A multi-output circuit, energy storage device

Abstract

The utility model provides a kind of multi-output circuit, energy storage equipment, and the multi-output circuit includes: rectifying module, first voltage reduction module, second voltage reduction module and voltage transformation module. Through the rectifying module receives AC input, rectifies and outputs as DC output to AC output. The output end of the rectifying module is connected by first voltage reduction module, and the DC output is voltage reduction processing and outputs first DC voltage. Bridge unit in the second voltage reduction module is connected with first voltage reduction module, and the first DC voltage is voltage reduction processing and outputs second DC voltage. Finally, bridge unit is connected with voltage transformation module to constitute resonant bridge conversion circuit, and third DC voltage is output according to first DC voltage by the resonant bridge conversion circuit. It can be realized that one voltage transformation module is connected to form resonant bridge conversion circuit by including a bridge unit in voltage reduction module in one circuit, and multi-output of different DC supply voltage can be realized, and the circuit architecture of multi-power supply circuit scheme is simplified.

Description

Technical Field

[0001] This utility model relates to the field of power electronics technology, specifically to a multi-output circuit and an energy storage device. Background Technology

[0002] With the development of power electronics technology, the internal circuits of equipment are becoming increasingly complex. There are situations where multiple circuits in the same equipment or system require different power supply voltages. For example, a device may contain multiple circuits such as communication circuits, control circuits, and battery management circuits. Different circuits require different power supply voltages. In this case, it is necessary to output the corresponding power supply voltage for the various different circuits of the device to ensure its normal operation.

[0003] Traditional multi-circuit power supply schemes often use different transformer circuits for different circuits to convert the input power voltage into different supply voltages. This results in a complex circuit structure and is prone to problems with unstable supply voltage. Utility Model Content

[0004] This invention provides a multi-output circuit and energy storage device to simplify traditional multi-power supply schemes and improve the stability of multi-output power supply voltage.

[0005] In a first aspect, this utility model provides a multi-output circuit, the multi-output circuit comprising: The rectifier module is used to receive AC input, rectify the AC output, and output DC output; The first step-down module is connected to the output terminal of the rectifier circuit and is used to step down the DC output and output a first DC voltage. The second step-down module includes a bridge unit connected to the first step-down module, which is used to step down the first DC voltage and output a second DC voltage. The transformer module, connected to the bridge unit, forms a resonant bridge converter circuit, which is used to output a third DC voltage based on the first DC voltage.

[0006] Secondly, this utility model provides an energy storage device, which includes a device body and a multi-output circuit as described in the first aspect, disposed within the device body.

[0007] This invention provides a multi-output circuit and an energy storage device. The multi-output circuit includes a rectifier module, a first step-down module, a second step-down module, and a transformer module. The rectifier module receives AC input, rectifies the AC output, and outputs DC output. The first step-down module is connected to the output of the rectifier module to step down the DC output and output a first DC voltage. The bridge unit in the second step-down module is connected to the first step-down module to step down the first DC voltage and output a second DC voltage. Finally, the bridge unit is connected to the transformer module to form a resonant bridge converter circuit, which outputs a third DC voltage based on the first DC voltage.

[0008] By using the multi-output circuit provided by this utility model, multiple different DC power supply voltages can be output by connecting a transformer module and the bridge unit inside the step-down module to form a resonant bridge converter circuit. This simplifies the circuit architecture of the multi-power supply circuit scheme. Furthermore, since the transformer module and the bridge unit are connected to form a resonant bridge converter circuit, the negative impact of leakage inductance of the transformer winding on voltage stability can be reduced, thereby improving the stability of the multi-output circuit.

