CN216387892U

CN216387892U - Voltage detection holding circuit for photovoltaic panel open circuit and voltage stabilization output device

Info

Publication number: CN216387892U
Application number: CN202123244264.6U
Authority: CN
Inventors: 佟天野; 张强; 付战超
Original assignee: Suzhou Luck Power Electronics Technology Co ltd
Current assignee: Suzhou Luck Power Electronics Technology Co ltd
Priority date: 2021-12-22
Filing date: 2021-12-22
Publication date: 2022-04-26
Anticipated expiration: 2031-12-22

Abstract

The utility model discloses a voltage detection holding circuit and a voltage stabilization output device for open circuit of a photovoltaic panel, wherein the voltage detection holding circuit comprises a comparator, a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, a third diode D3, a first capacitor C1 and a second capacitor C2, one end of the first resistor R1 is used for being connected to the output end of the photovoltaic panel, and the other end of the first resistor R1 is connected to the positive input end of the comparator and is connected with one end of a second resistor R2; the first diode D1 and the first capacitor C1 are connected in series to form a first branch circuit, and the second diode D2 and the second capacitor C2 form a second branch circuit; the third resistor R3 is connected in parallel with the second capacitor C2, the negative input end of the comparator is connected with a line connected between the second diode D2 and the second capacitor C2, and the voltage detection holding circuit and the voltage stabilization output device provided by the utility model use components such as the comparator to replace an MCU (microprogrammed control Unit), so that the cost is greatly reduced, and the stability is high.

Description

Voltage detection holding circuit for photovoltaic panel open circuit and voltage stabilization output device

Technical Field

The utility model relates to the technical field of voltage output of photovoltaic panels, in particular to a voltage detection holding circuit and a voltage stabilization output device for an open circuit of a photovoltaic panel.

Background

In the application of Maximum Power Point Tracking (MPPT) of a solar photovoltaic panel, a voltage method is a common mode, and the voltage method needs to collect open-circuit voltage of the photovoltaic panel for MPPT control. The industry generally uses a microcontroller, i.e., a detection MCU, to sample the open-circuit voltage. The following disadvantages exist with MCU sampling:

1) the cost is high: besides the cost of the MCU and its peripheral circuits, the MCU is usually powered by 5V or 3.3V, and the power execution circuit, such as MOSFET, is driven by 12V, so that a power supply is also needed. And thus the hardware cost is relatively high. Software development is needed, and the software development cost is increased;

2) stability: the microcontroller scheme has the phenomena of program crash and runaway and has unstable factors.

SUMMERY OF THE UTILITY MODEL

In order to solve the problems in the prior art, the utility model provides a voltage detection holding circuit and a voltage stabilization output device for the open circuit of a photovoltaic panel, and the technical scheme is as follows:

in one aspect, a voltage detection holding circuit for an open circuit of a photovoltaic panel is provided, which includes a comparator, a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, a third diode D3, a first capacitor C1 and a second capacitor C2, where one end of the first resistor R1 is used to be connected to an output end of the photovoltaic panel, and the other end of the first resistor R1 is connected to a positive input end of the comparator and connected to one end of the second resistor R2, the other end of the second resistor R2 is grounded, and two ends of the third diode D3 are respectively connected to the positive input end and the output end of the comparator;

the first diode D1 and the first capacitor C1 are connected in series to form a first branch circuit, the second diode D2 and the second capacitor C2 form a second branch circuit, one end of the first branch circuit and one end of the second branch circuit are used for being connected with the same auxiliary power supply, and the other ends of the first branch circuit and the second branch circuit are grounded; the third resistor R3 is connected in parallel with the second capacitor C2, the negative input end of the comparator is connected into a line connected between the second diode D2 and the second capacitor C2,

the comparator is used for controlling the switch of the power execution circuit on the photovoltaic panel, the output end of the comparator and the second capacitor C2 are both connected with the power execution circuit, the second capacitor C2 is used for storing voltage sampling values, and the power execution circuit is used for controlling and regulating the output voltage of the photovoltaic panel.

