In this paper, we show the result of building and simulating a model that can optimally operate electric power supply by a system combining Photovoltaic Power Generation (PV) and Storage Battery (BT), mainly for residential customers. Especially focusing attention on BTs, by solving the objective function that minimizes electricity charges of customers by using the internal temperature and life characteristics of the storage battery as constraint conditions, an optimal solution is obtained. Compared with the case where the constraint condition of the storage battery is not taken into consideration, although the electricity charge increases, it is evaluated that the system can be used stably for a long time. Also, in a system that combines PV and BT, DC power bus (DC Bus) is controlled to a constant value for the purpose of supplying electric power to DC load and stable power supply to AC load.
The paper proposes total optimization of smart community by multi-population global-best brains storm optimization with differential evolution strategies considering uncertainty of renewable energies. This paper tries to minimize total energy costs, actual electric power loads at peak load hours (peak shifting), and CO2 emission for whole of a smart community. The simulation results by the proposed method are compared with those by Differential evolutionary particle swarm optimization, brains storm optimization, brains storm optimization with differential evolution, global-best brains storm optimization.
The increase in integration of renewable energy sources (RESs) and reform of electricity system in Japan will increase generation uncertainty in power system. To handle the said uncertainty, the authors, in this paper, propose the novel voltage and reactive power management technology that can reduce the transmission loss and number of control of shunt devices and transformer taps thereby reducing the operating expenditure (OPEX). This paper introduces the Optimized Performance Enabling Network for Volt/var(Q) (OPENVQ) system for smart operation. The system comprises a look-ahead operational condition, an optimal power flow, a grid equipment control and an online voltage security assessment. To validate the performance of the OPENVQ system, a simulator has been developed that can handle multi-period operational conditions with time series data. Simulation results based on the IEEE 118-bus model show that a look-ahead operational condition is important for online optimization of voltage and reactive power management. Further, a new logic to reduce the number of control of shunt devices and transformer taps for managing grid voltage is evaluated.
This paper focuses on a novel variable deloaded operation of variable speed wind turbines with permanent magnet synchronous generators (VSWT-PMSGs) based offshore wind farm (OWF) to maintain primary reserve, which is connected to onshore grid through voltage source converter based high voltage DC (VSC-HVDC) transmission system. A centralized droop controller with dead band is designed for VSWT-PMSGs to utilize this reserve power to suppress the frequency fluctuations of the onshore grid due to the installations of large-scale fixed speed wind turbines with squirrel cage induction generators (FSWT-SCIGs) based wind farm (WF) and photovoltaic (PV) power station. The combination of variable deloaded operation and centralized droop controller can give better frequency regulation and decrease energy loss due to the deloaded operation. The effectiveness of the proposed variable deloaded operation and centralized droop controller is verified through simulation analyses on a modified IEEE nine-bus test system. The simulation results reveal that the variable deloaded operation can decrease the energy loss compared to the fixed deloaded operation as well as suppress the frequency fluctuations in the same level as the fixed deloaded operation.
A seed-free radio-frequency (RF) pre-ionized inert gas plasma MHD electrical power generation has been firstly demonstrated in fundamental experiments with a shock-tunnel facility. An enthalpy extraction ratio of 2.6% was successfully obtained even under an inlet total temperature of 2200K at which the power generation can be operated continuously. Since the RF input power required for the pre-ionization tends to be increased for lower inlet total temperature, the reduction of the RF input power is needed for further improvement in the total performance.
The R&D Steering Committee is working in planning and Steering of the Research and development of Power and Energy Society. In this article, activities of the committee of the last term are reported, and recent trend and future problems are also discussed. The process of planning and steering of the research and development, and the challenges to activation of Power and Energy Society are shown.