CN216981854U

CN216981854U - Photovoltaic power generation system

Info

Publication number: CN216981854U
Application number: CN202220518594.5U
Authority: CN
Inventors: 王一鸣; 许颇; 程琨; 李双
Original assignee: Ginlong Technologies Co Ltd
Current assignee: Ginlong Technologies Co Ltd
Priority date: 2022-03-10
Filing date: 2022-03-10
Publication date: 2022-07-15
Anticipated expiration: 2032-03-10

Abstract

The utility model discloses a photovoltaic power generation system which is provided with a charge-discharge circuit, a first switch element, a second switch element and a third switch element, wherein when the output of a photovoltaic unit needs to be turned off due to a fault, the on-off state of the switch elements is controlled by a control unit, so that the photovoltaic unit is turned off in time, the system is protected, and the safety and the reliability of the system are improved.

Description

Photovoltaic power generation system

Technical Field

The utility model relates to the technical field of photovoltaic power generation, in particular to a photovoltaic power generation system.

Background

With the advocation of national carbon neutralization and the implementation of new energy policy development, photovoltaic development is on the rise of the year of steaming, and a photovoltaic power generation system generally comprises a photovoltaic module and an inverter, wherein the photovoltaic module is connected with a power grid or a household load through the inverter, the photovoltaic module converts solar energy into direct current electric energy, and the inverter converts the direct current electric energy into alternating current electric energy which is sent to the power grid or supplied to a user load for use. When a building is in fire or other emergency situations, corresponding personnel are required to disconnect the photovoltaic modules in time, but because the photovoltaic modules are mostly installed on a roof, the connection between the photovoltaic modules cannot be cut off instantly, and the power generation system can break down. The series-parallel connection photovoltaic modules generally have higher voltage and energy, personnel can threaten personal safety if touching electrified parts by mistake, and some non-measurable dangers such as personal injury and the like can be caused when the personnel are turned off artificially, so that the timeliness and the safety of the turn-off of the photovoltaic modules are difficult to ensure, a turn-off protection device needs to be connected between the photovoltaic modules and the inverter, and the dangerous voltage in an operation area is cut off before the personnel operate.

The existing power switch tube is arranged between the photovoltaic module and the inverter, so that the photovoltaic module is cut off in time, but the switch tube is easily damaged when a gate pole is in overvoltage.

SUMMERY OF THE UTILITY MODEL

In view of the above analysis, the present invention provides a photovoltaic power generation system to solve the deficiencies of the prior art.

The utility model is mainly realized by the following technical scheme:

the utility model provides a photovoltaic power generation system which comprises a photovoltaic unit, a turn-off protection device, a control unit and an inverter, wherein the turn-off protection device comprises a charging and discharging circuit, a first switch element, a second switch element and a third switch element, the inverter comprises an inverter circuit, the second switch element is connected with the anode of the inverter circuit in series, the third switch element is connected with the cathode of the inverter circuit in series, the first switch element is connected between the anode of the photovoltaic unit and the second switch element in series, or the first switch element is connected between the cathode of the photovoltaic unit and the third switch element in series, the charging and discharging circuit is connected with two ends of the first switch element in parallel, and the control unit is respectively and electrically connected with the control ends of the first switch element, the second switch element and the third switch element.

The charging and discharging circuit, the first switch element, the second switch element and the third switch element are arranged, when the output of the photovoltaic unit needs to be turned off due to a fault, the on-off state of the switch elements is controlled through the control unit, the photovoltaic unit is turned off in time, the system is protected, and the safety and the reliability of the system are improved.

Further, the first switch element, the second switch element and the third switch element are mechanical switches or electronic switches.

Further, the mechanical switch is a contactor or a relay.

Furthermore, the electronic switch is one of a touch switch, an inductive switch, a voice-operated switch and a wireless switch.

Further, the control unit comprises a driving circuit, and the control unit is electrically connected with the first switching element, the second switching element and the third switching element through the driving circuit.

Further, the charge and discharge circuit comprises a capacitor and a resistor which are arranged in parallel.

Further, the control circuit is a manual control switch or a power supply control circuit.

Further, the driving circuit is one of a voltage driving circuit, a current driving circuit and a temperature driving circuit.

