Protection and lightning protection design: the difference between traditional and innovative lightning protection for AC power ports

Lightning protection design is closely related to circuit protection; both aim to ensure the safe operation of electrical equipment through various protective measures, even when subjected to power fluctuations and lightning strikes. There are many differences between traditional and innovative lightning protection technologies, especially in the application of AC power outlets. How to select appropriate lightning protection solutions based on different environments and requirements is a topic that requires in-depth discussion. This article will provide a detailed analysis of the differences between traditional and innovative lightning protection technologies for AC power outlets, helping readers better understand the characteristics, advantages, and applicable scenarios of these technologies.

Basic concepts of circuit protection and lightning protection design

1.Definition of circuit protection

Circuit protection is to prevent circuit failure due to abnormal current (such as overvoltage, overcurrent, short circuit, etc.) by designing protective measures in electrical equipment. Its main purpose is to avoid damage to the circuit system of equipment, so as to ensure the safety and stability of electrical equipment.

The key technologies for circuit protection include:

(1) Overcurrent protection: when the current exceeds the safe value of the circuit design, the protection device (such as fuse, circuit breaker, etc.) is triggered to open the circuit to prevent the circuit overload.

(2) Overvoltage protection: when the voltage exceeds the safe range, the protection device will be triggered to prevent electrical components from being impacted by overvoltage.

(3) Short circuit protection: when a short circuit occurs, the protection device will quickly cut off the power supply to prevent the equipment from being damaged due to the sharp increase of current.

2. Definition of lightning protection design

Lightning protection design refers to a series of preventive measures taken to prevent damage caused by lightning to electrical equipment and buildings. The strong current from a lightning strike can not only damage electronic devices but also trigger fires or electrical accidents. Therefore, the goal of lightning protection design is to ensure the safety of equipment through proper layout, selecting appropriate lightning protection devices, and establishing an effective grounding system.

The core components of lightning protection design include:

(1) Lightning rod and lightning belt: used to guide the lightning current into the ground, so as to avoid direct lightning strike on buildings or equipment.

(2) Grounding system: Ensure that the lightning current can flow to the ground through a low impedance path and prevent the voltage from being conducted through the building or equipment.

(3) Surge protection equipment (SPD): When overvoltage events caused by lightning or power fluctuations occur, SPD can quickly divert the current to prevent the current from exceeding the range of the equipment.

Traditional lightning protection technology

Traditional AC power port lightning protection design mainly relies on MOV (voltage sensitive resistor), GDT (gas discharge tube) and SPD (surge protection device) and other lightning protection components. These technologies have been widely used in home appliances, industrial equipment and communication facilities for many years.

1. MOV (voltage sensitive resistor)

MOV is a common overvoltage protection element, which uses its nonlinear resistance characteristics to absorb voltage surges. When the voltage exceeds the normal operating voltage of the equipment, MOV will reduce its resistance value to conduct overvoltage, thus protecting the equipment from damage.

merit:

(1) Overvoltage protection: The most important advantage of varistor is that it can effectively protect the circuit from instantaneous high voltage impact, such as lightning, surge voltage, etc.

(2) Fast response speed: it can respond to voltage changes in a very short time, quickly limit current, and protect the circuit from transient voltage damage.

(3) Small size and low cost: Pressure sensitive resistors are usually small in size and cheap, suitable for a variety of electronic equipment.

(4) Can withstand large current: in the protection circuit, the varistor can withstand large surge current, and can be used repeatedly, as long as it does not exceed its rated capacity.

(5) Self-recovery: Most varistors have self-recovery, even if they are subjected to high voltage for a short time, they can return to normal working state.

shortcoming:

(1) Poor durability: The durability of the varistor is relatively poor. Long-term overvoltage or frequent surge current may lead to the deterioration of its performance and eventually damage.

(2) Temperature sensitivity: The performance of the varistor is affected by temperature, and too high temperature will reduce its overvoltage protection ability.

(3) Not suitable for continuous work: They are not suitable for long-term continuous high voltage protection, because the working mechanism of varistor is to protect the circuit through nonlinear changes, which may lead to its long-term loss.

(4) Unsuitable for low-voltage precision protection: For low-voltage applications, the varistor may not be able to accurately adjust the protection voltage, and may cause false action.

2. GDT (Gas Discharge Tube)

GDT is a lightning protection element commonly used in high energy lightning impact. It uses the principle of gas discharge. When the voltage exceeds the set range, GDT will trigger gas discharge, release current and protect the circuit.

merit:

(1) High energy absorption capacity: gas discharge tube can withstand very high surge current and instantaneous high voltage, and has a strong protection ability for lightning strike and power grid fluctuations and other emergencies.

