電力・エネルギー部門（B部門）の皆さま，いつも部門の活動にご理解とご協力を賜りましてありがとうございます。元号が変わり令和元年の電力・エネルギー部門大会は，広島工業大学において9月3日から6日にかけて実施されました。1888年に創立された電気学会は，電気工学分野の

When a transformer of a customer is energized in a distribution system, inrush currents whose magnitudes reach tens of rated currents may occur. The inrush currents may lead to an instantaneous voltage drop and/or an unnecessary operation of an overcurrent relay, and thus they affect power quality in the distribution system. When a new customer is connected to a distribution system, transmission and distribution companies in Japan use current-versus-time data of transformer inrush currents for their studies. However, such studies using current-versus-time data give worst-case or overestimated results. So as to obtain more accurate results, current-versus-flux curves of transformers are required to carry out simulations using an electromagnetic transient analysis program such as XTAP. So far, we have developed a method for estimating the current-versus-flux curve of a single-phase transformer from its current-versus-time data. Considering the fact that most of customer transformers are three-phase ones, this paper proposes a method for estimating the current-versus-flux curve of a three-phase transformer. The proposed method is validated by inrush-current experiments using two different three-phase transformers.

In recent years, there have been growing needs for accurate estimation of photovoltaic (PV) power due to the widespread use of PV power generation. PV power is usually estimated based on the amount of solar radiation, air temperature, and wind velocity. However, when the PV panel is covered with snow, the solar radiation is blocked by the snow and expected PV output cannot be obtained. In this paper, for accurate PV power estimation, we propose an Extended Lambert-Beer Law, and investigate a method to estimate the degree of attenuation of PV power by snow cover. And, accuracy verification of the proposed method is carried out with actual PV power records when snow accumulates in the Tokyo Electric Power Company (TEPCO) service area in 2018.

The IEC 61850 based process bus system on a substation automation system is currently being verified in the world. Some typical IEC 61850 based process bus system contains “Sampled value” communication function and it requires the high accuracy time synchronization scheme to get sampling timing simultaneity in each merging unit. Authors surveyed the way of improving the process bus system, and focused to renovate availability of the time synchronization scheme for getting sampling timing that often used IEC 61588 “Precision Clock Synchronization Protocol” complied special network communication equipment and technics. This paper introduces a new process bus scheme using over sampling technology and new communication network using high reliable optical fiber splitter to as the renovation way. This paper also describes an example of verification test result to confirm the usability, e. g. the AC electricity measurement test to survey accuracy and current differential protection relay test to survey the real-time characteristic. Finally, this paper concludes the availability of this process bus system concept.

In order to realize more efficient procurement and activation of control reserves, the balancing market is going to be established in 2021 in Japan. As for Synchronized Frequency Restoration Reserve (S-FRR) that is called automatic Frequency Restoration Reserve (aFRR) in Europe and is operated continuously and automatically by load frequency control (LFC), the control logic and control cycle are different in each transmission system operator (TSO)'s control area. Therefore, it is necessary to identify the technical challenges and to study countermeasures for cross-regional operation of S-FRR based on computer simulations.

For the above reason, the power supply-demand and frequency simulation models of all TSO's control area were developed in this research. Each TSO's control area model consists of LFC system model and power plant models. LFC systems were modeled in detail based on the actual specifications, and power plant models were constructed based on the IEEJ AGC 30 model. In addition, cross-regional interconnected system models which consist of each TSO's control area system model and tie-line models were developed. The developed models were validated thorough the comparison between simulation results and measured data of frequency, tie-line power flow, area requirement (AR) and generator outputs.

This paper proposes dependable parallel multi-population modified brain storm optimization for load adjustment distribution state estimation (DSE) considering outliers using just in time (JIT) modeling and correntropy. If the outliers are measured at the measurement points, estimation results at the measurement points only using correntropy are affected by the outliers. The challenge is solved by JIT modeling in the proposed method. Evolutionary computation techniques have been applied to the DSE problem because practical equipment causes a nonlinear characteristic of the objective function in distribution systems. However, it is required to obtain high and stable estimation quality in a short time considering uncertain outputs of renewable energies. The challenge is solved by multi-population, and parallel and distributed computing. Moreover, it is also required to keep appropriate estimation quality using dependable calculation even if some of the calculation results of distributed processes cannot be obtained due to various faults of the processes. The proposed method is verified to estimate distribution system conditions more accurately regardless of the outliers, realize faster computation, obtain higher and stabler estimation results, and keep higher quality of solutions even with high fault probabilities than the conventional methods.

Energy data analytics and behavioral science knowledge are expected to improve the quality of information to promote energy efficiency behavior. Although there have been many studies on Home Energy Management System using in-home displays, few is known about the effectiveness of using smartphone apps as an information provision channel. This study proposes an automatic generation method of the hourly electricity usage alert based on smart meter data, which can also detect a period of high usage in 5-minute intervals. Moreover, we evaluate the impact of sending alert on electricity consumption by conducting a randomized controlled trial to smartphone app users.

