Multi-output auxiliary power supply circuit and solar photovoltaic power generation system

Abstract

The utility model relates to a multipath output auxiliary power supply circuit and a solar photovoltaic power generation system. The circuit comprises a flyback forward power supply control chip; one end of the first switch element is connected to the direct-current power supply, and the other end of the first switch element is connected to an enabling pin of the flyback forward power supply control chip; one end of a primary side coil of the transformer is connected to the direct-current power supply, and the other end of the primary side coil is connected to one end of the second switch element; the auxiliary coil is connected to the first power supply output end, the first secondary coil is connected to the second power supply output end, and the second secondary coil is connected to the third power supply output end; and the enabling end of the second switch element is connected to the PWM output pin of the flyback forward power supply control chip. A flyback forward power supply control chip is used as a DC voltage converter, so that the high anti-interference capability is realized, the product reliability is ensured, the cost optimization is realized, and the cost volume is reduced.

Description

Technical Field

[0001] The present application relates to the technical field of power supplies, and particularly relates to a multi-output auxiliary power supply circuit and a solar photovoltaic power generation system. Background Art

[0002] In an inverter power supply, circuits such as a DSP controller, a multi-channel voltage and current acquisition circuit, a control signal enabling circuit, and a main power drive need to be powered preferentially. Often, multiple different voltage outputs that need to be isolated are required, and multiple DC-DC converters are used as auxiliary power supplies. Moreover, the performance of this auxiliary power supply directly affects the stability of the whole machine. The need for multiple DC-DC converters with different voltage outputs that need to be isolated in the auxiliary power supply of the inverter leads to the defects of increased cost and increased volume. Summary of the Utility Model

[0003] In view of the above problems, the present application provides a multi-output auxiliary power supply circuit and a solar photovoltaic power generation system, which solve the problem of the defects of increased cost and increased volume caused by the need for multiple DC-DC converters with different voltage outputs that need to be isolated in the auxiliary power supply of the existing inverter.

[0004] To achieve the above object, the inventor provides a multi-output auxiliary power supply circuit, including:

[0005] A flyback forward power control chip;

[0006] A first switching element, the enabling end of the first switching element is connected to the control main board, one end of the first switching element is connected to the DC power supply, and the other end of the first switching element is connected to the enabling pin of the flyback forward power control chip;

[0007] A transformer, the transformer includes a primary coil, an auxiliary coil, a first secondary coil, and a second secondary coil. One end of the primary coil is connected to the DC power supply, and the other end of the primary coil is connected to one end of a second switching element; the auxiliary coil is connected to a first power output terminal, the first secondary coil is connected to a second power output terminal, and the second secondary coil is connected to a third power output terminal;

[0008] A second switching element, the enabling end of the second switching element is connected to the PWM output pin of the flyback forward power control chip, and the other end of the second switching element is grounded;

[0009] A first voltage stabilizing unit, the input end of the first voltage stabilizing unit is connected to the first output end, and the output end of the first voltage stabilizing unit is connected to a fourth power output terminal;

[0010] A second voltage stabilizing unit, the input end of the second voltage stabilizing unit is connected to the second power output end, and the output end of the second voltage stabilizing unit is connected to a fifth power output terminal.

[0011] In some embodiments, the other end of the second switching element is connected to an overcurrent protection circuit within the flyback forward power control chip through the SENSE pin of the flyback forward power control chip.

[0012] In some embodiments, both the first switching element and the second switching element are MOS transistors.

[0013] In some embodiments, it further includes:

[0014] A resistor divider, one end of the resistor divider is connected to the auxiliary coil, and the other end of the resistor divider is connected to the FB detection pin of the flyback forward power control chip.

[0015] In some embodiments, the primary coil of the transformer is provided with an RCD absorption circuit composed of a Schottky diode, an absorption resistor, and an absorption capacitor.

[0016] In some embodiments, it further includes a Y1 safety capacitor, and the Y1 safety capacitor is disposed between the power ground wire and the reference ground wire.

