WO2021142906A1

WO2021142906A1 - Photovoltaic module turn-off apparatus

Info

Publication number: WO2021142906A1
Application number: PCT/CN2020/078740
Authority: WO
Inventors: 罗宇浩
Original assignee: 海宁昱能电子有限公司
Priority date: 2020-01-14
Filing date: 2020-03-11
Publication date: 2021-07-22
Also published as: CN111224424A

Abstract

A photovoltaic module turn-off apparatus, comprising an auxiliary power supply, a control module, a switching device, and a series path for connecting a first photovoltaic module and a second photovoltaic module in series. The input end of the auxiliary power supply is connected to the output end of the first photovoltaic module or the input end of the auxiliary power supply is connected to the output end of the second photovoltaic module, and the auxiliary power supply is connected in series to the switching device; the switching device is arranged on an output path between the first photovoltaic module and the positive output end of the photovoltaic module turn-off apparatus or on an output path between the second photovoltaic module and the negative output end of the photovoltaic module turn-off apparatus or on the series path between the first photovoltaic module and the second photovoltaic module; the control module is connected to the control end of the switching device and configured to control on/off of the switching device. According to the photovoltaic module turn-off apparatus provided in the present application, connection between two photovoltaic modules and an inverter is controlled by one photovoltaic module turn-off apparatus, and compared with a photovoltaic module turn-off apparatus for a single photovoltaic module, the number of electronic devices is greatly reduced.

Description

Shut-off device for photovoltaic module

This application claims the priority of a Chinese patent application filed with the Chinese Patent Office on January 14, 2020, the application number is 202010036752.9, and the invention title is "a photovoltaic module shut-off device", the entire content of which is incorporated into this application by reference .

Technical field

This application relates to the technical field of photovoltaic grid-connected power generation, and in particular to a photovoltaic module shut-off device.

Background technique

Due to the renewable and clean nature of solar energy, photovoltaic grid-connected power generation technology has developed rapidly. In the usual photovoltaic system, multiple photovoltaic modules are connected in series to form a string, and then connected to an inverter to convert DC to AC and connect to the grid. PV modules connected in series form DC high voltage, which can cause personal hazards and fire accidents. The on-site photovoltaic system requires the inverter to have arc protection, that is, the inverter must be shut down immediately when an arc is detected. However, even if the inverter stops running, the DC cables after the PV modules are connected in series will still output high voltage, which is a safety risk. So the safest way is to have a control function to turn off the output voltage of each photovoltaic module, so that the DC high voltage should be completely eliminated.

Fig. 1 is a schematic diagram of the connection of a photovoltaic module switch in the prior art.

As shown in Figure 1, in the prior art, by adding a photovoltaic module shut-off device behind each photovoltaic module, the output end of the photovoltaic module shut-off device is connected to the inverter in series, and the photovoltaic module shut-off device usually has two The switch, set up the switch controller to control the internal switch of the switch to be disconnected, so that the voltage on the DC cable is very low.

However, with the increase in the number of photovoltaic modules connected in series, the number of photovoltaic module shutoffs has also increased, and the electronic devices, chips, cables and other devices involved have increased exponentially.

Summary of the invention

The purpose of this application is to provide a photovoltaic module shutdown device, which is used to save the number of photovoltaic module shutdown devices in a photovoltaic system, thereby saving corresponding devices and reducing costs.

In order to solve the above technical problems, the present application provides a photovoltaic module shutdown device, including an auxiliary power source, a control module, a switching device, and a series path for connecting a first photovoltaic module and a second photovoltaic module in series;

Wherein, the input terminal of the auxiliary power source is connected to the output terminal of the first photovoltaic device or the input terminal of the auxiliary power source is connected to the output terminal of the second photovoltaic module, and the auxiliary power source is connected to the switching device In series; the switching device is provided in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module switch or between the second photovoltaic module and the negative output terminal of the photovoltaic module switch At least one of the output path of the first photovoltaic module and the series path between the second photovoltaic module; the control module is connected to the control terminal of the switching device, and is used to control the switching of the switching device Off.

