Standard type verification of three-phase smart meters is performed under idealized balanced test conditions that do not fully reproduce the current unbalance, single-phase loading and voltage deviations found on real distribution networks, so that a channel-specific calibration fault can pass undetected. This paper presents a methodology combining standard IEC~62052-11 and EN~50470-3 verification with an extended set of near-real-network test conditions (unbalanced current distribution, single-phase loading, and voltage deviation from nominal), together with a statistical/machine-learning screening step applied to aggregated laboratory verification results and used to flag units for target... More >

From the confluence of the Lech River with the Danube to the Danube Delta, installed electricity generation capacities of approximately 16.983~GW directly use water from the Danube, namely: 6096.34~MW hydro, 4657.7~MW gas-fired (including one combined heat and power PP fueled primarily by natural gas and hydrogen), 1007~MW coal-fired and 5222~MW nuclear power plants (PPs). As is well known, hydro PPs use water to spin turbines, gas-fired PPs use water to cool and generate steam, coal-fired PPs use water to generate steam, cool equipment, and manage waste, while nuclear PPs use water to cool and generate steam, as well as to moderate fast-moving neutrons. If there is a record-low water level... More >

This paper presents a simple and efficient method for detecting harmonics, interharmonics, and subharmonics in voltage and current waveforms. The proposed technique is based on a series RLC resonant circuit and is characterized by its simplicity, relatively fast response, and ease of implementation. The performance of the proposed method is validated using both mathematically generated signals with severe waveform distortion and signals measured in real distribution networks with high penetration of renewable energy sources. The maximum relative errors in the frequency of detected harmonic components were 1.33% for the mathematically generated strongly distorted signals and 0.60% for the mea... More >

This paper investigates the influence of temperature- and current-dependent variations in alternating current (AC) resistance on the estimation of the operating temperature of aluminium conductor steel-reinforced (ACSR) conductors, with particular emphasis on the differences arising from the use of tabulated and experimentally determined resistance characteristics. Special attention is devoted to the current dependence of AC resistance in the single-layer ACSR conductor 48-AL1/8-ST1A, where pronounced resistance variations occur due to the electromagnetic interaction between the aluminum strands and the steel core. Experimental investigations were conducted under controlled laboratory condit... More >