Power circuit for new energy photovoltaic high-voltage transmission

Abstract

The utility model belongs to the field of new energy, and discloses a power circuit for new energy photovoltaic high-voltage transmission, which is arranged between a power supply input end and a power supply output end. The power circuit comprises a high-frequency coupling transformer, a switching tube, a rectifier diode and a coupling capacitor, the high-frequency coupling transformer comprises a primary winding and a secondary winding, the secondary winding adopts the rectifier diode for rectification, and the primary winding is connected with the power input end, the drain electrode of the switching tube and one end of the coupling capacitor; the secondary winding is respectively connected with a GND, an anode of the rectifier diode and the other end of the coupling capacitor, the other end of the rectifier diode is connected with a power supply output end, a grid electrode of the switch tube is connected with emitting electrodes of two triodes, base electrodes of the two triodes are jointly connected with a PWM output end of a signal control chip, and the two triodes are respectively N type and P type. The power circuit has the advantages that the stress of the power device is low, the size of the device is small, and equipment can be effectively prevented from being damaged.

Description

Technical Field

[0001] The utility model relates to the technical field of power supply circuits, and in particular to a power circuit for new energy photovoltaic high-voltage transmission. Background Art

[0002] Photovoltaic power supplies are used to power photovoltaic power generation equipment, photovoltaic charging equipment, photovoltaic power supply equipment and other photovoltaic equipment. Due to the complex photovoltaic use environment, the voltage of solar panels is extremely unstable, and the output voltage is between 500-900Vdc. Such a high voltage can easily cause equipment failure.

[0003] In order to solve the problem that existing power conversion circuits cannot cope with the extremely high power generation voltage of solar panels, the existing solution is to increase the size of DC converter devices so that they can withstand higher voltages, but this also reduces portability and increases costs. Utility Model Content

[0004] In view of the above technical problems, the utility model provides a power circuit for new energy photovoltaic high voltage transmission.

[0005] Other features and advantages of the present invention will become apparent from the following detailed description or may be learned in part from the practice of the present invention.

[0006] The utility model aims to provide a power circuit for new energy photovoltaic high-voltage transmission, wherein the power circuit is arranged between a power input terminal and a power output terminal; the power circuit comprises a high-frequency coupling transformer, a switch tube, a rectifier diode, and a coupling capacitor; the high-frequency coupling transformer comprises a primary winding and an auxiliary winding; the secondary winding is rectified by the rectifier diode; the primary winding is respectively connected to the power input terminal and the drain of the switch tube and one end of the coupling capacitor; the secondary winding is respectively connected to GND, an anode of the rectifier diode and the other end of the coupling capacitor; the other end of the rectifier diode is connected to the power output terminal; the gate of the switch tube is connected to the emitters of two transistors; the bases of the two transistors are commonly connected to the PWM output terminal of a signal control chip; the two transistors are respectively of N type and P type.

[0007] Furthermore, the power circuit also includes a charging capacitor, and the high-frequency coupling transformer also includes an auxiliary winding corresponding to the secondary winding, one end of the charging capacitor is connected to the rectifier diode, and the other end is connected to the auxiliary winding, the auxiliary winding provides VCC power supply to the signal control chip through a unidirectional diode and a current limiting resistor, and when the auxiliary winding has no output, the charging capacitor provides VCC power supply to the signal control chip.

[0008] Furthermore, in a switching cycle of the power circuit, when the switch tube connected to the primary winding is turned on, the rectifier diode connected to the secondary winding is turned off, at which time the high-frequency coupling transformer stores energy, the coupling capacitor charges the secondary winding, and the charging capacitor outputs energy to the power supply output end; when the switch tube is turned off, the high-frequency coupling transformer charges the coupling capacitor, the rectifier diode is turned on, and at this time the secondary winding outputs voltage to the signal control chip.

[0009] The technical solution of the utility model has the following beneficial effects:

[0010] The power circuit adopts single-ended primary side conversion with high conversion rate, can effectively withstand the voltage fluctuation generated by the solar panel power generation, reasonably utilizes the device stress, does not need to increase the size of the device on a large scale, and reduces costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 1 is a circuit schematic diagram of a power circuit according to an embodiment of this specification. DETAILED DESCRIPTION

[0012] Typical implementations that embody the features and advantages of the utility model will be described in detail in the following description. It should be understood that the utility model can have various changes in different implementations, all of which do not depart from the scope of the utility model, and the descriptions and illustrations therein are essentially used for illustrative purposes rather than to limit the utility model. In the description of the utility model, it should be noted that, unless otherwise clearly specified and limited, the term "connection" refers to the electrical connection of the relevant elements according to their inherent characteristics and scheme logical relationships in order to achieve its technical purpose. It can be an electrical connection relationship formed by direct connection, or it can be an indirect electrical connection through an intermediate medium. For ordinary technicians in this field, the specific meaning of each term in the application document in the utility model can be understood according to the specific circumstances.

