Investigation of Output Power and Efficiency of Wound-Rotor Brushless Doubly-Fed Machine

2012 ◽  
Vol 516-517 ◽  
pp. 1604-1609
Author(s):  
Jun Zhang ◽  
Xue Fan Wang
Keyword(s):  
Equivalent Circuit ◽  
Output Power ◽  
Power Distribution ◽  
Equivalent Circuit Model ◽  
Circuit Model ◽  
Maximum Output ◽  
The Core ◽  
Doubly Fed ◽  
Doubly Fed Machine ◽  
The Relationship

Brushless Doubly-fed Machine (BDFM) is a new type of the induction machine, which has wide application in the fields of variable-speed generator and drive systems. The key factor affecting its performance is the rotor structure. In this paper, taking wound-rotor BDFM for instance, firstly, according to the relationship between the equivalent circuit parameters of the BDFM, the core equivalent circuit model of the BDFM has been derived. Secondly, based on the core equivalent circuit model and the constraints of electromagnetic load, the power distribution between the power and control windings and the constraint condition of maximum output of active power has been obtained. Thirdly, according to the simplified model of the equivalent circuit, the copper loss and the relationship between the output power and efficiency of the machine have been investigated. Finally, the anlysis results are verified by the experimental data.

scholarly journals Improved Interface Circuit for Enhancing the Power Output of a Vibration-Threshold-Triggered Piezoelectric Energy Harvester

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3830
Author(s):  
Jiqiang Liu ◽  
Junjie Yang ◽  
Ruofeng Han ◽  
Qisheng He ◽  
Dacheng Xu ◽  
...  
Keyword(s):  
Equivalent Circuit ◽  
Piezoelectric Material ◽  
Output Power ◽  
Energy Harvester ◽  
Equivalent Circuit Model ◽  
Stage Structure ◽  
Circuit Model ◽  
Interface Circuit ◽  
Piezoelectric Energy ◽  
Vibration Threshold

The vibration-threshold-triggered piezoelectric energy harvester is a new type of piezoelectric energy harvester with a two-stage structure, which can generate electricity in a low frequency environment and recognize vibration intensity at the same time. In this study, a theoretical model of a vibration-threshold-triggered energy harvester was examined, and an equivalent circuit model of the energy harvester was obtained. Then, an interface circuit was proposed that can significantly improve the output power of the energy harvester. The interface circuit achieved impedance matching with the piezoelectric material to maximize the energy collected from the energy harvester. First, we calculated and analyzed the impedance characteristics of the energy harvester, based on the equivalent circuit model. It was found that because the piezoelectric material is in resonance as the energy harvester is in operation, the corresponding impedance is almost resistance. Therefore, a resistance-matching strategy was proposed. Last, we proposed an interface circuit with adjustable input impedance to achieve resistance matching. The experimental results show that the proposed interface circuit can increase the output power of the energy harvester by 48.1–55.7% over that achieved with the standard interface circuit.

Sign in / Sign up

Export Citation Format

Share Document