[0017] In some embodiments, the first voltage regulation unit includes:

[0018] A first voltage regulator, the input end of the first voltage regulator is connected to the first power output end;

[0019] A second voltage regulator, the input end of the second voltage regulator is connected to the output end of the first voltage regulator, and the output end of the second voltage regulator is connected to the fourth power output end.

[0020] Another technical solution is also provided. A solar photovoltaic power generation system includes:

[0021] A solar photovoltaic panel, which is used to convert solar energy into electrical energy;

[0022] A battery, the battery is connected to the solar photovoltaic panel;

[0023] A multi-output auxiliary power supply circuit, the multi-output auxiliary power supply circuit is the multi-output auxiliary power supply circuit described above, and the DC power supply of the multi-output auxiliary power supply circuit is the battery.

[0024] Different from the prior art, in the above technical solution, the enable pin of the flyback positive power control chip is connected to the DC power supply through the first switching element, and the first switching element is controlled to be turned on and off by the control main board. When the first switching element is turned on, the flyback positive power control chip obtains the startup working voltage, and the PWM output pin of the flyback positive power control chip outputs a PWM signal to drive the second switching element. When the second switching element is turned on, the DC power supply stores energy in the primary coil of the transformer. When the second switching element is turned off, the primary coil of the transformer releases energy, so that the first secondary coil and the second secondary coil of the transformer generate induced voltages, and corresponding working voltages are output through the second power output terminal and the second power output terminal respectively. The auxiliary coil also outputs a corresponding working voltage to the first power output terminal under the action of the induced voltages generated by the first secondary coil and the second secondary coil. At the same time, after the working voltage output by the first power supply is regulated by the first voltage regulating unit, the required working voltage is output to the fourth power output terminal. After the working voltage output by the second power supply is regulated by the second voltage regulating unit, the required working voltage is output to the fifth power output terminal. By using the flyback positive power control chip as the converter of the DC voltage, it has strong anti-interference ability, ensures the reliability of the product, realizes cost optimization, reduces the cost and volume, and realizes the functional characteristics of the whole product. At the same time, it has five power output terminals to meet the needs of different power supplies.

[0025] The above description of the utility model content is only an overview of the technical solution of this application. In order to enable those of ordinary skill in the art to more clearly understand the technical solution of this application, and then can be implemented according to the content recorded in the text of the specification and the drawings, and in order to make the above objects, other objects, features and advantages of this application more easily understood, the following is described in conjunction with the specific implementation manners and drawings of this application. Brief Description of the Drawings

[0026] The drawings are only used to illustrate the principles, implementation methods, applications, features and effects of the specific implementation manners and other related contents of this application, and should not be considered as a limitation to this application.

[0027] In the accompanying drawings of the specification:

[0028] Figure 1 It is a circuit schematic diagram of a multi-output auxiliary power supply circuit described in the specific implementation manner;

[0029] Figure 2 It is a circuit principle schematic diagram of a first voltage regulating unit described in the specific implementation manner;

[0030] Figure 3 It is a circuit principle schematic diagram of a second voltage regulating unit described in the specific implementation manner;

[0031] Figure 4 A circuit schematic diagram of the Y1 Ant capacitor described in the specific implementation manner;

[0032] Figure 5 A schematic diagram of the output parameters of the multi-output auxiliary power supply circuit described in the specific implementation manner;

[0033] Figure 6 A structural schematic diagram of the solar photovoltaic power generation system described in the specific implementation manner.

[0034] The descriptions of the reference numerals involved in the above-mentioned respective drawings are as follows:

[0035] 610, solar photovoltaic panel,

[0036] 620, battery,

[0037] 630, multi-output auxiliary power supply circuit. Specific implementation manner

[0038] To describe in detail the possible application scenarios, technical principles, specific implementable solutions, achievable purposes and effects, etc. of the present application, the following will be described in detail in combination with the listed specific examples and with reference to the drawings. The examples described herein are only used to more clearly illustrate the technical solutions of the present application, and therefore are only used as examples and cannot be used to limit the protection scope of the present application.

