Qingdao Kede Libang New Power Technology Co.,Ltd.

A voltage sag is where the voltage of the power grid fluctuates or drops temporarily but then recovers over a very short span of time. Voltage sags are usually caused by lightning strikes, post short-circuit re-closing, and significant voltage drops or short-term power loss in the power grid triggered by starting of large equipment and so on. Voltage sags may only last for few milliseconds to few seconds, but they can still lead to electrical equipment control system malfunctions, resulting in production interruption or even more serious consequences such as equipment damage and casualties. That is also why voltage sags have raised so much concerns in electric power sectors and industrial automation field. 

①Excessive and rapid voltage fluctuations in external distribution network or internal power network;

②Starting/engaging of large-size, unbalanced loads in the regional distribution network; 

③ Short-circuit triggered tripping and power outages caused by upper-stream thunder strikes in thunderstorms. In this case, additional energy supplementation is required, and the required energy level will be calculated and designed according to actual needs.

Even if voltage sags last shortly, they have a significant impact on sensitive equipment and industrial production: 

① Equipment shutdown: equipment such as factory motors, devices on assembly lines run on stable voltage. Voltage sags may shut down such equipment suddenly by tripping sub components such as contactors and relays. As a consequence, production efficiency will drop as restarting these equipment takes time.

② Loss of data: electronic devices such as computers, servers, PLCs (programmable logic controllers) may experience program interruptions, loss of data, and even hardware damage due to voltage sags. 

③ Product damage: in precision manufacturing industries (such as semiconductor and chemical), sudden equipment shutdown due to voltage sags during production may result in product damage, causing economic losses. 

④ Safety risks: if critical equipment (such as furnaces and reactors) in certain industries (such as metallurgy and pharmaceutical) are shut down due to voltage sags, severe accidents may occur.

Kede Libang's Dedicated Power-quality Management Equipment is installed in the main lines of the distribution network. It is able to deal with voltage sags rapidly through the built-in electronic compensation module, by drawing power from the distribution line and compensating it to the load line.

This device is able to detect and respond to voltage sags in less than 1 ms and manage it in less than 10ms. 

The above capability of this equipment is designed based on a low-voltage fluctuation range of ± 120V. We could also customize it according to your actual needs.In the process of voltage sag management, the load voltage will not experience any power failure, so that the load can overcome voltage sags smoothly without being impacted.

In cases of voltage sags induced by imbalance among the three phases, the electronic compensation module will deliver independent compensation to the three phases when dealing with voltage sags. 

Lightning strikes during thunderstorms may induce short circuits and tripping of the upstream line which may then lead to power outage or significant voltage sags that lasts generally within 2 seconds. Such cases call for a separate energy-storage supplementation unit which will be installed at the bus-bar power supply point or at the load end. Another option is to install such energy-storage units on both points. The final supplementation solution will depend upon multiple factors such as costs, capacity, depth of drop and its duration. In a word, independent treatment units might be needed when addressing voltage sags caused by thunder strikes.