CN221281148U - Photovoltaic direct current insulation monitoring device - Google Patents

Abstract

The utility model provides a photovoltaic direct current insulation monitoring device, which comprises: a direct current power supply; an inverter; a rectifier; a filter; an insulation monitoring module; the direct current power supply is positioned at the top of the photovoltaic direct current insulation monitoring device and is connected with the inverter through a wire; the inverter is positioned at the bottom of the photovoltaic direct current insulation monitoring device and is separated from the rectifier through a first isolation layer; the rectifier is packaged by adopting a metal shell, and a shielding structure is arranged in the rectifier; the connecting wires among the direct current power supply, the inverter, the rectifier, the filter and the insulation monitoring module are connected by adopting a shielding cable, and a shielding cover is added at the connecting position of the wires. By the scheme of the utility model, the interference of electromagnetic interference sources such as thunder and lightning, electromagnetic radiation and the like on the operation of the insulation monitoring device can be reduced.

Description

Photovoltaic direct current insulation monitoring device

Technical Field

The utility model relates to the technical field of photovoltaics, in particular to a photovoltaic direct current insulation monitoring device.

Background

A photovoltaic direct current insulation monitoring device is a device for monitoring insulation conditions of a photovoltaic direct current circuit. The main function of the system is to detect the insulation resistance between the photovoltaic battery pack and the ground so as to ensure the safe operation of the system. The device can monitor the change of the insulation resistance, and once the insulation resistance is detected to be lower than a certain threshold value, an alarm is sent out so as to take measures for maintenance or replacement in time. Through timely monitoring the insulation condition, the occurrence of electrical accidents can be prevented, and the safety of equipment and personnel is protected.

However, the photovoltaic direct current insulation monitoring device has the problem of low anti-interference capability. Since various electromagnetic interference sources exist in the environment, such as lightning, electromagnetic radiation, etc., these interferences can interfere with the operation of the insulation monitoring device. When the insulation monitoring device is interfered, the insulation condition may be misreported or not reported, so that the real insulation state of the system cannot be accurately judged. Especially under severe environmental conditions, the photovoltaic direct current insulation monitoring device with low anti-interference capability can frequently generate false alarm, bring unnecessary trouble to users, and reduce the reliability and accuracy of the device in practical application

Disclosure of utility model

In view of the above, the present utility model provides a photovoltaic dc insulation monitoring device, which at least partially solves the problems existing in the prior art.

The utility model relates to a photovoltaic direct current insulation monitoring device, which comprises:

The direct current power supply is provided with an input end and an output end;

the inverter is used for converting the electric energy of the direct-current power supply into alternating-current electric energy and outputting the alternating-current electric energy;

The rectifier is used for receiving the alternating current energy output by the inverter and rectifying to obtain a direct current signal;

the filter is used for filtering the direct current signal output by the rectifier to obtain a smooth signal;

The insulation monitoring module is used for detecting whether insulation faults exist in the smooth signal or not; wherein the method comprises the steps of

The direct current power supply is positioned at the top of the photovoltaic direct current insulation monitoring device and is connected with the inverter through a wire;

The inverter is positioned at the bottom of the photovoltaic direct current insulation monitoring device and is separated from the rectifier through a first isolation layer;

The rectifier is packaged by adopting a metal shell, and a shielding structure is arranged in the rectifier;

The connecting wires among the direct current power supply, the inverter, the rectifier, the filter and the insulation monitoring module are connected by adopting a shielding cable, and a shielding cover is added at the connecting position of the wires.

Preferably, a second isolation layer is arranged between the inverter and the direct current power supply.

Preferably, a sealing groove is arranged around the second isolation layer, and insulating oil or gas is injected into the sealing groove.

Preferably, the rectifier adopts a multi-stage rectifying structure, and a filter element is arranged between each stage.

Preferably, the filter element is a ceramic band-pass filter.

Preferably, the filter is a filter element with a metal housing, and the metal housing is connected to other components inside the device.

Preferably, a third isolation layer is arranged between the insulation monitoring module and other components.

