Ni-doped, urchin-like Bi2S3 particles for electrocatalytic oxidation of glucose

In order to develop non-noble metal-based electrocatalysts for glucose oxidation, the Ni-doped, urchin-like Bi2S3 particles were prepared by a solvothermal method using the solvent of ethylene glycol/H2O. The obtained products were characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy and X-ray diffraction. The background signal from capacitance current is relatively low and the electrocatalytic oxidation current of glucose relatively high due to the urchin-like nanostructure of Bi2S3 particles and high surface area where the presence of Bi also improves the electrocatalytic performance of NiII/NiIII shift.

Parallel Resonance Mechanism Analysis and Suppression of Inductance-Capacitance-Inductance Grid-Connected Inverters

The resonance problem of multi-paralleled grid-connected inverters with inductance-capacitance-inductance (LCL) filters is a core matter which bothers the safety and stability operation of new energy distribution networks. Based on the impedance model of the paralleled system of two inverters, the influence of inverters on grid-connected current was analyzed through the superposition principle, and the grid-connected current was decomposed. The resonant mechanism generated by interactive current and the common current was studied, and the resonance frequency characteristics were compared and analyzed by a paralleled system using the same and differently rated power inverters. Based on the resonance frequency generated by interactive current, a digital notch filter was introduced into the traditional capacitance current active damping control scheme, which realized the non-static control of base wave signal and satisfied the standard of multi-paralleled grid-connected inverters with LCL filters. Finally, simulation results verified the correctness and validity of the proposed strategy.

A Physics-Based Analytical Model for MgZnO/ZnO HEMT

In this paper, a physics-based compact model is developed for novel MgZnO/ZnO high-electron-mobility transistor (HEMT). Poisson’s equation coupled with 1D Schrödinger equation is solved self-consistently in the triangular quantum well to derive an expression of two-dimensional electron gas (2DEG) density with respect to gate voltage at the heterointerface of barrier (MgZnO) and buffer (ZnO) layers. A compact mathematical framework has been devised further for the first time for ZnO-based HEMT to the best of our knowledge using the expression of 2DEG density to compute surface potential, gate charge, gate current, gate capacitance, current–voltage characteristics, output conductance, transconductance and cut-off frequency with respect to gate voltage and along with the drain–source output resistance [Formula: see text].

A Single-Phase Grounding Fault Judgment Method Based on Mutation Current Logic Matrix

In order to solve the problem of single-phase grounding fault judgment in non-solid-earthed distribution network, the power flow in non-solid-earthed distribution is analyzed. A single-phase grounding fault judgment method based on mutation current logic matrix is proposed. The minimum fault judgment area model is constructed by the parent and child nodes. The feeder mutation current matrix is generated by the feeder real-time current matrix and the feeder history current matrix. The feeder mutation current matrix is transformed into the feeder mutation current logic matrix by the capacitance current threshold, and the non-zero elements of the feeder mutation current logic matrix are extracted into the mutation current logic sequence list. Then the single-phase grounding fault can be determined in the minimum fault judgment area of the last element of the mutation current logic sequence list as the parent node. The detailed calculation formulas are given. This method is also applicable to the non-solid-earthed distribution network containing distributed generation. The simulation results show that the method proposed in this paper has a good adaptability to the permanent grounding fault and it is worth popularizing.

SLG(Single-Line-to-Ground) Fault Location in NUGS(Neutral Un-effectively Grounded System)

This paper reviews the SLG(Single-Line-to-Ground) fault location methods in NUGS(Neutral Un-effectively Grounded System), including ungrounded system, resonant grounded system and high-resistance grounded system which are widely used in Northern Europe and China. This type of fault is hard to detect and location because fault current is the sum of capacitance current of the system which is always small(about tens of amperes). The characteristics of SLG fault in NUGS and the fault location methods are introduced in the paper.