[0013] like Figure 1As shown, the embodiment of the utility model provides a power circuit for new energy photovoltaic high-voltage transmission, and the power circuit is arranged between the power input end and the power output end; the power circuit includes a high-frequency coupling transformer, a switch tube Q1, a rectifier diode D6, and a coupling capacitor C13. The high-frequency coupling transformer includes a primary winding L1A and a secondary winding L1B. The secondary winding L1B is rectified by a rectifier diode D6. The primary winding L1A is respectively connected to the power input end and the drain of the switch tube Q1 and one end of the coupling capacitor C13. The secondary winding L1B is respectively connected to GND, the anode of the rectifier diode D6 and the other end of the coupling capacitor C13. The other end of the rectifier diode D6 is connected to the power output end. The gate of the switch tube Q1 is connected to the emitters of the two transistors Q5 and Q6. The bases of the two transistors Q5 and Q6 are commonly connected to the PWM output end of a signal control chip U1. The two transistors Q5 and Q6 are N-type and P-type, respectively.

[0014] The power circuit also includes charging capacitors C6 and C7. One end of the charging capacitors C6 and C7 is connected to the rectifier diode D6, and the other end is connected to the auxiliary winding. The high-frequency coupling transformer also includes an auxiliary winding corresponding to the secondary winding L1B. The auxiliary winding provides VCC power supply to the signal control chip U1 through the unidirectional diode D2 and the current limiting resistor R85. When the auxiliary winding has no output, the charging capacitors C6 and C7 provide VCC power supply to the signal control chip U1.

[0015] Working principle: In a switching cycle of the power circuit, when the switch tube Q1 connected to the primary winding L1A is turned on, the rectifier diode D6 connected to the secondary winding L1B is cut off. At this time, the high-frequency coupling transformer stores energy, the coupling capacitor C13 charges the secondary winding L1B, and the charging capacitors C6 and C7 output energy to the power output end; when the switch tube Q1 is cut off, the high-frequency coupling transformer charges the coupling capacitor C13, and the rectifier diode D6 is turned on. At this time, the secondary winding outputs voltage to the signal control chip U1.

[0016] The advantage of the power circuit of the present invention is that the power device stress is low. The voltage stress of the switch tube Q1 and the rectifier diode D6 is the maximum value of the input voltage + the maximum value of the output voltage. In this way, the volume of the device can be set smaller, and the device voltage is a complete square wave without voltage spikes and oscillations, which can effectively prevent equipment damage.

[0017] The power circuit of the utility model adopts single-ended primary side conversion, has a high conversion rate, can effectively withstand the voltage fluctuation generated by the solar cell panel, reasonably utilizes the device stress, does not need to increase the size of the device by a large area, and reduces the cost.

[0018] The utility model adopts an auxiliary winding to power the signal control chip U1, which can avoid the loss of linear power supply and save components.

[0019] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the utility model, rather than to limit them; although the utility model is described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the above embodiments, or replace some or all of the technical features therein by equivalent; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the various embodiments of the utility model. In addition, those skilled in the art can understand that although some embodiments described herein include certain features included in other embodiments instead of other features, the combination of features of different embodiments means that they are within the scope of the utility model and form different embodiments. For example, in the above claims, any one of the embodiments claimed for protection can be used in any combination. The information disclosed in this background technology section is only intended to deepen the understanding of the overall background technology of the utility model, and should not be regarded as admitting or suggesting in any form that the information constitutes prior art known to those skilled in the art.

Claims

1. A power circuit for new energy photovoltaic high voltage transmission, characterized in that: The power circuit is arranged between the power input end and the power output end; the power circuit includes a high-frequency coupling transformer, a switch tube, a rectifier diode, and a coupling capacitor. The high-frequency coupling transformer includes a primary winding and a secondary winding. The secondary winding is rectified by the rectifier diode. The primary winding is respectively connected to the power input end, the drain of the switch tube, and one end of the coupling capacitor. The secondary winding is respectively connected to GND, the anode of the rectifier diode, and the other end of the coupling capacitor. The other end of the rectifier diode is connected to the power output end. The gate of the switch tube is connected to the emitters of two transistors. The bases of the two transistors are commonly connected to the PWM output end of a signal control chip. The two transistors are N-type and P-type respectively.

2. The power circuit for new energy photovoltaic high voltage transmission according to claim 1, characterized in that: The high-frequency coupling transformer also includes an auxiliary winding corresponding to the secondary winding, and the power circuit also includes a charging capacitor, one end of the charging capacitor is connected to the rectifier diode, and the other end is connected to the auxiliary winding, the auxiliary winding provides VCC power supply for the signal control chip through a unidirectional diode and a current limiting resistor, and when the auxiliary winding has no output, the charging capacitor provides VCC power supply for the signal control chip.

3. The power circuit for new energy photovoltaic high voltage transmission according to claim 2, characterized in that: In a switching cycle of the power circuit, when the switch tube connected to the primary winding is turned on, the rectifier diode connected to the secondary winding is turned off. At this time, the high-frequency coupling transformer stores energy, the coupling capacitor charges the secondary winding, and the charging capacitor outputs energy to the power supply output end; when the switch tube is turned off, the high-frequency coupling transformer charges the coupling capacitor, the rectifier diode is turned on, and at this time, the secondary winding outputs voltage to the signal control chip.

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