CN220692819U - Flyback switching power supply with short-circuit protection and photovoltaic inverter equipment - Google Patents
Flyback switching power supply with short-circuit protection and photovoltaic inverter equipment Download PDFInfo
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- CN220692819U CN220692819U CN202322087573.XU CN202322087573U CN220692819U CN 220692819 U CN220692819 U CN 220692819U CN 202322087573 U CN202322087573 U CN 202322087573U CN 220692819 U CN220692819 U CN 220692819U
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Abstract
The application relates to a flyback switching power supply and photovoltaic inverter equipment with short-circuit protection, wherein, flyback switching power supply includes: the current sampling circuit is respectively connected with the input ends of the output circuit and the control circuit and is used for transmitting the short-circuit signals acquired by the output circuit to the control circuit; the non-inverting input end of the comparison circuit is connected with the first output end of the control circuit through the voltage dividing circuit; the inverting input end of the comparison circuit is connected with the second output end of the control circuit through the voltage dividing circuit; the feedback end of the comparison circuit is connected with the second output end of the control circuit; the control circuit is used for enabling the second output end to output a first voltage signal when receiving the short circuit signal; the first voltage signal is controlled by the comparison circuit and the voltage dividing circuit, so that the control circuit enters a short-circuit protection state; the problem of low reliability of short-circuit protection controlled by software in a control chip is solved; the short-circuit protection function by utilizing hardware is realized, and the operation reliability is improved.
Description
Technical Field
The application relates to the technical field of photovoltaic equipment, in particular to a flyback switching power supply with short-circuit protection and photovoltaic inverter equipment.
Background
In recent years, in the application of power electronics technology, a flyback switching power supply with multiple outputs is a power supply mode used by most control circuits, and the stability and reliability of the operation of the flyback switching power supply are increasingly important. The voltage regulation rate and the current regulation rate are required to meet the design requirement of products, and the short-circuit protection of any output of the flyback switching power supply is particularly important.
The current flyback switching power supply comprises a control chip, a feedback circuit and an output circuit; the feedback circuit is combined with the control chip to realize short-circuit protection. The method comprises the following steps: when the feedback circuit detects that the output circuit is short-circuited, a short-circuit signal is fed back to the control chip, and software in the control chip is used for closing the whole power supply, so that short-circuit protection is realized. The disadvantage of this solution is that: the software in the control chip controls the short-circuit protection, and the reliability is low.
At present, aiming at the problems of short-circuit protection and low operation reliability under the control of software in a control chip in the related technology, no effective solution is proposed yet.
Disclosure of Invention
In the embodiment, a flyback switching power supply and a photovoltaic inverter with short-circuit protection are provided to solve the problem that in the related art, software in a control chip controls short-circuit protection and operation reliability is low.
In a first aspect, in this embodiment, a flyback switching power supply with short-circuit protection is provided, including a control circuit, a current sampling circuit, an output circuit, a comparison circuit, and a voltage dividing circuit;
the current sampling circuit is respectively connected with the input ends of the output circuit and the control circuit and is used for transmitting the short-circuit signals acquired by the output circuit to the control circuit;
the non-inverting input end of the comparison circuit is connected with the first output end of the control circuit through the voltage dividing circuit; the inverting input end of the comparison circuit is connected with the second output end of the control circuit through the voltage dividing circuit; the feedback end of the comparison circuit is connected with the second output end of the control circuit;
the control circuit is used for enabling the second output end to output a first voltage signal when the short circuit signal is received; the first voltage signal is controlled by the comparison circuit and the voltage dividing circuit, so that the control circuit enters a short-circuit protection state.
In some embodiments, the voltage dividing circuit includes a first voltage dividing unit and a second voltage dividing unit;
the first voltage dividing unit is arranged between the first output end of the control circuit and the non-inverting input end of the comparison circuit and is used for dividing the voltage output by the first output end;
the second voltage dividing unit is arranged between the second output end of the control circuit and the inverting input end of the comparison circuit and is used for dividing the voltage output by the second output end.
In some of these embodiments, the first voltage dividing unit includes a resistor R1 and a resistor R2;
one end of the resistor R2 is connected with the first output end of the control circuit; the other end of the resistor R2 is respectively connected with one end of the resistor R1 and the non-inverting input end of the comparison circuit;
the other end of the resistor R1 is grounded.
