conducting or breaking current from the first pole to the second pole via control of the first control pole, and the first switching assembly being further capable of conducting current from the second pole to the first pole; an inductor disposed in a first current path having a first end and a second end, the first end connected to the second pole of the first switching component; a second switching assembly connected between the first end of the inductance and the second current path, having a second control pole, a third pole, and a fourth pole, the second switching assembly being capable of conducting or breaking current from the third pole to the fourth pole via control of the second control pole, and the second switching assembly also being capable of conducting current from the fourth pole to the third pole; a first switch disposed in a first current path capable of selectively connecting the first direct current terminal to a first pole of the first switch assembly or a second terminal of the inductor; a second switch disposed in the first current path capable of selectively connecting the second direct current terminal to the first pole of the first switch assembly or the second terminal of the inductor; wherein the first switch assembly, the second switch assembly, the first switch and the second switch are arranged to provide a boost circuit, a buck circuit or a bypass from the first dc terminal to the second dc terminal or from the second dc terminal to the first dc terminal.

According to an embodiment of the present invention, as shown in fig. 9, the DC-DC conversion device further includes: a first capacitor C1 connected between the first pole of the first switch assembly and the second current path; and/or a second capacitance C2 connected between the second dc terminal and the second current path; and/or a third capacitor C3 connected between the first direct current terminal and the second current path; and/or a fourth capacitance C4 connected between the second end of the inductance and the second current path.

The utility model discloses a DC-DC conversion device can use the voltage conversion between the different direct current ends to in figure 8 DC-DC conversion device's structure for example: when the first dc terminal voltage is higher than the second dc terminal voltage, as shown in fig. 10, the first switch connects the first dc terminal to the first pole of the first switch assembly, the second switch connects the second terminal of the inductor to the second dc terminal, the first switch assembly conducts current from the first pole to the second pole via the control of the first control pole, the second switch assembly cuts off current from the third pole to the fourth pole and conducts current from the fourth pole to the third pole via the control of the second control pole to realize a buck circuit from the first dc terminal to the second dc terminal and a boost circuit from the second dc terminal to the first dc terminal; when the first dc voltage is lower than the second dc voltage, as shown in fig. 11, the first switch connects the first dc terminal to the second terminal of the inductor, the second switch connects the second dc terminal to the first pole of the first switch assembly, the first switch assembly cuts off the current from the first pole to the second pole and conducts the current from the second pole to the first pole through the control of the first control pole, and the second switch assembly conducts the current from the third pole to the fourth pole through the control of the second control pole, so as to implement a voltage boosting circuit from the first dc terminal to the second dc terminal and a voltage dropping circuit from the second dc terminal to the first dc terminal; when the first dc terminal voltage is equal to the second dc terminal voltage, as shown in fig. 12, the first switch connects the first dc terminal to the second terminal of the inductor, and the second switch connects the second dc terminal to the second terminal of the inductor to bypass the first dc terminal to the second dc terminal.

According to the utility model discloses an embodiment, first switch module and second switch module are power switch tube and the anti-parallelly connected diode, and power switch tube is as long as can switch on or turn off the switch tube under control signal control all can, for example Metal Oxide Semiconductor Field Effect Transistor (MOSFET), insulated Gate Bipolar Transistor (IGBT), triode etc.. The anti-parallel diode can also be replaced by a power switch tube, and at the moment, the power switch tube needs to be correspondingly switched into a conducting state according to the working mode of the power switch tube. In addition, any switch that can achieve selective connection may be used as the first switch and the second switch, for example, a relay.

It should be noted that, for those skilled in the art, it is a known technique how to control different switch groups and power switches by control signals, and the present invention is not described in detail and only describes the circuit structure of the present invention.

Compared with the prior art, the utility model discloses a components and parts that DC-DC conversion device used are few, and the device is whole small, and the low power dissipation that generates heat, and can realize adopting the same battery to realize different voltage conversion output, have greatly improved the utilization ratio of battery, have reduced the hardware cost.

It should be noted that, although the steps are described in a specific order, the steps are not necessarily performed in the specific order, and in fact, some of the steps may be performed concurrently or even in a changed order as long as the required functions are achieved.

The present invention may be a system, method and/or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions embodied thereon for causing a processor to implement various aspects of the present invention.

The computer readable storage medium may be a tangible device that retains and stores instructions for use by an instruction execution device. The computer readable storage medium may include, for example, but is not limited to, an electronic memory device, a magnetic memory device, an optical memory device, an electromagnetic memory device, a semiconductor memory device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: a portable computer diskette, a hard disk, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), a Static Random Access Memory (SRAM), a portable compact disc read-only memory (CD-ROM), a Digital Versatile Disc (DVD), a memory stick, a floppy disk, a mechanical coding device, such as punch cards or in-groove projection structures having instructions stored thereon, and any suitable combination of the foregoing.

