1 Composition of communication power supply system
Power supply is an important part of communication system. A complete communication power supply system consists of five parts: AC power distribution unit, rectifier module, DC power distribution unit, battery pack and monitoring system.
2 Basic requirements and characteristics of communication power supply system
The basic requirements of communication power supply system are reliability and stability. Generally speaking, the impact of communication equipment failure is small and local, but if the communication power supply system fails, the communication system will be completely interrupted. Therefore, the power supply system should have spare equipment, spare parts for power supply equipment, two or more inputs for commercial power, and alternate current and DC for each other. China's requirements for communication power supply are: perfect lightning protection measures, wide fluctuation range of AC input voltage allowed by equipment, and multiple backup systems to prevent power system from completely interrupting power supply. Because the distribution of power grid and the conditions of using commercial power are very different, the commercial power voltage fluctuates greatly in many places. Especially in some substations, microwave stations, optical communication stations and modular stations, sometimes the fluctuation range of AC voltage reaches more than 30%. In order to improve the availability of commercial power, the power supply equipment is required to have a wider working voltage range, otherwise the voltage stabilizing device will be added.
3 Management of communication power supply
3. 1 Pay more attention to power equipment
Power supply equipment is very different from other equipment (such as switching and transmission) in communication network. In essence, power supply equipment is electromechanical equipment rather than communication equipment. Because of this, it has not been paid enough attention to in communication, and there is no guarantee in organization, personnel, funds and management. However, it must be noted that communication power supply, as the energy guarantee of the whole communication and telecommunication network, plays an indispensable overall role. Although it is not the mainstream equipment in the communication network, it is the most important and critical equipment in the communication network.
3.2 Strengthen the specialization of electric power management
For communication power supply, there should be independent professional power supply management institutions and personnel at all levels to manage, build and maintain communication networks. Because communication power supply is a specialty and contains many systems and disciplines, it should be managed accordingly. It is not enough and unscientific for other professionals to be responsible for power supply.
3.3 Pay attention to the preliminary design and installation of communication power supply system.
When designing the power supply system, we should fully consider the capacity, geographical location, spatial layout, future development, equipment quality, engineering survey and design, operation mode selection, construction management, operation and maintenance management and other links. Especially in the aspects of equipment selection, scheme design and project management, we should pay more attention to and manage it.
3.4 Specific measures for procurement and maintenance of power supply equipment
1) In the process of purchasing communication power supply, besides cost performance, we should also consider high reliability, multiple automatic protection functions, wide voltage range, good current sharing and balancing performance, online operation mode, whether the production is strictly organized according to ISO-9000 quality assurance system, system failure rate, lightning protection and surge measures, AC -DC power distribution integration, etc. All of these should be the focus of analysis and consideration. To choose highly reliable equipment, reasonably configure backup equipment.
2) Decentralized power supply should be vigorously promoted, with spare parts, communication equipment with the same DC voltage and more than two independent power supply systems. This can ensure that when one power supply device fails, the other power supply device can be eliminated in time.
3) In order to shorten the average repair time of equipment as much as possible, it is necessary to analyze the operation parameters frequently, predict the occurrence of faults and eliminate them in time.
4) The equipment shall be modular and hot-swappable, which is convenient for replacement and maintenance. The other is to establish emergency measures to ensure reliable power supply. Finally, it is necessary to improve the technical level and vigorously promote the centralized maintenance system.
Implementing centralized monitoring management is the inevitable trend of technology development, the need of modern communication network and one of the measures for enterprises to reduce staff and increase efficiency. With the increasing integration and miniaturization of communication equipment, all kinds of power supply equipment should be intelligent and standardized, in line with open communication protocols. Centralized monitoring must be implemented step by step. In the process of implementation, the equipment of three remote points (remote communication, telemetry and remote control) should be reasonable, and the more the better, otherwise the effect will be counterproductive.
4. Strengthen battery maintenance
Communication power supply covers a wide range, including at least AC high voltage, self-provided diesel generator, UPS rectifier, battery pack, lightning protection and grounding, power environment monitoring, etc. Among these systems, DC system and USP are the most important because they directly provide the communication load. In these systems, battery, as the guarantee of uninterrupted power supply, is the most critical in the whole power supply system. The battery can not only ensure uninterrupted power supply when there is a problem in the AC system or rectifier, but also provide protection when the mains electricity and the self-provided diesel generator switch normally. Therefore, the battery is the key to the maintenance of the whole communication power supply system.