In some of these embodiments, the second voltage dividing unit includes a resistor R3 and a resistor R4;
one end of the resistor R3 is respectively connected with the first output end of the control circuit and the feedback end of the comparison circuit; the other end of the resistor R3 is respectively connected with one end of the resistor R4 and the inverting input end of the comparison circuit;
the other end of the resistor R4 is grounded.
In some of these embodiments, the comparison circuit includes a comparator U2 and a short-circuit protection unit;
the output end of the comparator U2 is connected with the short-circuit protection unit;
the short-circuit protection unit is connected with the voltage dividing circuit and the second output end of the control circuit and is used for grounding the second output end of the control circuit when the output end of the comparator U2 outputs a first signal.
In some embodiments, the short-circuit protection unit includes a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a transistor Q2, and a transistor Q3;
the base electrode of the triode Q2 is respectively connected with the other end of the resistor R5, one end of the resistor R7 and one end of the resistor R9; the emitter of the triode Q2 is connected with one end of the resistor R6; the collector of the triode Q2 is connected with one end of a resistor R8;
one end of the resistor R5 is connected with the output end of the comparator U2;
the other end of the resistor R7 is respectively connected with the other end of the resistor R6, the voltage dividing circuit and the second output end of the control circuit;
the base electrode of the triode Q3 is respectively connected with the other end of the resistor R8 and one end of the resistor R10; the collector electrode of the triode Q3 is connected with the other end of the resistor R9; the emitter of the triode Q3 is grounded; the other end of the resistor R10 is grounded.
In some embodiments, the transistor Q2 and the transistor Q3 are one of NPN transistors and N-MOS transistors.
In some embodiments, the current sampling circuit includes a transistor Q1, a resistor R11, and a resistor R12;
the collector of the triode Q1 is connected with the primary winding of the output circuit, the base of the triode Q1 is connected with one end of the resistor R11, and the emitter of the triode Q1 is respectively connected with one end of the resistor R12 and the input end of the control circuit;
the other end of the resistor R12 is grounded;
the other end of the resistor R11 is connected with a third output end of the control circuit.
In some of these embodiments, the output circuit is a flyback transformer T1; the flyback transformer T1 comprises a primary winding and a secondary winding; a diode D1, a capacitor C1 and a resistor R13 are arranged in the secondary winding;
one end of the diode D1 is connected with the positive electrode of the secondary winding; the other end of the diode D1 is respectively connected with one end of the capacitor C1 and one end of the resistor R13;
the other end of the capacitor C1 and the other end of the resistor R13 are connected with the negative electrode of the secondary winding and grounded.
In a second aspect, in this embodiment, there is provided a photovoltaic inverter apparatus including a photovoltaic panel and a flyback switching power supply with short-circuit protection as described in the first aspect above connected to the photovoltaic panel.
Compared with the related art, the flyback switching power supply with the short-circuit protection and the photovoltaic inverter device provided in the embodiment, wherein the flyback switching power supply comprises a control circuit, a current sampling circuit, an output circuit, a comparison circuit and a voltage division circuit; the current sampling circuit is respectively connected with the input ends of the output circuit and the control circuit and is used for transmitting the short-circuit signals acquired by the output circuit to the control circuit; the non-inverting input end of the comparison circuit is connected with the first output end of the control circuit through the voltage dividing circuit; the inverting input end of the comparison circuit is connected with the second output end of the control circuit through the voltage dividing circuit; the feedback end of the comparison circuit is connected with the second output end of the control circuit; the control circuit is used for enabling the second output end to output a first voltage signal when receiving the short circuit signal; the first voltage signal is controlled by the comparison circuit and the voltage dividing circuit, so that the control circuit enters a short-circuit protection state; the problem of low reliability of short-circuit protection controlled by software in a control chip is solved; the comparison circuit and the voltage dividing circuit are used for controlling the first voltage signal output by the control circuit, so that the control circuit enters a short-circuit protection state, the short-circuit protection function by hardware is realized, and the operation reliability is improved.
The details of one or more embodiments of the application are set forth in the accompanying drawings and the description below to provide a more thorough understanding of the other features, objects, and advantages of the application.
