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Optimisation of reserve purchased in advance becomes increasingly essential to hedge against the growing level of power unbalance brought by the integration of large‐scale wind power. Moreover, due to the centralised integration mode of wind farms, cross‐region reserve sharing strategy becomes quite imperative. Therefore, this study presents a dynamic reserve demand estimation (DRDE) model, which synthetically considers N − 1 contingency along with load and wind forecast error. In the proposed approach, historical data is rearranged by a two‐dimensional binning technique and fitted by the versatile probability distribution model, which assisting the model reacts to different prediction level in each dispatch period dynamically. Furthermore, a cost‐effectivity oriented reserve allocation strategy for the multi‐area system is developed based on the DRDE model. The efficiency of the proposed method is tested in both 6‐bus test system and IEEE 118‐bus test system. The results show that, whether in the scenario of self‐sufficient reserve supplying or cross‐region reserve sharing strategy, the proposed estimation model effectively reduces the expectation of both load shedding and wind curtailment. Moreover, the proposed strategy improves the economy of system operation on the premise of ensuring system reliability. [ABSTRACT FROM AUTHOR]

Aimed to clarify the correlation characteristics between the internal partial discharge (PD) in the negative direct current (DC) gas‐insulated system (GIS) and gas pressure, and to establish an insulation fault diagnosis method based on decomposition component analysis, this study on PD decomposition of sulphur hexafluoride (SF6) was conducted under different pressures on the basis of constructing a SF6 decomposition experimental platform under DC PD. A stainless steel needle‐plate electrode was used to simulate the insulation defects of metal protrusions in GIS. SOF2, SO2 F2, CO2, SO2, and CF4 data generated from SF6 decomposition were obtained under different pressures. The variation law of component concentration and effective characteristic ratio with pressure were analysed in detail. In addition, a mathematical formula for pressure and decomposition components was deduced according to gas micro‐ionisation theory. The effective content and formation rate were defined to validate the relationship. Results show that the concentration of SF6 decomposition components decreased gradually with increasing pressure with a strong regularity. Furthermore, the relationship between pressure and component concentration derived from the theory can explain the relationship between the effective content of SF6 decomposition components and the effective formation rate and pressure variations. [ABSTRACT FROM AUTHOR]