Preferably, the third isolation layer is an electronic isolator.

Preferably, the insulation monitoring module adopts an optical fiber to transmit signals.

Preferably, the device is provided with a lightning protection device.

The photovoltaic direct current insulation monitoring device comprises: the direct current power supply is provided with an input end and an output end; the inverter is used for converting the electric energy of the direct-current power supply into alternating-current electric energy and outputting the alternating-current electric energy; the rectifier is used for receiving the alternating current energy output by the inverter and rectifying to obtain a direct current signal; the filter is used for filtering the direct current signal output by the rectifier to obtain a smooth signal; the insulation monitoring module is used for detecting whether insulation faults exist in the smooth signal or not; the direct current power supply is positioned at the top of the photovoltaic direct current insulation monitoring device and is connected with the inverter through a wire; the inverter is positioned at the bottom of the photovoltaic direct current insulation monitoring device and is separated from the rectifier through a first isolation layer; the rectifier is packaged by adopting a metal shell, and a shielding structure is arranged in the rectifier; the connecting wires among the direct current power supply, the inverter, the rectifier, the filter and the insulation monitoring module are connected by adopting a shielding cable, and a shielding cover is added at the connecting position of the wires. By the scheme of the utility model, the interference of electromagnetic interference sources such as thunder and lightning, electromagnetic radiation and the like on the operation of the insulation monitoring device can be reduced.

Drawings

In order to more clearly illustrate the technical solutions of the present utility model, the drawings that are needed in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present utility model, and that other drawings can be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a photovoltaic dc insulation monitoring device according to the present utility model;

fig. 2 is a schematic diagram of a rectifier structure of a photovoltaic dc insulation monitoring device according to the present utility model.

In the figure, a 1-direct current power supply, a 2-inverter, a 3-rectifier, a 4-filter, a 5-insulation monitoring module, a 6-first isolation layer, a 7-input end, an 8-output end, a 9-second isolation layer, a 10-filter element, a 11-third isolation layer, a 12-metal shell, a 13-shielding structure, a 14-multistage rectifying structure and a 15-lightning protection device.

Detailed Description

The present utility model will be described in detail with reference to the accompanying drawings.

Other advantages and effects of the present utility model will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present utility model with reference to specific examples. It will be apparent that the described embodiments are only some, but not all, embodiments of the utility model. The utility model may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present utility model. It should be noted that the following embodiments and features in the embodiments may be combined with each other without conflict. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

It is noted that various aspects of the embodiments are described below within the scope of the following claims. It should be apparent that the aspects described herein may be embodied in a wide variety of forms and that any specific structure and/or function described herein is merely illustrative. Based on the present disclosure, one skilled in the art will appreciate that one aspect described herein may be implemented independently of any other aspect, and that two or more of these aspects may be combined in various ways. For example, an apparatus may be implemented and/or a method practiced using any number of the aspects set forth herein. In addition, such apparatus may be implemented and/or such methods practiced using other structure and/or functionality in addition to one or more of the aspects set forth herein.

It should also be noted that the illustrations provided in the following embodiments merely illustrate the basic concept of the present utility model by way of illustration, and only the components related to the present utility model are shown in the drawings and are not drawn according to the number, shape and size of the components in actual implementation, and the form, number and proportion of the components in actual implementation may be arbitrarily changed, and the layout of the components may be more complicated.

In addition, in the following description, specific details are provided in order to provide a thorough understanding of the examples. However, it will be understood by those skilled in the art that the aspects may be practiced without these specific details.

As shown in fig. 1, a photovoltaic dc insulation monitoring device of the present utility model is an apparatus for detecting insulation of dc power in a photovoltaic system. The device comprises a direct current power supply 1, an inverter 2, a rectifier 3, a filter 4 and an insulation monitoring module 5.

First, the dc power supply 1 has an input terminal 7 and an output terminal 8. The direct current power supply 1 is located on top of the photovoltaic direct current insulation monitoring device and is connected with the inverter 2 through a wire. The function of which is to supply the inverter 2 with the required direct current power.

