One method for calculating flux-MMF relationship of an orthogonal core is described. The calculation is based on a three-dimensional magnetic circuit model of the orthogonal core. The model is derived by dividing the orthogonal core, inclusive of the surrounding region, into elements comprising a three-dimensional magnetic circuit. Using this model, the flux-MMF relationship of the orthogonal core with arbitrary dimensions can be calculated from the B-H characteristic of the core material. The calculation method presented is useful for optimum design of devices using an orthogonal core. >

One Method For Calculating Flux-MMF Relations Hip Of Orthogonal-core

This paper describes a fundamental consideration on high speed control of the orthogonal-core type variable-inductor. The variable-inductor is applicable to a VAR compensation in the electric power system. The transient characteristics of the variable-inductor under the condition of DC control are discussed based on simulation and experiment. For high speed operation, we present an instantaneous control of the primary current. A simple control circuit using a DC-DC converter is demonstrated in this paper.

High speed variable-inductor controlled with DC-DC converter

Performance analysis of the orthogonal-core type converters based on a circuit system combined with the reluctance network model of the orthogonal-core and the outer electric circuits

A simple circuit consisting of two saturable transformers for interfacing an alternative energy system to the utility grid is proposed. Each transformer has two windings, each one is connected in series and same polarity, and the other is connected in series and opposite polarity, respectively. This circuit has the inherent properties not only of isolation but also of spontaneous disconnection at the time of line fault. The quantity and direction of transmitted power are controlled by the phase lead angle of the inverter voltage to the utility one. The maximum power transmission from the DC source occurs when setting the phase inverter by 135/spl deg/ in lead, and this angle is independent of the inverter output voltage and load resistance. This high-frequency link scheme is effective for practical applications. >

An interfacing circuit using a biased saturable transformer for photovoltaic and alternative energy system with protection against the line fault

Rising demand for electric power has heightened the need for flow control in existing power systems.An orthogonal core has merit for a power controller, including simple construction and high reliability, because it consists of only a pair of cores and their windings. The orthogonal core can control net inductance of secondary windings easily and continuously.This paper presents an orthogonal core phase shifter for flow control in an electric power system. The phase shifter is constructed with the variable inductors and transformers. For reduction of harmonic currents, the orthogonal core utilizes wedge gaps and tertiary windings. In this paper, we examine the fundamental characteristics of the orthogonal core phase shifter.

Operating Characteristics of Orthogonal Core Phase Shifter.

Discusses transient operation of the orthogonal-core-type DC-AC converter for a grid-connection-type photovoltaic (PV) power system. In particular, they consider the transient operation when the converter is connected to and disconnected from the utility grid on the basis of simulation and experiment. Furthermore, they examine the converter behavior when a line-to-line fault occurs in the utility grid. It is shown that the DC-AC converter has excellent tolerance for various faults which occur in a PV power system. >

H. Takahashi

Papers

Transient operation of orthoginal-core type DC-AC converter for photovoltaic power system