Drawings
The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:
FIG. 1 is a block diagram of a flyback switching power supply according to an embodiment of the present application;
FIG. 2 is a circuit diagram of a voltage divider circuit according to an embodiment of the present application;
FIG. 3 is a circuit diagram of a comparison circuit provided in an embodiment of the present application;
fig. 4 is a circuit diagram of a flyback switching power supply according to a preferred embodiment of the present application.
In the figure: 10. a comparison circuit; 20. a voltage dividing circuit; 21. a first voltage dividing unit; 22. a second voltage dividing unit; 30. a control circuit; 40. a current sampling circuit; 50. and an output circuit.
Detailed Description
In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described and illustrated below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden on the person of ordinary skill in the art based on the embodiments provided herein, are intended to be within the scope of the present application. Moreover, it should be appreciated that while such a development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as having the benefit of this disclosure.
Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is to be expressly and implicitly understood by those of ordinary skill in the art that the embodiments described herein can be combined with other embodiments without conflict.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this application belongs. When an element is referred to herein as being "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "secured to" another element, it can be directly secured to the other element or intervening elements may also be present. The terms "first," "second," "third," and the like, as used herein, are merely distinguishing between similar objects and not representing a particular ordering of objects. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the present application. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.
Referring to fig. 1, the present utility model provides a flyback switching power supply with short-circuit protection, which includes a control circuit 30, a current sampling circuit 40, an output circuit 50, a comparison circuit 10 and a voltage dividing circuit 20;
the current sampling circuit 40 is respectively connected with the input ends of the output circuit 50 and the control circuit 30 and is used for transmitting the short-circuit signals acquired by the output circuit 50 to the control circuit 30;
the non-inverting input end of the comparison circuit 10 is connected with the first output end of the control circuit 30 through the voltage dividing circuit 20; the inverting input end of the comparison circuit 10 is connected with the second output end of the control circuit 30 through the voltage dividing circuit 20; the feedback end of the comparison circuit 10 is connected with the second output end of the control circuit 30;
a control circuit 30, configured to, when receiving the short-circuit signal, cause the second output terminal to output a first voltage signal; the first voltage signal is controlled by the comparison circuit 10 and the voltage dividing circuit 20, and brings the control circuit 30 into a short-circuit protection state.
Specifically, the control circuit 30, the current sampling circuit 40, the output circuit 50, the comparison circuit 10, the voltage dividing circuit 20, and the like may be configured by circuits such as an electronic device and a control chip, and are not limited thereto.
Wherein the output circuit 50 has a plurality of outputs that can power a plurality of products. When the output circuit 50 works normally, the second output end of the control circuit 30 outputs a second voltage signal, the second voltage signal enters the comparison circuit 10 through the voltage dividing circuit 20, and at this time, the comparison circuit 10 does not act (the control end of the comparison circuit 10 is open), so that the flyback switching power supply works normally. When the output circuit 50 is short-circuited, the current sampling circuit 40 is connected with the output circuit 50, so that the current sampling circuit 40 can transmit the collected short-circuit current to the control circuit 30, and at the moment, the second output end of the control circuit 30 outputs a first voltage signal; the first voltage signal enters the comparison circuit 10 through the voltage dividing circuit 20, the comparison circuit 10 acts (the control end of the comparison circuit 10 is short-circuited), the first voltage signal is grounded and pulled down, and the flyback switching power supply enters a short-circuit protection state; therefore, the voltage division circuit 20 and the comparison circuit 10 are used for completing the short-circuit protection of the flyback switch circuit in hardware, and complex software or algorithm processing is not needed in the controller, so that the use reliability is improved.
In this embodiment, each device in the upper part is an electronic device, if some control logic is involved, for example: the control logic in the control circuit 30 is also implemented in connection with existing control software and is not described here.
