CN219659465U - Power supply circuit and energy storage device - Google Patents

Abstract

The utility model relates to a power supply circuit and energy storage equipment. The power supply circuit includes: the switching circuit comprises a plurality of interface circuits, a plurality of switching circuits, an AC/DC conversion circuit and a DC/DC conversion circuit. The interface circuit is connected with the external equipment and the first end of the switch circuit, the second end of the switch circuit is connected with the first end of the AC/DC conversion circuit and the second ends of other switch circuits, the second end of the AC/DC conversion circuit is connected with the first end of the DC/DC conversion circuit through the first direct current bus, and the second end of the DC/DC conversion circuit is connected with the battery module through the second direct current bus. When the power of the external power supply is insufficient to drive the electric equipment, the electric equipment can be provided with enough driving power based on the electric energy of the battery module through the DC/DC conversion circuit and the AC/DC conversion circuit so as to normally work.

Description

Power supply circuit and energy storage device

Technical Field

The utility model belongs to the technical field of electronic circuits, and particularly relates to a power supply circuit and energy storage equipment.

Background

At present, the existing energy storage devices are usually direct current devices (such as batteries), but in charging and discharging, the alternating current is generally used for charging or converting the alternating current into the alternating current for discharging, so that the energy storage devices need to convert the alternating current and the direct current through corresponding converting circuits.

When the energy storage device works in the bypass mode (namely, the input interface of the energy storage device directly supplies power to the output interface of the energy storage device), if the rated power of the electric equipment connected with the output interface is larger than the power accessed by the input interface, the electric equipment connected with the output interface cannot work normally.

Disclosure of Invention

The utility model aims to provide a power supply circuit and energy storage equipment, and aims to solve the problem that the traditional energy storage equipment cannot drive electric equipment to work normally when input power is smaller than rated power of the electric equipment.

A first aspect of an embodiment of the present utility model provides a power supply circuit, including: a plurality of interface circuits, a plurality of switch circuits, an AC/DC conversion circuit and a DC/DC conversion circuit; the first end of the interface circuit is used for being connected with external equipment, the second end of the interface circuit is connected with the first end of the switch circuit, the second end of the switch circuit is respectively connected with the first end of the AC/DC conversion circuit and the second ends of other switch circuits, the second end of the AC/DC conversion circuit is connected with the first end of the DC/DC conversion circuit through a first direct current bus, and the second end of the DC/DC conversion circuit is used for being connected with a battery module through a second direct current bus; the switch circuit is used for conducting connection between the second end of the interface circuit and the first end of the AC/DC conversion circuit or connection between the second end of the interface circuit and the second ends of other interface circuits when receiving conducting operation; the AC/DC conversion circuit is used for converting alternating current from the external equipment and outputting direct current to the first direct current bus, or is used for converting direct current on the first direct current bus into alternating current and outputting the alternating current to the external equipment; the DC/DC conversion circuit is used for performing buck conversion on the direct current on the first direct current bus and outputting the direct current to the second direct current bus, or is used for performing boost conversion on the direct current on the second direct current bus and outputting the direct current to the first direct current bus.

In one embodiment, the AC/DC conversion circuit includes a plurality of T-type three-level inverter circuits, a first end of each of the T-type three-level inverter circuits is connected to a second end of each of the switch circuits, and a second end of each of the T-type three-level inverter circuits is connected to the first DC bus.

In one embodiment, the first dc bus is provided with two bus capacitors connected in series, and the power supply circuit further includes a balance bridge circuit; the balance bridge circuit is connected with the bus capacitors and is used for adjusting the voltage on the bus capacitors so as to enable the voltage difference between the two bus capacitors to be stabilized within a preset voltage range.

