Electric leakage alarm device for household photovoltaic grid-connected system

Abstract

The utility model discloses an electric leakage alarm device for a household photovoltaic grid-connected system. The electric leakage alarm device is composed of an audible and visual alarm, an independent grounding electrode and a time relay. The household photovoltaic grid-connected system is characterized in that a power input end L of the audible and visual alarm is connected to a housing of each device of the household photovoltaic grid-connected system or a grounding series connection circuit of the housing, and a power AC 220V input end L of the time relay is connected in parallel with the power input end L of the audible and visual alarm. A coil power input end L and a coil power input end N of the time relay are respectively connected in parallel with a power input end L and a power input end N of the audible and visual alarm, and the audible and visual alarm and the power input end N of the time relay are jointly connected to one upper end of the independent grounding electrode; the lower end of the independent grounding electrode is driven underground. The device solves the problem of electric shock danger caused by the fact that solar electric leakage cannot be directly found in time in a household photovoltaic grid-connected system of a large number of families, and the safety is improved. The device is simple, standardized and worthy of popularization and application.

Description

Technical Field

[0001] The utility model relates to a leakage warning device for a household photovoltaic grid-connected system. Background Art

[0002] The technical solutions of existing household photovoltaic grid-connected systems are as Figure 3 , Figure 4 shown. The household photovoltaic grid-connected system includes a photovoltaic module 1, a photovoltaic inverter 2, a photovoltaic grid connection box 3, a household switch box 4, and an energy storage device 5. The photovoltaic module 1 stores energy for the energy storage device 5 through the photovoltaic inverter 2, or feeds the electric energy into the municipal grid through the photovoltaic grid connection box 3 or supplies it for household use through the household switch box 4. There are two grounding states for existing household photovoltaic grid-connected systems: one is as Figure 3 shown, only the photovoltaic module 1 is grounded, and the other is as Figure 4 shown, where the photovoltaic module 1, the photovoltaic inverter 2, the photovoltaic grid connection box 3, and the energy storage device 5 are respectively grounded. With the increase in the installation of household / residential photovoltaic systems, while saving electricity costs for families and increasing income, it also responds to the country's energy conservation and emission reduction policies and uses clean energy at the same time. However, what worries the owners is the electric shock safety of the solar system. They cannot intuitively and obviously know whether there is a leakage situation in the solar system. If someone in the family, especially the elderly or children, accidentally touches it, there will be a risk of electric shock.

[0003] Currently, the most commonly used method for checking whether a photovoltaic system is leaking is to regularly check the electricity with an electroscope. Some people only know that the equipment is leaking electricity after someone touches it and feels an electric shock, and some check whether the equipment is leaking electricity by occasionally viewing it on the mobile phone APP. In short, they are all not intuitive and cannot detect the leakage phenomenon in time.

[0004] In the application of existing household / residential photovoltaic systems, grounding is mainly achieved by directly connecting the equipment to the ground nearby, or by directly connecting to a so-called neutral ground after the equipment casings are connected in series. There is no installed warning indication or warning sound that can intuitively see or hear the leakage of each device.

[0005] No detection and control device for whether any solar system equipment in the photovoltaic system is leaking and no external intuitive sound and light warning device are installed.

[0006] The objective disadvantages of existing household photovoltaic grid-connected systems are as follows:

[0007] 1. In the application of existing household / residential photovoltaic systems, grounding is mainly achieved by directly connecting the equipment to the ground nearby, or by directly connecting to a so-called neutral ground after the equipment casings are connected in series, and there are defects such as poor grounding or disconnection of the grounding point.

[0008] 2. The existing photovoltaic power generation system does not install a warning indication or warning sound that can intuitively see or hear the leakage of each device, and cannot remind the owner of a leakage warning.

[0009] 3. In the prior art, only the positive and negative poles on the DC side of the photovoltaic system can reflect the warning information of whether the solar components or cables are leaking electricity to the ground through the shutdown warning of the inverter. However, it is also necessary to check whether the photovoltaic system is normal to know.

[0010] 4. If the warning information of whether each solar device is leaking electricity cannot be intuitively reflected, it will affect personal electric shock safety and timely eliminate the potential leakage hazards. If a photovoltaic system leakage warning is found, the total power supply of the photovoltaic system cannot be temporarily turned off through time delay. Summary of the Invention

[0011] The purpose of the present utility model is to provide a leakage warning device for a household photovoltaic grid-connected system in order to overcome the problems in the prior art that the devices in the household photovoltaic grid-connected system are directly connected to the ground nearby, or are directly connected to a so-called neutral ground after being connected in series through the outer casings of the devices, and the warning indication or warning sound of leakage of each device cannot be intuitively seen or heard.