Optionally, the switching device specifically includes a first switch, a second switch and a third switch;

Wherein, the first switch is provided in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module switch; the second switch is provided in the first photovoltaic module and the first photovoltaic module. A series path between the two photovoltaic components; the third switch is arranged in the output path between the second photovoltaic component and the negative output terminal of the photovoltaic component switch.

Optionally, the positive terminal of the auxiliary power source is connected to the positive terminal of the first photovoltaic module, and the negative terminal of the auxiliary power source is connected to the negative terminal of the first photovoltaic module; The terminal is connected to the positive terminal of the auxiliary power supply, the second terminal of the first switch is connected to the positive output terminal of the photovoltaic module switch; the first terminal of the second switch is connected to the negative terminal of the auxiliary power supply , The second terminal of the second switch is connected to the positive terminal of the second photovoltaic module; the first terminal of the third switch is connected to the negative terminal of the second photovoltaic module, and the first terminal of the third switch is connected to the negative terminal of the second photovoltaic module. The two ends are connected with the negative output end of the photovoltaic module switch.

Optionally, the switching device further includes a fourth switch provided between the second terminal of the second switch and the positive terminal of the second photovoltaic component.

Optionally, the positive terminal of the auxiliary power source is connected to the positive terminal of the first photovoltaic module, and the negative terminal of the auxiliary power source is connected to the negative terminal of the first photovoltaic module; The terminal is connected to the positive terminal of the auxiliary power supply, the second terminal of the first switch is connected to the positive output terminal of the photovoltaic module switch; the first terminal of the second switch is connected to the negative terminal of the auxiliary power supply , The second terminal of the second switch is connected to the positive terminal of the second photovoltaic module; the first terminal of the third switch is connected to the positive terminal of the second photovoltaic module, and the third switch is connected to the positive terminal of the second photovoltaic module. The negative terminal of the second photovoltaic module is connected.

Optionally, the switching device further includes a fifth switch connected in parallel with the third switch.

When the number of the second photovoltaic module is multiple, the series path for connecting the first photovoltaic module and the second photovoltaic module in series includes the series connection between the first photovoltaic module and one of the second photovoltaic modules A series connection between a passage and each of the second photovoltaic modules;

Wherein, one of said series path is provided with one said second switch.

Optionally, it also includes a diode;

The anode terminal of the diode is connected with the negative output terminal of the photovoltaic module switch, and the cathode terminal of the diode is connected with the positive output terminal of the photovoltaic module switch.

Optionally, the switching device is specifically a MOS tube or an IGBT or a thyristor or a triode or a relay.

The photovoltaic module shutdown device provided by this application includes an auxiliary power supply, a control module, a switching device, and a series path for connecting a first photovoltaic module and a second photovoltaic module in series; wherein, the input end of the auxiliary power supply is connected to the first photovoltaic device The output terminal is connected or the input terminal of the auxiliary power supply is connected with the output terminal of the second photovoltaic module, and the auxiliary power supply is connected in series with the switching device; the switching device is located in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module switcher Or at least one of the output path between the second photovoltaic component and the negative output terminal of the photovoltaic component switcher or the series path between the first photovoltaic component and the second photovoltaic component; the control module is connected to the control terminal of the switching device, Used to control the on and off of switching devices. Through the photovoltaic module switch-off provided in this application, it is realized that the first photovoltaic module, the second photovoltaic module and the inverter are disconnected inside the photovoltaic module switch-off device, so that one photovoltaic module switch-off device can control two The connection between the photovoltaic module and the inverter, compared with the photovoltaic module switch for a single photovoltaic module, greatly reduces the number of electronic devices, reduces the mechanical parts, reduces the product cost, and reduces the power consumption.

Description of the drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are merely For some of the embodiments of the present application, for those of ordinary skill in the art, other drawings may be obtained based on these drawings without creative work.