[0039] Referring to "embodiment" in this article means that the specific features, structures or characteristics described in combination with the embodiment may be included in at least one embodiment of the present application. The term "embodiment" appearing in various positions in the specification does not necessarily refer to the same embodiment, nor does it particularly limit its independence or relevance to other embodiments. In principle, in the present application, as long as there is no technical contradiction or conflict, the technical features mentioned in each embodiment can be combined in any way to form the corresponding implementable technical solution.

[0040] Unless otherwise defined, the meanings of the technical terms used in this article are the same as those generally understood by those skilled in the technical field to which the present application belongs; the use of the relevant terms in this article is only for describing specific embodiments and is not intended to limit the present application.

[0041] In the description of the present application, the term "and / or" is an expression used to describe the logical relationship between objects, indicating that there can be three relationships, for example, A and / or B, indicating: the existence of A, the existence of B, and the simultaneous existence of A and B. In addition, the character " / " in this article generally represents an "or" logical relationship between the associated objects before and after.

[0042] In this application, terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual quantitative, primary-secondary, or sequential relationship between these entities or operations.

[0043] Without further limitation, in this application, the expressions such as "including", "comprising", "having", or other similar expressions used in a statement are intended to cover non-exclusive inclusion. These expressions do not exclude the possibility that there may be additional elements in the process, method, or product including the stated elements. Thus, a process, method, or product including a series of elements may include not only those defined elements, but also other elements not explicitly listed, or elements inherent to such process, method, or product.

[0044] Similar to the understanding in the Examination Guidelines, in this application, expressions such as "greater than", "less than", "exceeding", etc. are understood not to include the recited number; expressions such as "above", "below", "within", etc. are understood to include the recited number. In addition, in the description of the embodiments of this application, the meaning of "a plurality of" is two or more (including two). Similar expressions related to "multiple", such as "multiple groups", "multiple times", etc., are understood in the same way, unless otherwise specifically defined.

[0045] In the description of the embodiments of this application, spatial-related expressions such as "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "perpendicular", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the specific embodiment or the drawing. This is only for the convenience of describing the specific embodiments of this application or facilitating the understanding of the reader, and does not indicate or imply that the device or component referred to must have a specific position, a specific orientation, or be constructed or operated in a specific orientation. Therefore, it should not be construed as a limitation to the embodiments of this application.

[0046] Unless otherwise clearly specified or limited, in the description of the embodiments of this application, terms such as "installed", "connected", "joined", "fixed", "set", etc. should be understood in a broad sense. For example, the "connection" can be a fixed connection, a detachable connection, or an integral setting; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium; it can be the communication inside two elements or the interaction relationship between two elements. For those skilled in the art to which this application pertains, the specific meanings of the above terms in the embodiments of this application can be understood according to specific circumstances.

[0047] Please refer toFigures 1-3 , this embodiment provides a multi-output auxiliary power supply circuit, including:

[0048] Flyback forward power control chip U7;

[0049] The first switching element Q6, the enable end of the first switching element Q6 is connected to the control main board, one end of the first switching element Q6 is connected to the DC power supply, and the other end of the first switching element Q6 is connected to the enable pin of the flyback forward power control chip U7;

[0050] Transformer T2, the transformer T2 includes a primary coil, an auxiliary coil, a first secondary coil and a second secondary coil. One end of the primary coil is connected to the DC power supply, and the other end of the primary coil is connected to one end of the second switching element Q5; the auxiliary coil is connected to the first power output terminal, the first secondary coil is connected to the second power output terminal, and the second secondary coil is connected to the third power output terminal;

[0051] The second switching element Q5, the enable end of the second switching element Q5 is connected to the PWM output pin of the flyback forward power control chip U7, and the other end of the second switching element Q5 is grounded;

[0052] The first voltage stabilizing unit, the input end of the first voltage stabilizing unit is connected to the first output end, and the output end of the first voltage stabilizing unit is connected to the fourth power output end; wherein, the first voltage stabilizing unit includes:

[0053] The first voltage regulator, the input end of the first voltage regulator is connected to the first power output end, and the output end of the first voltage regulator is connected to the sixth power output end;

[0054] The second voltage regulator, the input end of the second voltage regulator is connected to the output end of the first voltage regulator, and the output end of the second voltage regulator is connected to the fourth power output end.