Further, the output end of the comparator is connected with the auxiliary power supply, and the auxiliary power supply is turned off when the output voltage of the comparator is 0.

Further, the comparator outputs a voltage of 0V when the voltage of its positive input terminal is equal to the voltage of the negative input terminal.

Further, the comparator outputs a first voltage value when the voltage of the positive input end of the comparator is greater than that of the negative input end of the comparator, and the power execution circuit is turned off; the comparator outputs a second voltage value when the voltage of the positive input end of the comparator is smaller than that of the negative input end of the comparator, the power execution circuit is opened, and the first voltage value is larger than the second voltage value.

Further, the capacitance value of the first capacitor C1 is larger than that of the second capacitor C2.

Furthermore, the comparator is connected to a direct current power supply and grounded at the same time, and the voltage of the direct current power supply is the same as that of the auxiliary power supply.

Further, the voltage detection holding circuit further comprises a fourth resistor R4 and a fifth resistor R5, the first branch and the second branch are connected to the auxiliary power supply through being sequentially connected with the fourth resistor R4 and the fifth resistor R5, and the output end of the comparator is connected to the auxiliary power supply through being connected with the fifth resistor R5.

In another aspect, a regulated output device for a photovoltaic panel is provided, which includes the voltage detection holding circuit and a power execution circuit, and the power execution circuit is connected to the output end of the photovoltaic panel.

Further, the power execution circuit comprises a PWM controller, a MOS transistor Q1, a fourth diode D4, and a third capacitor C3, wherein an anode of the fourth diode D4 is connected to the output end of the photovoltaic panel, a drain of the MOS transistor Q1 is connected to an anode of the fourth diode D4, a source thereof is grounded, a gate thereof is connected to the PWM controller, one end of the third capacitor C3 is connected to a cathode of the fourth diode D4, and the other end thereof is grounded, and the PWM controller is configured to control a linear state of operation of the MOS transistor Q1 according to a comparison result between a voltage sampling value and a preset value.

Further, the PWM controller increases output when the voltage sampling value is larger than a preset value, and decreases output when the voltage sampling value is smaller than the preset value.

The technical scheme provided by the utility model has the following beneficial effects:

a. the MCU is replaced by using components such as a comparator and the like, so that the cost is greatly reduced;

b. the stability is high, and the hardware circuit does not have the problem of halting.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic circuit structure diagram of a voltage detection holding circuit for open circuit of a photovoltaic panel according to an embodiment of the present invention;

fig. 2 is a schematic circuit structure diagram of a voltage stabilization output device for a photovoltaic panel according to an embodiment of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the utility model described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, apparatus, article, or device that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or device.

In one embodiment of the utility model, a voltage detection holding circuit for open circuit of a photovoltaic panel is provided, which comprises a comparator, a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, a third diode D3, a first capacitor C1 and a second capacitor C2, wherein the capacitance value of the first capacitor C1 is larger than that of the second capacitor C2;

one end of the first resistor R1 is connected to the output end of the photovoltaic panel, the other end of the first resistor R1 is connected to the positive input end of the comparator and is connected to one end of the second resistor R2, the other end of the second resistor R2 is grounded, and two ends of the third diode D3 are connected to the positive input end and the output end of the comparator respectively;

the first diode D1 and the first capacitor C1 are connected in series to form a first branch circuit, the second diode D2 and the second capacitor C2 form a second branch circuit, one end of the first branch circuit and one end of the second branch circuit are used for being connected with the same auxiliary power supply, and the other ends of the first branch circuit and the second branch circuit are grounded; the third resistor R3 is connected in parallel with the second capacitor C2, and the negative input end of the comparator is connected to a line connected between the second diode D2 and the second capacitor C2;

the output end of the comparator and the second capacitor C2 are both connected with a power execution circuit, the comparator can control the switch of the power execution circuit on the photovoltaic panel through a level signal output by the comparator, the comparator outputs a first voltage value when the voltage of the positive input end of the comparator is greater than that of the negative input end of the comparator, and the power execution circuit is closed; the comparator outputs a second voltage value when the voltage of the positive input end of the comparator is smaller than that of the negative input end of the comparator, and the power execution circuit is turned on, wherein the first voltage value is larger than the second voltage value. The second capacitor C2 can store voltage sampling values, and the power execution circuit controls and regulates the output voltage of the photovoltaic panel according to the voltage sampling values.

