Communication rooms, as the core hub of communication networks, carry critical businesses such as signal transmission, data storage, and equipment control. The power supply system is the lifeline of communication rooms, requiring 24/7 continuous, stable, and reliable power support. UPS (Uninterruptible Power Supply) and DC power supply are two core power protection devices in communication rooms: UPS focuses on ensuring uninterrupted power for AC loads (such as servers, monitoring hosts), while DC power supply (including rectifier modules, DC distribution screens, and battery packs) is mainly responsible for powering core DC loads (such as base station transceivers, transmission equipment). The coordination scheme of UPS and DC power supply integrates the advantages of both, constructs a "dual protection" power supply system, and solves the problems of single power supply risk, load mismatch, and low energy efficiency in traditional independent operation modes. Based on national standards such as GB/T 3797—2005 and industry specifications such as YD/T 585—2010, this article elaborates on the coordination architecture, working modes, technical key points, and application cases of UPS and DC power supply, providing a standardized solution for communication room power supply system optimization.
Note: The following coordination scheme is applicable to medium and large communication rooms (including operator core rooms, financial disaster recovery rooms, and enterprise communication hubs), supporting AC/DC hybrid load scenarios. The scheme design must comply with the technical requirements of power distribution equipment and electrical control devices, and be implemented by professional electrical engineers.
1. Coordination Architecture of UPS and DC Power Supply
The coordination architecture of UPS and DC power supply adopts a "three-layer integration" design (equipment layer, control layer, and distribution layer), realizing seamless connection and intelligent collaboration between the two systems. The architecture takes DC power supply as the core of stable power supply, UPS as the backup guarantee for AC loads, and relies on intelligent control modules to achieve unified scheduling and fault linkage.
1.1 Equipment Layer: Core Component Configuration
DC Power Supply System: Composed of rectifier modules, 240V DC total distribution screens, battery packs, and battery management systems (BMS). The DC total distribution screen serves as the hub of the DC power supply loop, connecting rectifier modules and battery packs through DC busbars, and distributing power to secondary distribution screens or power column cabinets <superscript>1. The rated voltage range of the system is 192~288V, and the input total rated current can be selected from 400A, 800A, 1200A, etc., according to the load capacity. The battery pack adopts lithium iron phosphate batteries with a cycle life of more than 3000 times, ensuring continuous power supply for 8~12 hours under full load.
UPS System: Select high-frequency online UPS with dual-conversion function, adopting modular design (N+1 redundancy configuration). The UPS input power factor is ≥0.99, the output voltage accuracy is ±1%, and the ripple coefficient is ≤0.5%, which can effectively reduce harmonic interference to the power grid. The UPS is connected to the DC busbar of the DC power supply system through an inverter interface, realizing mutual backup of power sources.
Auxiliary Equipment: Including static switches (zero-switching time ≤10ms), intelligent monitoring hosts, and voltage/current sensors. The static switch realizes seamless switching between UPS and DC power supply, while the monitoring host collects operating parameters of both systems in real time.
1.2 Control Layer: Intelligent Collaboration Mechanism
The control layer adopts DSP digital control technology and RS485 communication protocol to build a unified intelligent scheduling platform, realizing three core functions:
Data Synchronization: Real-time collection of operating parameters such as UPS output voltage/current, DC busbar voltage, battery SOC (State of Charge), and load status, ensuring data consistency between the two systems.
Automatic Scheduling: According to the power supply status (mains normal/interrupted) and load changes, dynamically adjust the power supply ratio of UPS and DC power supply to optimize energy efficiency.
Fault Linkage: When either system fails, immediately send a fault signal to the other system, triggering automatic switching and backup mechanisms to avoid load power interruption.
1.3 Distribution Layer: Unified Power Distribution Network
Construct a mixed power distribution network integrating AC and DC, with clear load division: DC power supply directly supplies power to core DC loads (such as communication transceivers, optical transmission equipment) through the DC distribution screen; UPS supplies power to AC loads (such as servers, air conditioners, monitoring equipment) through the AC distribution unit. The DC busbar in the distribution layer adopts insulated busbars with color distinction (brown for positive pole, blue for negative pole), and all distribution loops are equipped with overcurrent and short-circuit protection devices (fuses or DC circuit breakers) to ensure safe operation <superscript>1.