In one embodiment, the T-type three-level inverter circuit includes a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first filter inductor and a filter capacitor; the first conducting end of the first switching tube is connected with the positive electrode of the first direct current bus, the second conducting end of the first switching tube is connected with the first conducting end of the second switching tube, and the second conducting end of the second switching tube is connected with the negative electrode of the first direct current bus; the third switching tube and the fourth switching tube are sequentially connected in series between the second conducting end of the first switching tube and the connecting point between the two bus capacitors; the third switching tube and the fourth switching tube are reversely arranged; the first end of the first filter inductor is connected with the second conducting end of the first switch tube, the second end of the first filter inductor is connected with the second end of the switch circuit, the first end of the filter capacitor is connected with the second end of the first filter inductor, and the second end of the filter capacitor is connected with the connecting point between the two busbar capacitors.

In one embodiment, the balance bridge circuit includes a fifth switching tube, a sixth switching tube and an energy storage inductor; the first conduction end of the fifth switching tube is connected with the positive electrode of the first direct current bus, the second conduction end of the fifth switching tube is connected with the first conduction end of the sixth switching tube and the first end of the energy storage inductor, the second conduction end of the sixth switching tube is connected with the negative electrode of the first direct current bus, and the second end of the energy storage inductor is connected with a connecting point between two bus capacitors.

In one embodiment, the AC/DC conversion circuit includes at least two T-type three-level inverter circuits.

In one embodiment, the switching circuit includes at least one relay connected between the first and second terminals of the switching circuit, the relay being configured to close upon receipt of a turn-on operation.

In one embodiment, the power supply circuit further includes a dc output circuit; the input end of the direct current output circuit is connected with the second direct current bus, the output end of the direct current output circuit is used for being connected with direct current equipment, and the direct current output circuit is used for outputting direct current on the second direct current bus to the direct current equipment after reducing the voltage.

In one embodiment, the dc output circuit includes a half-bridge switching unit, a second series resonant unit, a second transformer, and a unidirectional conduction unit; the first end of the half-bridge switch unit is the input end of the direct current output circuit, the second end of the half-bridge switch unit is connected with the first end of the second series resonance unit, the second end of the second series resonance unit is connected with the first winding of the second transformer, the second winding of the second transformer is connected with the first end of the unidirectional conduction unit, and the second end of the unidirectional conduction unit is the output end of the direct current output circuit.

A second aspect of the embodiment of the present utility model provides an energy storage device, including a battery module and a power supply circuit as described above, where the power supply circuit is configured to control charging and discharging of the battery module.

Compared with the prior art, the embodiment of the utility model has the beneficial effects that: when each interface circuit is connected with the electric equipment and the external power supply respectively, the external power supply can directly supply power to the electric equipment, and meanwhile, when the power of the external power supply is insufficient to drive the electric equipment, the electric equipment can be provided with enough driving power based on the electric energy of the battery module through the DC/DC conversion circuit and the AC/DC conversion circuit so as to enable the electric equipment to work normally.

Drawings

Fig. 1 is a schematic diagram of a power supply circuit according to an embodiment of the utility model;

fig. 2 is a schematic structural diagram of a power supply circuit according to another embodiment of the present utility model;

FIG. 3 is a specific circuit diagram of a power supply circuit according to an embodiment of the present utility model;

FIG. 4 is a schematic diagram of a DC/DC converter circuit according to an embodiment of the present utility model;

fig. 5 is a schematic structural diagram of a power supply circuit according to another embodiment of the present utility model;

FIG. 6 is a schematic diagram of a DC output circuit according to an embodiment of the present utility model;

fig. 7 is a schematic structural diagram of an energy storage device according to an embodiment of the present utility model.

The above figures illustrate: 10. a power supply circuit; 20. an external device; 30. a battery module; 40. a direct current device; 50. an energy storage device; 60. a control module; 100. an interface circuit; 200. a switching circuit; 300. an AC/DC conversion circuit; 310. a T-type three-level inverter circuit; 400. a DC/DC conversion circuit; 410. a first full-bridge switching unit; 420. a second full-bridge switching unit; 430. a first series resonant cell; 440. a first transformer; 500. a first dc bus; 600. a second direct current bus; 700. a balanced bridge circuit; 800. a DC output circuit; 810. a half-bridge switching unit; 820. a second series resonant cell; 830. a second transformer; 840. and a unidirectional conduction unit.

