Nobuhisa Kobayashi

Security requirements for smart grid services in Japan

Security is one of the most important factors for success of smart grid services. This paper presents the security requirements for smart grid services in Japan. We consult two major documents for smart grid security in the U.S. and EU, “NISTIR 7628” and CENs “the Smart Grid Information Security”, and discuss the results of the security requirements extracted from these documents.

Energy efficient demand control for air-conditioning systems

We propose an energy efficient demand control method for air-conditioning systems for buildings installed with multi-split packaged air-conditioning systems (PAC). Energy efficiency is improved by controlling the operating point constantly to target power consumption while limiting PAC electricity power demand and recovering a normal condition without relying on PAC internal logic. The constant operating point is determined as the ratio of the number of units requiring 100% heat load among all indoor units when all units are set to either 100% or 0% using only ordinal external interface information such as temperature setting and operating mode. The proposed method is a practical measure that enables quick, precise, energy efficient control of PAC demand. The results of experiments and case studies showed that the proposed method is 10% more energy efficient than the conventional intermittent operation method and has 4-5% accuracy for operating point control.