Through the flyback switching power supply, when the output circuit 50 is short-circuited, the voltage signal output by the second output end of the control circuit 30 is mainly changed, and the voltage signal output is controlled by matching with the voltage dividing circuit 20 and the comparison circuit 10, so that the control circuit 30 enters a short-circuit protection state, thereby realizing the short-circuit protection function by utilizing hardware and improving the operation reliability; the problem of low reliability of short-circuit protection controlled by software in a control chip in the related art is solved;
the following describes each of the above devices in detail:
in some of these embodiments, as shown in fig. 2, the voltage dividing circuit 20 includes a first voltage dividing unit 21 and a second voltage dividing unit 22;
the first voltage dividing unit 21 is disposed between the first output terminal of the control circuit 30 and the non-inverting input terminal of the comparison circuit 10, and is configured to divide the voltage output from the first output terminal;
the second voltage dividing unit 22 is disposed between the second output terminal of the control circuit 30 and the inverting input terminal of the comparison circuit 10, and is configured to divide the voltage output from the second output terminal.
Specifically, the first voltage dividing unit 21 includes a plurality of resistors, and divides the voltage output from the first output terminal by the resistors. The second voltage dividing unit 22 includes a plurality of resistors, and divides the voltage output from the second output terminal by using the resistors. The number of resistors, the resistance value, and the connection relation in the first voltage dividing unit 21 and the second voltage dividing unit 22 may be set by specific use scenarios. Such as: the voltage output by the first output terminal of the control circuit 30 is 5V (normal operation)/5V (short circuit occurrence), and the voltage output by the second output terminal is 1.5V (normal operation)/5V (short circuit occurrence); for normal operation, the first voltage dividing unit 21 will reduce the 5V output from the first output terminal to between 1.5V and 3.3V; the second voltage division unit 22 will reduce the 1.5V output from the second output terminal to below 1.5V. For the occurrence of short circuit, the first voltage dividing unit 21 will reduce the 5V output by the first output terminal to between 1.5V and 3.3V; the second voltage division unit 22 will reduce the 5V output from the second output terminal to between 3.3V and 5V. In other embodiments, the value of the voltage value output by the control circuit 30 and the specific structure of the voltage dividing unit may be set according to the use scenario, which is not limited.
In this embodiment, the first voltage dividing unit 21 and the second voltage dividing unit 22 are used to divide the voltages output from the two output terminals of the control circuit 30, and then input the divided voltages into the comparison circuit 10 for logic judgment, so as to ensure the reliability of use.
In some of these embodiments, the first voltage dividing unit 21 includes a resistor R1 and a resistor R2;
one end of the resistor R2 is connected with the first output end of the control circuit 30; the other end of the resistor R2 is respectively connected with one end of the resistor R1 and the non-inverting input end of the comparison circuit 10;
the other end of the resistor R1 is grounded.
Specifically, the first voltage dividing unit 21 includes two resistors; resistor R1 and resistor R2, respectively. If it is to satisfy: the voltage output from the first output terminal of the control circuit 30 is 5V (normal operation)/5V (short circuit occurs), and for normal operation, the first voltage dividing unit 21 will reduce the voltage output from the first output terminal to between 1.5V and 3.3V. For the occurrence of a short circuit, the first voltage dividing unit 21 will reduce the 5V output from the first output terminal to between 1.5V and 3.3V. For this, the resistor R1 may be set to 20K, and the resistor R2 may be set to 10K.
In this embodiment, the first voltage dividing unit 21 is simple in device, reliable and stable in use, and reduces production cost.
In some of these embodiments, the second voltage dividing unit 22 includes a resistor R3 and a resistor R4;
one end of the resistor R3 is respectively connected with the first output end of the control circuit 30 and the feedback end of the comparison circuit 10; the other end of the resistor R3 is respectively connected with one end of the resistor R4 and the inverting input end of the comparison circuit 10;
the other end of the resistor R4 is grounded.
Specifically, the second voltage dividing unit 22 includes two resistors; resistor R3 and resistor R4, respectively. If it is to satisfy: the voltage output by the second output terminal of the control circuit 30 is 1.5V (normal operation)/5V (short circuit occurs), and the second voltage dividing unit 22 reduces the voltage output by the second output terminal to 1.5V or less under normal operation. For the occurrence of a short circuit, the second voltage dividing unit 22 reduces the 5V output from the second output terminal to between 3.3V and 5V. For this, the resistor R1 may be set to 20K, and the resistor R2 may be set to 10K.
In this embodiment, the second voltage dividing unit 22 is simple in device, reliable and stable in use, and reduces production cost.
