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Electric boiler and the combined heat and power (CHP) unit with thermal energy storage (TES) as the main means to solve the problem of wind curtailment into the micro-grid. In order to further eliminate wind curtailment, the wind curtailment coordination scheduling model with the lowest economic cost is established. Considering the influence of the electric boiler on the working state of CHP unit with TES, analyzing the operating characteristics of electric boiler and CHP with TES, calculating the wind power accommodating space for better eliminate wind curtailment, constraint on the maximum elimination of wind curtailment, the storage heat release power incremental model and the heating power model of the electric boiler is proposed. Taking differential evolution (DE) algorithm to solve the dispatch model. The results show that micro-grid scheduling model of electric boiler and CHP with TES can completely eliminate the wind and reduce the operating cost.

Some improvement on the icing flashover test procedures by taking into account the combined influences of the heavy ice accumulation was made. The test results demonstrated that the icing flashover voltages of the composite insulators with secondary contamination gave considerably lower values than the other two types of flashover voltages, namely the contamination flashover voltage obtained in the conventional clean-fog and the icing flashover voltage without secondary contamination, all the insulators being pre-contaminated with the same degree of equivalent salt deposit density (ESDD).

Ice accumulation on insulator surface imposes serious problems on power systems. One approach is to develop a hydrophobic coating with semiconducting characteristic resulting in heat generation, which is only coated on the bottom side. This paper focuses on the performance of the insulators treated with semiconductive coating during fog and pollution conditions. Three kinds of samples were tested, including insulator without any coating, insulator coated with normal RTV coatings and the one with semiconductive coatings. The artificial pollution tests were carried out in a fog chamber. The leakage current and the flashover voltage during the fog and polluted conditions were investigated. FEM calculation was also used to help understand the anti-contaminate performance. Test results indicate that the pollution flashover voltage of the semiconductive ones is almost twice of the pure ones, but a little lower than the RTV ones. The primary causes of high pollution flashover voltage are the joint action of the hydrophobicity of the coating and the drying effect generated by the leakage current.