[0009] These or other aspects of this invention will become more apparent in the following description of the embodiments. Attached Figure Description

[0010] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This diagram illustrates a structural schematic of a multi-output circuit provided in an embodiment of the present invention. Figure 2 This diagram illustrates another structural schematic of the multi-output circuit provided in an embodiment of the present invention; Figure 3 This diagram illustrates another structural schematic of the multi-output circuit provided in an embodiment of the present invention; Explanation of reference numerals in the attached figures: 1-Multi-output circuit, 11-Rectifier module, 12-First step-down module, 13-Second step-down module, 14-Transformer module, 141-Primary coil, 142-Secondary coil, 143-Resonant capacitor. Detailed Implementation

[0012] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0013] To enable those skilled in the art to better understand the solutions of this utility model, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0014] In this embodiment of the present invention, it should be noted that relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations.

[0015] Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0016] In the description of the embodiments of this utility model, the words "example" or "for example" are used to indicate illustration, explanation, or description. Any embodiment or design described as "example" or "for example" in the embodiments of this utility model is not to be construed as being more preferred or having more advantages than another embodiment or design. The use of the words "example" or "for example" is intended to present relative concepts in a clear manner.

[0017] Furthermore, in the embodiments of this utility model, "multiple" refers to two or more. Therefore, in the embodiments of this utility model, "multiple" can also be understood as "at least two". "At least one" can be understood as one or more, for example, one, two, or more. For example, including at least one means including one, two, or more, and it does not limit which ones are included. For example, including at least one of A, B, and C, then it could include A, B, C, A and B, A and C, B and C, or A and B and C.

[0018] It should be noted that in this embodiment of the utility model, "and / or" describes the relationship between the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the preceding and following associated objects have an "or" relationship.

[0019] It should be noted that in the embodiments of this utility model, "connection" can be understood as electrical connection. The connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components.

[0020] As described in the background section, traditional multi-power supply schemes typically use different transformer circuits to meet the different power supply voltage requirements of various circuits, resulting in complex circuit structures. Some traditional multi-power supply schemes use a flyback switching power supply (or simply flyback power supply) for transformer voltage conversion, controlling the primary and secondary windings of the transformer to output different power supply voltages by switching the power on and off. However, this type of flyback switching power supply scheme is prone to problems due to the incomplete coupling between the primary and secondary windings of the transformer, leading to insufficient release of magnetic field energy and significant output voltage fluctuations, resulting in unstable power supply voltage.

[0021] In view of this, the present invention provides a multi-output circuit and an energy storage device. Firstly, the present invention provides a multi-output circuit that can, as... Figure 1 As shown, the multiplexed output circuit 1 may include: Rectifier module 11 is used to receive AC input, rectify the AC output and output DC output; The first step-down module 12 is connected to the output terminal of the rectifier module and is used to step down the DC output and output a first DC voltage. The second step-down module 13 includes: a bridge unit, which is connected to the first step-down module and is used to step down the first DC voltage and output a second DC voltage; The transformer module 14 is connected to the bridge unit to form a resonant bridge converter circuit, which is used to output a third DC voltage based on the first DC voltage.

[0022] In this invention, the bridge unit in the second step-down module can be either a full-bridge unit or a half-bridge unit. Here, "bridge" refers to a circuit topology; a full-bridge unit refers to a circuit bridge formed by two sets of switching transistors, while a half-bridge unit refers to a circuit bridge formed by one set of switching transistors. As one implementation method, it can be as follows: Figure 2 As shown, the half-bridge unit includes a first switch Q1 and a second switch Q2. This half-bridge unit, together with the transformer module, forms an asymmetric half-bridge converter circuit. The left and right sides of the asymmetric half-bridge converter circuit have an asymmetric topology.

[0023] The circuit connection method within this half-bridge unit can be as follows: Figure 2 As shown, the first terminal of the first switch Q1 is connected to the first step-down module, the second terminal of the first switch Q1 is connected to the first terminal of the second switch Q2, and the second terminal of the second switch Q2 is grounded. The transformer module 14 is connected between the first terminal of the first switch Q1 and the second terminal of the first switch Q1.