In some of these embodiments, as shown in fig. 3, the comparison circuit 10 includes a comparator U2 and a short-circuit protection unit;
the output end of the comparator U2 is connected with the short-circuit protection unit;
and the short-circuit protection unit is connected with the voltage division circuit 20 and the second output end of the control circuit 30 and is used for grounding the second output end of the control circuit 30 when the output end of the comparator U2 outputs the first signal.
Specifically, the non-inverting input terminal of the comparator U2 is the non-inverting input terminal of the comparison circuit 10; the inverting input of the comparator U2 is the inverting input of the comparator circuit 10. The input voltage at the inverting input terminal is smaller than the input voltage at the non-inverting input terminal, and the comparator U2 outputs a low level; otherwise, the comparator U2 outputs a high level; the characteristics of the comparator are utilized to further improve the reliability and stability of use.
In some embodiments, the short-circuit protection unit includes a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a transistor Q2, and a transistor Q3;
the base electrode of the triode Q2 is respectively connected with the other end of the resistor R5, one end of the resistor R7 and one end of the resistor R9; an emitter of the triode Q2 is connected with one end of a resistor R6; the collector of the triode Q2 is connected with one end of a resistor R8;
one end of the resistor R5 is connected with the output end of the comparator U2;
the other end of the resistor R7 is respectively connected with the other end of the resistor R6, the voltage dividing circuit 20 and the second output end of the control circuit 30;
the base electrode of the triode Q3 is respectively connected with the other end of the resistor R8 and one end of the resistor R10; the collector of the triode Q3 is connected with the other end of the resistor R9; the emitter of the triode Q3 is grounded; the other end of the resistor R10 is grounded.
Specifically, during normal operation, the comparator U2 outputs a low level, and the low level is divided by the resistor R5 to the base of the triode Q2, so that the triode Q2 is not turned on; then the base of transistor Q3 is also not signaled so that transistor Q3 is not conductive; the output end (the other end of R7) of the short-circuit protection unit is disconnected. When short circuit occurs, the comparator U2 outputs high level, and the high level is divided by the resistor R5 and then reaches the base electrode of the triode Q2 to lead the triode Q2 to be conducted; the voltage of the second output end of the control circuit 30 is connected to the base electrode of the triode Q3 through the resistor R6 and the resistor R8 to conduct the triode Q3, so that the second output end of the control circuit 30 is grounded, and the voltage of the second output end of the control circuit 30 is pulled down; when the voltage of the second output terminal of the control circuit 30 is pulled down, the control circuit 30 will be powered off to stop working and enter a short-circuit protection state.
In this embodiment, the short-circuit protection unit is constructed using several simple electronic devices, further improving the reliability and stability of use.
In some of these embodiments, the current sampling circuit 40 includes a transistor Q1, a resistor R11, and a resistor R12;
the collector of the triode Q1 is connected with the primary winding of the output circuit 50, the base of the triode Q1 is connected with one end of a resistor R11, and the emitter of the triode Q1 is respectively connected with one end of a resistor R12 and the input end of the control circuit 30;
the other end of the resistor R12 is grounded;
the other end of the resistor R11 is connected to a third output terminal of the control circuit 30.
Specifically, transistor Q1, transistor Q2, transistor Q3 include, but are not limited to, NPN transistors, N-MOS transistors, and the like. The third output end of the control circuit 30 is connected with the base electrode of the triode Q1 through a resistor R11, and the work of the triode Q1 is controlled through a control signal output by the third output end of the control circuit 30.
Example: when the control circuit 30 works normally, the duty ratio signal output by the third output end of the control circuit 30 is greater than 0, the emitter of the triode Q1 is conducted with the collector of the triode Q1, so that the resistor R12 in the current sampling circuit 40 starts to work; if the control circuit 30 stops working and enters short-circuit protection, the duty ratio signal output by the third output end of the control circuit 30 is 0, the emitter of the triode Q1 is disconnected from the collector of the triode Q1, and the resistor R12 in the current sampling circuit 40 stops working.
