Yusuke Hida

Load following operation of NAS battery by setting statistic margins to avoid risks

Among various types of battery energy storage systems (BESSs), NAS battery is the most promising products. NAS battery is a commercial product implemented widely in the world. The first purpose of BESS was improvement of load factors. The second purpose is improvement of power quality, especially against voltage-sag. The recent interest is oriented to utilize BESS to mitigate the intermittency of renewable energy.

The role of battery systems and expandable distribution networks for smarter grid

Renewable energies such as wind power and PV energy sources are valuable energy resources which can contribute to improvement of self-sufficiency rate of energy and can be used to reverse global warming. However, when there is a large amount of penetration of renewable energy generations into a grid, some problems will arise in the present distribution power network, due to instability of power output and large reverse power flow caused by the renewable energy generation. In researches on recent new electricity supply system, there is a way of thinking of local production for local consumption by the so-called micro-grid and smart-grid which supply the area demand by the area electric power resources, and several demonstrations have been performed also in Japan. From the viewpoint of local production for local and its consumption of electric power energy, a new type of expandable distribution network is proposed to meet regional expansion of the areas electricity demand and supply by the addition of electricity-cluster. The role and operation of battery energy storage system (BESS) in the expandable distribution networks are also discussed. Dynamical models of the expandable network and BESS for computer simulations are developed by MATLAB/Simulink, and the dynamic properties to maintain frequency and voltages in the cluster by appropriate operations of BESS are presented.

Best-Mix Generation Planning with Battery Energy Storage System Including Carbon-Neutral Requirement

Battery energy storage system (BESS) is attracting attention all over the world. BESS yields two types of benefits, i.e., economical benefit and environmental benefit. Economical benefit is yielded by reducing the cost of power plants that is composed by the operation cost and the construction cost. Recent serious concern against environment will be more important in the near future and it might be treated as penalty and/or constraints. The installation merit of BESS stands out when load factor of demand is low. If base generators composed of inexpensive and clean sources, and if peak generators composed of expensive and dirty sources, the benefit against operation cost becomes more remarkable. Besides, BESS can contribute to developing countries by reducing construction cost of generation plants. In this paper, the numerical analysis of this benefit is presented. The optimal amount of BESS is searched by evaluating CO2-reductions and cost benefits.

Analysis for Short Period Forecasting of PV Output using Hemispherical Photograph

The spread and promotion of renewable energy is a worldwide subject. However, the intermittency of renewables, may cause troubles to power system operation. One of effective countermeasures to mitigate the intermittency is the battery energy storage system (BESS). The accurate forecasting of renewable energy output is also indispensable to reduce the capacity of BESS. In this paper, a new approach to forecast a photovoltaic power (PV) output using hemispherical photograph is presented. The photos are taken by fish-eye lens to get the whole sky cloud image data. The movement of cloud around the sun is analyzed and modeled to forecast the future output of PV. The numerical test results show a potential ability to forecast.

Evaluation of Controllable Load Management for Frequency Regulation in Cluster Interconnected Power Networks

AbstractThis paper presents the effectiveness evaluation approach of demand side management (dema nd control) for frequency regulation in regional power networks (so called Cluster-oriented networks). The analytical model of the frequency fluctuation for a three-cluster interconnected network model was developed with MATLAB/SIMULINK. The control method is similar to the conventional TBC (Tie Line Bias Control) widely used in power grids. In order to maintain the quality of frequency, Battery Energy Storage Systems (BESS) and controllable loads such as heat pumps installed in the customer side will play an effective role in clusters. By the results of conducted simulations, it shows that the proposed new frequency regulation scheme by utilizing controllable loads such as battery charges and heat pumps retains effectiveness to suppress frequency deviation when a large amount of natural renewable energy is installed in the regional cluster-oriented networks.

Optimal Arrangement and Operation of PV Generation System for Regional Smart Grid

Abstract The authors have investigated to optimize arrangement and operation of PV generation system to serve as an essential part of regional smart grids. The PV generation is expected mostly to bring about the reduction of CO 2 emission all over the world in order to solve problems of global warming and exhaustion of fossil fuel. However, The PV power output decreases due to the change of solar radiation and the influence of shadow. Therefore, the authors have analyzed the optimal install parameters such as direction and tilt angle of PV panels considering the influence of shadow. The authors have aimed at optimizing operation of PV generation for building smart grids in Japan.

Optimal Capacity of Battery Energy Storage System and Its Effect of CO2 Reduction

Abstract Battery Energy Storage System (BESS) is attracting attention all over the world. NAS (Sodium and sulfur) battery is one of the most promising BESSs, and it has been widely used by various customers in Japan. Although the conventional incentive to install NAS battery was load leveling, the recent users’ interests are not unique. Renewable energy expansion by reducing greenhouse gases such as CO2 against global warming is another strong incentive. In this paper, the economic advantage in introducing BESS is investigated as a new way of achieving of best mix. BESS can reduce both of the construction cost and the operation cost of generators. The reduction of CO2-emission, which is a worldwide obligation, can be performed by introducing BESS. In this paper, a numerical analysis of the optimal amount of BESS by evaluations of CO2-reduction and cost benefits is demonstrated.