Auxiliary power supply and energy storage system

Abstract

The utility model belongs to the technical field of auxiliary power supplies, and particularly relates to an auxiliary power supply and an energy storage system, the auxiliary power supply comprises an energy storage module, a transformer and a voltage output module; wherein the energy storage module is connected with a primary winding of the transformer, and the voltage output module is connected with a secondary winding of the transformer; the energy storage module is suitable for being connected with a direct current input bus so as to charge the energy storage module; the energy storage module is suitable for controlling energy to be released to the voltage output modules through the transformer so that the voltage output modules can output voltages of different grades. According to the utility model, a double-tube flyback structure is arranged in the energy storage module, so that the withstand voltage value of a single tube can be reduced, a high-voltage input occasion can be adapted, the leakage inductance energy of the transformer can be recycled, the energy utilization rate can be improved, and the auxiliary power supply can provide wide-range input voltage in cooperation with the transformer and the voltage output module. Meanwhile, the output voltage is stable and the voltage ripple is small.

Description

Technical Field

[0001] The utility model belongs to the technical field of auxiliary power supplies, and particularly relates to an auxiliary power supply and an energy storage system. Background Art

[0002] Existing auxiliary power supplies include linear regulated power supplies, capacitor step-down power supplies, self-excited switching power supplies, and single-ended flyback switching power supplies. Linear regulated power supplies have disadvantages such as being bulky, having very low efficiency, and limited power. Capacitor step-down power supplies are applied to occasions with AC input, low power, and not high voltage requirements. Self-excited switching power supplies have disadvantages such as relatively large ripple current and poor stability when the power is large, and are used in occasions below 60W and with not high voltage requirements. In a single-ended flyback switching power supply, the power transistor needs to withstand a very high voltage stress when the switching transistor is turned off, and has very high requirements for the breakdown voltage of the power transistor.

[0003] The auxiliary power supplies provided in the related art have problems such as low breakdown voltage, complex circuit, complex control, MOS transistor conduction, energy waste, and low operating efficiency.

[0004] Therefore, it is urgent to develop a new auxiliary power supply and energy storage system to solve the above problems. Summary of the Utility Model

[0005] The purpose of the utility model is to provide an auxiliary power supply and an energy storage system.

[0006] To solve the above technical problems, the utility model provides an auxiliary power supply, which includes: an energy storage module, a transformer, and a voltage output module; wherein the energy storage module is connected to the primary winding of the transformer, and the voltage output module is connected to the secondary winding of the transformer; the energy storage module is adapted to be connected to a DC input bus to charge the energy storage module; the energy storage module is adapted to control the energy to be released to each voltage output module through the transformer, so that the voltage output module outputs different levels of voltage.

[0007] Specifically, the energy storage module includes: a first switching transistor and a second switching transistor; the first switching transistor and the second switching transistor are respectively connected between the primary winding of the transformer and the access point of the DC input bus; the first switching transistor is turned on and the second switching transistor is turned on to charge the primary winding of the transformer by the DC input bus; the first switching transistor is turned off and the second switching transistor is turned off to release the energy of the primary winding of the transformer to the secondary winding of the transformer.

[0008] Specifically, the energy storage module further includes: at least one support capacitor; each of the support capacitors is connected in series between the first switching transistor and the second switching transistor in sequence.

[0009] Specifically, the energy storage module further includes: a first buffer capacitor and a second buffer capacitor; both ends of the first buffer capacitor are respectively connected to both ends of the first switching tube; both ends of the second buffer capacitor are respectively connected to both ends of the second switching tube.

[0010] Specifically, the energy storage module further includes: a first diode and a second diode; one end of the first diode is connected to the DC input bus access point, and the other end of the first diode is connected to the lower end of the primary winding of the transformer; one end of the second diode is connected to the upper end of the primary winding of the transformer, and the other end of the second diode is connected to the DC input bus access point.

[0011] Specifically, the voltage output module includes: at least one voltage output circuit; each of the voltage output circuits is adapted to output a voltage of a corresponding level respectively.

[0012] Specifically, corresponding RCD absorption circuits are respectively arranged in each of the voltage output circuits.