Based on the above steps, it can be considered that the current sampling circuit 40 detects whether the output circuit 50 is short-circuited in real time when the control circuit 30 is operating normally. The method comprises the following steps: whether the primary winding of the output circuit 50 has a short-circuit current is detected by the current sampling circuit 40. When the output of the secondary winding of the output circuit 50 is short-circuited, the secondary current increases instantaneously, and the current fed back to the primary winding also increases instantaneously, and the current sampled at this time is regarded as a short-circuit current; the sampling current is fed back to the input end of the control circuit 30, and when the short-circuit current exceeds the current threshold value built in the control chip U1, the PWM duty ratio output by the third output end is controlled to be reduced to 0, so that the triode Q1 is disconnected, and the short-circuit protection of the flyback switching power supply is realized.
In the present embodiment, the current sampling circuit 40 is used to detect the occurrence of short circuit, and the structure is simple and the production cost is low.
In some of these embodiments, the output circuit 50 is a flyback transformer T1; the flyback transformer T1 comprises a primary winding and a secondary winding; a diode D1, a capacitor C1 and a resistor R13 are arranged in the secondary winding;
one end of the diode D1 is connected with the positive electrode of the secondary winding; the other end of the diode D1 is respectively connected with one end of the capacitor C1 and one end of the resistor R13;
the other end of the capacitor C1 and the other end of the resistor R13 are connected with the negative electrode of the secondary winding and grounded.
In particular, the output circuit 50 may be a multi-output circuit. Such as: the output circuit 50 is a flyback transformer T1; flyback transformer T1 comprises a primary winding and a plurality of secondary windings; each secondary winding is provided with a diode and a capacitor. Such as: the number of the secondary windings is two; each secondary winding can be considered an output, the voltage of which is determined by the number of secondary windings and the number of primary windings. Each secondary winding is provided with a diode and a capacitor.
In this embodiment, a structure that is easy to be like the second secondary winding may be added to the secondary winding to increase the output end of the output circuit 50, without adjusting the overall circuit structure, thereby expanding the use scenario.
The present embodiment is described and illustrated below by way of preferred embodiments.
Fig. 4 is a circuit diagram of the flyback switching power supply of the preferred embodiment. As shown in fig. 4 and 2, the flyback switching power supply includes a control circuit 30, a current sampling circuit 40, an output circuit 50, a comparison circuit 10, and a voltage dividing circuit 20;
wherein the control circuit 30 is a pulse width modulator U1; wherein the voltage dividing circuit 20 includes a first voltage dividing unit 21 and a second voltage dividing unit 22; the first voltage dividing unit 21 includes a resistor R1 and a resistor R2; the second voltage dividing unit 22 includes a resistor R3 and a resistor R4; one end of the resistor R2 is connected with a first output end Vref of the pulse width modulator U1; the other end of the resistor R2 is respectively connected with one end of the resistor R1 and the non-inverting input end of the comparator U2; the other end of the resistor R1 is grounded. One end of the resistor R3 is respectively connected with the first output end Vref of the pulse width modulator U1 and the feedback end of the comparison circuit 10; the other end of the resistor R3 is respectively connected with one end of the resistor R4 and the inverting input end of the comparator U2; the other end of the resistor R4 is grounded.
The comparison circuit 10 includes a comparator U2, a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a transistor Q2, and a transistor Q3; the base electrode of the triode Q2 is respectively connected with the other end of the resistor R5, one end of the resistor R7 and one end of the resistor R9; an emitter of the triode Q2 is connected with one end of a resistor R6; the collector of the triode Q2 is connected with one end of a resistor R8; one end of the resistor R5 is connected with the output end of the comparator U2; the other end of the resistor R7 is respectively connected with the other end of the resistor R6, the voltage dividing circuit 20 and the second output end Comp of the pulse width modulator U1; the base electrode of the triode Q3 is respectively connected with the other end of the resistor R8 and one end of the resistor R10; the collector of the triode Q3 is connected with the other end of the resistor R9; the emitter of the triode Q3 is grounded; the other end of the resistor R10 is grounded.
The current sampling circuit 40 includes a transistor Q1, a resistor R11, and a resistor R12; the collector of the triode Q1 is connected with the primary winding of the output circuit 50, the base of the triode Q1 is connected with one end of a resistor R11, and the emitter of the triode Q1 is respectively connected with one end of a resistor R12 and the input end I-sense of the pulse width modulator U1; the other end of the resistor R12 is grounded; the other end of the resistor R11 is connected to the third output of the pulse width modulator U1.
