Search

The inter-turn short circuit fault of wingding is a typical serious fault of the new synchronous condenser, which has a serious impact on the long-term operation of the condenser and the stability of the power grid. In order to ensure the reliable and stable operation of the new synchronous condenser, a method of online diagnosis and location of rotor inter-turn short circuit fault is proposed in this paper. Based on the distortion of the air-gap magnetic field magnetomotive force caused by fault it is deduced that the phenomenon of even harmonic circulation will occur in the same phase and double branches of the stator. Through Fourier decomposition of the branch circulation, the obvious characteristic quantity of harmonics is extracted and analyzed. It is concluded that the characteristic quantity is only related to the spatial position of the rotor where the fault is located, and has nothing to do with the number of fault turns. Therefore, this characteristic quantity can help realize fault diagnosis and location. Based on the TTS-300-2 type synchronous condenser which has been put into use on a large scale, a simulation model is established with the actual condenser in the finite element software while an experiment platform is developed with a condenser simulator for experiments. The simulation and experimental results validate the effectiveness of locating rotor inter turn short circuit faults through branch circulating current harmonics.

HVE-400 ion implanter is special ion implantation equipment for semiconductor materials boron and phosphorus doping. The ion source and extraction deflection system are at high voltage platform, while the corresponding control system is at ground voltage position. The control signals and measurement signals of various parameters at the high-voltage end need to be transmitted between ground voltage and high voltage through optical fibers to isolate high voltage. Upgrading is carried out due to the aging of the optical fiber transmission control and monitoring system, which cannot work stably. The transformation replaces the original distributed single-point control method with an advanced distributed centralized control method, and integrates all control and monitoring functions into an industrial control computer for digital operation and display. In the computer software, two kinds of automatic calculation of ion mass number are designed. After upgrading, the implanter high-voltage platform control and monitoring system features digitalization, centralized control, high reliability, strong anti-interference, fast communication speed, and easy operation. [ABSTRACT FROM AUTHOR]

Using their own triazine groups as natural receptors, the introduction of various donor units to construct donor‐receptor configuration in covalent triazine frameworks (CTFs) has been shown to be an effective strategy to improve photocatalytic activity. In this work, the effect of donor unit content (D‐content) on the photoelectric properties and photocatalytic activity of CTFs was thoroughly investigated. Four analogous CTFs with different D‐content have been rationally designed and synthesized, in which the bithiophene (Btp) as the donor unit and triazine as the acceptor unit. And CTF‐Btp with the highest D‐content showed the best photocatalytic activity. The experimental and theoretical results indicated this improvement is attributed to stronger visible light absorption capacity and higher photoinduced charge carrier separation efficiency. This study elucidates the relationship between the structural features of CTFs with varying D‐content and their photocatalytic activity, offering a promising strategy for developing efficient photocatalysts. [ABSTRACT FROM AUTHOR]

Converting greenhouse gases into valuable products has become a promising approach for achieving a carbon-neutral economy and sustainable development. However, the conversion efficiency depends on the energy yield of the substrate. In this study, we developed an electro-biocatalytic system by integrating electrochemical and microbial processes to upcycle CO2 into a valuable product (ectoine) using renewable energy. This system initiates the electrocatalytic reduction of CO2 to methane, an energy-dense molecule, which then serves as an electrofuel to energize the growth of an engineered methanotrophic cell factory for ectoine biosynthesis. The scalability of this system was demonstrated using an array of ten 25 cm2 electrochemical cells equipped with a high-performance carbon-supported isolated copper catalyst. The system consistently generated methane at the cathode under a total partial current of approximately -37 A (~175 mmolCH4 h-1) and O2 at the anode under a total partial current of approximately 62 A (~583 mmolO2 h-1). This output met the requirements of a 3-L bioreactor, even at maximum CH4 and O2 consumption, resulting in the high-yield conversion of CO2 to ectoine (1146.9 mg L-1). This work underscores the potential of electrifying the biosynthesis of valuable products from CO2, providing a sustainable avenue for biomanufacturing and energy storage., (© 2024 Wiley‐VCH GmbH.)

Proton exchange membrane water electrolysers promise to usher in a new era of clean energy, but they remain a formidable obstacle in designing active and durable electrocatalysts for the acidic oxygen evolution reaction (OER). In this study, a protonated iridium oxide embedded with single-atom dispersed ruthenium atoms (H 3.8 Ir 1- x Ru x O 4 ) that demonstrates exceptional activity and stability in acidic water oxidation is introduced. The single Ru dopants favorably induce localized oxygen vacancies in the Ir─O lattice, synergistically strengthening the adsorption of OOH* intermediates and enhancing the intrinsic OER activity. In addition, the preferential oxidation of Ru and the electronegativity of the oxygen vacancies significantly stabilize the Ir─O active sites, improving the OER stability. Consequently, the H 3.8 Ir 1─ x Ru x O 4 catalyst shows an overpotential of 255 mV at 10 mA cm -2 and displays exceptional catalytic endurance in acidic electrolytes, surpassing 1100 h, representing a remarkable one-order-of-magnitude increase in stability compared to that of pristine H 3.8 IrO 4 . A proton exchange membrane electrolyser utilizing the H 3.8 Ir 1- x Ru x O 4 catalyst as an anode exhibits stable performance for more than 1280 h under a high current density of 2 A cm -2 ., (© 2024 Wiley‐VCH GmbH.)

Using their own triazine groups as natural receptors, the introduction of various donor units to construct donor-receptor configuration in covalent triazine frameworks (CTFs) has been shown to be an effective strategy to improve photocatalytic activity. In this work, the effect of donor unit content (D-content) on the photoelectric properties and photocatalytic activity of CTFs was thoroughly investigated. Four analogous CTFs with different D-content have been rationally designed and synthesized, in which the bithiophene (Btp) as the donor unit and triazine as the acceptor unit. And CTF-Btp with the highest D-content showed the best photocatalytic activity. The experimental and theoretical results indicated this improvement is attributed to stronger visible light absorption capacity and higher photoinduced charge carrier separation efficiency. This study elucidates the relationship between the structural features of CTFs with varying D-content and their photocatalytic activity, offering a promising strategy for developing efficient photocatalysts., (© 2023 Wiley-VCH GmbH.)