While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen in order to best explain the principles of the embodiments, the practical application, or improvements made to the technology in the marketplace, or to enable others of ordinary skill in the art to understand the embodiments disclosed herein.

Claims (10)

1. A DC-DC conversion apparatus, characterized in that the apparatus comprises:

a first DC terminal for receiving a DC input or providing a DC output;

a second dc terminal for receiving a dc input or providing a dc output;

a first current path connected between the first and second DC terminals and having a first polarity;

a second current path connected between the first and second DC terminals and having a second polarity;

a first switching assembly disposed in a first current path, having a first control pole, a first pole, and a second pole, the first switching assembly being capable of conducting or breaking current from the first pole to the second pole via control of the first control pole, and the first switching assembly being further capable of conducting current from the second pole to the first pole;

an inductor disposed in a first current path having a first end and a second end, the first end connected to the second pole of the first switching component;

a second switching assembly connected between the first end of the inductance and the second current path, having a second control pole, a third pole, and a fourth pole, the second switching assembly being capable of conducting or breaking current from the third pole to the fourth pole via control of the second control pole, and the second switching assembly also being capable of conducting current from the fourth pole to the third pole;

a first switch disposed in a first current path capable of selectively connecting the first direct current terminal to a first pole of the first switch assembly or a second terminal of the inductor;

a second switch disposed in the first current path capable of selectively connecting the second DC terminal to either the first pole of the first switch assembly or the second terminal of the inductor;

wherein the first switch assembly, the second switch assembly, the first switch and the second switch are arranged to provide a boost circuit, a buck circuit or a bypass from the first dc terminal to the second dc terminal or from the second dc terminal to the first dc terminal.

2. The apparatus of claim 1, wherein the first and second switching components are each a power switch tube and an anti-parallel diode.

3. The apparatus of claim 2, wherein the power switch is a MOS transistor.

4. The apparatus of claim 1, further comprising:

a first capacitor connected between a first pole of the first switch assembly and the second current path; and/or the presence of a gas in the gas,

a second capacitor connected between the second DC terminal and the second current path; and/or the presence of a gas in the gas,

a third capacitor connected between the first direct current terminal and the second current path; and/or the presence of a gas in the gas,

a fourth capacitance connected between a second terminal of the inductance and the second current path.

5. The apparatus of any of claims 1-4, wherein the first switching assembly, the second switching assembly, and the inductor form a DC-DC conversion unit, and the apparatus comprises a plurality of DC-DC conversion units connected in parallel.

6. The apparatus of claim 5, wherein the apparatus comprises two parallel DC-DC conversion units.

7. The apparatus of claim 1, wherein the apparatus is configured such that the first switch connects the first DC terminal to a first pole of the first switch assembly and the second switch connects the second terminal of the inductor to the second DC terminal when the first DC terminal voltage is higher than a second DC terminal voltage,

wherein the first switching assembly repeatedly conducts and cuts off current from the first pole to the second pole via control of the first control pole, and the second switching assembly cuts off current from the third pole to the fourth pole via control of the second control pole, thereby realizing a step-down output from the first direct current terminal to the second direct current terminal, or

Wherein the first switching assembly cuts off a current from a first pole to a second pole via control of a first control pole, and the second switching assembly repeatedly conducts and cuts off a current from a third pole to a fourth pole via control of a second control pole, thereby realizing a boosted output from the second direct current terminal to the first direct current terminal.

8. The apparatus of claim 1, wherein the apparatus is configured such that when the first DC terminal voltage is lower than a second DC terminal voltage, the first switch connects the first DC terminal to the second terminal of the inductor, the second switch connects the second DC terminal to the first pole of the first switching component,

wherein the first switching assembly cuts off a current from a first pole to a second pole via control of a first control pole, the second switching assembly repeatedly conducts and cuts off a current from a third pole to a fourth pole via control of a second control pole, thereby realizing a boosted output from the first direct current terminal to the second direct current terminal, or,

wherein the first switching assembly repeatedly conducts and cuts off current from the first pole to the second pole via control of the first control pole, and the second switching assembly cuts off current from the third pole to the fourth pole via control of the second control pole, thereby realizing a step-down output from the second direct current terminal to the first direct current terminal.

9. The apparatus of claim 1, wherein the apparatus is configured such that when the first DC terminal voltage is equal to a second DC terminal voltage, the first switch connects the first DC terminal to the second terminal of the inductor, and the second switch connects a second DC terminal to the second terminal of the inductor to bypass the first DC terminal to the second DC terminal.

10. An uninterruptible power supply system comprising an uninterruptible power supply and the DC-DC converter of any of claims 1 to 9, wherein the first DC terminal of the DC-DC converter is connected to a rechargeable battery, and the second DC terminal of the DC-DC converter is connected to the uninterruptible power supply.

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