Detailed Description

In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the utility model is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the utility model.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or be indirectly connected to the other element.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Fig. 1 shows a schematic configuration of a power supply circuit according to an embodiment of the present utility model, and for convenience of explanation, only the portions related to the present embodiment are shown in detail as follows:

the power supply circuit 10 includes: a number of interface circuits 100, a number of switching circuits 200, an AC/DC conversion circuit 300 and a DC/DC conversion circuit 400.

The first terminal of the interface circuit 100 is used for being connected to the external device 20, the second terminal of the interface circuit 100 is connected to the first terminal of the corresponding switch circuit 200, the second terminal of the switch circuit 200 is connected to the first terminal of the AC/DC conversion circuit 300 and the second terminals of the other switch circuits 200, respectively, the second terminal of the AC/DC conversion circuit 300 is connected to the first terminal of the DC/DC conversion circuit 400 through the first DC bus 500, and the second terminal of the DC/DC conversion circuit 400 is used for being connected to the battery module 30 through the second DC bus 600. The external device 20 may be an external power source or an electric device.

The switch circuits 200 are in one-to-one correspondence with the interface circuits 100, and the switch circuits 200 are configured to turn on a connection between the second terminal of the interface circuit 100 and the first terminal of the AC/DC conversion circuit 300 or a connection between the second terminal of the interface circuit 100 and the second terminal of the other interface circuit 100 when receiving the on operation.

The AC/DC conversion circuit 300 is used for converting AC power from the external device 20 and outputting DC power to the first DC bus 500, or converting DC power on the first DC bus 500 into AC power and outputting the AC power to the external device 20.

The DC/DC conversion circuit 400 is configured to down-convert the DC power on the first DC bus 500 and output the down-converted DC power to the second DC bus 600, or to up-convert the DC power on the second DC bus 600 and output the up-converted DC power to the first DC bus 500.

It should be noted that, since the second ends of the switch circuits 200 are connected to each other, when each interface circuit 100 is connected to the electric device and the external power source, the electric device can be directly powered by the external power source through each switch circuit 200 and the interface circuit 100, and the electric energy of the external power source is not required to be converted by the AC/DC conversion circuit 300, so that the utilization efficiency of the electric energy is improved. Meanwhile, when the power of the external power supply is insufficient to drive the electric device, the electric device can also be provided with sufficient driving power based on the electric energy of the battery module 30 through the DC/DC conversion circuit 400 and the AC/DC conversion circuit 300 so as to work normally.

As shown in fig. 2, in one embodiment, the AC/DC conversion circuit 300 includes a number of T-type three-level inverter circuits 310. A first terminal of the T-type three-level inverter circuit 310 is connected to a second terminal of each of the switching circuits 200, and a second terminal of the T-type three-level inverter circuit 310 is connected to the first dc bus 500. The number of the T-type three-level inverter circuits 310 can be configured according to actual requirements.

For example, when the AC/DC conversion circuit 300 needs to output only single-phase alternating current or to switch in single-phase alternating current, only one T-type three-level inverter circuit 310 is needed, and when the AC/DC conversion circuit 300 needs to output three-phase alternating current or to switch in three-phase alternating current, three T-type three-level inverter circuits 310 are needed.

As shown in fig. 3, in an embodiment, two series BUS capacitors are disposed on the first dc BUS 500, specifically, a BUS capacitor C1 and a BUS capacitor C2 are disposed on the first dc BUS 500, the BUS capacitor C1 and the BUS capacitor C2 are sequentially connected in series between the positive BUS1+ of the first dc BUS 500 and the negative BUS 1-of the first dc BUS 500, and the power supply circuit 10 further includes a balance bridge circuit 700. The balance bridge circuit 700 is connected to the bus capacitors C1 and C2, and is used for adjusting the voltages of the bus capacitors C1 and C2 so as to stabilize the voltage difference between the two bus capacitors C1 and C2 within a preset voltage range. The bus capacitors C1 and C2 can be used to stabilize the voltage on the first dc bus 500, and at the same time, the junction of the two bus capacitors C1 and C2 can also output the neutral voltage, so that the neutral voltage can be kept stable by the balance bridge circuit 700.