Further, the turn-off protection device is integrated in the inverter.

Further, the photovoltaic unit comprises at least one photovoltaic module.

Compared with the prior art, the technical scheme of the utility model has the beneficial effects that:

1. according to the photovoltaic power generation system provided by the utility model, the on-off state of the switch element is controlled by the control unit, so that the power generation end of the photovoltaic unit is connected with or disconnected from the inverter circuit, when the photovoltaic unit needs to be connected into the photovoltaic power generation system, the first switch element is controlled to be connected, so that the power generation end of the photovoltaic unit keeps a certain voltage, and then the second switch element and the third switch element are controlled to be connected, so that the power generation end of the photovoltaic unit is connected into the photovoltaic power generation system to be normally output; when the photovoltaic unit needs to be disconnected with the photovoltaic power generation system, the first switch element is controlled to be disconnected, the current of the power generation end of the photovoltaic unit is cut off, then the second switch element and the third switch element are controlled to be disconnected, the power generation end of the photovoltaic unit is disconnected with the inverter, when a fault occurs, the connection between the photovoltaic unit and the inverter can be timely disconnected, meanwhile, the switch elements are protected according to the switching sequence, and the switch elements are prevented from being damaged due to the occurrence of an arc phenomenon.

2. The switching element does not adopt a power switching tube, so that the cost, the system loss and the heat productivity can be reduced.

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 diagram of a photovoltaic power generation system embodiment 1 according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of embodiment 2 of a photovoltaic power generation system according to an embodiment of the present invention.

The reference numbers are as follows:

1. photovoltaic unit, 2, turn-off protection device, 21, charge and discharge circuit, 3, control unit, 4, inverter, 41, inverter circuit, 5, drive circuit, 6, electric wire netting.

Detailed Description

In order that those skilled in the art will better understand the utility model and thus more clearly define the scope of the utility model as claimed, it is described in detail below with respect to certain specific embodiments thereof. It should be noted that the following is only a few embodiments of the present invention, and the specific direct description of the related structures is only for the convenience of understanding the present invention, and the specific features do not of course directly limit the scope of the present invention. Conventional choices and substitutions made by those skilled in the art in light of the present disclosure are to be considered within the scope of the present invention as claimed.

The utility model is further described with reference to the following figures and specific examples.

Example 1

As shown in fig. 1-2, the present invention provides a photovoltaic power generation system, which includes a photovoltaic unit 1, a turn-off protection device 2, a control unit 3 and an inverter 4, wherein the turn-off protection device 2 includes a charging and discharging circuit 21, a first switch element S1, a second switch element S2 and a third switch element S3, the inverter 4 includes an inverter circuit 41, the second switch element S2 is connected in series with a positive electrode of the inverter circuit 41, the third switch element S3 is connected in series with a negative electrode of the inverter circuit 41, the first switch element S1 is connected in series between the positive electrode of the photovoltaic unit 1 and the second switch element S2, the charging and discharging circuit 21 is connected in parallel with two ends of the first switch element S1, and the control unit 3 is electrically connected with control ends of the first switch element S1, the second switch element S2 and the third switch element S3, respectively. The inverter 4 is connected to a grid 6.

Specifically, the charge and discharge circuit 21 includes a capacitor C and a resistor R arranged in parallel.

In particular, the shutdown protection device 2 is integrated within the inverter 4. The device design is simpler, and the turn-off protection device 2 and the inverter 4 can be arranged in a split mode according to requirements.

In particular, the photovoltaic unit 1 comprises at least one photovoltaic module.

When the photovoltaic unit 1 comprises a plurality of photovoltaic modules connected in series or in parallel, the plurality of photovoltaic modules can be controlled to be turned off in time through one turn-off protection device 2, the structure is simpler, and the cost can be saved.

Preferably, the first switching element S1, the second switching element S2, and the third switching element S3 are mechanical switches or electronic switches.

Specifically, the mechanical switch is a contactor or a relay.

Specifically, the electronic switch is one of a touch switch, an inductive switch, a voice-operated switch and a wireless switch.

Each switching element is within the range of voltages that it can withstand, including but not limited to the above configurations.