Figure 1 is a schematic diagram of the connection of a photovoltaic module switch in the prior art;

FIG. 2 is a schematic diagram of the connection of a photovoltaic module shutdown device provided by an embodiment of the application;

FIG. 3 is a circuit diagram of the first photovoltaic module shutdown device provided by an embodiment of the application;

FIG. 4 is a circuit diagram of a second type of photovoltaic module shutdown device provided by an embodiment of the application;

FIG. 5 is a schematic diagram of the working state of the photovoltaic module switcher shown in FIG. 4;

FIG. 6 is a circuit diagram of a third type of photovoltaic module shutdown device provided by an embodiment of the application;

FIG. 7 is a circuit diagram of a fourth type of photovoltaic module shutdown device provided by an embodiment of the application;

Fig. 8 is a schematic diagram of the working state of the photovoltaic module switcher shown in Fig. 7;

FIG. 9 is a schematic diagram of the shutdown state of the photovoltaic module shutdown device shown in FIG. 7;

FIG. 10 is a schematic diagram of the connection of another photovoltaic module shut-off device provided by an embodiment of the application.

Detailed ways

The core of this application is to provide a photovoltaic module shut-off device, which is used to save the number of photovoltaic module shut-off devices in a photovoltaic system, thereby saving corresponding devices and reducing costs.

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of this application.

Example one

Fig. 2 is a schematic diagram of the connection of a photovoltaic module shut-off device provided by an embodiment of the application.

The embodiment of the present application provides a photovoltaic module shutdown device that can be connected to multiple photovoltaic modules. As shown in FIG. 2, taking a photovoltaic module shutdown device connected to two photovoltaic modules as an example, the photovoltaic module shutdown device provided by the embodiment of the application is The breaker is connected to the output terminals of the two photovoltaic modules, which can control whether the two photovoltaic modules are connected to the inverter. The output terminals of each photovoltaic module switch-off device are connected in series, and finally connected to the inverter.

In order to achieve the effect shown in Figure 2, the photovoltaic module switch provided by the embodiment of the present application may include an auxiliary power source, a control module, a switching device, and a series path for connecting the first photovoltaic module and the second photovoltaic module in series;

Wherein, the input end of the auxiliary power supply is connected with the output end of the first photovoltaic device or the input end of the auxiliary power supply is connected with the output end of the second photovoltaic module, and the auxiliary power supply is connected in series with the switching device; the switching device is set in the first photovoltaic module and the photovoltaic module. The output path between the positive output terminal of the module switch or the output path between the second photovoltaic module and the negative output terminal of the photovoltaic module switch or the series path between the first photovoltaic module and the second photovoltaic module At least one; the control module is connected to the control end of the switching device, and is used to control the on and off of the switching device.

In the photovoltaic module shutdown device provided by the embodiment of the present application, there are provided an output path between the first photovoltaic module and the positive output terminal of the photovoltaic module shutdown device, and the second photovoltaic module and the negative output terminal of the photovoltaic module shutdown device are provided. The output path between and the series path between the first photovoltaic module and the second photovoltaic module. Through the series path, the first photovoltaic module and the second photovoltaic module are connected in series in the photovoltaic module switch-off provided in the embodiment of this application, and the photovoltaic module switch-off provided in the embodiment of this application is further connected in series with other photovoltaic modules, Finally, it is connected to the inverter.

Since the paths in the photovoltaic module shut-off device provided by the embodiments of the present application are in a series relationship, the switching device can be arranged in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module shut-off device, or it may be arranged in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module shut-off device. The output path between the second photovoltaic module and the negative output terminal of the photovoltaic module switch can also be provided in the series path between the first photovoltaic module and the second photovoltaic module. The switching device can be a MOS tube, or other devices that can achieve the same function, such as an IGBT, a thyristor, a triode, or a relay.

The power source of the auxiliary power source comes from the first photovoltaic component or the second photovoltaic component, and is used to supply power to the circuit of the entire photovoltaic component breaker.