The inverter 2 is a device that converts electric power supplied from the dc power supply 1 into ac electric power and outputs the ac electric power. In the photovoltaic dc insulation monitoring device, the inverter 2 is located at the bottom and is separated from the rectifier 3 by a first isolation layer 6. This design effectively prevents the risk of high voltages due to faults.

The rectifier 3 is a device that receives the ac power output from the inverter 2 and performs shaping processing to obtain a dc signal. In order to protect the shaped signal from external disturbances, the rectifier 3 according to the utility model is, as shown in fig. 2, encapsulated by a metal shell 12 and provided with a shielding structure 13 inside.

The filter 4 performs filtering processing on the shaped dc signal to obtain a smoothed signal. Thus, noise and interference in the signals can be eliminated, and the accuracy of insulation monitoring is improved.

Finally, the insulation monitoring module 5 is a core component of the photovoltaic direct current insulation monitoring device. It is used to detect whether an insulation fault exists in the smoothed signal. When an insulation fault is found, the module can give an alarm in time and take corresponding measures to repair or isolate.

In order to solve the problem of electromagnetic interference prevention, the photovoltaic direct current insulation monitoring device adopts the following measures:

First, the inverter 2 and the rectifier 3 are isolated in design by the first isolation layer 6. Thus, the interference of external electromagnetic waves on the shaped direct current signal can be effectively blocked.

Next, a shielding structure 13 is provided inside the rectifier 3. This shielding structure 13 may act to inhibit external electromagnetic radiation from entering the interior of the shaper and affecting the signal quality.

In addition, in order to further improve the anti-interference capability, a shielding cover can be added at the connection part of the wires or shielding wires can be used for reducing the influence of electromagnetic waves on the transmission process.

In a specific embodiment, a photovoltaic dc insulation monitoring device of the present utility model is further provided with a second isolation layer 9 between the inverter 2 and the dc power source 1. The purpose of this feature is to prevent a malfunction or abnormal condition in the dc power supply 1 from adversely affecting the inverter 2 in order to enhance the safety of the system.

The second isolation layer 9 may be realized, for example, by adding a layer of insulating material between the inverter 2 and the dc power source 1. The insulating material layer may be a high voltage tape, insulating paper or other material with good insulating properties. It is placed between the inverter 2 and the dc power supply 1, and serves to completely isolate the two.

In addition, a sealed environment may be provided around the second separator 9 in order to ensure that it functions effectively. For example, a sealing groove is provided around the second separator 9, and insulating oil or gas is injected to provide a better insulating effect.

In one embodiment, as shown in fig. 2, the rectifier 3 in a photovoltaic dc insulation monitoring device of the present utility model adopts a multi-stage rectifying structure 14, that is, the whole rectifying process is divided into a plurality of stages for processing, and a filter element 10 is disposed between each stage.

Specifically, the rectifier 3 in the photovoltaic direct current insulation monitoring device adopts a three-stage rectifying structure. At a first level, the input direct current signal is subjected to a preliminary filtering process by a filtering element 10; then, at the second level, the signal output through the first level is further filtered again through another filter element 10; finally, at the third level, the signal output by the first two levels is subjected to a final filtering process again by a filtering element 10. By means of the multistage rectification and filtering, interference factors such as noise and spurious signals which may exist in an input signal can be effectively reduced or eliminated.

The cooperation between the multistage rectifying structure 14 and the filter element 10 realizes the accurate control and optimization processing of the input signals in the photovoltaic direct current insulation monitoring device. At the same time, according to specific requirements, a higher or lower number of levels and appropriate types and parameters of the filter elements 10 can be selected according to different application scenarios to achieve different rectifying effects and performance requirements.

In one embodiment, the filter 4 of the photovoltaic DC insulation monitoring device of the present utility model is provided with a filter element 10 having a metal housing 12, and the metal housing 12 is connected to other components inside the device.

