Quantitative calculation method for unbalance responsibility at common coupling point in distribution system

Abstract

The invention discloses a quantitative calculation method for the unbalance responsibility at a common coupling point in a distribution system. The method comprises the following steps of: 1, establishing an equivalent circuit diagram for the quantitative calculation of the unbalance responsibility at the common coupling point in the distribution system; 2, calculating a relation between the unbalance rate of the voltage and the current at the common coupling point of the system when the imbalance completely comes from a system side; 3, calculating a relation between the unbalance rate of the voltage and the current at the common coupling point of the system when the unbalance completely comes from a user side; 4, obtaining the unbalance contribution quantitative values of the system side and the user side; and 5, identifying the main unbalanced disturbance source of the common coupling point of the system. The method can calculate the quantitative contribution of the unbalanced disturbance source in the distribution system and identify the position of the main unbalanced disturbance source based on the three-phase voltage and current data and the load capacity measured by the common coupling point in the system.

Description

technical field [0001] The invention relates to the technical field of identification of main unbalanced disturbance sources, in particular to a quantitative calculation method for unbalanced responsibilities at public coupling points in a power distribution system. Background technique [0002] In a power system, the three-phase voltages are ideally perfectly balanced. The amplitudes of the three-phase voltages are equal, and the phase angles differ by 120 degrees. However, the actual voltage of the system is usually unbalanced for many reasons, such as uneven distribution of three-phase loads, unbalanced three-phase loads, asymmetric transfer impedance and asymmetric transformer winding impedance, etc. Due to the increase in the number of large-capacity single-phase loads, the unbalance becomes more serious than before. Three-phase voltage unbalance can cause many adverse effects in power system. For example, unbalanced power supply voltage will threaten the safety and ...

AI Technical Summary

Problems solved by technology

Unbalanced three-phase voltage can cause many adverse effects in the power system

At the same time, the current industrial production and life are highly automated and highly dependent on the quality of the voltage. Therefore, in order to reduce the inconvenience and economic losses caused by the unbalanced power supply voltage, it is necessary to conduct in-depth research on the unbalanced voltage. The main source of voltage imbalance, clarify the responsibility for the contribution of voltage imbalance, implement reasonable mitigation measures for the main source of imbalance, and finally provide safe and stable power supply voltage for electricity customers, increase benefits for the power sector, and contribute to the safe operation of the power grid provide the necessary protection

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