[0055] The second voltage stabilizing unit, the input end of the second voltage stabilizing unit is connected to the second power output end, and the output end of the second voltage stabilizing unit is connected to the fifth power output end.

[0056] The enable pin of the flyback positive power control chip U7 is connected to the DC power supply through the first switching element Q6, and the first switching element Q6 is controlled to be turned on and off by the control main board. When the first switching element Q6 is turned on, the flyback positive power control chip U7 obtains the startup working voltage. The PWM output pin of the flyback positive power control chip U7 outputs a PWM signal to drive the second switching element Q5. When the second switching element Q5 is turned on, the DC power supply stores energy in the primary coil of the transformer T2. When the second switching element Q5 is turned off, the primary coil of the transformer T2 releases energy, causing the first secondary coil and the second secondary coil of the transformer T2 to generate induced voltages, and corresponding working voltages are output through the second power output terminal and the second power output terminal respectively. The auxiliary coil also outputs a corresponding working voltage to the first power output terminal under the action of the induced voltages generated by the first secondary coil and the second secondary coil. At the same time, after the working voltage output by the first power supply is regulated by the first voltage regulating unit, the required working voltage is output to the fourth power output terminal. After the working voltage output by the second power supply is regulated by the second voltage regulating unit, the required working voltage is output to the fifth power output terminal. By using the flyback positive power control chip U7 as the converter of the DC voltage, it has strong anti-interference ability, ensures the reliability of the product, realizes cost optimization, reduces the cost and volume, and realizes the functional characteristics of the whole product. At the same time, it has five power output terminals to meet the needs of different power supplies.

[0057] In some embodiments, the other end of the second switching element Q5 is connected to the overcurrent protection circuit inside the flyback positive power control chip U7 through the SENSE pin of the flyback positive power control chip U7.

[0058] After the other end of the second switching element Q5 is grounded through the sampling resistor, the voltage signal at the other end is sent into the overcurrent protection circuit inside the flyback positive power control chip U7 through the SENSE pin, and overcurrent protection is provided through the overcurrent protection circuit.

[0059] In some embodiments, the first switching element Q6 and the second switching element Q5 are both MOS transistors. MOS transistors, also known as metal-oxide-semiconductor field-effect transistors (MOSFETs), are voltage-controlled semiconductor devices widely used in electronic circuits, especially in amplification and switching circuits. In other embodiments, the first switching element Q6 and the second switching element Q5 can also use other transistors, such as bipolar junction transistors, IGBTs, etc. Among them, when the first switching element Q6 is a MOS transistor, the gate of the first switching element Q6 is connected to the control main board. When receiving a low-level signal sent by the control main board, the first switching element Q6 conducts. The source of the first switching element Q6 is connected to the DC power supply, and the drain of the first switching element Q6 is connected to the enable pin of the flyback forward power control chip U7. When the second switching element Q5 is a MOS transistor, the gate of the second switching element Q5 is connected to the PWM output pin of the flyback forward power control chip U7, the drain of the second switching element Q5 is connected to the primary coil of the transformer T2, and the source of the second switching element Q5 is grounded and connected to the SENSE pin of the flyback forward power control chip U7.

[0060] In some embodiments, it further includes:

[0061] A resistor divider, one end of the resistor divider is connected to the auxiliary coil, and the other end of the resistor divider is connected to the FB detection pin of the flyback forward power control chip U7. The auxiliary coil is feedback sampled by the resistor divider composed of resistors R93 and R94, so that the FB detection pin of the flyback forward power control chip U7 detects the voltage of the auxiliary coil. Among them, according to parameters such as the turns ratio of the transformer T2, the values of the resistors R93 and R94 are adjusted to make the output voltage meet the requirements.

[0062] In some embodiments, the primary coil of the transformer T2 is provided with an RCD absorption circuit composed of a Schottky diode D14, absorption resistors R70 and R71, and an absorption capacitor C50. The RCD absorption circuit composed of the Schottky diode D14, absorption resistors R70 and R71, and the absorption capacitor C50 is used to suppress overvoltage of the primary components of the transformer T2.