[0024] As one implementation method, it can be as follows Figure 2 As shown, the transformer module 14 includes: a transformer unit (not shown in the figure), a resonant capacitor 143, and a transformer output unit (not shown in the figure). The transformer unit includes: a primary coil 141 and a secondary coil 142. The internal circuit connection of the transformer module is as follows: The first end of the primary coil 141 is connected to the first end of the first switch Q1, the second end of the primary coil 141 is connected to the first end of the resonant capacitor 143, and the second end of the resonant capacitor 143 is connected to the second end of the first switch Q1. The transformer output unit is connected to the secondary coil 142, and the transformer output unit is used to output the third DC voltage.

[0025] In one implementation method, to ensure the resonant bridge converter circuit achieves its resonant effect, the frequency difference between the resonant frequency of the resonant bridge converter circuit and the switching frequencies of the first switch Q1 and the second switch Q2 in the second step-down module needs to be less than a preset frequency difference threshold. That is, the resonant frequency of the resonant bridge converter circuit is close to the switching frequency of the second step-down module, thereby ensuring the stability and accuracy of the electrical energy output from the transformer capacitor.

[0026] In this invention, the AC power supply refers to the power input of the multi-output circuit provided by this invention. Specifically, it can be 220V or 380V AC power, and the specific voltage can be flexibly selected according to actual needs. The rectifier module 11 receives the AC voltage signal by connecting to this AC power supply, and then rectifies it to convert the AC power into DC power. In one embodiment, the rectifier module 11 is a rectifier bridge, which can rectify the high-voltage AC power and output a high-voltage DC voltage signal, providing the basic DC voltage signal for subsequent multi-output voltage outputs.

[0027] Furthermore, in this invention, the first step-down module 12 is connected to the output terminal of the rectifier module, and is used to convert the high-voltage DC voltage signal rectified by the rectifier module 11 into a first DC voltage. The magnitudes of the high-voltage DC voltage signal and the first DC voltage depend on the specific application scenario, and this invention does not impose strict limitations. For example, the first step-down module 12 can step down a 220V high-voltage DC voltage signal to a 15V DC voltage signal and output it.

[0028] In one implementation, the first step-down module can be a high-voltage step-down module, specifically a high-voltage step-down chopper circuit module, including a high-voltage BUCK circuit, i.e., a high-voltage step-down chopper circuit. The output first DC voltage can be adjusted by the on-time and off-time of the power transistor in the high-voltage step-down chopper circuit (which can be adjusted by the set duty cycle).

[0029] Conversely, based on the magnitude of the required first DC voltage and the magnitude of the high-voltage DC voltage signal output by the rectifier module, the on and off times of the power transistors in the high-voltage buck chopper circuit can be controlled using a duty cycle D1 = first DC voltage / high-voltage DC voltage signal. This allows the first buck module to output the required first DC voltage. Alternatively, the required first DC voltage can be used as the main feedback signal, and a feedback control mechanism can be used to adjust the operating state of the power transistors in the high-voltage buck chopper circuit, ensuring that the first buck module can stably output the corresponding first DC voltage.

[0030] In this invention, the magnitudes of the first DC voltage, the second DC voltage, and the third DC voltage depend on the actual application scenario and are not strictly limited here. As an example, the first DC voltage is 15V, the second DC voltage is 5V, and the third DC voltage is 24V.

[0031] In this invention, the second step-down module includes a second DC voltage output unit, which, as one embodiment, can be implemented as follows: Figure 2 As shown, the second DC voltage output unit is connected between the first terminal and the second terminal of the second switch Q2 to output the second DC voltage. The second DC voltage output unit includes an output capacitor C1 and an output inductor L, which are connected in series between the first and second terminals of the second switch Q2. The second DC voltage is output through the output capacitor C1. The output capacitor C1 and the output inductor L form a resonant circuit, allowing the output current of the second DC voltage output unit to be a sine wave. The rate of change of this sine wave current is smaller than that of a triangular wave current, which reduces the high-frequency noise caused by the large rate of change of current in the triangular wave current (V=L·di / dt) due to leakage inductance in traditional solutions, resulting in poor electromagnetic compatibility (EMC) issues.