[0013] Specifically, a linear voltage regulator is arranged in the voltage output circuit.

[0014] Specifically, the auxiliary power supply further includes: a VCC power supply circuit; the VCC power supply circuit is connected to the primary winding of the transformer.

[0015] On the other hand, the present invention provides an energy storage system, which includes: a plurality of the above-mentioned auxiliary power supplies; wherein each of the auxiliary power supplies is respectively connected to the DC input bus.

[0016] The beneficial effects of the present invention are that by setting a dual-switch flyback structure in the energy storage module, the present invention can reduce the withstand voltage value of a single switch, adapt to high-voltage input occasions, and at the same time realize the recycling of the energy of the leakage inductance of the transformer, improve the energy utilization rate, and cooperate with the transformer and the voltage output module to enable the auxiliary power supply to provide a wide range of input voltages, and at the same time the output voltage is stable and the voltage ripple is small.

[0017] Other features and advantages of the present invention will be described in the following specification, and, in part, will be obvious from the specification, or will be understood by implementing the present invention.

[0018] To make the above objects, features and advantages of the present invention more obvious and understandable, the following specific preferred embodiments are given, and in conjunction with the accompanying drawings, the detailed description is as follows. Description of the Drawings

[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 is the circuit diagram of the auxiliary power supply of the present invention;

[0021] Figure 2 is the topological structure diagram of the auxiliary power supply of the present invention;

[0022] Figure 3 is the equivalent circuit diagram when the first switching tube and the second switching tube in the auxiliary power supply of the present invention are turned off.

[0023] In the figure:

[0024] DCbus, DC input bus; T1, transformer; Q1, first switching tube; Q2, second switching tube; C2, first buffer capacitor; C11, second buffer capacitor; D1, first diode; D2, second diode. Specific embodiments

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions of the present invention with reference to the drawings. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0026] Embodiment 1. In this embodiment, as Figure 1 shown, this embodiment provides an auxiliary power supply, which includes: an energy storage module, a transformer T1, and a voltage output module; wherein the energy storage module is connected to the primary winding of the transformer T1, and the voltage output module is connected to the secondary winding of the transformer T1; the energy storage module is adapted to be connected to the DC input bus DCbus to charge the energy storage module; the energy storage module is adapted to control the energy to be released to each voltage output module through the transformer T1, so that the voltage output module outputs different levels of voltage.

[0027] Specifically, the input voltage range of the DC input bus DCbus is 100 - 800V.

[0028] Specifically, the transformer T1 functions to isolate and transfer energy.

[0029] In this embodiment, by providing a dual-switch flyback structure in the energy storage module, the breakdown voltage of a single switch can be reduced to adapt to high-voltage input scenarios. Meanwhile, the energy of the leakage inductance of transformer T1 can be recycled to improve the energy utilization rate. In cooperation with transformer T1 and the voltage output module, an auxiliary power supply can provide a wide range of input voltages, and the output voltage is stable with small voltage ripple.

[0030] In this embodiment, the energy storage module includes: a first switch tube Q1 and a second switch tube Q2; the first switch tube Q1 and the second switch tube Q2 are respectively connected between the primary winding of transformer T1 and the access point of the DC input bus DCbus; when the first switch tube Q1 is turned on and the second switch tube Q2 is turned on, the DC input bus DCbus charges the primary winding of transformer T1; when the first switch tube Q1 is turned off and the second switch tube Q2 is turned off, the primary winding of transformer T1 releases energy to the secondary winding of transformer T1.

[0031] Specifically, the first switch tube Q1 and the second switch tube Q2 are respectively connected between the primary side of transformer T1 and the DC input bus DCbus, and the first switch tube Q1 and the second switch tube Q2 are switched simultaneously. Resistors R2 and R3 function to switch the first switch tube Q1, and resistors R5 and R6 function to switch the second switch tube Q2.

[0032] Specifically, when the first switch tube Q1 and the second switch tube Q2 are turned on simultaneously, windings 1 and 2 store energy; when the first switch tube Q1 and the second switch tube Q2 are turned off simultaneously, windings 1 and 2 release energy to the secondary winding, and at the same time, when triode D3, triode D4, triode D5, and triode D6 are turned on, a path is provided for the load.

