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The proliferation of massive non‐linear loads, large motor loadings, renewable energy generation systems etc. creates many problems to the electrical power systems, such as harmonics, oscillations, which lead to the unnecessary economic cost. It is critical to implement satisfying continuous monitoring of the power quality (PQ) over the power systems. Previous works have proposed many PQ detection methodologies with promising accuracy and performance, but as more and more renewable energy is integrated into the power systems, a new challenge of frequency deviation has been raised. The accuracy of the conventional methodologies will be degraded under the frequency deviated environment, then the authors proposed in this study an instantaneous PQ indices (PQIs) detection methodology based on adaptive data resampling technique to improve the accuracy of PQIs detection within a frequency deviated environment. Finally, they validated the effectiveness of the proposal, which obtains better accuracy and performance under a frequency deviated environment with less readjustment, through simulation and measurement. Furthermore, the proposed methodology satisfies the definitions and recommendations of the IEEE Std 1459 and IEEE Std 519. [ABSTRACT FROM AUTHOR]

Building‐integrated photovoltaics (PVs) is one of the most promising and elegant ways of producing on‐site electricity. The compact and cost‐effective PV integration system needs to be developed to convert dc voltage into ac compatible with the grid. A single‐stage PV inverter is proposed, and its design and control system implementation are focused on. The proposed system is able to transfer active power to the grid with maximum power point tracking. At the same time, the PV inverter can control reactive power and suppress harmonics due to non‐linear loads. By coupling to grid via a series LC branch, the proposed system operates on a dc bus voltage much lower than that of the conventional PV inverter, so that less PV panels need to be connected in series. Therefore, the proposed system is a low‐cost and multi‐functional alternative to PV inverters in building‐integrated applications. Simulation and experimental results are provided to validate its effectiveness. [ABSTRACT FROM AUTHOR]

The 3‐level boost (3LB) converters have the characteristics of higher‐voltage conversion ratio and efficiency, lower inductor current ripples, output voltage ripples and voltage stresses on switches when compared with the conventional boost converters in continuous conduction mode (CCM). When implemented into an integrated circuit, the 3LB converter discontinuous conduction mode (DCM) operation cannot be avoided due to a smaller inductance. Its DCM operation analysis is deduced including CCM/DCM boundary, DCM voltage gain and DCM small signal transfer function. The deduced DCM operation theory is verified using MATLAB and Cadence, to obtain a feasible DCM closed‐loop controller design in future. [ABSTRACT FROM AUTHOR]

A KY converter has the characteristics of non‐pulsating output current, low‐output voltage ripple and no right‐half plane zero in continuous conduction mode which can overcome the drawbacks of the conventional boost and buck–boost converters. However, when the KY converter is implemented into an integrated circuit, its discontinuous conduction mode (DCM) operation cannot be avoided due to a small‐inductor value. The boundary for the DCM operation region, DCM dc voltage and small‐signal transfer functions are proposed, which fill the gap of the DCM operation theory for the KY converter. Simulation results, using MATLAB and Cadence, are provided to verify the deduced DCM operation theory of the KY converter. The DCM closed‐loop controller design can be achievable in future. [ABSTRACT FROM AUTHOR]