Further, the photovoltaic module shutdown device provided by the embodiment of the present application further includes a diode;

The photovoltaic module shutdown device provided by the embodiment of the present application includes an auxiliary power supply, a control module, a switching device, and a series path for connecting a first photovoltaic module and a second photovoltaic module in series; wherein, the input terminal of the auxiliary power supply is connected to the first photovoltaic device The output terminal of the auxiliary power supply is connected or the input terminal of the auxiliary power supply is connected with the output terminal of the second photovoltaic module, and the auxiliary power supply is connected in series with the switching device; the switching device is set between the first photovoltaic module and the output terminal of the positive output terminal of the photovoltaic module switch At least one of the output path or the output path between the second photovoltaic module and the negative output terminal of the photovoltaic module switch or the series path between the first photovoltaic module and the second photovoltaic module; the control module is connected to the control terminal of the switching device , Used to control the on-off of switching devices. Through the photovoltaic module switch-off provided in this application, it is realized that the first photovoltaic module, the second photovoltaic module and the inverter are disconnected inside the photovoltaic module switch-off device, so that one photovoltaic module switch-off device can control two The connection between the photovoltaic module and the inverter, compared with the photovoltaic module switch for a single photovoltaic module, greatly reduces the number of electronic devices, reduces the mechanical parts, reduces the product cost, and reduces the power consumption.

Example two

On the basis of the first embodiment, in order to achieve single-point failure redundancy and improve shutdown reliability, the switching device specifically includes a first switch, a second switch, and a third switch;

Wherein, the first switch is provided in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module switch; the second switch is provided in the series path between the first photovoltaic module and the second photovoltaic module; the third switch The output path is provided between the second photovoltaic module and the negative output terminal of the photovoltaic module switch.

Example three

FIG. 3 is a circuit diagram of the first type of photovoltaic module shut-off device provided by an embodiment of the application; FIG. 4 is a circuit diagram of a second type of photovoltaic module shut-off device provided by an embodiment of the application; FIG. 5 is the photovoltaic module shown in FIG. 4 Schematic diagram of the working state of the switch.

Based on the second embodiment, the circuit of a photovoltaic module switch-off provided by the embodiment of the present application is shown in FIG. 3. The positive terminal of the auxiliary power source is connected to the positive terminal PV1+ of the first photovoltaic module, and the negative terminal of the auxiliary power source is connected to the first photovoltaic module. The negative terminal PV1- of the photovoltaic module is connected; the first terminal of the first switch S1 is connected to the positive terminal of the auxiliary power source, and the second terminal of the first switch S1 is connected to the positive output terminal of the volt module switch; The first terminal is connected to the negative terminal of the auxiliary power supply, the second terminal of the second switch S2 is connected to the positive terminal PV2+ of the second photovoltaic module; the first terminal of the third switch S3 is connected to the negative terminal PV2- of the second photovoltaic module, The second terminal of the third switch S3 is connected to the negative output terminal OUT- of the photovoltaic module switch.

In practical applications, FIG. 3 is a schematic diagram of the shutdown state of the first photovoltaic module shutdown device provided by the embodiment of the present application. In the working state, the control module controls the first switch S1, the second switch S2, and the third switch S3 to be turned on. In the off state, the control module controls the first switch S1, the second switch S2, and the third switch S3 to turn off, so that the first photovoltaic module and the second photovoltaic module fall off the series path of the entire photovoltaic module, and the first The photovoltaic module is no longer connected to the second photovoltaic module. Even if one of the first switch S1, the second switch S2, and the third switch S3 is faulty, the above-mentioned switching off of the first photovoltaic module and the second photovoltaic module can be realized by disconnecting the other switches.

The auxiliary power source can be connected to the output end of the first photovoltaic component, or can be connected to the output end of the second photovoltaic component.

In order to further improve the turn-off reliability, as shown in FIG. 4, the switching device further includes a fourth switch S4 arranged between the second terminal of the second switch S2 and the positive terminal PV2+ of the second photovoltaic component.

In practical applications, the fourth switch S4 and the second switch S2 form redundancy, and the control method is the same as that of the second switch S2. FIG. 4 is a schematic diagram of the shutdown state of the second photovoltaic module shutdown device provided by an embodiment of the application. The working state of the second photovoltaic module shut-off device provided by the embodiment of the present application is shown in FIG. 5.