Wherein the output circuit 50 is a flyback transformer T1; the flyback transformer T1 comprises a primary winding and a secondary winding; the positive electrode of the primary winding is used as an input end Vin to be connected with external input voltage; the negative electrode of the primary winding is connected with the collector electrode of the triode Q1; a diode D1, a capacitor C1 and a resistor R13 are arranged in the secondary winding; one end of the diode D1 is connected with the positive electrode of the secondary winding; the other end of the diode D1 is used as an output end Vout and is respectively connected with one end of the capacitor C1 and one end of the resistor R13; the other end of the capacitor C1 and the other end of the resistor R13 are connected with the negative electrode of the secondary winding and grounded.
In this embodiment, the sensitivity of the short-circuit protection is improved, the comparison circuit 10 and the voltage dividing circuit 20 are used to control the first voltage signal output by the control circuit 30, so that the control circuit 30 enters the short-circuit protection state, thereby realizing the short-circuit protection function by using hardware, and improving the reliability of operation.
The embodiment also provides photovoltaic inverter equipment, which comprises a photovoltaic panel and the flyback switching power supply, wherein the flyback switching power supply is connected with the photovoltaic panel and used for switching on and off the photovoltaic panel.
The photovoltaic inversion equipment solves the problems of short-circuit protection and low reliability caused by software control in a control chip; the comparison circuit and the voltage dividing circuit are used for controlling the first voltage signal output by the control circuit, so that the control circuit enters a short-circuit protection state, the short-circuit protection function by hardware is realized, and the operation reliability is improved.
It should be noted that, specific examples in this embodiment may refer to examples described in the foregoing embodiments and alternative implementations, and are not described in detail in this embodiment.
It should be understood that the specific embodiments described herein are merely illustrative of this application and are not intended to be limiting. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present application, are within the scope of the present application in light of the embodiments provided herein.
It is evident that the drawings are only examples or embodiments of the present application, from which the present application can also be adapted to other similar situations by a person skilled in the art without the inventive effort. In addition, it should be appreciated that while the development effort might be complex and lengthy, it would nevertheless be a routine undertaking of design, fabrication, or manufacture for those of ordinary skill having the benefit of this disclosure, and thus should not be construed as an admission of insufficient detail.
The term "embodiment" in this application means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive. It will be clear or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.
The above examples only represent a few embodiments of the present application, which are described in more detail and are not to be construed as limiting the scope of the patent. It should be noted that it would be apparent to those skilled in the art that various modifications and improvements could be made without departing from the spirit of the present application, which would be within the scope of the present application. Accordingly, the scope of protection of the present application shall be subject to the appended claims.
Claims (10)
1. The flyback switching power supply with the short-circuit protection is characterized by comprising a control circuit (30), a current sampling circuit (40), an output circuit (50), a comparison circuit (10) and a voltage division circuit (20);
the current sampling circuit (40) is respectively connected with the input ends of the output circuit (50) and the control circuit (30) and is used for transmitting the acquired short-circuit signals of the output circuit (50) to the control circuit (30);
the non-inverting input end of the comparison circuit (10) is connected with the first output end of the control circuit (30) through the voltage dividing circuit (20); the inverting input end of the comparison circuit (10) is connected with the second output end of the control circuit (30) through the voltage dividing circuit (20); the feedback end of the comparison circuit (10) is connected with the second output end of the control circuit (30);
the control circuit (30) is configured to, when receiving the short-circuit signal, cause the second output terminal to output a first voltage signal; the first voltage signal is controlled by the comparison circuit (10) and the voltage dividing circuit (20), so that the control circuit (30) enters a short-circuit protection state.
2. Flyback switching power supply with short-circuit protection according to claim 1, characterized in that the voltage dividing circuit (20) comprises a first voltage dividing unit (21) and a second voltage dividing unit (22);
the first voltage dividing unit (21) is arranged between a first output end of the control circuit (30) and a non-inverting input end of the comparison circuit (10) and is used for dividing the voltage output by the first output end;
the second voltage dividing unit (22) is arranged between the second output end of the control circuit (30) and the inverting input end of the comparison circuit (10) and is used for dividing the voltage output by the second output end.
