No abstract

The recent trends to design more efficient and versatile maritime (both marine and offshore) vessels have attracted significant attention toward high penetration of power electronics systems in electric ship systems, which trigged a variety of power system architectures in civilian and naval ships. The availability of advanced power electronics converters further supported to improve maneuverability, efficiency, and compactness at reduced greenhouse gas emission in marine vessels. The fast-growing penetration of these power electronics converters adds a number of advantages to the ship power system. However, risk factors associated with the quality and reliability of the whole system should be considered. Power quality issues in marine networks have been reported from recent field accidents, therefore, the marine regulatory bodies need to revise and/or develop new power quality standards to ensure the reliability and scrutinize the safety of the whole ship system and crews. This paper presents 1) a classification of marine vessels and their power system architectures; 2) power electronics converters topologies and their non-linear characteristics; 3) control and protection architecture; 4) energy efficiency indicators; 5) a comprehensive case study to elaborate power quality in the marine system, and; 6) extensive discussion about power quality standards and highlights the urgency to update existing power quality standards. INDEX TERMS Marine and ship networks, power system architectures, micro grids, distribution networks, power quality, energy efficiency, regulations, standardization, grid robustness.

Due to the significant advances in fast switching semiconductor devices, harmonic emissions caused by the adjustable speed drives (ASDs) have been changed in terms of frequency range and magnitude. The frequency range of 2-150 kHz has been distinguished as a new interfering frequency range, disturbing the distribution networks. This paper proposes a behavioral model of an AC motor to predict the common-mode (CM) current in ASDs. An approach is presented to calculate the parameters of the model, through which the dominant impact of each element at a specific frequency is considered. Moreover, along with the proposed motor model, a system modeling strategy is presented for filter design considerations at the emerging frequency range of 2-150 kHz. To verify the effectiveness of the proposed model, real-time experiments are conducted. The results prove that the introduced model can accurately predict the resonances of the CM loop created by the motor. Consequently, the proposed model is suitable for EMI filter design covering the 2-150 kHz standard.

Lifetime prediction of DC-link capacitors in a single drive has been discussed before, which indicates that the capacitor in a standard drive meets serious reliability challenge and in slim drive does not. However, in most of the applications, drives are connected in parallel with the power grid. The large amount of harmonic distortion produced by nonlinearity drives may transmit and couple between grid and drives, which changes the stresses of devices as well as the DC-link filters. Therefore, the estimated results in single drive can not be extended to multiple drives any more. This paper investigates the lifetime of DC-link capacitors in multiple drives system. Firstly, by decoupling the interactions among grid-connected drives, a simplified equivalent circuit model and its analytical model to obtain the DC-link continuous current in multiple drives is proposed, which releases the designers from configuraing the large simulation for multiple drives. Then, applying the lifetime prediction method, the lifetime of DC-link capacitors in multiple drives are investigated, in terms of types of drives, numbers of drives and grid conditions. The results show that the lifetime of the standard drives extend in the multi-drive systems and lifetime of the slim drives decrease in the multi-drive systems, which break the previous mind. Finally, based on the proposed analytical model and lifetime estimation method, the capacitor sizing from reliability aspect for multiple slim drives are given. The outcomes of the lifetime investigation could be a guideline for the design of capacitive DC-link in multidrive systems.

Mining is an important industry in many countries including Australia and plays a vital role in their economy. The industry heavily depends on electricity as it employs different types of electrical loads. Consequently, a stable and reliable supply of electricity is vital for running the production smoothly. In this review paper, electrical characteristics of mining power systems are described and common power quality and energy efficiency concerns in these systems are stated and classified. Different types of common power electronics topologies used in the industry are also studied and main requirements for reliable and robust operation of the system are categorized. A comprehensive case study to elaborate power quality challenges in mining distribution network is performed.INDEX TERMS Distorted grid, distribution network, energy efficiency, mining industry, power quality, power system robustness.

Summary Nonlinear load results in inferior power quality and a non‐uniform power demand curve. This gets aggravated due to the charging of electric vehicles. This paper presents a new control approach of integrating a photovoltaic (PV) cell with battery storage to a shunt active power filter (SAPF) for electric vehicle (EV) applications. The multifunctional PV‐Battery‐integrated SAPF (PV‐Battery‐SAPF) performs harmonic mitigation along with clean power generation, energy storage, uniform load demand curve, and battery swapping. It is achieved through a two‐stage topology. In the first stage, maximum power point (MPP) of a PV array is robustly tracked using metaheuristic algorithms like cuckoo search algorithm and particle swarm optimization. In the second stage, an ant colony optimization‐tuned controller is developed which adaptively controls the SAPF to improve the power quality. The suggested method provides efficient MPP tracking, lesser total harmonic distortion, better dynamic system performance, and appropriate charging/discharging of battery leading to increased system reliability. The proposed system is validated in real time on a hardware‐in‐the‐loop (HIL) testing platform.

No abstract

No abstract