Upper and lower double-gap metal oxide lightning arrester special for photovoltaic power generation

Abstract

The utility model belongs to the field of high-voltage electric appliances, and particularly relates to an upper-lower double-gap metal oxide arrester special for photovoltaic power generation. The metal oxide resistor comprises a composite jacket, and a first metal oxide resistor unit, a second metal oxide resistor unit, a third metal oxide resistor unit and a fourth metal oxide resistor unit which are sequentially arranged in the composite jacket from top to bottom, the upper end of the composite outer sleeve is provided with an upper gap alloy grading ring, and the lower end of the composite outer sleeve is provided with a lower gap alloy grading ring. According to the utility model, through the upper and lower double-gap combined structure, the multi-unit metal oxide resistor disc group absorbs overvoltage, and the filter capacitor absorbs high-frequency impact interference and harmonic waves, the lightning overvoltage and operation overvoltage generated in a power generation system can be absorbed, and the surge protection circuit is sensitive in starting, low in residual voltage value, strong in impact resistance, small in standby loss and long in service life.

Description

Technical Field

[0001] The utility model belongs to the field of electric high-voltage electrical appliances, and in particular relates to a special upper and lower double-gap metal oxide arrester for photovoltaic power generation. Background Art

[0002] Photovoltaic power generation systems generate electricity by converting light energy into electrical energy. Their equipment is usually installed outdoors and exposed to various natural environments. Among them, lightning is one of the main natural disasters faced by photovoltaic power generation systems. The strong current and voltage generated by lightning may cause serious damage to photovoltaic modules, inverters, cables and other equipment, and may even cause safety accidents such as fires. Secondly, there are many conversion links in grid-connected operation, and the switching action is frequent, which is easy to cause system operation overvoltage; the electric field is located in an open area and occupies a large area, so it is easy to be struck by lightning, so lightning overvoltage is also relatively frequent; in addition, the lightning arrester is damp and the resistor is aging, the reactive power consumption is large, and the power resources are wasted. Therefore, lightning protection measures for photovoltaic power generation systems are crucial.

[0003] At present, traditional lightning arresters have some limitations in dealing with lightning protection of photovoltaic power generation systems. Although metal oxide lightning arresters have excellent nonlinear characteristics and current carrying capacity, they have the problem of unstable breakdown voltage. Therefore, a new type of lightning arrester is needed to better protect photovoltaic power generation systems from lightning overvoltage and operating overvoltage. Utility Model Content

[0004] In order to solve the problems existing in the prior art, the utility model provides a special upper and lower double-gap combined oxide lightning arrester device for wind power and photovoltaic power generation, which can reliably protect against lightning overvoltage and operating overvoltage generated in the power generation system, has low standby loss, long service life, easy installation and disassembly, and adjustable angle.

[0005] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0006] A double-gap metal oxide arrester specially used for photovoltaic power generation comprises a composite outer jacket and a first metal oxide resistor unit, a second metal oxide resistor unit, a third metal oxide resistor unit and a fourth metal oxide resistor unit which are sequentially arranged from top to bottom in the composite outer jacket; an upper gap alloy equalizing ring is arranged at the upper end of the composite outer jacket, and a lower gap alloy equalizing ring is arranged at the lower end of the composite outer jacket.

[0007] Preferably, the metal oxide is zinc oxide.

[0008] Preferably, the first metal oxide resistor unit, the second metal oxide resistor unit, the third metal oxide resistor unit and the fourth metal oxide resistor unit are sequentially connected in series to form a first circuit; and the first circuit is connected in parallel with the second absorption capacitor.

[0009] Preferably, a first connecting hanging ring is provided on the top of the upper gap alloy equalizing pressure ring.

[0010] Preferably, the upper gap alloy grading ring is connected in parallel with a first absorption capacitor.

[0011] Preferably, a second connecting ring is provided at the bottom of the lower gap alloy equalizing pressure ring.

[0012] Preferably, the lower gap alloy grading ring is connected in parallel with a third absorption capacitor.