2. Core Working Modes of Coordinated Operation
The coordinated system of UPS and DC power supply has four typical working modes, which can be automatically switched according to the mains status, equipment operation, and load changes, ensuring continuous power supply for communication room loads.
2.1 Normal Mains Mode (Dual System Parallel Operation)
When the mains is stable, the UPS and DC power supply operate in parallel, each responsible for their respective loads: the rectifier module of the DC power supply converts the mains into stable 240V DC power, supplying power to DC loads and charging the battery pack; the UPS rectifies the mains into DC power, inverts it into standard AC power (220V/380V, 50Hz) to supply power to AC loads, and the built-in battery is in a floating charge state. The intelligent platform monitors the load rate of both systems in real time, and adjusts the power distribution to keep the load rate of each system between 50%~80%, optimizing energy efficiency.
2.2 Mains Interruption Mode (Battery Backup Coordination)
When the mains is interrupted, the system immediately switches to battery backup mode, and the UPS and DC power supply realize coordinated power supply through the DC busbar: the DC battery pack supplies power to DC loads through the distribution screen, and at the same time supplies power to the UPS inverter through the DC busbar; the UPS inverts the DC power into AC power to continue supplying power to AC loads. This mode realizes the sharing of battery energy, avoids the waste of independent battery configurations, and extends the overall backup time by 30%~50% compared with independent operation.
2.3 Single System Fault Mode (Mutual Backup Switching)
DC Power Supply Fault: When the DC power supply fails (such as rectifier module damage, battery undervoltage), the UPS immediately switches the inverter to the extended supply mode, supplying stable DC power to critical DC loads through the DC busbar while maintaining AC load power supply. The fault recovery time is ≤10ms, ensuring no impact on core business.
UPS Fault: When the UPS fails (such as inverter failure, overload), the static switch automatically switches AC loads to the bypass power supply (mains normal) or the DC power supply inverted bypass (mains interrupted). The DC power supply maintains stable operation of DC loads, and the AC loads are seamlessly connected to the backup power source, avoiding business interruption.
2.4 Mains Recovery Mode (Smooth Switching and Charging)
When the mains recovers, the system smoothly switches back to normal mains mode: the rectifier module of the DC power supply first resumes operation, charges the battery pack with constant current and constant voltage, and supplies power to DC loads; the UPS rectifier resumes working, switches from battery mode to mains mode, and charges its built-in battery. The switching process is controlled by the intelligent platform to avoid voltage fluctuations and inrush current, ensuring stable operation of the load.
3. Key Technical Points of Coordination Scheme
To ensure the reliability, safety, and efficiency of the coordinated system, the following technical points must be strictly implemented in accordance with national and industry standards.
3.1 Power Matching and Redundancy Design
The rated power of the UPS shall be 1.25~1.5 times the total power of AC loads, to cope with load surge and harmonic current impact<superscript>2. The total capacity of the DC power supply shall be ≥1.2 times the total power of DC loads, and the DC busbar current-carrying capacity shall meet the system total capacity requirements.
Adopt N+1 redundancy configuration for UPS modules and rectifier modules of DC power supply. When a single module fails, the redundant module automatically starts, ensuring no impact on system operation.
3.2 Switching Control and Protection Technology
The static switch between UPS and DC power supply shall adopt zero-switching technology, with a switching time ≤10ms, avoiding power interruption during switching. The bypass of the UPS shall have voltage stabilization function to ensure stable power supply for AC loads during switching <superscript>3.
All distribution loops of the DC power supply shall be equipped with overcurrent and short-circuit protection devices. The positive and negative poles of the loop shall be separately installed with protection devices, and the same brand and series of products shall be selected to ensure selective matching of protection functions <superscript>1.
The system shall integrate multiple protection functions such as overvoltage, undervoltage, overtemperature, and insulation monitoring. The insulation resistance between the DC busbar and ground shall be ≥2MΩ, and an alarm shall be issued immediately when the resistance is lower than the standard.
3.3 Wiring and Cabling Standards
The DC total distribution screen shall adopt top-in and top-out wiring mode, with a rectangular wire inlet of at least 80mm×500mm at the top. The cross-sectional area of the connecting conductor shall meet the design current-carrying capacity requirements, and the maximum voltage drop of the screen shall not exceed 1V under full load <superscript>1.
The wiring of UPS and DC power supply shall be separated by ≥30cm to avoid electromagnetic interference. Shielded cables shall be used for communication wiring between the two systems, and the shielding layer shall be grounded at one end to prevent ground loop interference.