In an embodiment, each of the T-type three-level inverter circuits 310 has the same structure, and taking one of the T-type three-level inverter circuits 310 as an example, the T-type three-level inverter circuit 310 includes a first switching tube Q1, a second switching tube Q2, a third switching tube Q3, a fourth switching tube Q4, a first filter inductor L1 and a first filter capacitor C3.

The first conducting end of the first switching tube Q1 is connected with the positive electrode BUS1+ of the first direct current BUS 500, the second conducting end of the first switching tube Q1 is connected with the first conducting end of the second switching tube Q2, and the second conducting end of the second switching tube Q2 is connected with the negative electrode BUS1-of the first direct current BUS 500. The third switching tube Q3 and the fourth switching tube Q4 are sequentially connected in series between the second conducting end of the first switching tube Q1 and the connecting point between the two bus capacitors. The third switching tube Q3 and the fourth switching tube Q4 are reversely arranged, namely, the first conducting end of the third switching tube Q3 is connected with the second conducting end of the first switching tube Q1, the second conducting end of the third switching tube Q3 is connected with the second conducting end of the fourth switching tube Q4, and the first conducting end of the fourth switching tube Q4 is connected with a connecting point between two bus capacitors. The first end of the first filter inductor L1 is connected to the second conducting end of the first switching tube Q1, the second end of the first filter inductor L1 is connected to the second end of each switching circuit 200, the first end of the first filter capacitor C3 is connected to the second end of the first filter inductor L1, and the second end of the first filter capacitor C3 is connected to a connection point between two bus capacitors.

By controlling the on and off of the first, second, third, and fourth switching tubes Q1, Q2, Q3, and Q4, the direct current on the first direct current bus 500 may be converted into alternating current, or the alternating current input from the external power source may be converted into direct current and supplied to the first direct current bus 500.

In one embodiment, the balanced bridge circuit 700 includes a fifth switching tube Q9, a sixth switching tube Q10, and an energy storage inductance L3. The first conducting end of the fifth switching tube Q9 is connected with the positive electrode BUS1+ of the first direct current BUS 500, the second conducting end of the fifth switching tube Q9 is connected with the first conducting end of the sixth switching tube Q10 and the first end of the energy storage inductor L3, the second conducting end of the sixth switching tube Q10 is connected with the negative electrode BUS1-of the first direct current BUS 500, and the second end of the energy storage inductor L3 is connected with a connecting point between the two BUS capacitors C1 and C2.

The first switching tube Q1, the second switching tube Q2, the third switching tube Q3, the fourth switching tube Q4, the fifth switching tube Q9 and the sixth switching tube Q10 may be NPN transistors. The collector of the NPN triode corresponds to the first conducting end of each switching tube, and the emitter of the NPN triode corresponds to the second conducting end of each switching tube.

When the voltage (zero line voltage) of the connection point between the two bus capacitors C1, C2 is equal to the preset voltage, the balance bridge circuit 700 does not need to operate. When the voltage at the connection point between the two bus capacitors C1 and C2 does not reach the preset voltage, the voltage at the connection point between the two bus capacitors C1 and C2 can be adjusted by controlling the on time of the fifth switching tube Q9 and the sixth switching tube Q10 in the balance bridge circuit 700, that is, controlling the duty ratio of the fifth switching tube Q9 and the sixth switching tube Q10, wherein the voltage at the connection point between the two bus capacitors C1 and C2 is larger as the duty ratio of the fifth switching tube Q9 is larger, and the voltage at the connection point between the two bus capacitors C1 and C2 is smaller as the duty ratio of the sixth switching tube Q10 is larger. The preset voltage is related to the voltage on the first dc bus 500 and the ratio of the capacitance values of the two bus capacitors C1 and C2.

