Yasuhiro Noro

Power fluctuation suppression system for large scale PV

The large scale photovoltaic (PV) generation station is expected to spread in the future. However, output power of renewable energy sources such as PV is affected by weather conditions and their output tends to be unstable. As a result, the penetration of PV power station makes it difficult to maintain frequency of power system in allowable range. The authors have developed a suppression system to stabilize output power fluctuation of a large scale PV generation station. To reduce short term fluctuation, storage batteries applying SCiBTM are used. In this paper, verification test results are explained and simulation results to improve control performance are also shown.

System study of direct current power transmission system connected to wind farm

This paper discusses the DC transmission from a large-scale wind farm. The useful controls are proposed and studied by the digital simulation. Many advantages of the system are reported, and the robustness of this system is shown. This system enables usage of simple squirrel-cage induction generator. The rating capacity of 12 MW with the voltage source converter for the DC system is assumed in this study.

DEVELOPMENT OF HIGH PRECISION POWER SYSTEM SIMULATOR

Abstract This paper presents a recently developed low-power analog power system simulator with increased operability and precision over conventional simulators. The simulator is composed of miniature models of actual equipment with characteristics as close as possible to those of actual power systems. Reactors, capacitors and resistors are carefully designed and used in combination to simulate transmission lines, filters and loads. Since miniature models of machines such as synchronous generators can not produce accurate characteristics, equivalent electronic circuits representing the machines are developed. Generally, loss in the simulators circuits is larger than that in an actual network. Therefore, network components realized by electronic circuits, such as circuit breakers and thyristors, are designed to compensate the voltage drop. Saturation elements for generator models and transformer models, and non-linear elements for arrester models are incorporated. A computer is used to improve operability in parameter selection, simulation control and data processing all through menu selection. Simulation results are described in comparison to EMTP calculation results.

Study of modeling method of distributed generators considering partial dropout for trunk transmission system

Simultaneous dropout of a large amount of distributed generators caused by a fault in a power line with voltage drop and/or phase change may worsen power stability of a trunk power system. A reduced model of distributed generators in secondary systems considering partial dropout is proposed for the stability analyses. To verify the reduced model, a detailed model and the proposed reduced model are compared under same conditions for a variety of load and fault conditions. For an example of practical applications, a relative comparison of power stability in IEE of Japan EAST 10 machine system model under fault ride through (FRT) requirements is demonstrated.