Example four

6 is a circuit diagram of a third type of photovoltaic module shutdown device provided by an embodiment of this application; FIG. 7 is a circuit diagram of a fourth type of photovoltaic module shutdown device provided by an embodiment of this application; FIG. 8 is the photovoltaic module shown in FIG. 7 A schematic diagram of the working state of the shutdown device; FIG. 9 is a schematic diagram of the shutdown state of the photovoltaic module shutdown device shown in FIG. 7.

Based on the second embodiment, the circuit of a photovoltaic module switcher provided by the embodiment of the present application is shown in FIG. 6. The positive terminal of the auxiliary power source is connected to the positive terminal PV1+ of the first photovoltaic module, and the negative terminal of the auxiliary power source is connected to the first photovoltaic module. The negative terminal PV1- of the photovoltaic module is connected; the first terminal of the first switch S1 is connected to the positive terminal of the auxiliary power source, and the second terminal of the first switch S1 is connected to the positive output terminal OUT+ of the photovoltaic module switch; the second switch S2 The first terminal of the second switch S2 is connected to the negative terminal of the auxiliary power supply, the second terminal of the second switch S2 is connected to the positive terminal PV2+ of the second photovoltaic module; the first terminal of the third switch S3 is connected to the positive terminal PV2+ of the second photovoltaic module, The third switch S3 is connected to the negative terminal PV2- of the second photovoltaic component.

In practical applications, in the working state, the control module controls the first switch S1 and the second switch S2 to turn on, and controls the third switch S3 to turn off. In the off state, the control module controls the first switch S1 and the second switch S2 to be turned off to disconnect the connection between the first switch S1 and the positive output terminal OUT+ of the photovoltaic module switch and the first switch S1 and the second switch S1. The series connection between the switches S2 controls the third switch S3 to be turned on to short-circuit the second photovoltaic component, so as to turn off the second photovoltaic component.

In order to further improve the turn-off reliability, as shown in FIG. 7, the switching device further includes a fifth switch S5 connected in parallel with the third switch S3. In practical applications, the fifth switch S5 and the third switch S3 form redundancy, and the control method is the same as that of the third switch S3. The working state of the fourth photovoltaic module shut-off device provided by the embodiment of the present application is shown in FIG. 8, and the shut-off state of the fourth photovoltaic module shutoff device provided in the embodiment of the present application is shown in FIG. 9.

Example five

Based on the above embodiment, when the number of second photovoltaic modules is multiple, the series path used to connect the first photovoltaic module and the second photovoltaic module in series includes the series path between the first photovoltaic module and one second photovoltaic module and Series paths between the second photovoltaic modules;

Among them, a series path is provided with a second switch S2.

In specific implementation, when a first photovoltaic module is connected to multiple second photovoltaic modules, there are multiple serial paths between the first photovoltaic module and the second photovoltaic module, and a second switch may be provided for each serial path S2, it is also possible to provide only one second switch S2 in one series path.

As shown in Fig. 10, taking the number of second photovoltaic modules as two, that is, one photovoltaic module cut-off device is connected to three photovoltaic modules as an example, the photovoltaic module cut-off device provided in the embodiment of the present application and the output of the three photovoltaic modules The three photovoltaic modules are connected in series in the photovoltaic module switch, and then the output terminals of each photovoltaic module switch are connected in series, and finally connected to the inverter. There are two series paths between the three photovoltaic modules, which can correspond to two second switches S2, or only one second switch S2 can be provided on one of the series paths.

When the number of second photovoltaic modules is multiple, the specific installation position of each switching device and the corresponding control scheme and redundant arrangement scheme can refer to the above-mentioned embodiment, which will not be repeated here.

A detailed description of the photovoltaic module shutdown device provided by the present application has been given above. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other. It should be pointed out that for those of ordinary skill in the art, without departing from the principles of this application, several improvements and modifications can be made to this application, and these improvements and modifications also fall within the protection scope of the claims of this application.

