Application of the hottest A9800 system in Lishui

2022-07-31
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The application of A9800 system in Lishui mountain area of Zhejiang Province Abstract: the one point multiple access dispatching communication of Lishui power has been running normally since it was opened in 1998, which has greatly improved the lagging situation of Lishui power dispatching communication. Engineering practice has proved that this is an advanced, reliable and economic group scheme for power dispatching communication in mountainous areas with complex terrain. It is not only applicable to mountainous areas in southern Zhejiang, but also can be used for reference in Hilly and alpine areas in central and Western China

key words: application of A9800 system of one point multiple access dispatching communication in Mountain Power in Lishui, Zhejiang P {font-size: 12pt; font-family: "Song Ti"}p {margin top: 0px; margin bottom: 0px; text-index: 24pt; line-height: 200%} 1 according to the characteristics of Lishui area, such as complex terrain, wide coverage area and scattered stations, The digital one point multiple access microwave communication project of Lishui electric power bureau adopts two sets of A9800 one point multiple access communication systems manufactured by French albote group to construct the full digital backbone communication covering the main substations, power plants and nine county and municipal bureaus in Lishui area, so as to solve the channel problems required for automation and administrative communication due to the huge market demand for regional power dispatching. In areas where the backbone is difficult to cover, spread spectrum microwave is used as the backbone extension. The project is divided into two phases. The first phase covers 7 stations in 4 counties and cities in the northern region, and the second phase covers 9 stations in 4 counties and cities in the southern region. The two central station switch interface units (Xbs) of phase I and phase II projects are set in the communication room of Lishui Electric Power Bureau. All circuits are connected to the dispatching center through Xbs and connected to the dispatching desk or administrative switch. Through the OMS system connected with Xbs, maintenance personnel can monitor the operation of all equipment at any time, which is only an additional condition for the new national standard to detect the combustion performance of thermal insulation materials. The wireless central station (RSC) of phase I project is set in the original microwave room in Chenliao mountain by taking advantage of the features that the wireless central station of A9800 system can be put into use. In this way, the original machine room facilities of Chenliao mountain can be used, and the height of Chenliao mountain can be used to extend the system northward, westward and eastward, and cover the northern area of Lishui. The existing Harris microwave connection is used between RSC and Xbs. The substations near Lishui City are covered by the RSC on Chenliao mountain and the relay station (RSN) on Nanming mountain, and the stations in Jinyun County are covered by the RSN on Gugu mountain; Songyang bureau is covered by RSN on Dazhong mountain; Suichang Bureau, Jinxi substation and Gushi substation are covered by the one point multiple address relay station on Baima Mountain through microwave. The RSC of phase II project is set at 409 microwave station to cover the southern area of Lishui. The original 2m channel is also used to connect it with Xbs in Lishui Power Bureau. 2. Link indicators and capacity requirements since the one point multiple access microwave communication network will be used as the backbone communication of power dispatching in Lishui area after it is completed, strict requirements are put forward for the indicators of communication links in the planning stage. Refer to ccittg 821 document, and referring to the corresponding indicators of the same type of one point multiple access communication system, under the influence of fading, interference and other deterioration factors, the bit error rate (BER) performance indicators of each 64K rate channel of the system shall meet the following requirements: (1) the average bit error rate in one second shall not be greater than 1e-6 in any month of more than 1.5%; (2) The average bit error rate per second shall not be greater than 1e-3 in any month with a time of more than 0.015%; (3) The cumulative time of error code seconds in any month shall not be greater than 1.2% of the whole month. Under the condition that the above conditions are met, with reference to CCIR and CCITT recommendations, the system is a user level circuit availability recommendation, which assumes that the annual availability index of the digital channel is 99.8%. 3. The user interface users share the voice channel of the system in the way of on-demand distribution to improve the channel utilization of the system. The data users are allocated a fixed channel by the system in the way of pre distribution to transmit normal data. In the spread spectrum microwave transmission section, the voice and data share the same fixed channel for transmission by using the multiplexing technology. See Figure 1 for the interface of digital one point multiple access communication system: Figure 1 for the interface of one point multiple access communication system, see Figure 2 for the spread spectrum microwave interface at the end of the interface; Figure 2 for the stable growth of spread spectrum microwave interface, the imported interface system provides rich communication interfaces, The original communication terminal equipment can be easily connected to the unified digital communication. To solve this problem, it is necessary to ensure that the product has a sufficiently high alternating structure. For the terminal equipment with data interface, the system provides V.24, V.28 (RS-232), v.11, V.35 and other data adapters through RTU to directly connect to the one point multiple access digital communication. However, for the old telecontrol equipment with more operation on the, since it does not have a digital interface, we use 4we/m interface to establish a direct analog channel for transmission. For administrative, dispatching and other voice users, the system adopts 2W voice interface or 4we/m interface to flexibly realize common, direct access for dispatching and interconnection of branch exchanges. The traditional one point multiple access microwave communication system with special antenna feeder structure generally uses omni-directional antenna as the signal transceiver in the central station. This configuration is more suitable for use in areas where peripheral stations are concentrated and close to the central station. However, Lishui has a special geographical shape. The East-West span of stations covered in phase I is very large. At the same time, there are a large number of stations near the central station that need access. To meet this special requirement, we have designed a special antenna feeder structure in chenliaoshan central station and Dazhongshan repeater station, which greatly expands the adaptability of one point multiple access equipment in complex terrain. Conclusion since the one point multiple access dispatching communication of Lishui hydropower station was opened in 1998, it has been running normally, which has greatly improved the lagging situation of Lishui hydropower dispatching communication. Engineering practice has proved that this is an advanced, reliable and economic group scheme for power dispatching communication in mountainous areas with complex terrain. It is not only applicable to mountainous areas in southern Zhejiang, but also can be used for reference in Hilly and alpine areas in central and Western China

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