Urban power grid multi-terminal interconnection low-frequency four-phase power transmission system

Abstract

The urban power grid multi-terminal interconnection low-frequency four-phase power transmission system comprises a three-phase high-voltage looped network formed by a three-phase power grid, the three-phase high-voltage looped network is connected with the high-voltage sides of a plurality of three-phase power frequency step-down transformers used for voltage reduction, and the low-voltage side of each three-phase power frequency step-down transformer is connected with the input end of a three-phase-to-four-phase converter. The output ends of the plurality of three-phase to four-phase converters are connected with an annular low-frequency four-phase tie line; according to the low-frequency four-phase power transmission system, interconnection and mutual assistance between urban areas are achieved in a safer and more efficient mode, increase of cost and operation and maintenance workloads caused by connection of multiple loops between two cities is avoided, and the electric energy transmission quality and the electric energy use reliability are improved.

Description

technical field [0001] The invention belongs to the technical field of power system power transmission, and in particular relates to a multi-terminal interconnected low-frequency four-phase power transmission system of an urban power grid. Background technique [0002] With the continuous expansion of the scale of the power system, the span of the city has increased, and the scale of the urban power transmission system has also increased steadily. The contradiction is prominent, and the transmission capacity has become one of the basic problems of urban power transmission technology. Improving the transmission capacity and transmission distance of urban transmission lines is an important research direction; the current mainstream UHVDC transmission technology is not suitable for the partition interconnection and multi-terminal of urban power grids. In terms of AC transmission, the development of AC voltage tends to be saturated, and at the same time, problems such as difficu...

AI Technical Summary

Problems solved by technology

[0002] With the continuous expansion of the scale of the power system, the span of the city range increases, and the scale of the urban power transmission system also increases steadily. Contradictions are prominent, and transmission capacity has become one of the basic problems of urban power transmission technology. Improving the transmission capacity and transmission distance of urban power transmission lines is an important research direction; the current mainstream UHV DC transmission technology is not suitable for urban power grids. District interconnection and multi-terminal In terms of AC transmission, the development of AC voltage tends to be saturated, and at the same time, problems such as difficulty in improving stability, complicated operation and maintenance, and difficulty in scaling up also hinder the progress of AC technology

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