[0032] In this invention, the first switch Q1 and the second switch Q2 determine the current flow direction in the circuit. When Q1 and Q2 are both on, both the first and second switches are short-circuited. When Q1 and Q2 are both off, the current flows out from the output terminal of the first step-down module and is grounded through the second DC voltage output unit, but a current loop cannot be formed. At this time, the entire multi-output circuit has no DC voltage output.

[0033] It is evident that a current loop exists after the current outputs from the first step-down module, allowing for DC voltage output, only when one of Q1 and Q2 is on and the other is off, thus ensuring a current loop. Specifically, when Q1 is on and Q2 is off, the primary coil 141 and resonant capacitor 143 are short-circuited, and the second DC voltage output unit draws power from the first step-down module. When Q1 is off and Q2 is on, the second DC voltage output unit is short-circuited, and the primary coil 141 and resonant capacitor 143 draw power from the first step-down module. Therefore, controlling the states of Q1 and Q2 is crucial for stable output of multiple DC voltages.

[0034] In some embodiments, the control terminal of the first switch Q1 receives a first drive control signal, and the control terminal of the second switch Q2 receives a second drive control signal, wherein the sum of the duty cycles of the first drive control signal and the second drive control signal is equal to 1. Thus, in this embodiment, the first switch Q1 is turned on or off according to the first drive control signal, and the second switch Q2 is turned on or off according to the second drive control signal. It is necessary to ensure that when the first switch Q1 is turned on according to the first drive control signal, the second switch Q2 is turned off according to the second drive control signal, and vice versa.

[0035] That is, in this invention, the conduction time of the first drive control signal and the conduction time of the second switch can be staggered. As one implementation, the sum of the duty cycles of the first drive control signal and the second drive control signal is equal to 1. This allows the first switch Q1 to operate under the control of the first drive control signal, and the second switch Q2 to operate under the control of the second drive control signal, at different time points within a cycle, thus achieving staggered conduction times. For example, the first switch Q1 can be controlled to conduct for 1 / 3T (T is the switching cycle of the second step-down module's switching circuit), and the second switch Q2 can be controlled to conduct for the remaining 2 / 3T.

[0036] In some embodiments, the working principle of the second step-down module 13 is similar to that of the first step-down module 12. The conduction and disconnection durations of the switching circuit in the second step-down module 13 are set according to the input voltage and the required output second DC voltage.

[0037] The duty cycle of the first drive control signal and the second drive control signal depends on the actual DC voltage that needs to be output, specifically on the voltage ratio between the second DC voltage signal and the first DC voltage that needs to be output.

[0038] In one implementation, the second buck module 13 can be a synchronous buck chopper circuit module, where the first switch Q1 and the second switch Q2 are MOSFETs in the synchronous buck chopper circuit module. A half-bridge circuit is constructed using the first switch Q1 and the second switch Q2. That is, in some embodiments, the bridge unit is integrated inside the synchronous buck chip, and the on and off times of the internal switching circuit are set according to the magnitude of the second DC voltage output and the magnitude of the first DC voltage input to the second buck module.

[0039] Among them, the duty cycle D of the first switch Q1 q1 =Second DC voltage / First DC voltage. By controlling the first switch Q1 to D... q1 When the duty cycle is turned on, the output capacitor C1 can be charged to store the energy of the second DC voltage. Then, during the remaining time, the first switch Q1 is turned off, and the output capacitor C1 can stably release the energy of the second DC voltage, thereby obtaining the second DC voltage.

[0040] For example, taking the aforementioned first DC voltage as 15V and second DC voltage as 5V, the duty cycle D of the first switch Q1... q1 The second DC voltage / the first DC voltage = 5 / 15 = 1 / 3, meaning that the first switch is on for 1 / 3T of a switching cycle T, during which time the output capacitor C1 is charged to obtain 5V of electrical energy. The first switch is off for 2 / 3T of a time, during which time the output capacitor C1 outputs 5V of electrical energy.

