In order to solve the collaborative optimization scheduling of multi‐microgrid under the high penetration rate of new energy, this paper considered the energy interaction between micro‐grids in multi‐microgrid and the relationship between new energy consumption and electricity cost, constructed a collaborative scheduling model considering both micro‐grid load and main grid wind and optical energy storage, proposed objective function based on economic cost, and improved Genetic Algorithm (GA). The elite thought and catastrophe thought are used to optimize the selection operation, and the particle swarm optimization algorithm is used to optimize the mutation operation. Furthermore, three scenarios were selected to verify the effectiveness of the proposed model and the improved GA. The results show that the proposed model can ensure the stable operation of the multi‐microgrid system with a high proportion of new energy access and reduce the operation cost. In addition. the improved algorithm solves the problems of easy to fall into local optimum and slow iteration speed, and has better performance in solving the model.

Shaft voltage often exists in synchronous generators due to the assembly error or various faults after the long‐term performance. The article investigates the shaft voltage characteristic under the stator interturn short circuit (SISC) condition. Different from other studies, this article mainly considers the mapping relationship between the amplitude–frequency characteristics of the shaft voltage and the SISC degrees. The detailed shaft voltage expressions are first derived based on the magnetic flux density under the normal condition and SISC condition. Then the finite element analysis and the experiment is studied on a CS‐5 prototype synchronous generator with two poles in order to validate the theoretical formula. The result shows that there is no shaft voltage in the normal condition, while the shaft voltage is generated obviously under the SISC condition. Meanwhile, the frequency component of the shaft voltage is mainly composed of odd harmonics including the first, third and fifth harmonics.

A multi-reliability index evaluation and maintenance period optimization method of wind turbine considering failure correlation is proposed to address the problems that the most existing reliability evaluation methods of wind turbine fail to consider the failure correlation among system components and often rely on a single reliability index to conduct reliability evaluation. Firstly, considering the failure correlation among system components, the reliability model of wind turbine and its comprehensive reliability model for component are established. Secondly, based on the sequential Monte Carlo simulation, a multi-reliability index evaluation method of wind turbine considering failure correlation and maintenance combination strategy is presented. Moreover, the maintenance period optimization method of wind turbine is proposed by using the unit time cost as the objective function. Finally, the effectiveness of the proposed method is verified through example analysis.

This paper studies the electromechanical characteristics of synchronous generators under dynamic stator interturn short circuit (DSISC). First, the air gap magnetic flux density (MFD) of the generator under normal and DSISC fault was obtained. Then, the expression for the phase current and the electromagnetic torque (EMT) were obtained. After this, the phase current and EMT were analyzed by finite element analysis (FEA). Finally, the measured electromechanical characteristics of the CS-5 generator under different conditions were analyzed in accordance with theory and simulation. It was shown that with the occurrence, and deterioration, of DSISC, the amplitude of the first harmonic, third harmonic and fifth harmonic of the phase current became more affected by the pulse. Meanwhile, the even-numbered harmonics components of EMT increased.