In one embodiment, the AC/DC conversion circuit 300 includes at least two T-type three-level inverter circuits 310, and the interface circuit 100 and the switch circuit 200 include at least two power transmission lines, so that the two T-type three-level inverter circuits 310 can be independently output through the two power transmission lines, respectively. Split phase input or split phase output can be achieved by two T-type three-level inverter circuits 310. When the AC/DC conversion circuit 300 performs split phase input, the two T-type three-level inverter circuits 310 may operate independently, charging the first DC bus 500 based on the split phase current supplied from the external power source. When the AC/DC conversion circuit 300 performs split phase output, the two T-type three-level inverter circuits 310 may output alternating currents having different phases based on the direct currents on the first direct current bus 500, respectively, and a phase difference between the two alternating currents may be 180 °. The two T-type three-level inverter circuits 310 can increase power conversion efficiency compared to the AC/DC conversion circuit 300 using a single T-type three-level inverter circuit 310.

In an embodiment, at least one relay is provided between the first and second terminals of the switching circuit 200, the relay being adapted to close upon receipt of a turn-on operation. The number of relays of the switching circuit 200 may correspond to the interfaces of the corresponding interface circuit 100.

For example, one of the interface circuits 100 includes four interfaces, i.e., a first interface LA, a second interface LB, a third interface LC, and a fourth interface LD, the switching circuit 200 corresponding to the interface circuit 100 includes four relays, i.e., a first relay S1, a second relay S2, a third relay S3, and a fourth relay S4, the first interface LA is connected to a first end of one T-type three-level inverter circuit 310 through the first relay S1, the second interface LB is connected to a first end of the other T-type three-level inverter circuit 310 through the second relay S2, the third interface LC is connected to a connection point between the two bus capacitors C1, C2 through the third relay S3, and the fourth interface LD is grounded and connected to a connection point between the two bus capacitors C1, C2 through the fourth relay S4.

As shown in fig. 4, in an embodiment, the DC/DC conversion circuit 400 includes a first full-bridge switching unit 410, a second full-bridge switching unit 420, a first series resonant unit 430, and a first transformer 440;

the first end of the first full-bridge switching unit 410 is connected to the first dc bus 500, the second end of the first full-bridge switching unit 410 is connected to the first winding of the first transformer 440 through the first series resonant unit 430, the first end of the second full-bridge switching unit 420 is connected to the second winding of the first transformer 440, the second end of the second full-bridge switching unit 420 is connected to the target dc device 40 through the second dc bus 600, the first full-bridge switching unit 410 and the first full-bridge switching unit 410 are used for voltage inversion or rectification, and the first series resonant unit 430 is used for reducing switching losses of the first full-bridge switching unit 410.

Specifically, as shown in fig. 4, in an example, the first full-bridge switching unit 410 includes a first full-bridge switching tube Q11, a second full-bridge switching tube Q12, a third full-bridge switching tube Q13, and a fourth full-bridge switching tube Q14, the second full-bridge switching unit 420 includes a fifth full-bridge switching tube Q15, a sixth full-bridge switching tube Q16, a seventh full-bridge switching tube Q17, and an eighth full-bridge switching tube Q18, and the first series resonant unit 430 includes a first resonant inductance and a first resonant capacitance. The first transformer 440 includes a first winding and a second winding coupled to each other.

The first conducting end of the first full-bridge switching tube Q11 is connected with the positive electrode BUS1+ of the first direct-current BUS 500, the second conducting end of the first full-bridge switching tube Q11 is connected with the first conducting end of the second full-bridge switching tube Q12, the second conducting end of the second full-bridge switching tube Q12 is connected with the negative electrode BUS1-of the first direct-current BUS 500, the first conducting end of the third full-bridge switching tube Q13 is connected with the positive electrode BUS1+ of the first direct-current BUS 500, the second conducting end of the third full-bridge switching tube Q13 is connected with the first conducting end of the fourth full-bridge switching tube Q14, and the second conducting end of the fourth full-bridge switching tube Q14 is connected with the negative electrode BUS1-of the first direct-current BUS 500.