[0013] Preferably, a voltage equalizing ring is provided between adjacent metal oxide resistor units; the metal oxide resistor unit comprises a plurality of metal oxide resistor sheets; a high-temperature epoxy glass fiber winding cylinder is provided outside the metal oxide resistor sheet, and both ends of the metal oxide resistor sheet are fixed by electrodes.

[0014] Preferably, fuses are connected in series between the metal oxide resistors.

[0015] Preferably, both ends of the metal oxide resistor unit are sealed with silicone rubber and stainless steel electrodes and corrugated springs are screwed in and pressed tightly.

[0016] Compared with the prior art, the utility model has the following beneficial effects:

[0017] The utility model absorbs lightning overvoltage and operating overvoltage generated in the power generation system through the upper and lower double gap combination structure, the multi-unit metal oxide resistor group absorbs overvoltage, and the filter capacitor absorbs high-frequency impact interference and harmonics. It has sensitive starting, low residual voltage value, strong impact resistance, small standby loss and long service life.

[0018] Furthermore, the utility model is provided with a voltage grading ring, which can improve the voltage distribution and eliminate the uneven voltage distribution of the resistor caused by the stray capacitance to the ground.

[0019] Furthermore, the metal oxide resistor of the utility model is installed in a high-temperature and high-strength epoxy glass fiber insulation tube, and both ends are fixed with electrodes, thereby achieving outdoor corrosion and oxidation resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings described herein are for explanation purposes only and are not intended to limit the scope of the present invention in any way. In addition, the shapes and proportional dimensions of the components in the drawings are only for illustration purposes to help understand the present invention, and are not intended to specifically limit the shapes and proportional dimensions of the components of the present invention.

[0021] In the attached picture:

[0022] Figure 1It is a structural schematic diagram of the utility model;

[0023] Figure 2 It is a schematic diagram of the appearance of the utility model.

[0024] In the figure, 1-first connecting ring; 2-upper gap alloy equalizing ring; 3-first absorption capacitor; 4-first metal oxide resistor unit; 5-second absorption capacitor; 6-lower gap alloy equalizing ring; 7-third absorption capacitor; 8-second connecting hanging ring; 9-second metal oxide resistor unit; 10-third metal oxide resistor unit; 11-fourth metal oxide resistor unit. DETAILED DESCRIPTION

[0025] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0026] It should be noted that when an element is referred to as being "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only embodiment.

[0027] like Figure 1 and Figure 2 As shown, the utility model includes a composite jacket, which can prevent the influence of external forces and environmental factors on the arrester and extend its service life. The first metal oxide resistor unit 4, the second metal oxide resistor unit 9, the third metal oxide resistor unit 10 and the fourth metal oxide resistor unit 11 are arranged in sequence from top to bottom in the composite jacket. A voltage equalizing ring is arranged between adjacent metal oxide resistor units, and the first metal oxide resistor unit 4, the second metal oxide resistor unit 9, the third metal oxide resistor unit 10 and the fourth metal oxide resistor unit 11 form a first circuit, and the first circuit is connected in parallel with the second absorption capacitor 5; the overvoltage is absorbed by four groups of metal oxide resistor units, and the capacitor absorbs the high-order harmonics generated in the photovoltaic discharge system, thereby realizing the absorption of lightning overvoltage and operation overvoltage generated in the photovoltaic power generation system. Preferably, the second absorption capacitor 5 is a high-frequency pulse protection absorption capacitor, and the metal oxide is zinc oxide.

[0028] The appearance of the utility model adopts an organic insulating composite structure, and the metal oxide resistor unit includes a plurality of metal oxide resistor sheets, and the metal oxide resistor sheets all adopt resistor sheets with a square wave current capacity of 400A, and all adopt fuses in series with varistor sheets. A high-temperature epoxy glass wire winding cylinder is arranged outside the metal oxide resistor sheets, and the two ends of the zinc oxide resistor wire are fixed with electrode crimping corrugated sheets, and the two ends of the metal oxide resistor unit are sealed with silicone rubber, and the corrugated spring sheets are screwed in and pressed tightly, and then the high-temperature epoxy glass wire winding cylinder is vulcanized with silicone rubber once, so as to achieve reliable sealing of the product.