[0041] As described above, the resonant capacitor 143 in the resonant bridge converter circuit is also responsible for charging and discharging. By controlling the first switch Q1 and the second switch Q2 to conduct at different times within the same switching cycle, the energy transfer ratio between the resonant capacitor 143 and the output capacitor C1 in the second DC voltage output unit is changed. The conduction duration of the second switch Q2 directly affects the charging duration of the transformer capacitor; that is, the larger the duty cycle of the second drive control signal, the longer the conduction duration of the second switch Q2, the longer the charging duration of the resonant capacitor 143, and the greater the final output energy. To accurately control the output energy of the resonant capacitor 143 to meet the requirements of the third DC voltage, it can be determined based on the third DC voltage, the first DC voltage, and the turns ratio of the transformer windings.

[0042] For example, taking the aforementioned first DC voltage as 15V and the second DC voltage as 5V, if the third DC voltage needs to output 24V, according to the duty cycle D of the first switch as described above... q1 If the duty cycle D of the second switch is 1 / 3T, then... q2 D can be selected. q2 =1-D q1 =2 / 3T, at this time, the second switch can be turned on and the first switch can be turned off within the switching cycle of 2 / 3T. At this time, the resonant capacitor 143 can be charged with 15*2 / 3=10V of energy. If the coil turns ratio of the transformer module is adjustable, a coil turns ratio of 10V / 24V can be set, or a transformer module with a coil turns ratio of 10V / 24V can be selected to ensure that the transformer module output can output the required 24V DC voltage.

[0043] If the turns ratio of the transformer module's coil is not adjustable, the charging voltage of the transformer capacitor can be calculated by multiplying the output third DC voltage by the coil turns ratio. Then, the duty cycle D of the second switch Q2 can be determined based on the voltage ratio of the input charging voltage to the first DC voltage. q2 .

[0044] As one implementation method, the transformer module 14 can be as follows: Figure 3 As shown, the transformer output unit includes a diode D1 and a bridging capacitor C2. In this embodiment, when the second switch Q2 is turned on and the first switch Q1 is turned off, the resonant capacitor 143 connected to the primary coil charges to obtain electrical energy. At this time, the diode D1 is turned off to prevent energy transfer from interfering with the charging voltage of the resonant capacitor 143, thus improving the stability of the output voltage. Then, when the first switch Q1 is turned on, the resonant capacitor 143 releases electrical energy, and the voltage polarity of the primary winding of the transformer module reverses, correspondingly reversing the voltage polarity of the secondary winding. When the resonant capacitor 143 releases electrical energy, D1 is turned on, and energy is transferred to the secondary side through windings 141 and 142, achieving a stable output of the third DC voltage.

[0045] If the transformer module is a full-bridge transformer module, the two windings of the transformer module must be in phase, and the transformer capacitor must be a DC blocking capacitor to block the DC component and prevent the transformer module from being affected by magnetic saturation due to DC bias, which would affect the stability of energy transfer.

[0046] In some possible embodiments, the multi-output circuit can be applied to a frequency converter or the internal power system of a residential energy storage system. The frequency converter and the internal power system of the residential energy storage system can be referred to in relevant technical documents, which are not the focus of this utility model and will not be described in detail here.

[0047] In this invention, the first DC voltage is the feedback voltage of the first buck module. By comparing this first DC voltage with the output voltage of the rectifier module, the duty cycle of the switching circuit of the first buck module can be determined, thus obtaining a stable first DC voltage. The second DC voltage is the feedback voltage of the second buck module. By comparing this second DC voltage with the first DC voltage output by the first buck module, the duty cycle of the first switch of the second buck module can be determined, thereby controlling the charging time of the output capacitor C1 to output a stable second DC voltage. Then, by connecting the primary coil of the transformer module with the second buck module to form a resonant bridge converter circuit, the influence of the leakage inductance of the transformer coil on the load regulation and cross regulation can be eliminated, improving the stability of the third DC voltage.