The first end of the first resonant inductor is connected with the second conducting end of the first full-bridge switching tube Q11, the second end of the first resonant inductor is connected with the first end of the first winding, the second end of the first winding is connected with the first end of the first resonant capacitor, and the second end of the first resonant capacitor is connected with the second conducting end of the third full-bridge switching tube Q13.

The first conducting end of the fifth full-bridge switching tube Q15 is connected with the positive electrode BUS2+ of the second direct-current BUS 600, the second conducting end of the fifth full-bridge switching tube Q16 is connected with the first conducting end of the sixth full-bridge switching tube Q16, and the second conducting end of the sixth full-bridge switching tube Q16 is connected with the negative electrode BUS 2-of the second direct-current BUS 600. The first conducting end of the seventh full-bridge switching tube Q17 is connected with the positive electrode BUS2 < + > of the second direct current BUS 600, the second conducting end of the seventh full-bridge switching tube Q17 is connected with the first conducting end of the eighth full-bridge switching tube Q18, and the second conducting end of the eighth full-bridge switching tube Q18 is connected with the negative electrode BUS2 < + > of the second direct current BUS 600. The first end of the second winding is connected with the second conducting end of the fifth full-bridge switching tube Q15, and the second end of the second winding is connected with the second conducting end of the seventh full-bridge switching tube Q17. The controlled ends of the first full-bridge switching tube Q11, the second full-bridge switching tube Q12, the third full-bridge switching tube Q13, the fourth full-bridge switching tube Q14, the fifth full-bridge switching tube Q15, the sixth full-bridge switching tube Q16, the seventh full-bridge switching tube Q17 and the eighth full-bridge switching tube Q18 are all connected with a main control circuit.

The first full-bridge switching tube Q11, the second full-bridge switching tube Q12, the third full-bridge switching tube Q13, the fourth full-bridge switching tube Q14, the fifth full-bridge switching tube Q15, the sixth full-bridge switching tube Q16, the seventh full-bridge switching tube Q17 and the eighth full-bridge switching tube Q18 can be N-type MOS tubes, the first conducting end of the full-bridge switching tube corresponds to the drain electrode of the N-type MOS tube, the second conducting end of the full-bridge switching tube corresponds to the source electrode of the N-type MOS tube, and the controlled end of the full-bridge switching tube corresponds to the grid electrode of the N-type MOS tube.

A BUS capacitor C6 is arranged between the positive electrode BUS2+ of the second dc BUS 600 and the negative electrode BUS 2-of the second dc BUS 600.

As shown in fig. 5, in an embodiment, the power supply circuit 10 further includes a dc output circuit 800. The input end of the dc output circuit 800 is connected to the second dc bus 600, the output end of the dc output circuit 800 is used to be connected to the dc device 40, and the dc output circuit 800 is used to step down the dc power on the second dc bus 600 and output the dc power to the dc device 40, where the dc device 40 may be a display module, and for example, the dc device 40 may be a liquid crystal screen.

As shown in fig. 6, in an embodiment, the dc output circuit 800 includes a half-bridge switching unit 810, a second series resonant unit 820, a second transformer 830, and a unidirectional conducting unit 840. The first end of the half-bridge switching unit 810 is an input end of the dc output circuit 800, the second end of the half-bridge switching unit 810 is connected to the first end of the second series resonant unit 820, the second end of the second series resonant unit 820 is connected to the first winding of the second transformer 830, the second winding of the second transformer 830 is connected to the first end of the unidirectional conducting unit 840, and the second end of the unidirectional conducting unit 840 is an output end of the dc output circuit 800. The half-bridge switching unit 810 and the second series resonant unit 820 are configured to invert the current on the second dc bus 600, regulate the voltage by the second transformer 830, and rectify the voltage by the unidirectional conducting unit 840 to output the rectified voltage.