The output end of the comparator is connected with the auxiliary power supply, the auxiliary power supply is closed when the output voltage of the comparator is 0, and the comparator outputs 0V voltage when the voltage of the positive input end of the comparator is equal to the voltage of the negative input end of the comparator. The comparator is connected to a direct current power supply and grounded at the same time, the voltage of the direct current power supply is the same as that of the auxiliary power supply and can be set to 12V, and the direct current power supply can also be used for supplying power to the power execution circuit.

In an embodiment of the utility model, the voltage detection holding circuit further includes a fourth resistor R4 and a fifth resistor R5, the first branch and the second branch are both connected to the auxiliary power supply by sequentially connecting the fourth resistor R4 and the fifth resistor R5, and the output end of the comparator is connected to the auxiliary power supply by connecting the fifth resistor R5.

Referring to fig. 1, the photovoltaic panel input voltage is grounded through a first resistor R1 and a second resistor R2, the voltage value between the first resistor R1 and the second resistor R2 is denoted as V1, and the voltage value is input to the positive input end of the comparator; the auxiliary power supply charges a second capacitor C2 through a fifth resistor R5, a fourth resistor R4 and a second diode D2, the charging voltage is denoted as V2 and is simultaneously input to the negative input terminal of the comparator, and the output terminal of the comparator outputs an ON/OFF voltage which is used for controlling the switching of the power execution circuit. When the voltage of the input end of the comparator is just switched on, the voltage of V1 is immediately established, V1 is 3V, the voltage of V2 is slowly increased from 0V along with the voltage of two ends of a second capacitor C2, the voltage of V2 is lower than V1 at the moment, and the comparator outputs high voltage, namely a first voltage value, so that a power execution circuit is closed and the photovoltaic panel is kept open-circuited;

when the voltage of V2 increases to V1, V1 and V2 are both 3V, the comparator outputs 0V, the auxiliary power supply is turned off, and the second diode D2 is cut off. At this moment, the voltage of V2 is equal to the divided voltage of the open-circuit voltage of the photovoltaic panel divided by the second resistor R2, the voltage of V1 is pulled low due to the action of the third diode D3, so that V1 is far lower than V2, V1 suddenly drops from 3V to 0.7V, the comparator state maintains to output a low voltage, i.e. the second voltage value, at this moment, the power execution circuit works, and the photovoltaic panel starts to output power. The fourth resistor R4 can be used to set the operating time of the photovoltaic panel, and the voltage on the second capacitor C2 is discharged through the fourth resistor R4, so that when the voltage of V2 is reduced to be lower than V1 (at this time, V1 is about 0.7V), the comparator outputs high voltage, the power execution mechanism is turned off, the photovoltaic panel stops operating, and the open-circuit voltage is output. The circuit returns to the initial power-on state and the process is repeated. The charging point voltage of the first branch circuit is consistent with that of the second branch circuit, so that the voltage V of the first capacitor C1_OUTThe voltage is charged to the same voltage as V2, and the larger capacitance value of the first capacitor C1 keeps the voltage unchanged at the working moment of the photovoltaic panel, namely, the maximum voltage sampling value of the photovoltaic panel is stored.

