Maintenance points for power supply equipment of mobile communication base stations

The base station power system is one of the supporting systems for mobile main equipment and transmission equipment, involving a variety of professional knowledge such as power mechanics, chemistry, electronics, communication and automatic control technology, computer application, etc. The purpose of its maintenance work is to ensure that communication equipment obtains continuous, stable and reliable energy, provide a normal operating environment for communication equipment, and ensure the safety of the system. To this end, maintenance personnel need to have certain professional skills.

There are many types of power supply equipment, which are greatly affected by external factors. If the maintenance is not effective, the overall failure rate of the equipment will be very high, the power environment monitoring system will lose its effectiveness, the operating cost will be high, and the base station will have a large number of unsafe factors. In order to reduce operating costs and prevent the early scrapping of battery packs, this paper analyzes the base station environment and the focus of power supply maintenance, and proposes solutions.

1. Base station mains power environment factors

In the entire communications industry, the environment of mobile communication base stations is relatively complex. The construction of the mains power supply is subject to the environmental conditions of the base station, and the construction configuration requirements and maintenance requirements are different. For example, many base stations are built on high buildings or mountains. Objectively speaking, the mains power environment of base stations is mostly not as high as that of exchange offices, but the quality requirements for batteries are relatively high, which adds many difficulties to the configuration, maintenance and management of battery packs. If the maintenance is not done properly, it will cause the battery pack to fail early.

(1) High-rise base station

This type of base station is located in the city, and the power supply is generally stable. The two major factors that affect the long power outage time are: when the city's energy is relatively tight, the power supply department will increase the load on the city. This problem usually occurs in summer, when the user's telephone is low and the city power failure occurs. In this case, the owner does not have his own oil generator, and the failure time generally does not exceed 24 hours. For this type of problem, measures to limit the DC load should be taken in conjunction with the power environment monitoring system to prevent the battery group from over-discharging, and the battery maintenance and charging should be strengthened afterwards.

(2) High mountain base station

Refers to rural hill base stations far away from the city. Such base stations use agricultural electricity and have high requirements for city electricity construction. The author believes that the construction of such base stations should use a higher city electricity introduction method according to local conditions and safety conditions. If conditions permit, it is best to use 10kV high-voltage city electricity introduction. In rural power supply, high-voltage city electricity introduction is more stable than 380V city electricity introduction and is less affected by human factors. If possible, an automatic generator set can be configured to realize AC power supply automation. The base station is located in a rural hill. Since it is inconvenient to connect the mobile oil engine to power generation, the base station is equipped with an automatic generator set. Due to the problem of city electricity, over-discharge occurs. In addition, with the cooperation of the power environment monitoring system, system problems can be handled in time. In this way, the introduction of external city electricity is stable and reliable to ensure smooth communication.

(3) General base station

Regardless of the base station, the construction of mains power supply should be emphasized. The mains power supply of any base station will go through a process from construction to maintenance, and then further optimization and improvement according to the local mains power conditions, to ensure that when the mains power is blocked, the fixed oil generator or mobile oil generator can be reliably connected to charge the battery pack. Therefore, the mobile oil generator power generation access should establish a "mobile oil generator power generation system" to ensure that with the cooperation of the power environment monitoring system, it can be operated immediately, reliably and safely, and the battery maintenance is done well.

2. Battery Maintenance

Battery maintenance is the focus of the entire power supply maintenance work, and all power supply maintenance revolves around this work. Generally speaking, the key to the maintenance of valve-regulated lead-acid batteries lies in controlling the temperature of the environment and the charging and discharging of the battery. Therefore, controlling the charging and discharging of the battery is an important part of battery maintenance. Battery charging is divided into floating charging and balanced charging. The so-called floating charging means that when the mains power is normal, the battery and the switching power supply are connected in parallel, and the output voltage of the switching power supply meets the requirements of the battery manufacturer, generally 2.23V/battery, which is used to meet the needs of battery self-discharge and oxygen circulation. From the definition, it can be seen that the floating charge voltage can only meet the needs of battery self-discharge and oxygen circulation, and cannot be used as supplementary charging after the battery is discharged. The supplementary charging of the battery is completed by the balanced charging of the switching power supply. During balanced charging, the charging voltage is increased to 2.35-2.40V, and the battery is charged with a current of ≤0.10C10A. The control of the charging process is achieved by the setting of the switching power supply and the intelligent control of the switching power supply. In daily maintenance, the power environment monitoring system can be used to regularly check it to prevent changes in rectifier equipment parameters and avoid damage to the battery.