The half-bridge switching unit 810 includes a first half-bridge switching transistor Q19 and a second half-bridge switching transistor Q20, the second series resonant unit 820 includes a second resonant inductor L5 and a second resonant capacitor C7, and the unidirectional conductive unit 840 includes a first unidirectional conductive device D1 and a second unidirectional conductive device D2. The first conducting end of the first half-bridge switching tube Q19 is connected with the positive electrode BUS2+ of the second direct current BUS 600, the second conducting end of the first half-bridge switching tube Q19 is connected with the first conducting end of the second half-bridge switching tube Q20 and the first end of the second series resonance unit 820, and the second conducting end of the second half-bridge switching tube Q20 is connected with the negative electrode BUS2+ of the second direct current BUS 600. The first end of the second resonant capacitor C7 is connected to the second conducting end of the first half-bridge switching tube Q19, the second end of the second resonant capacitor C7 is connected to the first end of the second resonant inductor L5, and the second end of the second resonant inductor L5 is connected to the first end of the first winding of the second transformer 830. The second end of the first winding of the second transformer 830 is connected with the negative electrode BUS 2-of the second direct current BUS 600, the first end of the second winding of the second transformer 830 is connected with the anode of the first unidirectional conductor D1, the second end of the second winding of the second transformer 830 is connected with the anode of the second unidirectional conductor D2, the cathodes of the first unidirectional conductor D1 and the second unidirectional conductor D2 are both connected with the output positive electrode pd+ of the direct current output circuit 800, and the midpoint of the second winding of the second transformer 830 is connected with the output negative electrode PD-of the direct current output circuit 800. The output positive pole pd+ of the dc output circuit 800 and the output negative pole PD-of the dc output circuit 800 may be used for connection with the dc device 40. The first unidirectional conductive device D1 and the second unidirectional conductive device D2 may be diodes, the anode of the unidirectional conductive device corresponds to the anode of the diode, and the cathode of the unidirectional conductive device corresponds to the cathode of the diode.

The dc output circuit 800 is configured to implement voltage isolation to prevent the dc device 40 connected to the dc output circuit 800 from being damaged due to excessive voltage on the second dc bus 600. The direct current device 40 may obtain electric power from the battery module 30 or from an external power source.

In an embodiment, the dc output circuit 800 further includes a second filter capacitor C8, where the second filter capacitor C8 is connected between the output positive pole pd+ of the dc output circuit 800 and the output negative pole PD "of the dc output circuit 800, and is used to filter the ac component in the current output by the dc output circuit 800.

Fig. 7 is a schematic structural diagram of an energy storage device according to an embodiment of the present utility model, and for convenience of explanation, only the portions relevant to the embodiment are shown, which are described in detail below:

the energy storage device 50 includes a battery module 30 and the power supply circuit 10 of any of the above embodiments, the power supply circuit 10 being configured to control charging and discharging of the battery module 30.

In an embodiment, the energy storage device 50 further includes a control module 60, where the control module 60 is connected to the power supply circuit 10 and is configured to detect a voltage in the power supply circuit 10 and control on/off of each switch in the power supply circuit 10 to control the power supply circuit 10 to work normally. For example, the control module 60 may detect the voltage across the two bus capacitances C1, C2 (or the voltage at the junction between the two bus capacitances C1, C2) and control the operation of the balanced bridge circuit 700 based on the voltage. The control module 60 may also send on or off operations to the respective switching circuits 200 to control the on and off of the respective switching circuits 200.

In the foregoing embodiments, the descriptions of the embodiments are emphasized, and in part, not described or illustrated in any particular embodiment, reference is made to the related descriptions of other embodiments.

The above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present utility model, and are intended to be included in the scope of the present utility model.

Claims (10)

1. A power supply circuit, comprising: a plurality of interface circuits, a plurality of switch circuits, an AC/DC conversion circuit and a DC/DC conversion circuit;

the first end of the interface circuit is used for being connected with external equipment, the second end of the interface circuit is connected with the first end of the switch circuit, the second end of the switch circuit is respectively connected with the first end of the AC/DC conversion circuit and the second ends of other switch circuits, the second end of the AC/DC conversion circuit is connected with the first end of the DC/DC conversion circuit through a first direct current bus, and the second end of the DC/DC conversion circuit is used for being connected with a battery module through a second direct current bus;

the switch circuit is used for conducting connection between the second end of the interface circuit and the first end of the AC/DC conversion circuit or connection between the second end of the interface circuit and the second ends of other interface circuits when receiving conducting operation;

the AC/DC conversion circuit is used for converting alternating current from the external equipment and outputting direct current to the first direct current bus, or is used for converting direct current on the first direct current bus into alternating current and outputting the alternating current to the external equipment;

the DC/DC conversion circuit is used for performing buck conversion on the direct current on the first direct current bus and outputting the direct current to the second direct current bus, or is used for performing boost conversion on the direct current on the second direct current bus and outputting the direct current to the first direct current bus.