[0063] Please refer to Figure 4 , in some embodiments, it further includes a Y1 safety capacitor CY5, and the Y1 safety capacitor CY5 is arranged between the power ground wire and the reference ground wire. By adding the Y1 safety capacitor CY5, high-frequency signals are filtered to suppress common-mode interference.

[0064] Such as Figure 5The output parameters of the multi-output auxiliary power supply circuit shown are as follows. The input terminal is the battery DC voltage rated at 24.0Vdc, which is compatible with the energy storage battery with an input voltage range requirement of 18 - 26Vdc. It has a total of 6 output terminals, namely: the first power output terminal L_12V for supplying power to the primary main power drive circuit; the sixth power output terminal L_+5V for supplying power to the primary voltage and current acquisition circuit; the fourth power output terminal L_+3.3V for supplying power to the 5V to 3.3V conversion and control enable signal circuit; the second power output terminal P_+7V; the third power output terminal P_+12V for supplying power to drive the secondary main power drive circuit of the relay; the fifth power output terminal L_+3.3V for supplying power to the secondary DSP controller through the 7V to 3.3V conversion. Among them, the DSP controller and its peripheral circuits of the system require a +3.3V power supply. In order to make the DSP controller work stably and improve EMC, the +3.3V power supply in this design is realized by using a micro-power and low-ripple LDO to convert +5V / 7V to +3.3V.

[0065] As Figure 1 For the multi-output auxiliary power supply circuit shown, the 4th pin -VIN of the power chip U7 serves as the enable pin. After the control board sends a low-level signal, the MOS transistor Q6 conducts, and the power chip U7 obtains the startup working voltage. The 3rd pin -EN of the power chip U7 serves as the under-voltage enable, and the startup voltage of the VIN pin can be programmed through the resistor divider composed of R73 and R75. If VEN drops to about 1.8V, the GATE / SYNC signal can be disabled, and the maximum recommended voltage for EN is 6.5V. The 10th pin -GATE outputs a PWM signal to drive the MOS transistor Q5. The source of the MOS transistor Q5 is grounded through the sampling resistors R89 and R90, and the source voltage signal of Q5 is sent to the internal over-current protection circuit through the 2nd pin -SENSE. The 7th pin -FB detects the auxiliary winding voltage, and the resistor divider R93 and R94 are used for feedback sampling. In the design, according to parameters such as the turns ratio of the transformer T2, the values of the resistors R93 and R94 are adjusted to make the output voltage meet the requirements.

[0066] Treatment of EMI suppression in the multi-output auxiliary power supply circuit. Due to the existence of the leakage inductance of transformer T2, in the flyback high-frequency switching power supply, the common-mode inductive current formed under the action of the dv / dt of the MOS transistor switch passes through the parasitic capacitance Cgd between the drain and source of the MOS transistor, the coupling capacitance Cp between the primary side of transformer T2 and the magnetic core to the ground plane, and the coupling capacitance Cps between the primary and secondary sides of transformer T2 to form an EMI loop. In the circuit design, the following methods are adopted for control in this scheme: (1) Optimize the process design of transformer T2 to reduce the leakage inductance L-Leak, thereby reducing the common-mode inductive current, and reduce Cps to suppress the common-mode inductive current; ground the magnetic core of transformer T2; (2) Optimize the MOS transistor parameters to reduce Cgd to suppress the common-mode inductive current; (3) Add an RCD absorption circuit (Schottky diode D14, absorption resistors R70, R71, absorption capacitor C50) to the primary side of transformer T2; (4) Optimize the PCB wiring and try to shorten the wiring distance from the -10th pin - GATE drive output of the power supply chip U7 to the gate of MOS transistor Q5; (5) Add the safety capacitor Y1, CY5, for filtering high-frequency signals to suppress common-mode interference.