To this end, the appropriate filter element 10 may be selected during design and manufacture and packaged in a structure having a metal housing 12. The metal housing 12 may be made of a conductive material (e.g., aluminum or steel) and may be electrically connected to other components within the device by connectors or soldering, etc. Furthermore, during installation, it is necessary to ensure that there is good physical contact and reliable electrical connection between the filter 4 and other components.

For example, a ceramic band-pass filter having a metal case 12 may be used as the filter element 10. The ceramic bandpass filter has a metal housing 12 for protecting the internal sensitive components and providing mechanical strength. During the assembly process, the ceramic band-pass filter 4 is placed in a photovoltaic direct current insulation monitoring device and fixed in place by means of screws or welding. Meanwhile, the metal shell 12 of the filter 4 is electrically connected with other components (such as a power supply, a control unit and the like) in the device through wires or connectors so as to ensure effective transmission and filtering effects of signals.

In a specific embodiment, a third isolation layer 11 is disposed between the insulation monitoring module 5 and other components of the photovoltaic dc insulation monitoring device of the present utility model. The purpose of this feature is to further improve the reliability and stability of the device while ensuring electrical safety.

In one embodiment, the third isolation layer 11 may be implemented by adding a physical isolation layer between the insulation monitoring module 5 and other components. This physical isolation layer may be made of a non-conductive material, such as plastic or rubber. The device can effectively prevent any possible electrical short circuit or leakage, and ensure that the signal transmission and data acquisition processes are not interfered by the outside.

Another implementation is to use an electronic isolator as the third isolation layer 11. Such electronic devices are capable of fully electrically isolating the input signal from the output signal to prevent any anomalies that may cause a malfunction or damage from propagating into other components. Through the use of the electronic isolator, efficient signal transmission and data acquisition can be realized, and the photovoltaic direct current insulation monitoring device can be ensured to normally operate under various environmental conditions.

In one embodiment, the insulation monitoring module 5 in the photovoltaic direct current insulation monitoring device of the utility model adopts optical fibers to transmit signals. This means that in this device, the insulation monitoring module 5 internally uses optical fibers as signal transmission medium to realize monitoring of the insulation state of the photovoltaic direct current system.

For example, one or more optical fibers may be introduced inside the insulation monitoring module 5 in a photovoltaic dc insulation monitoring device. These fibers may be connected to corresponding sensors or probes and convert the electrical signals they acquire into optical signals. These optical signals are then transmitted through optical fibers and ultimately sent to external devices for analysis and processing. By adopting the optical fiber to transmit signals, the electric signals can be effectively isolated and protected, the interference and loss are reduced in the long-distance transmission process, and the stability and reliability of the system are improved.

In a specific embodiment, the direct current power supply 1, the inverter 2, the rectifier 3, the filter 4 and the insulation monitoring module 5 of the photovoltaic direct current insulation monitoring device are connected by adopting shielded cables.

This feature may be implemented using, for example, a cable with a shielding layer. Such shielded cables are typically composed of a conductor, an insulating layer, a shielding layer, and an outer jacket. The conductor is used for transmitting current, the insulating layer is used for isolating the conductor from other parts, and the shielding layer plays a role in preventing interference signals from entering or preventing interference signals from leaking out of the cable. In the photovoltaic direct current insulation monitoring device, each component is connected by using the cable with the shielding layer, so that the influence of external interference on the running stability and accuracy of the system can be effectively reduced, and the monitoring capability of the system on the insulation state is improved.

In one embodiment, a photovoltaic dc insulation monitoring device of the present utility model is provided with a lightning protection device 15. This means that the device is designed with regard to protection against external environmental factors such as lightning and corresponding measures are taken to reduce or eliminate potential damage caused by lightning strikes.

To achieve this feature, one of the following technical measures may be added to the photovoltaic dc insulation monitoring device: using lightning rods, lightning networks or grounding systems to direct and disperse lightning energy; a metal shell or shielding material is adopted to block external electromagnetic interference and electrostatic discharge; overvoltage protectors, lightning arresters or other similar devices are installed to absorb and disperse excessive voltage shocks, etc.