[0033] Specifically, please refer to Figure 1 , resistors R8 and R9 function to detect current and play a role in protecting the first switch tube Q1, the second switch tube Q2, and transformer T1.

[0034] In this embodiment, the energy storage module further includes: at least one support capacitor; each of the support capacitors is connected in series between the first switch tube Q1 and the second switch tube Q2 in sequence.

[0035] Specifically, support capacitor C6 and support capacitor C12 are connected in series.

[0036] In this embodiment, the energy storage module further includes: a first buffer capacitor C2 and a second buffer capacitor C11; both ends of the first buffer capacitor C2 are respectively connected to both ends of the first switch tube Q1; both ends of the second buffer capacitor C11 are respectively connected to both ends of the second switch tube Q2.

[0037] In this embodiment, the energy storage module further includes: a first diode D1 and a second diode D2; one end of the first diode D1 is connected to the DC input bus DCbus access point, and the other end of the first diode D1 is connected to the lower end of the primary winding of the transformer T1; one end of the second diode D2 is connected to the upper end of the primary winding of the transformer T1, and the other end of the second diode D2 is connected to the DC input bus DCbus access point.

[0038] Specifically, the first diode D1 and the second diode D2 play the role of clamping voltage and providing freewheeling for the leakage inductance current when the first switching transistor Q1 and the second switching transistor Q2 are turned off, effectively clamping the leakage inductance spike voltage, and improving the efficiency and reliability of the auxiliary power supply.

[0039] In this embodiment, the voltage output module includes: at least one voltage output circuit; each of the voltage output circuits is adapted to output a voltage corresponding to a corresponding level.

[0040] In this embodiment, corresponding RCD absorption circuits are respectively provided in each of the voltage output circuits.

[0041] Specifically, the resistor R1, the capacitor C1, and the triode D3 form an RCD absorption circuit, the resistor R4, the capacitor C7, and the triode D4 form an RCD absorption circuit, the resistor R7, the capacitor C13, and the triode D5 form an RCD absorption circuit, and the resistor R12, the capacitor C17, and the triode D6 form an RCD absorption circuit, which can reduce the spike voltage of the rectifier diode.

[0042] In this embodiment, a linear voltage regulator is provided in the voltage output circuit.

[0043] Specifically, please refer to Figure 1 , where two voltage output circuits output 5V voltage to supply power to the DSP and the operational amplifier chip, and the linear voltage regulator improves the stability and reduces the ripple.

[0044] In this embodiment, the auxiliary power supply further includes: a VCC power supply circuit; the VCC power supply circuit is connected to the primary winding of the transformer T1.

[0045] Specifically, the voltage of windings 4 and 5 is rectified by the diode D7 and filtered by the capacitors C21 and C22 to supply power to the VCC of the control chip.

[0046] Specifically, please refer to Figure 2, the first diode D1 and the second diode D2 are primary side freewheeling diodes, the diode D3 is a secondary side rectifying diode, L1 is the leakage inductance, LP is the primary side inductance, Vdc is the input voltage of the auxiliary power supply, Vout is the output voltage of the auxiliary power supply, LP is the exciting inductance, NP is the number of turns of the primary side of the transformer T1, NS is the number of turns of the secondary side, and the capacitor C1 is the power output filter capacitor. When the first switching tube Q1 and the second switching tube Q2 are turned on simultaneously, the first diode D1, the second diode D2, and the third switching tube D3 are turned off. The primary winding of the transformer T1 bears the voltage Vdc, and the current linearly rises to the maximum value IP at a slope of dI1 / dt = Vdc / (LP + L1). The transformer T1 completes the energy storage process. When the first switching tube Q1 and the second switching tube Q2 are turned off simultaneously, the primary and secondary voltages of the transformer T1 are reversed. At this time, the first diode D1, the second diode D2, and the third switching tube D3 are all turned on. Since the third switching tube D3 is turned on, the energy stored in the primary winding is transferred to the load. The first diode D1 clamps the potential at the upper end of LP to the negative end of Vdc, and the second diode D2 clamps the potential at the lower end of L1 to the positive end of the power supply. At this time, the voltage across the exciting inductance LP is equal to the secondary refraction voltage Vr, that is, Vr = (NP / NS)·(Vout + VD3). The input voltage is equal to the exciting inductance voltage plus the leakage inductance voltage. Therefore, the leakage inductance voltage V1 = Vdc - Vr.