[0012] The technical solution adopted by the present utility model is as follows:

[0013] A leakage warning device for a household photovoltaic grid-connected system is composed of an audible and visual alarm, an independent grounding electrode and a time relay; its characteristics are: the power input terminal L of the audible and visual alarm is connected to the grounding series connection line of the outer casings of each device in the household photovoltaic grid-connected system or the outer casings, the AC 220V power input terminal L of the time relay is connected in parallel with the power input terminal L of the audible and visual alarm, the power input terminal L and the power input terminal N of the coil of the time relay are respectively connected in parallel with the power input terminal L and the power input terminal N of the audible and visual alarm, and the power input terminal N of the audible and visual alarm and the time relay are jointly connected to an upper end of the independent grounding electrode; the lower end of the independent grounding electrode is driven into the ground.

[0014] When the audible and visual alarm is powered on, a red flashing light or a beeping sound appears.

[0015] The independent grounding electrode is an angle steel, round steel pipe, copper pipe, copper rod, aluminum pipe, or aluminum rod with a length of 2-3 meters.

[0016] The power input terminal L of the audible and visual alarm is connected to the grounding series connection line of the outer casings of each device in the household photovoltaic grid-connected system through a copper wire.

[0017] The power input terminal N of the audible and visual alarm and the time relay is fixed to the upper end of the independent grounding electrode through a copper terminal.

[0018] The time relay can output a set of closing time delay control dry contacts to the total power supply control terminal of the photovoltaic grid-connected box, and can delay and temporarily control the shutdown of the total power supply of the household photovoltaic grid-connected system.

[0019] The lower end of the independent grounding electrode is made into a pointed shape and driven into the ground to a depth of 2 - 3 meters to maintain a certain humidity and grounding reliability, and the measured grounding resistance is not greater than 4Ω.

[0020] The leakage warning device of the household photovoltaic grid-connected system of the present utility model uses mature and commonly used accessories, such as an independent grounding electrode, an audible and visual alarm, and a time relay, which are installed through technical function combination wiring to form a new control device, and the conventional wiring installation is convenient. When the household photovoltaic grid-connected system is normal and there is no leakage, there is no warning. When there is a leakage situation, there will be an audible and visual warning, and the total power supply can be temporarily controlled through the dry contact signal of the time relay. At the same time, the audible and visual alarm can be installed anywhere in the home where it is easy to see or hear. This device is applicable to household solar power generation AC 220V and 380V grid-connected systems.

[0021] The technical principle is that first, new grounding connections are added to the outer shells of each device in the household photovoltaic grid-connected system, and they are connected through a grounding wire loop network. One end of the loop network is connected to the power input terminal L of the audible and visual alarm and the time relay. If there is a leakage voltage and current flowing through the audible and visual alarm and the time relay, the other end is connected to the neutral grounding electrode to form a closed-loop path to cause the audible and visual alarm to give an alarm; at the same time, the total power supply of the household photovoltaic grid-connected system can be temporarily turned off through time delay.

[0022] When there is no leakage in any device of the household photovoltaic grid-connected system, there is no voltage and current signal flowing through the power supply terminal of the audible and visual alarm, so there will be no alarm and the total power supply of the household photovoltaic grid-connected system will not be turned off through time delay. When there is a leakage in any device, the audible and visual alarm starts to give an alarm (sound or red light), and at the same time, the total power supply of the photovoltaic system can be temporarily turned off through time delay.

[0023] The audible and visual alarm of this device can be installed anywhere that is easy to discover or hear according to the warning needs. In addition, the total power supply of the household photovoltaic grid-connected system can be temporarily turned off through time delay according to the requirements.

[0024] This device solves the problem that in the household photovoltaic grid-connected systems of a large number of families, it is impossible to directly and timely discover solar energy leakage, which may lead to electric shock danger, especially the safety problems of the elderly and children at home, and improves safety. This device has the value of simplicity, standardization and popularization and application, and is applicable to various household solar grid-connected power generation system scenarios such as any villa family, self-built house, rural area and mobile residence. Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the present utility model.