In one embodiment of the present invention, a regulated output device for a photovoltaic panel is provided, and referring to fig. 2, the regulated output device comprises the voltage detection holding circuit and a power execution circuit, wherein the power execution circuit is connected to the output end of the photovoltaic panel. The power execution circuit comprises a PWM controller, a MOS tube Q1, a fourth diode D4 and a third capacitor C3, wherein the anode of the fourth diode D4 is connected to the output end of the photovoltaic panel, the drain of the MOS tube Q1 is connected to the anode of the fourth diode D4, the source of the MOS tube Q1 is grounded, the grid of the MOS tube Q4 is connected to the PWM controller, one end of the third capacitor C3 is connected to the cathode of the fourth diode D4, the other end of the third capacitor C3 is grounded, and the PWM controller is used for controlling the linear state of the work of the MOS tube Q1 according to the comparison result of a voltage sampling value and a preset value. And the PWM controller increases output when the voltage sampling value is larger than a preset value, and reduces output when the voltage sampling value is smaller than the preset value for adjustment.

The voltage detection holding circuit and the voltage stabilization output device for the open circuit of the photovoltaic panel realize the detection and the holding of the open circuit voltage of the photovoltaic panel through hardware, have lower cost, can use the same power supply of a power execution circuit, and only need one comparator and a plurality of capacitance resistance diodes for component cost; the voltage regulation sampling range is wide, and the delay comparator can be used for realizing the setting of the sampling interval time; and software development is not needed, the stability is high, and the problem of crash of a hardware circuit does not exist.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the utility model, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. A voltage detection holding circuit for open circuit of a photovoltaic panel is characterized by comprising a comparator, a first resistor R1, a second resistor R2, a third resistor R3, a first diode D1, a second diode D2, a third diode D3, a first capacitor C1 and a second capacitor C2, wherein one end of the first resistor R1 is used for being connected to the output end of the photovoltaic panel, the other end of the first resistor R1 is connected to the positive input end of the comparator and is connected with one end of the second resistor R2, the other end of the second resistor R2 is grounded, and two ends of the third diode D3 are respectively connected to the positive input end and the output end of the comparator;

2. The voltage detection hold circuit of claim 1, wherein the output of the comparator is connected to the auxiliary power supply, and the auxiliary power supply is turned off when the output voltage of the comparator is 0.

3. The voltage detection hold circuit of claim 2, wherein the comparator outputs a voltage of 0V when the positive input voltage thereof is equal to the negative input voltage.

4. The voltage detection hold circuit of claim 1, wherein the comparator outputs a first voltage value when its positive input voltage is greater than a negative input voltage, the power execution circuit being turned off; the comparator outputs a second voltage value when the voltage of the positive input end of the comparator is smaller than that of the negative input end of the comparator, the power execution circuit is opened, and the first voltage value is larger than the second voltage value.

5. The voltage detection hold circuit of claim 1, wherein the capacitance value of the first capacitor C1 is greater than the capacitance value of the second capacitor C2.

6. The voltage detection hold circuit of claim 2, wherein the comparator is connected to a dc power supply and ground at the same time, and the dc power supply has the same voltage as the auxiliary power supply.

7. The voltage detection holding circuit of claim 1, further comprising a fourth resistor R4 and a fifth resistor R5, wherein the first branch and the second branch are both connected to the auxiliary power supply by connecting the fourth resistor R4 and the fifth resistor R5 in sequence, and wherein the output terminal of the comparator is connected to the auxiliary power supply by connecting the fifth resistor R5.

8. A regulated output device for a photovoltaic panel comprising a voltage detection and hold circuit according to any one of claims 1 to 7 and a power execution circuit, said power execution circuit being connected to said photovoltaic panel output.

9. The voltage-stabilized output device according to claim 8, wherein the power execution circuit includes a PWM controller, a MOS transistor Q1, a fourth diode D4 and a third capacitor C3, an anode of the fourth diode D4 is connected to the output end of the photovoltaic panel, a drain of the MOS transistor Q1 is connected to an anode of the fourth diode D4, a source thereof is grounded, a gate thereof is connected to the PWM controller, one end of the third capacitor C3 is connected to a cathode of the fourth diode D4, and the other end thereof is grounded, and the PWM controller is configured to control a linear state of operation of the MOS transistor Q1 according to a comparison result between a voltage sampling value and a preset value.

10. The voltage-stabilized output device according to claim 9, wherein the PWM controller increases the output when the voltage sample value is larger than a preset value, and decreases the output when the voltage sample value is smaller than the preset value.