Overview: In substations, the DC system is essential for ensuring the safe and stable operation of critical equipment such as protection devices, measurement and control systems, and other important circuits. Unlike AC systems, the field line direction in a DC system is less intuitive, which makes it necessary to rely on wiring diagrams to clearly understand the interconnections between various devices.

The following DC system diagram is used as an example

The DC charger provides power in two directions:

The first output direction connects to the DC feeder screen via the charge output switch on the DC charging screen, allowing for the distribution of DC power to the substation.

The second output direction is routed to the battery bank through the battery switch to charge the battery pack, ensuring that backup power is available in case of failures or grid disturbances.

DC Bus Configuration:

The DC bus is divided into two segments:

Control Bus (KM): This bus is connected to control, monitoring, and signaling circuits, typically with low, stable current loads. These circuits are used to display the positions of switches, knife switches, and other devices, ensuring that the operational mode of the system is clearly reflected. In case of abnormal conditions, the central signal device will trigger alarms (visual or audible) to alert the operational staff.

Closing Bus (HM): The closing bus connects to the closing coil circuit of the electromagnetic operating mechanism of the circuit breaker. When a breaker is closed, the system experiences a large impact current. Historically, the control bus was set at 220V, and the closing bus at 240V due to voltage drops when closing the breaker. However, with the advent of spring operating mechanisms that reduce the closing current, this distinction is no longer necessary. The closing bus continues to store energy for the spring mechanism, and many modern DC panels combine both buses into one.

EVEREXCEED DC Power Supply System: The EVEREXCEED DC Power Supply System provides reliable and efficient DC power by transforming and rectifying AC power, storing it in the battery bank, and distributing it to the necessary components. This system supports multiple vital functions, including:

Switch Cabinet Operation: Providing DC power for switch opening and closing.

Measurement and Instrumentation: Powering instruments and meters within the system.

Relay Protection and Fault Lighting: Ensuring safety with backup protection and fault signaling.

Key Features of the EVEREXCEED DC Power Supply System:

1.Large LCD Display for Easy Operation:The system features a large LCD screen that simplifies operations with an intuitive user interface. For added convenience, an optional touch screen supports 8 language selections, making maintenance and operation easier for operators from diverse backgrounds. The system also supports intelligent communication and remote monitoring for enhanced operational control.

2.Leading Technology for Superior Performance: The embedded microcomputer controller processes signals 10 times faster than traditional analog methods, ensuring rapid and efficient system response. This cutting-edge technology increases the overall reliability and responsiveness of the substation DC system.

3.High Reliability and Increased MTBF (Mean Time Between Failures):The system is designed with "Four Remote" capabilities—remote monitoring, remote control, remote diagnostics, and remote maintenance. This allows for unattended operation, making it ideal for remote or unmanned substation applications. Furthermore, the system features fully automatic battery management, optimizing performance and extending the lifespan of the battery bank.

4.Flexible Maintenance and Reduced MTTR (Mean Time to Repair):The system is designed for easy maintenance, with modular components that can be quickly replaced or serviced from the front panel. It supports multiple charging modes (constant voltage and constant current), and features intelligent communication through RS232, RS485, and Ethernet, allowing for remote diagnostics, data recording, and seamless integration into the substation's wider monitoring system. This flexibility minimizes downtime and reduces MTTR.

Conclusion: The EVEREXCEED DC Power Supply System offers a highly reliable, efficient, and flexible solution for substations, ensuring the continuous operation of critical DC-powered devices such as protection systems, meters, and relays. With cutting-edge technology, advanced battery management, and intelligent monitoring, this system is designed to meet the demanding requirements of modern substations, offering peace of mind to operators by ensuring seamless, stable, and safe operations.