scholarly journals Open-Circuit Fault-Tolerant Characteristics of a New Four-Phase Doubly Salient Electro-Magnetic Generator

2018 ◽  
Vol 10 (11) ◽  
pp. 4136 ◽  
Author(s):  
Liwei Shi ◽  
Bing Yan ◽  
Xiaoyu Zhou ◽  
Xueyi Zhang
Keyword(s):  
Fault Tolerant ◽  
Open Circuit ◽  
Sustainable Mobility ◽  
Half Wave ◽  
Doubly Salient ◽  
Bridge Rectifier ◽  
Load Characteristics ◽  
Electro Magnetic ◽  
The Mathematical Model ◽  
Magnetic Generator

In order to improve the reliability of a more sustainable mobility generator, a four-phase Doubly Salient Electro-Magnetic Generator (DSEG) and its phase-isolated rectifier are proposed in this paper. The mathematical model of the machine and fault-tolerant rectifiers is proposed, which indicates that the four-phase fault-tolerant DSEG should have symmetric phases. With the asymmetry analysis of the traditional 8/6-pole DSEG, a new 12/9-pole DSEG with symmetric phases is proposed. The four-phase full bridge rectifier, positive half-wave rectifier and four-phase H bridge rectifier are presented. The voltage waveforms, no-load characteristics and loading characteristics with different rectifiers will be given based on the simulation and the experiment on a prototype of DSEG, and the results show that the four-phase H bridge rectifier has the best fault tolerant no-load characteristic and external characteristic, except that it needs more diodes.

scholarly journals Open-Circuit Fault-Tolerant Design of the Cascaded H-Bridge Rectifier Incorporating Reactive Power Compensation

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1490
Author(s):  
Ting Chen ◽  
Hong Cheng ◽  
Cong Wang ◽  
Wenbo Chen ◽  
Zhihao Zhao
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Power Transmission ◽  
Fault Tolerant ◽  
Reactive Power Compensation ◽  
Open Circuit ◽  
Normal Operation ◽  
Bridge Rectifier ◽  
Drive Signals ◽  
Fault Tolerant Design

This paper proposes an open-circuit fault-tolerant design for the cascaded H-Bridge rectifier incorporating reactive power compensation. If one or two switching devices of the H-bridge modules are fault, the drive signals of the faulty H-bridge modules will be artificially redistributed into the bridgeless mode (including the boost bridgeless mode, the symmetric boost bridgeless mode, the totem-pole bridgeless mode and the symmetry totem-pole bridgeless mode) and cooperate with the normally operated H-bridge modules. In this case, the faulty cascaded H-bridge rectifier is not only able to achieve active power transmission, but also can still provide part of reactive power compensation when injecting reactive power from the power grid. Nonetheless, the reactive power that it can supply will be limited, due to the unidirectional characteristics of the bridgeless mode for the faulty modules. Therefore, a method for calculating its adjustable power factor angle range is also presented, which provides the basis for the faulty modules switching to the bridgeless mode. Then, a control strategy of the cascaded H-bridge rectifier incorporating reactive power compensation under the faulty condition and normal operation is presented. Finally, an experimental platform with a single-phase cascaded H-bridge rectifier containing three cells is given to verify the proposed theories.

Non-uniform air gap modeling and electromagnetic characteristics of a new six-phase doubly salient electro-magnetic generator

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1325-1335
Author(s):  
Xiaoyu Zhou ◽  
Liwei Shi ◽  
Junhao An ◽  
Fukang Ding
Keyword(s):  
Finite Element ◽  
Linear Structure ◽  
Mutual Inductance ◽  
Air Gap ◽  
Electromagnetic Properties ◽  
Element Analysis ◽  
Doubly Salient ◽  
Electro Magnetic ◽  
Magnetic Generator ◽  
Gap Structure

The voltage harmonics of the six-phase doubly salient electro-magnetic generator (DSEG) are large, and the electromagnetic isolation is poor due to the mutual inductance of the armature winding. An optimization scheme for the stator non-uniform air gap structure is proposed. By establishing a non-uniform air gap angle function model, the analytical expression of the induced electromotive force in the non-uniform air gap structure is derived. Using finite element and mathematical model to verify that the stator tip is changed from circular arc to linear structure can increase power and reduce voltage high harmonics, improve the power quality of the generator. Based on the equivalent magnetic circuit, the influence of the winding method of the excitation winding on the mutual inductance of the armature winding is studied. When the field winding is wound interval every two stator poles, the mutual inductance is small. The electromagnetic properties of the new six-phase electric excitation double salient pole are analyzed by two-dimensional finite element analysis. The rationality of the proposed motor structure is verified by experiments.

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