What is a disturbance-free quick switch device? What is the principle of the disturbance-free quick switching device? What are the functions of a disturbance-free quick switching device?

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I. Overview: The disturbance-free rapid switching device is suitable for the disturbance-free switching of backup power supplies in the petrochemical, coal, metallurgy, building materials, thermal power plant, or power generation industry. When there is a failure in the system’s power supply, the faulty power source is quickly disconnected depending on the system’s operating status. The voltage quality on both sides where switching is to occur is checked; if it meets the requirements for switching, the backup power source is activated. This prevents power interruptions or damage to equipment that could result from rapid power switching, ensuring that the load continues to operate without interruption. Uninterrupted switching of power supplies is an important measure to ensure power supply reliability. What is power supply reliability? A relatively traditional misconception is that ensuring power supply reliability means that a load can obtain a new power source once it loses its existing one. The correct understanding of power supply reliability is that, after regaining a power source, the end-users can maintain their previous production processes without disruption and continue to operate normally to the greatest extent possible. To ensure the continuity of the production process, a backup power supply should be activated before the critical voltage is reached. In this way, the motor power contactors in many industrial enterprises will no longer experience the so-called \"fluctuating voltage\" problem caused by slow activation of the backup power supply, and the motors will not trip automatically. file:///C:/Users/MARKET~1/AppData/Local/Temp/ksohtml816/wps21.jpg II. Working Principle: To address the issue of voltage fluctuations, the desired outcome is to ensure continuous production, prevent disruptions to the equipment under load, and maintain safety. When a transient voltage disturbance occurs, the grid voltage drops. Since there are many inductive devices such as motors connected to the load side, these motors remain in a \"free-running\" state due to inertia; they feed voltage back to the bus, resulting in a high residual voltage on the bus that declines slowly. The trajectory of the bus’s residual voltage is shown in the following diagram: file:///C:/Users/MARKET~1/AppData/Local/Temp/ksohtml816/wps22.jpg Here, VS represents the voltage of the backup power supply, VD represents the residual voltage on the bus, and △U represents the difference between the bus’s residual voltage and the voltage of the backup power supply. A quantitative analysis can be carried out using the equivalent circuit diagram shown below. file:///C:/Users/MARKET~1/AppData/Local/Temp/ksohtml816/wps23.jpg Where VS represents the backup power supply, XS denotes the equivalent reactance of the power supply, VM is the residual voltage of the motor, and XM is the equivalent reactance of the motor assembly. When the motor has its power supply reconnected, the voltage across the motor is given by: UM = △U × (XM/(XS + XM)). Here, let K = XM/(XS + XM); then UM = K × △U. In other words, UM = K△U