No abstract

This study presents a minimum inverter capacity design for three-phase four-wire centre-split inductor-capacitor (LC) coupling hybrid active power filters (LC-HAPFs). Based on its equivalent circuit models in d-q-0 coordinate, the coupling part filtering characteristics of the LC-HAPF without or with neutral inductor can be more clearly illustrated and easily understood, compared with the past analysis based on the generic filter structure. According to the current quality data, the minimum dc-link voltage expressions for the LC-HAPF without and with neutral inductor are deduced and compared. Conventionally, the coupling LC is usually tuned at a higher fifth-or seventh-order harmonic frequency to reduce its cost and size compared with third-order case. When triplen harmonic currents exist significantly, the LC-HAPF with a small tuned neutral inductor can further reduce its minimum dc-link voltage requirement. Thus, the initial cost, switching loss and switching noise of the LC-HAPF can be lowered. Representative simulation and experimental results of the three-phase four-wire LC-HAPF with neutral inductor are presented to verify the filtering characteristics analysis and minimum dc-link voltage expressions, to show the effectiveness of reducing its inverter capacity, switching loss and switching noise in current quality compensation compared with the conventional LC-HAPF.

The coloration of carbon nanotube (CNT) fibers (CNTFs) is a long-lasting challenge because of the intrinsic black color and chemically inert surfaces of CNTs, which cannot satisfy the aesthetic and fashion requirements and thus significantly restrict their performance in many cutting-edge fields. Recently, a structural coloration method of CNTFs was developed by our group using atomic layer deposition (ALD) technology. However, the ALD-based structural coloration method of CNTFs is expensive, time-consuming, and not suitable for the large-scale production of colorful CNTFs. Herein, we developed a very simple and scalable liquid-phase method to realize the structural coloration of CNTFs. A SiO 2 /ethanol dispersion containing SiO 2 nanospheres with controllable sizes was synthesized. The SiO 2 nanospheres could selfassemble into photonic crystal layers on the surface of CNTFs and exhibited brilliant colors. The colors of SiO 2 nanoparticle-coated CNTFs could be easily changed by tuning the sizes of SiO 2 nanospheres. This method provides a simple, effective, and promising way for the large-scale production of colorful CNTFs.

No abstract

A new type of extended small signal stability region (E-SSSR) is presented in this paper so that it can consider the low frequency oscillation phenomena captured in power system operations. The definition of the extended small signal stability region is first given, and its boundary structure is discussed. Then an optimal-based approach is given to trace E-SSSR's boundaries. Finally, a 3-bus and WSCC 3-generator-9bus system are employed to do dome case studies. E-SSSR's characteristics, boundary composition and influence facts are also analyzed based on the case studies. This paper is helpful to find effective methods to avoid various small signal instabilities and low frequency oscillations in power systems.

No abstract

In operating of a flow battery, a certain flow rate should be maintained in order to guarantee its performance. But the pump consumed power may cause significant losses for the overall battery system. In this paper, a fresh electrical model is proposed for the novel single flow zinc-nickel battery. The model consists of both battery stack part and pump power part, which consequently not only predicts accurately the battery electrical output, but also estimates the pump consumed power at different electrolyte flow rate. Based on the validated model, the influence of pump power on flow battery’s system efficiency can be evaluated at different operating modes. At last, possible means to further improve the system efficiency of battery is discussed.

In designing high-speed system, signal reflection and crosstalk often cause many signal integrity issues. We are using Mentor PADS2007/HyperLynx to design a high-speed system with TMS320DM6446, a high performance video processing chip. The pre-layout high-speed signal lines of this DSP image processing system are throughout simulated. These widespread issues of signal integrity, especially reflection and crosstalk in the high-speed printed circuit board are addressed, and the corresponding solutions are presented.