[0047] Specifically, please refer to Figure 3 , the secondary side circuit is equivalent to the primary side. The energy stored in the exciting inductance is directly supplied to the load through the diode D3. The energy stored in the leakage inductance 1 / (2L1L12) flows back to the power supply through the first diode D1 and the second diode D2. The time consumed in this process is equal to the time for the leakage inductance to reset. To ensure that the circuit operates in the DCM mode and maximize the energy flow to the load, the leakage inductance reset time needs to be shortened, which can be achieved by reducing the leakage inductance and the NP / NS turns ratio. The smaller the NP / NS, the smaller the Vr, the larger the V1, and the shorter the leakage inductance reset time. The value of NP / NS is set to 0.7Vi / Vo, where Vi and Vo are the input and output voltages of the power supply respectively.

[0048] Specifically, calculate the core power of the transformer T1. The power capacity AP of the core is (1); In the formula: A m is the core window area; A e is the effective cross-sectional area of the core; P o is the rated output power; f is the switching frequency; B m is the core magnetic flux change; δ is the coil wire current density; η is the power supply conversion efficiency; K w is the window filling factor; K m is the core filling factor.

[0049] Calculate the turns ratio n. To reduce the leakage inductance reset time, select the turns ratio according to the following formula: (2); where: V min is the lowest input voltage; V o is the main output voltage; V d is the voltage drop of the rectifier diode.

[0050] Calculate the duty cycle D. The duty cycle D refers to the ratio of the on-time T on of the switching transistor to the switching period T of the switching transistor. According to the volt-second balance: (3); where: T on,max is the maximum conduction time of the switching transistor, which occurs at the moment of the lowest input voltage; T off is the off-time of the switching transistor. Because the switching transistor has on and off times and is affected by other parasitic parameters in the circuit, the on-time T on and the off-time T off are usually taken as: (4); By combining equations (2) to (4), it can be known that the maximum duty cycle D = 0.37.

[0051] Calculate the peak value of the primary winding current of transformer T1. Determine the calculation formula for the peak value I pk of the primary winding current of transformer T1 as follows: (5); where: D max is the maximum duty cycle.

[0052] Calculate the inductance of the primary winding. The inductance LP of the primary winding is determined by the following formula: (6); Calculate the number of turns of the primary and secondary windings. The calculation formulas for the number of turns of the primary and secondary windings are as follows: (7); (8); where ΔB is the magnetic flux change of the magnetic core; Calculate the air gap of transformer T1. The calculation formula for the air gap l g of transformer T1 is as follows: (9); Calculate the reverse voltage of the output rectifier diode. The calculation formula for the reverse voltage V D of the output rectifier diode is as follows: (10); Calculate the peak current of the output rectifier diode. The peak current I Dpk of the output rectifier diode is calculated by the following formula: (11); The rated output power of the set power supply is 80W, the input DC voltage is 100 - 800V, the output voltages are 24V, 9V, 5V, 5V respectively, and the operating frequency is 46kHz. Calculations are performed according to the above parameter calculation formulas. Finally, it is set that the transformer T1 uses an EE36 magnetic core, the turns ratio of the primary and secondary sides is 150:20:8:4:4, and the primary inductance is 1.2mH; the first switching transistor Q1 and the second switching transistor Q2 use 2SK2611 MOS transistors of Toshiba with 900V / 9A, the first diode D1 and the second diode D2 use STTH512FP fast recovery diodes of ST with 1200V / 5A, and the diodes D3 and D4 use MBRF20H150CTG Schottky diodes with 150V / 20A.

[0053] Embodiment 2, based on Embodiment 1, this embodiment provides an energy storage system, which includes: several auxiliary power supplies as provided in Embodiment 1; wherein each of the auxiliary power supplies is respectively connected to the DC input bus DCbus.

