Construction and development of the hottest rural

Construction and development of rural substations

Abstract: most rural substations in southern China use 35/10kv power supply, while most in Northeast China use 63/10kv power supply. According to the current situation of rural substations, the layout is not perfect. Now it is analyzed and discussed from several aspects

key words: 35/10kv power supply 63/10kv power supply substation Untitled Document most rural substations in southern China use 35/10kv power supply, while most in Northeast China use 63/10kv power supply. According to the current situation of rural substations, the layout is not perfect. Now it is analyzed and discussed from several aspects. 1. Current situation and existing problems of rural substations in the past, from the perspective of the main electrical equipment and layout, there are roughly the following two types of rural substations: the first is that the 63kV side of the main transformer of the substation is equipped with oil circuit breakers, current, voltage transformers and other protection and measurement equipment, the 10kV side is equipped with indoor high-voltage switchgear, high-voltage cabinet room and control duty room, and the control room is equipped with control meter screen, relay protection screen, metering screen Signal panel, etc. this kind of substation has relatively complete equipment, perfect protection, relatively high operation reliability, but the cost is also relatively high, the construction period is long, and the floor area and operation and maintenance costs are also relatively large. Therefore, this kind of substation should not be widely promoted and constructed in rural areas. The second type is usually a simple substation. Only high-voltage fuse protection is installed on the 63kV side of the main transformer, and outdoor oil circuit breaker on the column is installed on the 10kV side. There is no control room and high-voltage switchgear room. This kind of substation has less equipment and low cost, but the performance of electrical equipment is poor, and the reliability of power supply is low. For example, the interrupting capacity of oil circuit breaker on the 10kV column is relatively small, which often fails to meet the requirements, and is prone to failure to operate Instead, the film is punched and cut off and attached to the components. This kind of circuit breaker has to be repaired after several trips, which is inconvenient for maintenance. In addition, the ampere second characteristics of the high-voltage fuse on the 63kV side are unstable, and the upper and lower protection can not cooperate well, reducing the protection level. This kind of substation needs to be transformed and improved. 2. The construction and development of rural substations in the future from the current rural power consumption situation in China and the development trend of rural power at home and abroad, the new rural substation should fully reflect the safety, reliability, economy and progressiveness, and its main connection line should be simple, clear, safe and reliable; The equipment layout should be compact and reasonable, easy to maintain, and the equipment with advanced technical performance should be selected, the secondary wiring and devices should be simplified, and the telecontrol facilities should be gradually developed. The suggestions for the construction of substation in the future are as follows: (1) when building the hub substation, consider installing oil circuit breakers, current and voltage transformers and other equipment on the 63kV high-voltage side, and improve the protection and control facilities; 10kV side outgoing circuit breaker selects indoor high-voltage switchgear or outdoor SF6 circuit breaker and vacuum circuit breaker according to the breaking capacity. When there are many 10kV outgoing lines, a single bus section can be set. If there are class I and II important loads, a bypass bus can be installed in order to maintain the circuit breaker without power failure; The DC operation power supply in the substation can adopt maintenance free battery or high-frequency switching power supply, etc. It not only meets the needs of closing capacity, but also provides reliable DC power supply; The protection, control, measurement and signal devices can adopt advanced microcomputer protection devices to replace the traditional control meter screen, relay protection screen and signal screen. At present, the domestic microcomputer control protection and integrated circuit protection centralized control console have the functions of control, protection and signal, and some also have the functions of selective measurement, selective control, public reclosing I, grounding exploration, automatic protection patrol inspection and telecontrol coordination, which can be selected according to needs. (2) Rural terminal substations should be divided into two construction schemes according to the situation. The first is a relatively easy to realize short-term scheme, that is, when the breaking capacity of the 63kV side main transformer protection of the substation meets the requirements, controllable air blown fuses or new high-voltage fuses are selected. At present, some 35kV substations have used new high-voltage fuses imported from abroad. This new type of high-voltage fuse has stable ampere second characteristics and can realize the protection cooperation between upper and lower levels (under certain conditions), replace the oil circuit breaker and eliminate the old high-voltage fuse. The main transformer of the substation shall be energy-saving transformer; The 10kV outgoing circuit breaker adopts SF6 circuit breaker, which has overcurrent and short-circuit protection. It can disconnect the short-circuit current for 30 times, which is about 6 times more than the oil circuit breaker on the column, and the interrupting capacity is 2 ~ 3 times larger than the oil circuit breaker on the column. In addition, the non maintenance cycle is long, and the action is sensitive and reliable. At present, there are many domestic manufacturers; 10kV metering equipment can adopt outdoor metering device, without control duty room, and all equipment are arranged outdoors. The construction scheme of the second rural terminal substation is also the development direction in the future. The 63kV side of the main transformer of the substation is equipped with a new type of high-voltage fuse with stable ampere second characteristics. The main transformer is a domestic energy-saving transformer, which is equipped with a voltage regulator to automatically adjust the voltage and ensure the voltage quality; Equipped with telecontrol devices, realize telemetry, remote signaling, remote control (remote adjustment), observe and understand the power, current, voltage, circuit breaker position and other parameters of the substation and the operation status of the equipment in the dispatching room far away from the substation, and control and adjust when promoting the rare earth Enterprises in Zibo, Yantai, Jining and other cities to vigorously improve the industrialization level of rare earth magnetic materials and their utilization devices, so as to achieve the advanced operation and management level. Conclusion in the future, the construction and development of rural substations according to the above principles and schemes will gradually improve the rural power supply layout, continuously improve the safe power supply level and reliability, and gradually increase the economic and social benefits of the power supply department. Due to the small investment and short construction period of rural terminal substation, its development speed can also be accelerated. The implementation and future development of the above rural substation construction plan are inseparable from the adoption of advanced technology and equipment, so we should speed up the development and introduction of various electrical equipment in China, which is a very key technology and development work of tension machine. Produce and promote domestic electrical equipment with high quality and low cost to meet the needs of the transformation and development of rural substations