Design and analysis of 12 MW offshore wind turbine

Permanent magnet synchronous motors are widely used in various fields for the advantages of high power density, high efficiency and high reliability. This paper analyzes the cogging torque of generators with different slot and pole coordination, and selects the optimal pole–slot ratio. Then, this paper analyzes the structural differences between the outer rotor and the inner rotor of permanent magnet synchronous motor, and selects the structural form of the outer rotor for analysis. Based on the electromagnetic design parameters of the motor, a two-dimensional finite element model is established in Maxwell to simulate and analyze the performance at no-load, rated load and short-circuit. The internal magnetic field, the distortion rate of voltage waveform, torque and short circuit current of the motor are studied, and the demagnetization of the permanent magnet under the worst operating condition is investigated. The simulation results show that the design scheme meets the design objectives

Neural Point Cloud Rendering via Multi-Plane Projection

We present a new deep point cloud rendering pipeline through multi-plane projections. The input to the network is the raw point cloud of a scene and the output are image or image sequences from a novel view or along a novel camera trajectory. Unlike previous approaches that directly project features from 3D points onto 2D image domain, we propose to project these features into a layered volume of camera frustum. In this way, the visibility of 3D points can be automatically learnt by the network, such that ghosting effects due to false visibility check as well as occlusions caused by noise interferences are both avoided successfully. Next, the 3D feature volume is fed into a 3D CNN to produce multiple layers of images w.r.t. the space division in the depth directions. The layered images are then blended based on learned weights to produce the final rendering results. Experiments show that our network produces more stable renderings compared to previous methods, especially near the object boundaries. Moreover, our pipeline is robust to noisy and relatively sparse point cloud for a variety of challenging scenes. Comment: 17 pag

Study on the effect of different pre-excitation factors on the output characteristics of MCSR

This paper takes the BKFSZT-30000/400 three-phase eight-limb magnetically controlled shunt reactor as the research object. Firstly, an electromagnetic transient simulation model is established based on the parity principle to verify the operating characteristics of the MCSR during direct energization and pre-excitation energization. On this basis, the influence of the pre-excitation capacity and the target capacity on the output characteristics of the MCSR is investigated. The results show that during the pre-excitation process the currents of working and control winding produce a DC component and a harmonic component dominated by the second harmonic, with the size of both DC components mainly influenced by the pre-excitation capacity and the attenuation determined by MCSR; the variation of the working harmonics is mainly influenced by the target capacity, while the size and attenuation of the control harmonics are determined by the pre-excitation capacity and the target capacity respectively. The results of the study clarify the output characteristics of the MCSR when energization with pre-excitation and provide a reference for further analysis of the interaction with the grid. Finally, to solve the problem of no reliable external power supply for pre-excitation, a fast excitation energization method with short-connected of the compensation winding is provided and verified by simulation