A universal unbalanced overvoltage lightning protection circuit

Abstract

The invention discloses a general type unbalanced overvoltage and lightning protection circuit. The trigger amplification circuit of an overvoltage protection part is respectively connected with the secondary side of a zero-sequence current transformer and an electromagnetic relay coil. A circuit breaker switch part comprises an electromagnetic relay and a circuit breaker switch. An anti-interference part comprises an anti-interference assembly. Two leads at the load end of a protection circuit pass through the zero-sequence current transformer to be connected with a phase line and a zero line respectively through the circuit breaker switch. An over-voltage protection and detection assembly is connected in parallel with the load end and is in bridge joint with the line incoming end and the line outgoing end of the zero-sequence current transformer. The current path of the over-voltage protection and detection assembly does not pass through the zero-sequence current transformer. The circuit breaker switch is connected with a trigger amplifier. The two leading-out ends of the anti-interference assembly are connected in parallel with the phase line and the zero line of the load end. When a high-voltage surge current arrives, the circuit breaker switch is quickly switched off. Therefore, a subsequent load circuit is protected, while a varistor is prevented from being completely subjected to overcurrent. The reliability of lightning protection is improved.

Description

technical field [0001] The invention relates to an overvoltage lightning protection technology, in particular to a general-purpose unbalanced overvoltage lightning protection circuit. Background technique [0002] At present, zinc oxide varistors are widely used in various surge protectors (SPD) on the market, which have faster response speed (25ns), greater energy absorption capacity (5-40KA 8 / 20us) and no follow-up Current problem. However, the disadvantages of varistors are easy aging and high distributed capacitance. The distributed capacitance problem can be ignored when used in 50Hz power lines, and the aging problem must be considered. [0003] In addition, in the vast rural areas, most houses are not equipped with any lightning protection facilities, nor are they equipped with independent grounding wires. All kinds of surge protectors on the market need grounding wires to better play their role in lightning protection and discharge. , almost no one wants to install...

AI Technical Summary

Problems solved by technology

However, the disadvantages of varistors are easy aging and high distributed capacitance. The distributed capacitance problem can be ignored when used in 50Hz power lines, and the aging problem must be considered.

[0003] In addition, in the vast rural areas, most houses are not equipped with any lightning protection facilities, nor are they equipped with independent grounding wires. All kinds of surge protectors on the market need grounding wires to better play their role in lightning protection and discharge. , almost no one is willing to install an additional ground wire in order to install a surge protector, so it is very rarely used in rural areas

Every year in the thunderstorm season, there will be a large number of incidents of lightning damage to electrical appliances, resulting in a large amount of property loss

Although there are also lightning protection products that do not need to be installed with ground wires such as lightning protection sockets, their lightning protection level is low, the input power cannot be disconnected, and the price is relatively high, and the cost performance is low, so they have not been widely used.

There are also TV manufacturers that produce lightning protection TVs for the rural market. The lightning protection circuit adopts a simple method of connecting varistors in parallel with the power port, and the lightning protection effect is not ideal.

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