FSC Medium and Low Voltage Disturbance-Free Switching Cabinet

Product Overview

Voltage disturbances are primarily caused by faults in external and internal power grids. These disturbances are often accompanied by voltage sags. Voltage sags lasting more than 80 milliseconds can trigger alarms and shutdowns in high and low voltage frequency converters, as well as cause malfunctions in secondary control circuits, leading to production system halts and potentially serious production accidents.

There are typically two ideal solutions for mitigating voltage sags: one is to install low-voltage ride-through (LVRT) devices, with different configurations for different loads. The MSPower Boost series LVRT devices are mainly designed for frequency converters, while the MSPower DVR series LVRT devices are primarily intended for direct-start motors. The other solution involves using a fast transfer device to switch to a secure power source, which requires the secure power source to have sufficient capacity and the switching process to be fast enough to be imperceptible to sensitive equipment, achieving truly disturbance-free switching. It also demands high reliability, accurate fault detection both inside and outside the zone, composite criteria for PT disconnection, and the ability of the disturbance-free fast transfer device to accurately record voltage and current waveforms during system sags.

The FSC series medium and low voltage disturbance-free transfer cabinets mainly consist of the DCM635 disturbance-free fast transfer device, PBG series phase-controlled high-speed circuit breakers, GMP711 microprocessor-based comprehensive line protection devices, and various transformers. They represent a new generation of integrated medium and low voltage complete transfer cabinets. The integrated complete solution enables better coordination among the control unit (DCM635 disturbance-free fast transfer device), the execution unit (PBG phase-controlled high-speed circuit breakers), and the protection unit (GMP711 microprocessor-based comprehensive line protection devices), making plant power switching faster and safer.

The following provides a brief introduction to the main components of the disturbance-free fast transfer cabinet.

DCM635 Disturbance-Free Fast Transfer Device
The DCM-635 series power disturbance-free fast transfer device is an upgraded product of the DCM633 series. It is widely used in continuous production industries such as petrochemicals, steel metallurgy, and semiconductors for disturbance-free power switching. When a voltage sag occurs in the system power supply, the complete fast transfer device quickly disconnects the sagging power source and safely closes the backup power source, ensuring no power interruption or impact during the fast switching process, and enabling long-term continuous system operation.

PBG Series Phase-Controlled High-Speed Vacuum Circuit Breakers
This series of high-speed circuit breakers features unique permanent magnet high-speed vacuum technology, with three-phase independent high-speed magnetic operating mechanisms. Each phase responds accurately, and the vacuum arc-extinguishing contacts operate smoothly without refusal to close, refusal to open, or misoperation. The three-phase opening and closing times are precise, providing effective suppression of overvoltage and inrush currents in transmission lines, transformers, capacitors, and reactors.

GMP711 Microprocessor-Based Line Protection Device
The GMP711 microprocessor-based line protection and monitoring device quickly identifies faults within the zone and works in conjunction with the DCM635 to achieve rapid isolation of internal faults. The device is equipped with three-stage directional overcurrent protection, inverse-time overcurrent protection, charging protection, overload alarm, and other functions.

Product Main Features

☆  Disturbance-Free Switching

One-click disturbance-free switching during normal switching operations;
When a voltage sag occurs in the grid, it quickly and disturbance-free switches to the backup incoming line, ensuring that high and low voltage frequency converters, direct-start motors, soft-start motors, etc., do not shut down, control circuits do not release, the load bus experiences no operational overvoltage or switching inrush current, with a switching time of less than 15 ms, achieving truly disturbance-free switching.

☆ Optoelectronic Integrated Control

Through deep integration of optical and electrical primary and secondary technologies, the fast transfer device and high-speed switch are designed with integrated optical direct control. Optical encoding precisely controls the opening and closing of the high-speed switch, with a control delay of less than 200 μs, offering absolute advantages such as fewer links, high reliability, short delay, strong anti-interference capability, and corrosion resistance.     

☆  Intelligent Protection

The FSC medium and low voltage disturbance-free transfer cabinet is equipped with an independent microprocessor-based comprehensive protection device. The disturbance-free switching control system and the relay protection system are completely independent, greatly enhancing cabinet reliability. It enables rapid identification of faults both inside and outside the zone, protection for the circuit breaker itself, and alarms for temperature and humidity inside the cabinet.

☆  Disturbance Recording

Automatic recording of bus voltage disturbances, automatic recording upon switching initiation, holographic recording of voltage, current, and circuit breaker positions, supporting local printing of recording information or remote transmission of recording data, facilitating grid disturbance monitoring, switching process replay, and switching disturbance analysis. 

☆ Remote Maintenance

The cabinet is equipped with standard dual RS485 communication and dual 100M Ethernet communication, supporting conventional communication protocols. It can be configured with a 4G communication module based on user requirements, enabling remote maintenance via mobile devices and waveform viewing through encrypted gateways.

Product External Diagram

Product Selection Table