Providing electricity is quite important to sustain modern society. In order to realize high quality electricity reliability, sophisticated generator control is required so that stable frequency and voltage are maintained. This online PBL (Project Based Learnin or Program Based Learning) provides opportunity to understand how to control generator with learning control theory. In beginning, students at each university learn control theory using a kit. After understanding the control theory, students try to design generator controller to maintain good power quality.
The large-scale deployment of renewable energy requires a power system that can minimize operating costs while maintaining a stable supply. One way to reduce Variable Renewable Energy (VRE) suppression is to expand tie lines. VRE suppression can also be reduced by locating large power demands, such as hydrogen/ammonia production and direct air capture, near VRE. In Japan, where general transmission and distribution utilities are responsible for electricity supply and demand in their areas, it is necessary to consider the calculation results for each area in detail. This study clarified the effects of tie line expansion and load relocating on the operation cost, VRE suppression, and shortage of tertiary for the entire national grid and each of the nine areas. The results of the full-year Unit Commitment simulation showed that the national operating costs were similar for the tie line expansion and load relocating. In the generation plan for a representative day when both are used together, Hokkaido-Chubu areas show strong characteristics of the case of tie line expansion, while Kansai-Kyushu areas show strong characteristics of the case of load relocating.
In this study, disconnector switching surge was measured at electric-supply stations with different equipment types. Regarding the measured surge, differences of surge waveform characteristics between AIS (air insulated substation) equipment and GIS (gas insulated switchgears) equipment, voltage class were investigated. Besides, relationships of induced peak voltage between outdoor equipment and indoor low-voltage circuit were examined. In addition, the estimation of maximum surge voltage in the housing of equipment was shown by means of statistical method.
In recent years, Power to Gas, which converts surplus renewable energy into gaseous fuels for storage and utilization, has been attracting attention. One such Power to Gas project involves hydrocarbon production technology. In this paper, a hydrocarbon production system using Solid Oxide Electrolysis Cell (SOEC) co-electrolysis was devised and the effects of the system components on efficiency were investigated. First, we conducted a comparative analysis of energy efficiency at different SOEC operating temperatures: 750°C, 800°C, and 850°C. The results indicate that operating the SOEC at 750°C yields the highest energy efficiency. Secondly, we compared the effects of H2O and CO2 utilization, as well as the heat loss rates of the SOEC, with the thermal and heat loss rates of the heat exchanger on overall efficiency. The findings highlight that variations in heat loss rates within the SOEC have the most significant impact on energy efficiency. Additionally, when comparing the heat loss per heat exchanger in our study, we observed that the steam generator and heat exchanger for air introduced from outside exhibited high heat loss rates within the system. Furthermore, we investigated the influence of the supplied air quantity on energy efficiency, revealing that reducing the amount of supplied air is essential for achieving high efficiency.