In the daily maintenance of communication power supply system, the maintenance, testing, diagnosis and treatment of batteries are very complicated and must be very detailed. Maintenance-free sealed batteries are widely used in communication systems, and their daily maintenance is much simpler. Battery maintenance items are as follows:
The battery is fully charged when it leaves the factory, and some capacity will be lost due to self-discharge during transportation or storage, so it should be charged and discharged before use to supplement the electrical parameters. When handling the battery, please hold the bottom of the battery and do not apply any force to the terminal. Never open the exhaust valve; There is no need to check the liquid level and add water before using the valve-regulated lead-acid maintenance-free battery. Don't put the battery near objects that generate sparks or in a sealed place. Maintenance-free lead-acid batteries can be placed horizontally or vertically, but they should be used vertically under frequent vibration. The connection between adjacent batteries can be closer, but the distance between columns should be kept at about 10mm for better heat dissipation when multiple columns are used side by side. After connection, cover each wire with an insulating cover and tighten it; If you don't use it immediately after charging, you should try to avoid placing it in a high temperature environment. The higher the temperature, the greater the self-discharge. After long-term storage, sometimes the capacity can not be fully recovered without several charge and discharge cycles; When discharging, the ambient temperature should be controlled within the range of-15 ~+45℃; The best charging and discharging voltage accuracy is within 2%; Whether the battery is used or not, it should be charged and discharged regularly (3 months or 6 months); Use a damp cloth when cleaning the battery. Dry cloth or chemical fiber cloth may crack the battery case, causing liquid leakage or corrosion and fire. Wear protective articles such as rubber gloves and rubber shoes during inspection and maintenance; If the battery capacity drops below 60% of the rated capacity, it can be regarded as the end of life; When used on converters such as USP, capacitors should be installed to prevent the return current of the converter from flowing into the battery.
5 Lightning protection of communication power supply system
The management of communication power supply also includes the management measures of introducing current and voltage from outside. Touching the power line and lightning strike are the main ways to introduce strong current and voltage.
5. 1 lightning damage
The strong current and high voltage generated by lightning strike will cause great harm to human body and equipment. Both direct lightning and indirect lightning will do great harm to communication equipment. Lightning protection is a systematic project. Adopting some effective technologies and equipment can only reduce the probability of lightning damage and destruction. All incoming and outgoing cables and wires must be shielded and lightning-protected, and a perfect grounding system should be adopted, which should be grounded in strict accordance with the requirements of the specification, so as to reduce lightning damage.
5.2 Lightning protection grounding
In order to prevent overvoltage and overcurrent caused by lightning from damaging power supply equipment, in communication power supply system, communication stations are generally equipped with lightning protection grounding devices, and the grounding resistance is ≤ 5 Ω. In places with low soil resistivity, the grounding resistance should be ≤1Ω. In communication power supply system, lightning protection grounding wire must be separated from working grounding and protective grounding wire, while in power communication power supply system, lightning protection grounding, working grounding and protective grounding all require a set of grounding wire.
At present, various lightning protection and grounding technologies have been developed, which are important technologies to ensure the reliability of communication networks and important basic technologies in the communication field. Common grounding system, lightning protection system for incoming and outgoing lines and various safety devices are effective methods widely used at present. Do a good job in lightning protection of communication equipment, and at the same time, use lightning rod, lightning belt, lightning wire, lightning protection network and other equipment with mature theory and practice to induce lightning current to enter the earth through grounding wire. Facts have proved that sharing grounding system and lightning protection system for incoming and outgoing lines can greatly reduce the probability of lightning damage.
For the purpose of grounding, especially outdoor equipment grounding, leakage prevention and lightning protection are particularly important. The requirements for its grounding resistance shall be implemented in accordance with the provisions of technical specifications. In order to ensure that the grounding resistance meets the specification requirements, it is very necessary to check and test the grounding resistance after construction. It is a necessary system to test grounding resistance and check grounding device system regularly or irregularly.
6 concluding remarks
To sum up, in the composition of communication network, power supply is its "blood" and is a necessary condition to ensure smooth communication. Only by paying enough attention subjectively, creating a good objective operating environment, realizing professional and institutionalized management, advanced equipment technology and modern operation and maintenance can we ensure the safe operation of communication power supply system and communication management system and ensure the reliable and smooth communication.