Abstract
Given the importance of reliable operation of metro communication power systems for overall metro operation, this article examines the significance and effective measures for safety control of these systems. It summarizes the importance of safety control, describes the main system components, and proposes improvement measures for current operations, including implementing uninterrupted UPS power, increasing energy storage devices, and strengthening safety management.
Overview
The metro communication power system is one of the key electromechanical subsystems that ensures uninterrupted communication. It is primarily responsible for energy transmission and supplies power to motors. There are two main supply modes: DC and AC. DC supply commonly uses DC high-frequency switching power supplies and batteries, introduced from AC distribution panels and output as DC to feed communication equipment. AC supply typically involves uninterruptible power supply (UPS) equipment and AC distribution cabinets, generally arranged as independent main and backup three-phase five-wire circuits; the main circuit handles normal supply and switches to the backup circuit on fault.
Significance of Safety Control
The metro communication power system supplies power to communication equipment at operation centers and underpins safe metro operation. The communication system is the data source for online monitoring and diagnostics of the control system. Power system faults that degrade control system performance can seriously impair overall metro operation. If the power system fails to supply properly, consequences range from communication disruption and data loss to loss of control at the operations center and system-wide paralysis. Therefore, safety control of the communication power system is critical for both communication continuity and operational safety.
Current power supply issues include:
- Insufficient independence of the communication power supply;
- Inadequate capacity of power energy storage equipment;
- Insufficient protection measures and low supply security level.
These problems undermine the stability, reliability, and safety of the communication power system. Personnel responsible for the system should implement necessary measures to improve safety management and reduce the risk of incidents.
System Components and Safety Controls
The metro communication power system comprises DC high-frequency switching power supplies, UPS units, batteries, and monitoring systems. Effective monitoring of each component is the core of safety control. The main elements are described below.
1. DC high-frequency switching power supply
The DC high-frequency switching power supply consists of rectifiers, monitoring equipment, and DC distribution modules. Under normal operation, the rectifier both supplies the load and charges the batteries. When AC supply is unavailable, batteries continue to power communication equipment. Modern high-performance, high-efficiency high-frequency switching supplies are compact, have strong interference immunity, fast response, high stability, and robust protection functions.
2. UPS
UPS units are core components of the metro communication power system. Static online UPS architectures are commonly used, composed of rectifiers, static switches, and batteries. The UPS provides AC 380 V to the communication AC distribution panel, which distributes 220 V to communication equipment and downstream branches. The UPS stabilizes voltage transients, compensates undervoltage, and protects battery life. Battery reliability is critical: surveys indicate that more than 45% of UPS failures are caused by battery faults.
Insufficient UPS backup capacity is a common cause of unstable supply: if normal supply fails and backup cannot engage, larger safety hazards may follow. The internal structure of the communication power system is complex, and small operational errors can disrupt communication or cause major incidents.
3. Batteries
Most batteries in metro communication power systems are maintenance-free valve-regulated sealed lead-acid batteries. Battery faults are a frequent root cause of system incidents, so timely inspection of battery condition is essential to ensure capacity and service life.
Safety Control Methods
To maintain safe and reliable operation of the communication power system, the following improvement measures are recommended.
1. Implement uninterrupted UPS power
A UPS is a power protection device with energy storage that ensures uninterrupted power when other supply sources fail. Modern UPS units typically feature:
- High reliability through advanced control and comprehensive protection;
- Wide input voltage and frequency range to extend battery life;
- Automatic emergency start so that battery packs can directly start UPS backup power when normal supply is unavailable;
- Intelligent control systems with automatic monitoring and remote management capabilities;
- Strong electromagnetic interference immunity and minimized harmonic distortion on the grid.
These capabilities give staff sufficient time to address outages, short circuits, or overloads and provide comprehensive protection for loads.
2. Increase energy storage devices
Energy storage devices act as electrochemical elements providing reliable backup power. They offer high power density and are often deployed as system backup sources without causing environmental pollution. Increasing the number of energy storage units proportionally to communication power demand helps ensure safe, efficient operation and facilitates system expansion when business demand grows.
3. Strengthen safety management
Safety control requires both higher automation/intelligence of power equipment and improved management mechanisms. Establish regular inspections and random checks of system equipment and enhance staff procedures. Implement scientifically designed maintenance schedules so that any detected issues are addressed promptly with emergency measures to prevent escalation. Regularly check grounding resistance to prevent looseness or corrosion that could affect supply safety.
Overall, the communication power system contains many components and complex risk factors, so improvement measures must address multiple areas.
Conclusion
This article offers a concise discussion of the significance of safety control for metro communication power systems and possible improvement measures. Building a scientifically designed, highly intelligent communication power system requires further research. Strengthened management, early detection, root-cause analysis of problems, and targeted corrective actions are essential to ensure that the communication power system fulfills its role in safe metro operation.