This paper proposes an efficient method for photovoltaic (PV) system output forecasting by Deep Boltzmann Machines (DBM) with Scatter Search-Predator-Prey Brain Storm Optimization (SS-PPBSO). DBM plays a key role to extract features of input variables while SS-PPBSO is a new evolutionary computation that combines PPBSO with Scatter Search. In recent years, as renewable energy, PV systems are positively introduced into power network in Japan so that power system operation becomes complicated due to the uncertainty. To overcome this challenge, it is required to forecast PV outputs that are influenced by weather conditions significantly. This paper proposes a new efficient PV output forecasting method with DBM that makes use of SS-PPBSO in learning. The effectiveness of the proposed method is demonstrated for real data of a PV system.

Introduction of variable renewable energies (VREs) is proceeding all over the world. However, output fluctuation due to inherent intermittency reduce stability of the power system. Therefore, more spinning reserve is needed for stability of the power system than before. In order to secure spinning reserve efficiently, electricity-adjustment auction was introduced in Japan recently. One candidate for the auction is a District Heating and Cooling system (DHC) with a Combined Heat and Power (CHP). The original use of a DHC is to satisfy regional heat and cold demand. On the other hand, in recent DHCs, CHPs are installed to improve efficiency, therefore, they are able to generate additional electricity and sell it to commercial power system. It means the DHC with CHP has the potential of electricity-adjustment as a large-scale energy resource. In the previous study, the usefulness of the electricity-adjustment by a DHC was evaluated. However, because it was a daily optimal operation planning problem, it was not possible to consider the operation continuity of multiple days. In general, a one-week collective operation plan for DHC is required because of the demand cycle characteristics. However, the mixed integer non-linear programming problem (MINLP) considering the unit commitment (UC) constraints of each device has a huge computational load. Therefore, in this paper, first of all, sufficient conditions to secure the operation continuity for multiple days are focused. Then, in order to reduce the amount of calculation and obtain a solution considering the operation continuity, a partitioning method for the large-scale operation planning problem of a DHC for electricity-adjustment is proposed.

Penetration level of large-scale wind power into the existing grid has been increasing significantly which impacts on the frequency stability during transient condition. This paper proposes a novel virtual synchronous generator (VSG) control strategy based on PID fuzzy logic control for HVDC transmission line to stabilize the power system during outage of fixed speed induction generator based wind farm.

The recovery voltages between contacts of circuit-breaker during capacitive current interruption on transmission lines with high resistance earthed neutral system were investigated. Actually operating transmission line systems including multi-parallel circuits, with cables and with branch circuits are modeled and recovery voltages during capacitive current interruption are investigated. All the results indicate that the recovery voltages for cases with high resistance earthed neutral system and with direct earthed neutral system are almost the same.

The electrolysis current control methods for HTES (High Temperature Electrolysis of Steam) hydrogen production plants are proposed. The methods enable the plants to produce Hydrogen in various production rates that is necessary for following fluctuating power sources, such as a wind power generation plant. The HTES plant simulator is developed to design and to evaluate the control system. The simulator consists of the SOEC model, the heat exchanger model, and the pressure difference estimation model. PWM electrolysis current control method is proposed and steam flow following current control method is evaluated by the simulator.

This paper describes a method for estimating lightning fault rates of transmissions line by statistical calculation using XTAP. Lightning current waveforms have been observed in Hokuriku area along the coast of the Japan Sea to use them for lightning surge simulation. Also we developed the method for estimating lightning fault rate of transmission line considering on dispersion of flashover voltage of arcing horns. Based on the observed current waveforms and the frequency of strokes to the transmission tower, the transmission line fault rate was calculated using the statistical function of XTAP. The calculated and actual transmission line fault rates were agreed well.

This paper introduces a novel method for synthesis of the equivalent circuit of an electromagnetic system described by a homogenized FE equation via model order reduction. The homogenization method replaces fine-structured material such as multi-turn coils, soft magnetic composite and laminated iron sheets with uniform material with complex permeability. The present method reduces the FE equation including the complex permeability to a circuit equation for small variables which can be solved with small computational cost. The present method is effective for time-domain analysis and makes it possible to consider magnetic saturations.

The 30^th Power and Energy Society Annual Conference was held on September 3-6, 2019 at Itsukaichi Campus of Hiroshima Institute of Technology in Hiroshima, Japan. The total number of presented technical papers was 409 and that of technical sessions was 50 (49 oral sessions and one poster session). A panel discussion and a special lecture were also organized during the conference period. The seats of the most events held during the period were fully occupied with audiences, and the final enrollment attained to 1,118. The conference was successfully completed with the great contribution from all the participants. This report reports the outline of the conference.