[0026] Figure 2 It is a schematic diagram of the circuit connection of the present utility model.

[0027] Figure 3 It is a grounding schematic diagram of an existing household photovoltaic grid-connected system.

[0028] Figure 4 It is another grounding schematic diagram of the existing household photovoltaic grid-connected system. Specific implementation manner

[0029] The present utility model will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, which is convenient for clearly understanding the present utility model, but they do not constitute a limitation to the present utility model.

[0030] As Figure 1 、 Figure 2 shown, the household photovoltaic grid-connected system includes a photovoltaic module 1, a photovoltaic inverter 2, a photovoltaic grid-connected box 3, a household switch box 4, and an energy storage device 5. A leakage warning device for a household photovoltaic grid-connected system of the present utility model is composed of an audible and visual alarm 6, an independent grounding electrode 7, and a time relay 8; it is characterized in that: the power input terminal L of the audible and visual alarm 6 is connected to the grounding series connection line of the outer shells of each device of the household photovoltaic grid-connected system or the outer shell through a copper wire, the AC 220V power input terminal L of the time relay 8 is connected in parallel with the power input terminal L of the audible and visual alarm, the power input terminal L and the power input terminal N of the N coil of the time relay 8 are respectively connected in parallel with the power input terminal L and the power input terminal N of the audible and visual alarm 6, and the power input terminal N of the audible and visual alarm 6 and the time relay 8 are jointly fixed to an upper end of the independent grounding electrode 7 through a copper terminal; the lower end of the independent grounding electrode 7 is made into a pointed head and driven into the ground to a depth of 2.5 meters. The independent grounding electrode 7 is a 50mm * 50mm * 5mm angle steel with a length of 2.5 meters; to maintain a certain humidity and grounding reliability, the grounding resistance is measured to be not more than 4Ω and then driven into the ground; when the audible and visual alarm 6 is powered on, a red flashing light or a beeping sound appears, such as devices like speakers, horns, and lights. The time relay 8 can output a group of closing time delay control dry contacts to the total power control terminal of the photovoltaic grid-connected box 3, and can temporarily control the shutdown of the total power of the household photovoltaic grid-connected system with a time delay.

Claims

1. A leakage alarm device for a household photovoltaic grid-connected system, comprising an audible and visual alarm (6), an independent grounding electrode (7) and a time relay (8); characterized in that: The power input terminal L of the sound and light alarm (6) is connected to the housing of each device of the household photovoltaic grid-connected system or the grounding series line of the housing, the AC 220V power input terminal L of the time relay (8) is connected in parallel with the power input terminal L of the sound and light alarm, the coil power input terminal L and the power input terminal N of the time relay (8) are respectively connected in parallel with the power input terminal L and the power input terminal N of the sound and light alarm (6), and the power input terminal N of the sound and light alarm (6) and the time relay (8) are connected to an upper end of an independent grounding electrode (7); and the lower end of the independent grounding electrode (7) is driven into the ground.

2. The household photovoltaic grid-connected system leakage alarm device according to claim 1, characterized in that: The sound and light alarm (6) emits a red flashing light or a buzzing sound when the power is turned on.

3. The household photovoltaic grid-connected system leakage alarm device according to claim 1, characterized in that: The independent grounding electrode (7) is a 2-3 meter long angle steel, round steel pipe, copper pipe, copper rod, aluminum pipe, or aluminum rod.

4. The household photovoltaic grid-connected system leakage alarm device according to claim 1, characterized in that: The power input terminal L of the sound and light alarm (6) is connected to the housing of each device of the household photovoltaic grid-connected system or the grounding series line of the housing through a copper wire.

5. The household photovoltaic grid-connected system leakage alarm device according to claim 1, characterized in that: The power input terminal N of the coil of the sound and light alarm (6) and the time relay (8) is fixed to the upper end of the independent grounding electrode (7) through a copper terminal.

6. The household photovoltaic grid-connected system leakage alarm device according to claim 1, characterized in that: The time relay (8) can output a group of closing time delay control dry contacts to the main power control end of the photovoltaic grid-connected box (3), and can delay setting to temporarily control the shutdown of the main power of the household photovoltaic grid-connected system.

7. The household photovoltaic grid-connected system leakage alarm device according to claim 1, characterized in that: The lower end of the independent grounding electrode (7) is made into a pointed tip and driven into the ground at a depth of 2-3 meters. The measured grounding resistance is no more than 4Ω.

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