原 亮一(ハラ リヨウイチ) |
情報科学研究院 システム情報科学部門 システム融合学分野 |
准教授 |
In distribution systems, a large amount of photovoltaic systems (PVs) is being introduced, which may make the voltage profile more complicated. In order to accommodate PVs as much as possible, more advanced voltage management scheme should be developed. For such purpose, online voltage profile monitoring would be helpful. however, it needs installation of many sensors into the distribution system. On the other hand, smart meters and IT switches are being installed in Japan. That is, the distribution systems are being rich-information circumstances. Based on the above recent trend, this paper proposes voltage profile estimation methods based on the state estimation technique. The numerical case studies for the distribution network model with 2,160 consumers were carried out to validate the estimation performance.
Recent growth of renewable energy (RE) generations with natural variability, would make the demand and supply regulation in a whole power system more difficult, and therefore, alternatives for demand and supply regulation resources would be required. The authors focus on co-generation system (CGS) owned by the consumers as one of regulation resources and have proposed a novel optimal operation strategy of CGSs to provide the demand and supply regulation. This paper discusses the optimal installation design including two configurations of CGS based on the economic viewpoints considering the energy supply cost and the financial incentive associated with the contribution for demand and supply regulation. The discussions are based on numerical case studies with the actual electrical and thermal demand profiles and equipment cost of CGS.
From growing interests in the environment issues, promotion of photovoltaic power generation (PV) is accelerated in the world. Meanwhile, rapid chargers (RCs) for popularized electric vehicles are being installed in urban areas. These two trends in distribution system might cause severer voltage fluctuation problems. On the other hand, a RC can provide the reactive power support, which is capable of voltage regulation. Based on this viewpoint, this paper proposes a new framework of voltage regulation, in which the reactive power compensation by RCs is actively utilized. The proposed voltage regulation method combines two different control functions with consideration for over-compensation avoidance. This paper ascertains the validity of proposed voltage regulation method through numerical simulations.
Recently, a large number of renewable energy (RE) sources such as wind farms (WFs), photovoltaic generations (PVs) have been introduced to power systems as a solution for the worldwide environmental issue. On the other hand, with the deregulation of the electric power industry such as the full liberalization of retail sector, power producer and suppliers who own RE sources have traded the generated electricity in the electric market. However, power outputs of RE sources fluctuate every moment and it is impossible to predict the power output perfectly. Thus, to operate RE sources according to the generation schedule notified in the market while suppressing their power output fluctuation, cooperation of energy storage systems with RE sources are required. This paper proposes a method for determining the scheduled generation of WFs by cooperating the predicted WF power output and heat pumps (HP)/biogas engine generator (BG) heat supply system (HP/BG heat supply system) which is a new energy storage technology developed by the authors. The proposed methods consist of two steps. In the first step, optimal operations of HP and BG are determined by utilizing the predicted WF generation so that the flexibility of HP/BG system can be ensured. In the second step, the operations of HP and BG are modified based on actual WF outputs including predicted errors. The validity and effectiveness of the proposed method are investigated through some computational simulations using MATLAB.