Preferably, the control unit 3 is a manually controlled switch or a power control circuit.

Preferably, a driving circuit 5 is further included, and the control unit 3 is electrically connected to the first switching element S1, the second switching element S2, and the third switching element S3 through the driving circuit 5.

Specifically, the driving circuit 5 is one of a voltage driving circuit 5, a current driving circuit 5, and a temperature driving circuit 5.

The control unit 3 can simultaneously control the on-off states of the three switch elements through one driving circuit, and can also independently control the on-off states of the three switch elements through at least two driving circuits.

The photovoltaic power generation system provided by the utility model has the following working principle:

when the photovoltaic unit 1 is required to be connected to the photovoltaic power generation system, at the moment of power supply of the power generation end of the photovoltaic unit 1, two ends of the capacitor C are charged, the control unit 3 controls the driving circuit 5 to drive the first switching element S1 to be conducted, meanwhile, the capacitor C discharges the resistor R until the voltage at two ends of the capacitor C is equal to the conducting voltage at two ends of the first switching element S1, and the control unit 3 controls the driving circuit 5 to drive the second switching element S2 and the third switching element S3 to be conducted, so that connection between the photovoltaic unit 1 and the inverter 4 is completed.

When the photovoltaic unit 1 needs to be disconnected from the photovoltaic power generation system, the control unit 3 controls the driving circuit 5 to drive the first switching element S1 to be disconnected, at this time, the capacitor C is charged fully instantly, the resistance R is too large, so that the current of the photovoltaic power generation end is cut off, and the arc phenomenon is prevented from occurring, and the control unit 3 controls the driving circuit 5 to drive the second switching element S2 and the third switching element S3 to be disconnected, so that the photovoltaic unit 1 is disconnected from the inverter 4.

Example 2

The only difference from embodiment 1 is the position where the first switching element S1 is provided, wherein the first switching element S1 is connected in series between the negative electrode of the photovoltaic unit 1 and the third switching element S3.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the utility model may occur to those skilled in the art without departing from the principle of the utility model, and are considered to be within the scope of the utility model.

Claims

1. A photovoltaic power generation system, characterized in that: comprises a photovoltaic unit (1), a turn-off protection device (2), a control unit (3) and an inverter (4), the turn-off protection device (2) comprises a charge-discharge circuit (21), a first switching element, a second switching element and a third switching element, the inverter (4) comprises an inverter circuit (41), the second switching element is connected with the positive pole of the inverter circuit (41) in series, the third switching element is connected with the negative electrode of the inverter circuit (41) in series, the first switching element is connected between the positive electrode of the photovoltaic unit (1) and the second switching element in series, or the first switching element is connected in series between the negative pole of the photovoltaic unit (1) and the third switching element, the charging and discharging circuit (21) is connected in parallel at two ends of the first switch element, and the control unit (3) is respectively and electrically connected with control ends of the first switch element, the second switch element and the third switch element.

2. The photovoltaic power generation system of claim 1, wherein: the first switch element, the second switch element and the third switch element are mechanical switches or electronic switches.

3. The photovoltaic power generation system of claim 2, wherein: the mechanical switch is a contactor or a relay.

4. The photovoltaic power generation system of claim 2, wherein: the electronic switch is one of a touch switch, an inductive switch, a voice-operated switch and a wireless switch.

5. The photovoltaic power generation system of claim 2, wherein: the control unit (3) is electrically connected with the first switch element, the second switch element and the third switch element through the drive circuit (5).

6. The photovoltaic power generation system according to claim 2 or 5, characterized in that: the charge and discharge circuit (21) comprises a capacitor and a resistor which are arranged in parallel.

7. The photovoltaic power generation system according to claim 2 or 5, characterized in that: the control unit (3) is a manual control switch or a power supply control circuit.

8. The photovoltaic power generation system of claim 5, wherein: the driving circuit (5) is one of a voltage driving circuit (5), a current driving circuit (5) and a temperature driving circuit (5).

9. The photovoltaic power generation system of any one of claims 1-5, wherein: the shut-down protection device (2) is integrated in the inverter (4).

10. The photovoltaic power generation system of any one of claims 1-5, wherein: the photovoltaic unit (1) comprises at least one photovoltaic module.