(2) Good isolation: under normal working conditions, the impedance of the gas discharge tube is very high, which will hardly affect the normal operation of the circuit; it will only conduct and play a protective role when the voltage exceeds a certain threshold.

(3) Long life: Compared with other overvoltage protection components, the life of gas discharge tube is longer, especially under frequent surge current impact, which shows particular durability.

(4) Rapid response: The gas discharge tube can respond quickly when encountering overvoltage, and can provide overcurrent channel almost instantly to protect the circuit.

(5) High temperature and high current tolerance: it has strong ability to withstand high temperature and large current, suitable for some more demanding working environment.

shortcoming:

(1) Fixed threshold: The working voltage threshold of the gas discharge tube is usually fixed, so it cannot be adjusted within a certain range, which may not be suitable for some specific applications.

(2) Slow response speed: Although the gas discharge tube can be quickly connected, its response speed may be slightly slower than some other protective elements (such as TVS diode), which may lead to a decrease in protection effect under some high frequency voltage fluctuations.

(3) Large volume: Compared with other overvoltage protection components, such as varistor or TVS diode, gas discharge tube has a large volume and is not suitable for applications with limited space.

(4) Regular inspection is required: Although the durability of gas discharge tube is strong, it may be damaged if it has experienced extreme surge voltage, so regular inspection and maintenance are required.

(5) Unsuitable for high-frequency protection: Because the conduction mechanism of gas discharge tube mainly depends on the process of gas ionization, it may not be as effective as other protection elements in high-frequency applications.

3. SPD (Surge Protection Device)

Surge protection device (SPD) is mainly used by MOV, GDT and other components, which can effectively suppress the overvoltage caused by lightning or power surge, and ensure the normal operation of equipment.

Type of surge protection device:

(1) Gas discharge tube (GDT): used to withstand large surge current and conduct current through gas ionization. Suitable for lightning and high energy surge protection.

(2) Varistor (MOV): When the surge voltage occurs, the resistance value of the varistor drops rapidly to absorb the excess voltage and protect the circuit. It is commonly used in small power equipment.

(3) Transient voltage suppression diode (TVS diode): When the voltage exceeds a specific threshold, TVS diode will conduct instantly to guide away excess voltage, suitable for high frequency and fast response surge protection.

(4) Metal oxide varistor (MOV) and diode combination: combines the characteristics of both, providing more comprehensive protection for different occasions.

merit:

(1) Efficient protection: can quickly and effectively prevent the damage caused by voltage surge to equipment.

(2) Long-term reliability: The durability of surge protection devices is usually strong and can work stably for a long time, especially the life of gas discharge tubes and MOV is long.

(3) Multiple specifications: According to different application occasions, surge protection devices provide a variety of different specifications and protection levels, can meet the needs from low power appliances to large power equipment.

(4) Rapid response: When surge voltage occurs, SPD will respond instantly to reduce the risk of equipment damage.

(5) Easy to install: Modern surge protection devices are usually small in size and easy to install, which can be integrated into power sockets, power boards, power systems and other equipment.

shortcoming:

(1) Limited durability: Although the life of the surge protection device is long, after bearing multiple overvoltage protection, its protective effect will gradually decrease, especially in frequent high energy surge voltage.

(2) Limited to surge protection: The surge protection device can only prevent sudden voltage surges, and cannot provide continuous voltage or current protection, and still needs to work together with fuses, overcurrent protection devices, etc.

(3) Limited response speed and protection degree: Although the surge protection device responds quickly, it may not provide complete protection for some high frequency or super large energy surge voltage, and may need to be combined with other protection devices.

(4) Installation and maintenance costs: Although surge protection devices themselves are relatively inexpensive, for some larger systems (such as industrial equipment, data centers, etc.), installation and maintenance can involve higher costs.

Innovate lightning protection technology

The combination of TSS (thermal switch) and MOV

1.TSS+MOV technology is a modern surge protection solution, widely used in the circuit protection of all kinds of equipment. TSS (Transient Suppression System) and MOV (Metal Oxide Varistor) work together to effectively deal with surge, transient voltage and other problems.

2.TSS (Transient suppression system): TSS system can make a quick response to surge and transient voltage changes, usually including transient voltage suppressor (such as TVS diode). TSS avoids damage to electrical equipment by suppressing the peak voltage of surge, with very fast response time.

3.MOV (Metal oxide varistor): A MOV is a common voltage suppression element that can quickly divert excess current to the ground when the voltage exceeds the set threshold, thus protecting the equipment from high voltage damage. MOV is usually used in conjunction with TSS systems to provide double protection for the equipment.

With its high efficiency of surge suppression and fast response speed, TSS+MOV combination technology can deal with different types of electrical interference, especially suitable for the circuit protection requirements of modern high-tech equipment and precision instruments.

The difference between traditional lightning protection technology and innovative lightning protection technology