3. Flyback switching power supply with short-circuit protection according to claim 2, characterized in that the first voltage dividing unit (21) comprises a resistor R1 and a resistor R2;
one end of the resistor R2 is connected with the first output end of the control circuit (30); the other end of the resistor R2 is respectively connected with one end of the resistor R1 and the non-inverting input end of the comparison circuit (10);
the other end of the resistor R1 is grounded.
4. Flyback switching power supply with short-circuit protection according to claim 2, characterized in that the second voltage dividing unit (22) comprises a resistor R3 and a resistor R4;
one end of the resistor R3 is respectively connected with the first output end of the control circuit (30) and the feedback end of the comparison circuit (10); the other end of the resistor R3 is respectively connected with one end of the resistor R4 and the inverting input end of the comparison circuit (10);
the other end of the resistor R4 is grounded.
5. Flyback switching power supply with short-circuit protection according to claim 1, characterized in that the comparison circuit (10) comprises a comparator U2 and a short-circuit protection unit;
the output end of the comparator U2 is connected with the short-circuit protection unit;
the short-circuit protection unit is connected with the voltage division circuit (20) and the second output end of the control circuit (30) and is used for grounding the second output end of the control circuit (30) when the output end of the comparator U2 outputs a first signal.
6. The flyback switching power supply with short-circuit protection according to claim 5, wherein the short-circuit protection unit comprises a resistor R5, a resistor R6, a resistor R7, a resistor R8, a resistor R9, a resistor R10, a triode Q2 and a triode Q3;
the base electrode of the triode Q2 is respectively connected with the other end of the resistor R5, one end of the resistor R7 and one end of the resistor R9; the emitter of the triode Q2 is connected with one end of the resistor R6; the collector of the triode Q2 is connected with one end of a resistor R8;
one end of the resistor R5 is connected with the output end of the comparator U2;
the other end of the resistor R7 is respectively connected with the other end of the resistor R6, the voltage dividing circuit (20) and the second output end of the control circuit (30);
the base electrode of the triode Q3 is respectively connected with the other end of the resistor R8 and one end of the resistor R10; the collector electrode of the triode Q3 is connected with the other end of the resistor R9; the emitter of the triode Q3 is grounded; the other end of the resistor R10 is grounded.
7. The flyback switching power supply with short-circuit protection according to claim 6, wherein the triode Q2 and the triode Q3 are one of NPN triode and N-MOS transistor.
8. Flyback switching power supply with short-circuit protection according to claim 1, characterized in that the current sampling circuit (40) comprises a transistor Q1, a resistor R11 and a resistor R12;
the collector of the triode Q1 is connected with the primary winding of the output circuit (50), the base of the triode Q1 is connected with one end of the resistor R11, and the emitter of the triode Q1 is respectively connected with one end of the resistor R12 and the input end of the control circuit (30);
the other end of the resistor R12 is grounded;
the other end of the resistor R11 is connected with a third output end of the control circuit (30).
9. Flyback switching power supply with short-circuit protection according to claim 1, characterized in that the output circuit (50) is a flyback transformer T1; the flyback transformer T1 comprises a primary winding and a secondary winding; a diode D1, a capacitor C1 and a resistor R13 are arranged in the secondary winding;
one end of the diode D1 is connected with the positive electrode of the secondary winding; the other end of the diode D1 is respectively connected with one end of the capacitor C1 and one end of the resistor R13;
the other end of the capacitor C1 and the other end of the resistor R13 are connected with the negative electrode of the secondary winding and grounded.
10. A photovoltaic inverter apparatus comprising a photovoltaic panel and a flyback switching power supply with short-circuit protection according to any one of claims 1 to 9 connected to the photovoltaic panel.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322087573.XU CN220692819U (en) | 2023-08-04 | 2023-08-04 | Flyback switching power supply with short-circuit protection and photovoltaic inverter equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202322087573.XU CN220692819U (en) | 2023-08-04 | 2023-08-04 | Flyback switching power supply with short-circuit protection and photovoltaic inverter equipment |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN220692819U true CN220692819U (en) | 2024-03-29 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202322087573.XU Active CN220692819U (en) | 2023-08-04 | 2023-08-04 | Flyback switching power supply with short-circuit protection and photovoltaic inverter equipment |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN220692819U (en) |
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2023
- 2023-08-04 CN CN202322087573.XU patent/CN220692819U/en active Active
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