It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply these entities or operations. There is any such actual relationship or sequence between operations. Moreover, the terms "include", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes those that are not explicitly listed Other elements of, or also include elements inherent to this process, method, article or equipment. If there are no more restrictions, the element defined by the sentence "including a..." does not exclude the existence of other same elements in the process, method, article, or equipment that includes the element.

Claims

A photovoltaic module switch, which is characterized by comprising an auxiliary power supply, a control module, a switching device, and a series path for connecting a first photovoltaic module and a second photovoltaic module in series;

Wherein, the input terminal of the auxiliary power source is connected to the output terminal of the first photovoltaic device or the input terminal of the auxiliary power source is connected to the output terminal of the second photovoltaic module, and the auxiliary power source is connected to the switching device In series; the switching device is provided in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module switch or between the second photovoltaic module and the negative output terminal of the photovoltaic module switch At least one of the output path of the first photovoltaic module and the series path between the second photovoltaic module; the control module is connected to the control terminal of the switching device, and is used to control the switching of the switching device Off.
The photovoltaic module shutdown device according to claim 1, wherein the switching device specifically comprises a first switch, a second switch and a third switch;

Wherein, the first switch is provided in the output path between the first photovoltaic module and the positive output terminal of the photovoltaic module switch; the second switch is provided in the first photovoltaic module and the first photovoltaic module. A series path between the two photovoltaic components; the third switch is arranged in the output path between the second photovoltaic component and the negative output terminal of the photovoltaic component switch.
The photovoltaic module shutdown device according to claim 2, wherein the positive terminal of the auxiliary power source is connected to the positive terminal of the first photovoltaic module, and the negative terminal of the auxiliary power source is connected to the first photovoltaic module. The negative terminal of the first switch is connected; the first terminal of the first switch is connected to the positive terminal of the auxiliary power source, and the second terminal of the first switch is connected to the positive output terminal of the photovoltaic module switch; the second switch The first terminal of the third switch is connected to the negative terminal of the auxiliary power source, the second terminal of the second switch is connected to the positive terminal of the second photovoltaic module; the first terminal of the third switch is connected to the second photovoltaic module The negative terminal of the component is connected, and the second terminal of the third switch is connected to the negative output terminal of the photovoltaic module switch.
The photovoltaic module shutdown device according to claim 3, wherein the switching device further comprises a fourth switch provided between the second terminal of the second switch and the positive terminal of the second photovoltaic module .
The photovoltaic module shutdown device according to claim 2, wherein the positive terminal of the auxiliary power source is connected to the positive terminal of the first photovoltaic module, and the negative terminal of the auxiliary power source is connected to the first photovoltaic module. The negative terminal of the first switch is connected; the first terminal of the first switch is connected to the positive terminal of the auxiliary power source, and the second terminal of the first switch is connected to the positive output terminal of the photovoltaic module switch; the second switch The first terminal of the third switch is connected to the negative terminal of the auxiliary power source, the second terminal of the second switch is connected to the positive terminal of the second photovoltaic module; the first terminal of the third switch is connected to the second photovoltaic module The positive terminal of the component is connected, and the third switch is connected to the negative terminal of the second photovoltaic component.
The photovoltaic module shutdown device according to claim 5, wherein the switching device further comprises a fifth switch connected in parallel with the third switch.
The photovoltaic module shutdown device according to claim 2, wherein when the number of the second photovoltaic module is multiple, the series path for connecting the first photovoltaic module and the second photovoltaic module in series includes all A series path between the first photovoltaic module and one of the second photovoltaic modules, and a series path between each of the second photovoltaic modules;

Wherein, one of said series path is provided with one said second switch.
The photovoltaic module shutdown device of claim 1, further comprising a diode;

The anode terminal of the diode is connected with the negative output terminal of the photovoltaic module switch, and the cathode terminal of the diode is connected with the positive output terminal of the photovoltaic module switch.
The photovoltaic module shutdown device according to any one of claims 1 to 8, wherein the switching device is specifically a MOS tube or an IGBT or a thyristor or a triode or a relay.