Low-Temperature Resistance Solution for Power Supply Systems at Lithuanian Telecom Sites

Ensuring reliable operation of telecom power systems in cold climates requires a combination of battery selection, thermal management, and adherence to ITU-T L.1240 standards.

Battery and Power Supply Considerations

For low-temperature environments, 48 V Li-ion LiFePO4 metal-cased batteries are recommended due to their superior cold-weather performance, long cycle life, and high energy density. These batteries should be equipped with Battery Management Systems (BMS) that monitor charge/discharge rates, temperature, and state-of-health to prevent capacity loss below 80% after six years of operation (as per ITU-T L.1240) . Redundant battery strings (up to 32 in parallel) and thermal-diffusion containment help maintain reliability during extreme cold.

Thermal Management and Cooling

Telecom power systems generate heat even in low ambient temperatures, and proactive thermal management is essential. Options include:

• Air cooling: Simple and cost-effective for moderate-density cabinets, but may be insufficient for high-power modules .
• Liquid cooling: Immersion or direct-to-chip cold plate cooling can reduce energy use by up to 75% and support higher power densities, ensuring stable operation even in compact cabinets .
• Phase-change heat sinks: Useful for high-power electronics like IGBTs or SiC modules, maintaining optimal temperature without excessive energy consumption .

System Redundancy and Safety

To maintain low-temperature resistance and operational reliability:

• Dual-channel power supply and redundant transformers for higher-class sites.
• Automatic standby switching and interlocks to prevent downtime.
• Insulation monitoring for DC buses and routine checks to detect degradation.
• Temperature-controlled transformers with oil monitoring to prevent cold-induced failures .

Energy Storage Integration

Lithuania has successfully integrated battery storage systems at telecom and grid sites to stabilize power supply and provide ultra-fast response (<200 ms) during fluctuations . These systems can complement telecom power systems by:

• Providing emergency backup during extreme cold.
• Supporting voltage regulation and frequency control.
• Reducing dependency on external AC mains during outages.

Compliance and Monitoring

Adhering to ITU-T L.1240 ensures systematic evaluation of power-supply reliability, including:

• AC mains and medium-voltage distribution assessment.
• Low-voltage distribution and reactive compensation.
• EMC compliance and integrated fire-extinguishing systems.
• Continuous monitoring with alarms for temperature spikes or airflow blockages .

Practical Recommendations

1. Use LiFePO4 batteries with integrated BMS and thermal containment.
2. Implement liquid or phase-change cooling for high-density power modules.
3. Ensure redundancy in transformers and power channels.
4. Monitor temperature and system health continuously with sensors and alarms.
5. Follow ITU-T L.1240 evaluation framework for systematic reliability assessment. By combining these strategies, Lithuanian telecom sites can achieve robust low-temperature resistance, maintain uninterrupted service, and optimize energy efficiency in harsh winter conditions.