In addition, the effect of the whole photovoltaic direct current insulation monitoring device on lightning protection can be improved by using a specially designed circuit layout, selecting proper materials, adding an additional isolation layer and the like.

The working process of the photovoltaic direct current insulation monitoring device is as follows:

The photovoltaic direct current insulation monitoring device comprises a direct current power supply 1, an inverter 2, a rectifier 3, a filter 4 and an insulation monitoring module 5. First, the dc power supply 1 connects input dc power to the inverter 2 through a wire. The inverter 2 is a key component that converts direct-current electric power into alternating-current electric power and outputs the same.

Next, the ac power output from the inverter 2 is received by the rectifier 3, and is subjected to rectification processing to obtain a dc signal. The rectification process is a unidirectional signal that converts alternating voltage or current into a constant direction. In this process, the shaped signal may be better used in subsequent steps.

Then, the shaped direct current signal is sent to the filter 4 for filtering processing to obtain a smoothed signal. The filtering process is mainly to remove high frequency noise and interference that may be present in the signal, making the smoothed signal more stable and reliable.

Finally, in the event of a possible insulation fault in the smoothed signal, the insulation monitoring module 5 detects and issues an alarm or triggers a corresponding protection mechanism. The module plays a role in monitoring the running state and the safety of the system in real time, and ensures the normal running of the photovoltaic direct current insulation monitoring device.

The foregoing is merely illustrative of the present utility model, and the present utility model is not limited thereto, and any changes or substitutions easily contemplated by those skilled in the art within the scope of the present utility model should be included in the present utility model. Therefore, the protection scope of the utility model is subject to the protection scope of the claims.

Claims (10)

1. A photovoltaic dc insulation monitoring device, comprising:

A DC power supply (1) having an input and an output;

An inverter (2) for converting the electric energy of the DC power supply (1) into AC electric energy and outputting the AC electric energy;

the rectifier (3) is used for receiving the alternating current energy output by the inverter (2) and rectifying to obtain a direct current signal;

The filter (4) is used for filtering the direct current signal output by the rectifier (3) to obtain a smooth signal;

an insulation monitoring module (5) for detecting whether an insulation fault exists in the smoothed signal; wherein the method comprises the steps of

The direct current power supply (1) is positioned at the top of the photovoltaic direct current insulation monitoring device and is connected with the inverter (2) through a wire;

The inverter (2) is positioned at the bottom of the photovoltaic direct current insulation monitoring device and is separated from the rectifier (3) through a first isolation layer;

The rectifier (3) is packaged by adopting a metal shell, and a shielding structure is arranged in the rectifier;

The direct current power supply (1), the inverter (2), the rectifier (3), the filter (4) and the insulation monitoring module (5) are connected through a shielded cable, and a shielding cover is added at the connection position of the wires.

2. The photovoltaic direct current insulation monitoring device according to claim 1, characterized in that a second isolation layer is arranged between the inverter (2) and the direct current power supply (1).

3. A photovoltaic dc insulation monitoring device according to claim 2, characterized in that the second insulating layer (9) is provided with a sealing groove around and filled with insulating oil or gas.

4. A photovoltaic dc insulation monitoring device according to claim 1, characterized in that the rectifier (3) is of a multi-stage rectifying structure and that a filter element is arranged between each stage.

5. The photovoltaic dc insulation monitoring device of claim 4 wherein the filter element is a ceramic bandpass filter.

6. A photovoltaic dc insulation monitoring device according to claim 1, characterized in that the filter (4) is a filter element with a metal housing and that the metal housing is connected to other components inside the device.

7. A photovoltaic direct current insulation monitoring device according to claim 1, characterized in that a third isolation layer is provided between the insulation monitoring module (5) and the other components.

8. The photovoltaic dc insulation monitoring device of claim 7, wherein the third isolation layer is an electronic isolator.

9. A photovoltaic dc insulation monitoring device according to claim 1, characterized in that the insulation monitoring module (5) internally employs optical fibers to transmit signals.

10. A photovoltaic dc insulation monitoring device according to claim 1, characterized in that the device is provided with a lightning protection device.