2. The power supply circuit of claim 1, wherein the AC/DC conversion circuit comprises a plurality of T-shaped three-level inverter circuits, a first end of each of the T-shaped three-level inverter circuits being connected to a second end of each of the switching circuits, a second end of each of the T-shaped three-level inverter circuits being connected to the first DC bus.

3. The power supply circuit of claim 2, wherein the first dc bus is provided with two bus capacitors in series, the power supply circuit further comprising a balanced bridge circuit;

the balance bridge circuit is connected with the bus capacitors and is used for adjusting the voltage on the bus capacitors so as to enable the voltage difference between the two bus capacitors to be stabilized within a preset voltage range.

4. The power supply circuit of claim 3, wherein the T-type three-level inverter circuit comprises a first switching tube, a second switching tube, a third switching tube, a fourth switching tube, a first filter inductance and a filter capacitance;

the first conducting end of the first switching tube is connected with the positive electrode of the first direct current bus, the second conducting end of the first switching tube is connected with the first conducting end of the second switching tube, and the second conducting end of the second switching tube is connected with the negative electrode of the first direct current bus;

the third switching tube and the fourth switching tube are sequentially connected in series between the second conducting end of the first switching tube and the connecting point between the two bus capacitors; the third switching tube and the fourth switching tube are reversely arranged;

the first end of the first filter inductor is connected with the second conducting end of the first switch tube, the second end of the first filter inductor is connected with the second end of the switch circuit, the first end of the filter capacitor is connected with the second end of the first filter inductor, and the second end of the filter capacitor is connected with the connecting point between the two busbar capacitors.

5. The power supply circuit of claim 3, wherein the balanced bridge circuit comprises a fifth switching tube, a sixth switching tube, and an energy storage inductance;

the first conduction end of the fifth switching tube is connected with the positive electrode of the first direct current bus, the second conduction end of the fifth switching tube is connected with the first conduction end of the sixth switching tube and the first end of the energy storage inductor, the second conduction end of the sixth switching tube is connected with the negative electrode of the first direct current bus, and the second end of the energy storage inductor is connected with a connecting point between two bus capacitors.

6. The power supply circuit according to any one of claims 2 to 5, wherein the AC/DC conversion circuit includes at least two of the T-type three-level inverter circuits.

7. The power supply circuit of any of claims 1-5, wherein the switching circuit includes at least one relay connected between a first terminal and a second terminal of the switching circuit, the relay being configured to close upon receipt of a turn-on operation.

8. The power supply circuit of any one of claims 1-5, wherein the power supply circuit further comprises a direct current output circuit;

the input end of the direct current output circuit is connected with the second direct current bus, the output end of the direct current output circuit is used for being connected with direct current equipment, and the direct current output circuit is used for outputting direct current on the second direct current bus to the direct current equipment after reducing the voltage.

9. The power supply circuit of claim 8, wherein the dc output circuit comprises a half-bridge switching unit, a second series resonant unit, a second transformer, and a unidirectional conduction unit;

the first end of the half-bridge switch unit is the input end of the direct current output circuit, the second end of the half-bridge switch unit is connected with the first end of the second series resonance unit, the second end of the second series resonance unit is connected with the first winding of the second transformer, the second winding of the second transformer is connected with the first end of the unidirectional conduction unit, and the second end of the unidirectional conduction unit is the output end of the direct current output circuit.

10. An energy storage device comprising a battery module and a power supply circuit as claimed in any one of claims 1 to 9 for controlling the charging and discharging of the battery module.