[0067] Compared with traditional flyback topology converters, it often requires adding optocouplers, TL431 and related resistor-capacitor components on the secondary side to feedback the output voltage information, so as to realize the closed-loop voltage stabilization control of the output voltage. The additional components increase the cost and consume additional power. The multi-output auxiliary power supply circuit in this embodiment uses primary-side feedback on the original flyback topology converter and uses the auxiliary coil to extract the output voltage signal on the secondary coil. Since the voltages on the auxiliary coil and the secondary coil are related to the turns ratio, and at the end of the demagnetization of the secondary coil (i.e., when the current on the coil drops to zero), the power supply output voltage is equal to the voltage on the secondary coil. Sample this feedback voltage signal, and after being processed by the control chip, an ideal PWM control signal is obtained, which is used to control the switching of the primary-side power transistor. The switching time of the power transistor determines the amount of energy stored in transformer T2, and thus directly affects the magnitude of the secondary output voltage. Using this series of feedback relationships, a stable voltage output can be finally obtained. On the basis of primary-side feedback and on the basis of the existing auxiliary winding, add 2 windings of transformer T2, and then regulate the voltage of each output through a three-terminal linear voltage regulator. When the voltage of each output can be accurately regulated, the reliability of the product can be ensured, the function can be realized, and the cost can be optimized.

[0068] In the multi-output auxiliary power supply circuit of this embodiment, the DC voltage of the battery at the input end of the inverter is used as the power supply. It can obtain the auxiliary voltage of the inverter with wide-range multi-output according to the wide-range input DC voltage of the inverter. Using the DC voltage of the battery at the input end of the inverter as the power supply can also avoid the insulation protection problem and the electromagnetic interference problem of the secondary circuit caused by adding an external power supply as the power supply. In addition, the auxiliary power supply uses a flyback converter as the DC voltage converter and has strong anti-interference ability. In this case, the reliability of the product is ensured to optimize the cost, reduce the product volume, and realize the functional characteristics of the whole product. It can not only meet the requirements of multiple different voltage outputs (P_+3.3V for DSP controller power supply, multi-channel voltage and current acquisition circuit power supply L_+5V, control signal enable circuit power supply P_+3.3V, L_+3.3V, and main power drive circuit power supply P_+12V, L_12V), but also reduce the self-power supply loss at wide-range input voltages and realize the functional characteristics of the whole product.

[0069] Please refer to Figure 6 , in another embodiment, a solar photovoltaic power generation system includes:

[0070] A solar photovoltaic panel 610, which is used to convert solar energy into electrical energy;

[0071] A battery 620, which is connected to the solar photovoltaic panel 610;

[0072] A multi-output auxiliary power supply circuit 630, which is the multi-output auxiliary power supply circuit 630 in the above embodiment, and the DC power supply of the multi-output auxiliary power supply circuit 630 is the battery 620. It should be noted that in the prior art, in order to charge the battery, actually the voltage of the solar photovoltaic panel needs to flow into the battery after being controlled by the charging circuit for charging. The charging circuit is an existing circuit. For example, the following patent applied by the applicant also discloses it. The patent number is 202321794586.4, and the name is "A Solar Charging Input Overvoltage Protection Circuit and Its Energy Storage Terminal". It discloses the circuit for charging the battery through the solar photovoltaic panel. Here in this application, it is only for power supply indication. For voltage matching and charging control, the existing charging circuit can be adopted.

[0073] Solar energy is converted into electrical energy by the solar photovoltaic panel 610 and stored in the battery 620. The battery 620 provides DC power for the multi-output auxiliary power supply circuit 630. The enable pin of the flyback forward power control chip U7 is connected to the DC power supply through the first switching element Q6, and the first switching element Q6 is controlled to be turned on and off by the control main board. When the first switching element Q6 is turned on, the flyback forward power control chip U7 obtains the startup working voltage. The PWM output pin of the flyback forward power control chip U7 outputs a PWM signal to drive the second switching element Q5. When the second switching element Q5 is turned on, the DC power supply stores energy in the primary coil of the transformer T2. When the second switching element Q5 is turned off, the primary coil of the transformer T2 releases energy, causing the first secondary coil and the second secondary coil of the transformer T2 to generate induced voltages, and corresponding working voltages are output through the second power output terminal and the second power output terminal respectively. The auxiliary coil also outputs a corresponding working voltage to the first power output terminal under the action of the induced voltages generated by the first secondary coil and the second secondary coil. At the same time, after the working voltage output by the first power supply is regulated by the first voltage regulating unit, the required working voltage is output to the fourth power output terminal. After the working voltage output by the second power supply is regulated by the second voltage regulating unit, the required working voltage is output to the fifth power output terminal. By using the flyback forward power control chip U7 as the DC voltage converter, it has strong anti-interference ability, ensures product reliability, realizes cost optimization, reduces cost and volume, and realizes the functional characteristics of the whole product. At the same time, it has five power output terminals to meet the needs of different power supplies.

