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With the rapid changes in the actual power system operation mode, power system wide area real time state estimation based on phasor measurement unit (PMU) plays an increasingly important role in energy management system (EMS). However, complex distribution characteristics of PMU measurement error pose challenges to the accuracy of state estimation. Therefore, a state estimation method combining PMU linear measurement model and linear Bayesian estimation is proposed. Considering the prior information of estimated parameters and the complex probability density function of measurement error, linear Bayesian estimation is applied to power system state estimation based on PMU. The correlation between real measurement error and imaginary measurement error is analyzed, and the prior information of estimated parameters is obtained according to the analysis of system state volatility. Compared with complex number least squares (CLS) method, the applicability and accuracy of this method were verified in IEEE 39 bus system.

As a promising electrocatalyst for hydrogen evolution reaction (HER), molybdenum disulfide (MoS2) owns inadequate edge active sites and inferior conductivity which restricts its effective application. In this study, the expanded graphite matrix (EGM) cathode was fabricated by tableting worm-like expanded graphite (EG), acetylene black and poly tetra fluoroethylene (PTFE) emulsion, and MoS2 grew on EGM via a hydrothermal synthesis process, subsequently employed for the HER process. Benefiting from the superior conductivity and sufficient exposure of edge active sites on the rough structure of EGM, MoS2/EGM exhibits a small overpotential of 230 mV (j = 10 mA cm−2), a low Tafel slope of 77 mV·dec−1 and a lower value of charge transfer resistance (Rct, 0.919 Ω cm2). The improvement of HER performance of MoS2/EGM could be due to the participation of the EGM as a highly conductive substrate. Excellent electrochemical durability of MoS2/EGM was attested by the cyclic voltammetry and the amperometric (i−t) measurements. This work may have the potential to develop a promising path to design advanced electrode materials for HER.

Corrugated horn is often preferred due to having low cross polarization over a very wide bandwidth in C-band satellite communication, but the corrugated horn is challenging to fabricate and weight. Therefore, a novel smooth-walled horn is proposed in this paper. The horn has low cross-polarization (