[0054] In summary, by setting a double-switch flyback structure in the energy storage module, the present invention can reduce the breakdown voltage value of a single transistor, adapt to high-voltage input occasions, and at the same time realize the recycling of the leakage inductance energy of the transformer, improve the energy utilization rate. Cooperating with the transformer and the voltage output module can enable the auxiliary power supply to provide a wide range of input voltages, and at the same time the output voltage is stable and the voltage ripple is small.

[0055] Each device (components without specific structures described) selected in this application is a general standard component or a component known to those skilled in the art, and its structure and principle can be known by those skilled in the art through technical manuals or through conventional experimental methods. And, the software programs involved in this application are all prior arts, and this application does not involve any improvement to the software programs.

[0056] In the description of the embodiments of the present invention, unless otherwise clearly defined and limited, the terms "installation", "connection", "connection" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection or an electrical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the internal communication of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0057] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0058] In several embodiments provided by the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. The device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there may be other division methods. For another example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection between each other can be through some communication interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical, mechanical or other form.

[0059] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place, or they can be distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0060] In addition, in each embodiment of the present utility model, the functional units can be integrated in a processing unit, or each unit can exist physically alone, or two or more units can be integrated in one unit.

[0061] Based on the above inspiration from the ideal embodiments of the present utility model, through the above description, relevant staff can completely make various changes and modifications without departing from the technical idea of the present utility model. The technical scope of the present utility model is not limited to the content in the specification, and its technical scope must be determined according to the scope of the claims.

Claims

1. An auxiliary power supply, characterized in that, Comprising: Energy storage module, transformer, and voltage output module; Wherein The energy storage module is connected to the primary winding of the transformer, and the voltage output module is connected to the secondary winding of the transformer; The energy storage module is adapted to be connected to the DC input bus to charge the energy storage module; The energy storage module is adapted to control the energy to be released to each voltage output module through the transformer, so that the voltage output module outputs different levels of voltage.

2. The auxiliary power supply according to claim 1, characterized in that The energy storage module includes: a first switching tube and a second switching tube; The first switching tube and the second switching tube are respectively connected between the primary winding of the transformer and the access point of the DC input bus; The first switching tube is turned on and the second switching tube is turned on, so that the DC input bus charges the primary winding of the transformer; The first switching tube is turned off and the second switching tube is turned off, so that the primary winding of the transformer releases energy to the secondary winding of the transformer.

3. The auxiliary power supply according to claim 2, characterized in that The energy storage module further includes: at least one support capacitor; Each of the support capacitors is connected in series between the first switching tube and the second switching tube in sequence.

4. The auxiliary power supply according to claim 2, characterized in that The energy storage module further includes: a first buffer capacitor and a second buffer capacitor; Both ends of the first buffer capacitor are respectively connected to both ends of the first switching tube; Both ends of the second buffer capacitor are respectively connected to both ends of the second switching tube.

5. The auxiliary power supply according to claim 2, characterized in that The energy storage module further includes: a first diode and a second diode; One end of the first diode is connected to the access point of the DC input bus, and the other end of the first diode is connected to the lower end of the primary winding of the transformer; One end of the second diode is connected to the upper end of the primary winding of the transformer, and the other end of the second diode is connected to the access point of the DC input bus.

6. The auxiliary power supply according to claim 2, characterized in that The voltage output module includes: at least one voltage output circuit; Each of the voltage output circuits is adapted to output a corresponding level of voltage respectively.

7. The auxiliary power supply according to claim 6, characterized in that A corresponding RCD absorption circuit is respectively provided in each of the voltage output circuits.

8. The auxiliary power supply according to claim 6, characterized in that A linear voltage regulator is provided in the voltage output circuit.

9. The auxiliary power supply according to claim 1, characterized in that Further comprising: VCC power supply circuit; The VCC power supply circuit is connected to the primary winding of the transformer.

10. A energy storage system, characterized in that, Comprising: A plurality of auxiliary power supplies according to any one of claims 1-9; Wherein Each of the auxiliary power supplies is respectively connected to the DC input bus.

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