Exposed busbars in the distribution screen shall be protected by insulating layers or jackets, and clear danger warning signs shall be attached. All cables shall comply with the requirements of YD/T 1173—2001 "Flame-Retardant and Fire-Resistant Flexible Cables for Communication Power Supplies".
3.4 Intelligent Monitoring and Management
The unified monitoring platform shall realize real-time monitoring of the operating status of UPS and DC power supply, including voltage, current, temperature, battery SOC, and fault information. The platform supports remote parameter adjustment, fault alarm, and data statistics, and can transmit operating data to the upper-level DCS system through RS232/RS485 interface <superscript>3. For battery management, the BMS shall realize balanced management of battery modules and predictive warning of thermal runaway risks.
4. Typical Application Cases
4.1 Case 1: Operator Core Communication Room
A certain operator's core communication room in North China undertakes the signal transmission business of 5G base stations and fixed-line networks, with a total load of 800kW (DC load 500kW, AC load 300kW). The room adopted the coordination scheme of UPS and DC power supply, configuring a 240V DC power supply system (1200A total distribution screen, 1MWh lithium battery pack) and a 400kVA modular UPS (N+1 redundancy). The DC power supply supplies power to 5G transceivers and transmission equipment, while the UPS supplies power to servers and air conditioners.
After commissioning, the system realized seamless switching between various working modes, and the power supply reliability reached 99.9999%. During a mains outage lasting 6 hours, the coordinated system shared battery energy, ensuring continuous operation of all loads. The overall energy efficiency of the power supply system was improved by 15% compared with the original independent operation mode, and the annual energy saving was about 120,000 kWh.
4.2 Case 2: Financial Disaster Recovery Communication Room
A large bank's disaster recovery communication room has extremely high requirements for power supply stability, requiring zero business interruption during power outages. The room adopted a 2N redundancy coordination scheme: two sets of independent DC power supply systems (800A total distribution screen, 800kWh battery pack) and two sets of 300kVA UPS systems. The two sets of systems operate in parallel, and each system can independently carry the full load of the room.
The system realized mutual backup between UPS and DC power supply, and between dual systems. During a single UPS fault test, the static switch completed switching within 8ms, and the AC load operation was not affected; during a DC power supply module failure, the UPS extended the DC power supply to critical DC loads. The system passed the industry level-4 disaster recovery certification, ensuring the safe operation of core financial businesses.
5. Optimization Strategies and Operation Guarantee
5.1 Optimization Strategies
Energy Efficiency Optimization: Select high-efficiency UPS (full-load efficiency ≥99%) and rectifier modules (efficiency ≥98.5), and adjust the load rate of the system to the optimal range through intelligent scheduling to reduce energy loss.
Space Optimization: Adopt integrated cabinet design for UPS and DC power supply, reducing the occupied space by 30% compared with independent installation. The DC distribution screen adopts a fully enclosed structure, ensuring safe operation and convenient maintenance <superscript>1.
Expansion Optimization: The modular design of UPS and DC power supply supports on-demand expansion. The DC total distribution screen can be connected in parallel with multiple units, and the UPS can expand capacity by adding modules, adapting to the load growth of the communication room.
5.2 Operation and Maintenance Guarantee
Conduct quarterly inspections of the coordinated system, including testing insulation resistance, grounding resistance, and switching function. Clean the distribution screen and UPS cooling system regularly to avoid overheating caused by dust accumulation.
Perform annual full-link joint debugging, simulate mains interruption, single system fault, and other scenarios to verify the reliability of the coordination mechanism and the sensitivity of protection functions.
Establish a battery full-life cycle management system, monitor the battery SOC and cycle life in real time through BMS, and replace aging battery modules in a timely manner when the capacity decays to 80% of the rated capacity.
Conclusion
The coordination scheme of UPS and DC power supply in communication rooms realizes the organic integration of AC and DC power supply systems, breaking through the limitations of traditional independent operation modes. Through scientific coordination architecture, flexible working modes, and strict technical standards, the scheme not only improves the reliability and stability of the power supply system but also optimizes energy efficiency and reduces operation and maintenance costs. With the development of 5G, AI, and big data, the load density and reliability requirements of communication rooms will continue to increase. The coordination scheme will be further upgraded in terms of intelligent scheduling, new energy integration, and safety protection, providing a more solid power guarantee for the high-quality development of communication networks.