1. Battery selection and configuration

Improper use of batteries will directly affect the battery's future operating performance and service life. In particular, base station batteries are greatly affected by the mains electricity, so more attention should be paid to their selection skills. When selecting base station batteries, three factors should be considered: load nature and load size, room load requirements, and basic battery support time.

(1) Load nature and load size: including the power consumption of the main equipment, the power consumption of the transmission equipment and the power consumption of the monitoring equipment.

(2) Equipment room load requirement: The load of the building after treatment. For safety reasons, the load of the building must not exceed the building load after all equipment is installed.

(3) Basic battery support time: This mainly refers to the emergency response time after a fault occurs in the AC power supply equipment. The support time is usually determined based on the city power conditions and is generally 8 to 10 hours.

The power requirements of the main equipment of the base station are not as high as those of the switching equipment. The interruption of the base station power supply will not cause data loss and cannot be restored, and there is no need to use two sets of batteries in parallel. After long-term use and observation, in the base station mains power environment, two sets of batteries in parallel are not conducive to the long-term use of batteries under harsh conditions, because the two sets of batteries are completely in two different chemical sets. Affected by factors such as battery connection and nut tightening, it is not easy to keep the internal resistance of the two sets of power consistent. After a period of operation, the internal resistance of the battery changes, causing individual batteries to become lagging batteries due to long-term lack of supplementary charging, thereby making the probability of battery capacity damage higher than when a set of batteries is used alone. The author believes that it is better to configure a set of base station batteries.

Pre-inspection and pre-repair

The occurrence of any equipment failure has a process from accumulation (the increase of unsafe factors exceeds the allowable limit of the equipment) to concentrated outbreak. Only by further understanding the impact of environmental factors on it and taking proactive preventive measures can we take the initiative in maintenance work.

Three major factors that affect the normal operation of power supply equipment: the impact of seasonal changes on power supply; the impact of human factors on the power supply system; and equipment aging.

(1) The impact of seasonal changes on power supply: After winter, the weather is rainy and foggy, and the insulation of outdoor lines is reduced. Therefore, the increase in heating appliances is a period of frequent power failures. In addition, the humidity is high in midsummer, and the insulation is relatively low. Therefore, the large-scale increase in refrigeration appliances is a period of frequent power failures. In order to prevent major accidents and eliminate potential accidents, safety inspections should be strengthened, and the inspection points should be the mains power supply lines, power distribution equipment, and air conditioning units.

(2) The impact of human factors on the power supply system: For rural public transformers connected to 380V or 220V power supply, major faults caused by the mismatch of the live and neutral wires should be prevented.

(3) Equipment aging: This type of failure is mostly caused by aging of cable lines.

3. Pay attention to the construction and maintenance of the power environment monitoring system of power auxiliary equipment

The base station power environment monitoring system is an important remote online testing tool to ensure the normal operation of mobile supporting equipment under unattended conditions. It is the basic network for supporting equipment maintenance. Therefore, strengthening the maintenance and management of the base station power environment monitoring system is the basis for ensuring the stable and reliable operation of the remote power system. The focus of the base station power environment monitoring system maintenance work is to prevent system false alarms, improve system stability, and complete system measurement functions. The basic tasks are:

(1) Ensure the smooth operation of the base station power environment monitoring system, regularly clean up and transfer important information, and prevent virus attacks.

(2) Ensure that the electrical detection performance, equipment control performance, system alarm performance, important maintenance technical indicators, and network indicators of the base station power environment monitoring system's supporting equipment meet the standards.

(3) Rationally adjust the system network to ensure safe operation of the system, improve equipment utilization, extend the use time of system equipment, and maximize its efficiency.

(4) Troubleshoot quickly and accurately to avoid the impact of system failures on supporting equipment and losses caused by delayed equipment maintenance.

(5) Adopt new technologies, optimize system configuration, improve maintenance methods, and improve work efficiency.

(6) Properly preserve technical information, including project completion information including system line configuration diagram, intelligent device communication protocol text (provided by the equipment manufacturer), protocol development completion document and equipment configuration list.

(7) In principle, the expansion and upgrading of the monitoring system shall not affect the normal operation of the system. If there is an impact on the system, the affected parts, processing time limit and processing plan must be stated before the expansion and upgrading, and it can only be implemented after approval by the relevant management department.

(8) After the monitoring system is opened for interactive use, the base station monitoring system and the county return monitoring system shall not be interrupted arbitrarily. If the interruption time exceeds 24 hours, it will be treated as a major fault.