[0029] An upper gap alloy grading ring 2 is provided at the upper end of the composite jacket, the upper gap alloy grading ring 2 is connected in parallel with the first absorption capacitor 3, and a first connecting hanging ring 1 is provided at the top of the upper gap alloy grading ring 2. A lower gap alloy grading ring 6 is provided at the lower end of the composite jacket, a second connecting hanging ring 8 is provided at the bottom of the lower gap alloy grading ring 6, and a third absorption capacitor 7 is connected in parallel to the lower gap alloy grading ring 6. Both the first absorption capacitor 3 and the third absorption capacitor 7 are high-frequency absorption capacitors. The upper and lower double gap alloy grading rings are connected as a universal connection ball head.

[0030] The utility model uses a multi-unit upper and lower double-gap alloy equalizing ring structure to absorb overvoltage in the middle metal oxide resistor group, bypass the second absorption capacitor 5 to absorb the high-order harmonics generated in the system, and can effectively absorb and discharge lightning overvoltage and operation overvoltage generated in the power generation system. The equalizing ring between the metal oxide resistors can improve the voltage distribution and eliminate the uneven voltage distribution of the resistors caused by stray capacitance to the ground. The upper and lower double-gap alloy equalizing ring structure, the first absorption capacitor 3 and the third absorption capacitor 7 can also absorb overvoltage. The utility model can improve the discharge safety level and has the characteristics of low residual pressure, maintenance-free and good sealing performance, and convenient installation and transportation. The double-gap connection is a universal connection ball head, which can be adjusted and installed at any angle. The device has a standby power consumption of nearly zero <10uA, which is energy-saving and environmentally friendly, and convenient for large-scale optimization and transformation.

[0031] The utility model clearly stipulates the arrester parameters for voltage levels from 20kV to 35kV, as shown in Table 1.

[0032] Table 1

[0033]

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art in the technical field of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

Claims

1. A double-gap metal oxide arrester for photovoltaic power generation, characterized in that: The invention comprises a composite outer jacket and a first metal oxide resistor unit (4), a second metal oxide resistor unit (9), a third metal oxide resistor unit (10) and a fourth metal oxide resistor unit (11) which are arranged in sequence from top to bottom in the composite outer jacket; an upper gap alloy equalizing pressure ring (2) is arranged at the upper end of the composite outer jacket, and a lower gap alloy equalizing pressure ring (6) is arranged at the lower end of the composite outer jacket.

2. A photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: The metal oxide is zinc oxide.

3. A photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: The first metal oxide resistor unit (4), the second metal oxide resistor unit (9), the third metal oxide resistor unit (10) and the fourth metal oxide resistor unit (11) are sequentially connected in series to form a first circuit; the first circuit is connected in parallel with the second absorption capacitor (5).

4. The photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: A first connecting hanging ring (1) is arranged on the top of the upper gap alloy equalizing pressure ring (2).

5. The photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: The upper gap alloy grading ring is connected in parallel with a first absorption capacitor (3).

6. The photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: A second connecting hanging ring (8) is arranged at the bottom of the lower gap alloy equalizing pressure ring (6).

7. The photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: The lower gap alloy grading ring (6) is connected in parallel with a third absorption capacitor (7).

8. The photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: A voltage equalizing ring is arranged between adjacent metal oxide resistor units; the metal oxide resistor unit comprises a plurality of metal oxide resistor sheets; a high temperature epoxy glass fiber winding cylinder is arranged outside the metal oxide resistor sheet, and both ends of the metal oxide resistor sheet are fixed by electrodes.

9. A photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 8, characterized in that: The metal oxide resistors are connected in series by fuses.

10. The photovoltaic power generation dedicated upper and lower double gap metal oxide arrester according to claim 1, characterized in that: The two ends of the metal oxide resistor unit are sealed with silicone rubber and stainless steel electrodes with corrugated springs are screwed in and pressed tightly.

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