1.1 General Introduction During the past two decades, the increase in electrical energy demand has presented higher requirements from the power industry. More power plants, substations, and transmission lines need to be constructed. However, the most commonly used devices in present power grid are the mechanically-controlled circuit breakers. The long switching periods and discrete operation ma...

A generalised instantaneous non-active power theory is presented. Comprehensive definitions of instantaneous active and non-active currents, as well as instantaneous, average and apparent powers, are proposed. These definitions have flexible forms that are applicable to different power systems, such as single-phase or multi-phase, periodic or non-periodic and balanced or unbalanced systems. By ...

The optimization of reactive power compensation plays an important role in power system planning and designing. A mathematical model in the 10kV distribution network is established in this paper. Its objective function is the cost of investment in equipment of reactive power compensation and active power loss of the system should be the least. The node voltages beyond limited and the generator ...

This paper proposes a new algorithm to find the optimization method of reactive regulation in power system to solve the problem of the var compensation and voltage control in center-substations. Using the daily data collected in power substations, the algorithm is combined with improved ant colony algorithm and Apriori data mining techniques. The mathematic model of var optimization of power sy...

We theoretically investigate charged collective modes in a two-dimensional conductor with hot electrons where the instantaneous mode frequencies gradually increase or decrease with time. We show that the loss compensation or even amplification of the modes may occur. We apply our theory to two types of collective modes in graphene, the plasmons and the energy waves, which can be probed in optic...

An inherent characteristic of most translinear (TL) filters is instantaneous companding. This brief describes a distortionless syllabic companding TL filter based on the “analog floating-point technique” [1]. Through the addition of a compensation current to each of the capacitances in the filter, distortion is eliminated. By applying syllabic companding to a TL filter, the input current can be...