[0074] Finally, it should be noted that although the above embodiments have been described in the text of the specification and drawings of this application, the patent protection scope of this application cannot be limited thereby. Any technical solutions obtained by equivalent structure or equivalent process substitution or modification based on the substantial concept of this application, using the content recorded in the text of the specification and drawings of this application, as well as directly or indirectly implementing the technical solutions of the above embodiments in other related technical fields, etc., are all included in the patent protection scope of this application.

Claims

1. A multi-output auxiliary power supply circuit, characterized in that, Comprising: Flyback positive power control chip; A first switching element, the enable terminal of the first switching element is connected to the control main board, one end of the first switching element is connected to the DC power supply, and the other end of the first switching element is connected to the enable pin of the flyback positive power control chip; A transformer, the transformer includes a primary coil, an auxiliary coil, a first secondary coil and a second secondary coil, one end of the primary coil is connected to the DC power supply, and the other end of the primary coil is connected to one end of the second switching element; The auxiliary coil is connected to the first power output terminal, the first secondary coil is connected to the second power output terminal, and the second secondary coil is connected to the third power output terminal; A second switching element, the enable terminal of the second switching element is connected to the PWM output pin of the flyback positive power control chip, and the other end of the second switching element is grounded; A first voltage stabilizing unit, the input end of the first voltage stabilizing unit is connected to the first output end, and the output end of the first voltage stabilizing unit is connected to the fourth power output end; A second voltage stabilizing unit, the input end of the second voltage stabilizing unit is connected to the second power output end, and the output end of the second voltage stabilizing unit is connected to the fifth power output end.

2. The multi-output auxiliary power supply circuit according to claim 1, characterized in that The other end of the second switching element is connected to the overcurrent protection circuit in the flyback positive power control chip through the SENSE pin of the flyback positive power control chip.

3. The multi-output auxiliary power supply circuit according to claim 1, characterized in that, Both the first switching element and the second switching element are MOS transistors.

4. The multi-output auxiliary power supply circuit according to claim 1, wherein, Further comprising: A resistor divider, one end of the resistor divider is connected to the auxiliary coil, and the other end of the resistor divider is connected to the FB detection pin of the flyback positive power control chip.

5. The multi-output auxiliary power supply circuit according to claim 1, characterized in that, The primary coil of the transformer is provided with an RCD absorption circuit composed of a Schottky diode, an absorption resistor and an absorption capacitor.

6. The multi-output auxiliary power supply circuit according to claim 1, characterized in that, Further comprising a Y1 safety capacitor, and the Y1 safety capacitor is arranged between the power ground wire and the reference ground wire.

7. The multi-output auxiliary power supply circuit according to claim 1, characterized in that, The first voltage stabilizing unit includes: A first voltage regulator, the input end of the first voltage regulator is connected to the first power output end; A second voltage regulator, the input end of the second voltage regulator is connected to the output end of the first voltage regulator, and the output end of the second voltage regulator is connected to the fourth power output end.

8. A solar photovoltaic power generation system, characterized in that, Comprising: A solar photovoltaic panel for converting solar energy into electrical energy; A battery connected to the solar photovoltaic panel; A multi-output auxiliary power supply circuit, the multi-output auxiliary power supply circuit is the multi-output auxiliary power supply circuit according to any one of claims 1-7, and the DC power supply of the multi-output auxiliary power supply circuit is the battery.

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