[0048] Furthermore, the resonant circuit output allows the output current signal to approximate a sine wave, resulting in a slower rate of current change, reduced harmonics, and optimized electromagnetic compatibility (EMC). Additionally, the use of a synchronous buck chopper module as the second step-down module allows for flexible adjustment of the duty cycle of its internal switching circuit. This enables the rapid determination of the appropriate duty cycle based on the required output voltage, improving circuit versatility and helping to reduce circuit costs.

[0049] Secondly, this utility model provides an energy storage device. Specifically, the energy storage device includes a main body and a multi-output circuit as described in the first aspect, disposed within the main body. This energy storage device can be used in practical application scenarios such as frequency converters and internal power systems of residential energy storage systems. The beneficial effects of this utility model are as follows: By selecting the energy storage device provided by this utility model, a stable multi-output power supply voltage can be provided through the internally configured multi-output circuit, meeting the power supply scenarios requiring various stable power supply voltages.

[0050] The above are merely preferred embodiments of the present utility model and are not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to preferred embodiments, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. A multi-output circuit, characterized in that, The multi-output circuit includes: The rectifier module is used to receive AC input, rectify the AC output, and output DC output; The first step-down module is connected to the output terminal of the rectifier module and is used to step down the DC output and output a first DC voltage. The second step-down module includes a bridge unit connected to the first step-down module, which is used to step down the first DC voltage and output a second DC voltage. The transformer module, connected to the bridge unit, forms a resonant bridge converter circuit, which is used to output a third DC voltage based on the first DC voltage.

2. The multi-output circuit according to claim 1, characterized in that, The bridge unit is a half-bridge unit, and the half-bridge unit is connected to the transformer module to form an asymmetric half-bridge converter circuit.

3. The multi-output circuit according to claim 2, characterized in that, The half-bridge unit includes a first switch and a second switch. The first terminal of the first switch is connected to the first step-down module, the second terminal of the first switch is connected to the first terminal of the second switch, and the second terminal of the second switch is grounded. The transformer module is connected between the first terminal of the first switch and the second terminal of the first switch.

4. The multi-output circuit according to claim 3, characterized in that, The transformer module includes: a transformer unit, a resonant capacitor, and a transformer output unit. The transformer unit includes: a primary coil and a secondary coil; wherein: The first end of the primary coil is connected to the first end of the first switch, the second end of the primary coil is connected to the first end of the resonant capacitor, and the second end of the resonant capacitor is connected to the second end of the first switch. The transformer output unit is connected to the secondary coil, and the transformer output unit is used to output the third DC voltage.

5. The multi-output circuit according to claim 3, characterized in that, The second step-down module includes a second DC voltage output unit, which is connected between the first terminal of the second switch and the second terminal of the second switch, and is used to output the second DC voltage.

6. The multi-output circuit according to claim 5, characterized in that, The second DC voltage output unit includes an output inductor and an output capacitor. The output inductor and the output capacitor are connected in series and between the first terminal of the second switch and the second terminal of the second switch. The output capacitor outputs the second DC voltage.

7. The multi-output circuit according to claim 3, characterized in that, The control terminal of the first switch receives a first drive control signal, and the control terminal of the second switch receives a second drive control signal. The sum of the duty cycles of the first drive control signal and the second drive control signal is equal to 1.

8. The multi-output circuit according to any one of claims 1 to 7, characterized in that, The bridge unit is integrated inside the synchronous buck chip.

9. The multi-output circuit according to claim 1, characterized in that, The first step-down module is a high-voltage step-down module.

10. An energy storage device, characterized in that, The energy storage device includes a main body and a multi-output circuit as described in any one of claims 1-9 disposed within the main body.

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