Magnetic Amplifier Reactance Control via Anti-Symmetric Windings
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Solution Overview
Problem
Existing power systems face challenges in efficiently controlling high-voltage power flow due to high impedance and the need for significant biasing current to saturate cores, which requires superconductive windings and cryogenic equipment, limiting practical applications.
Innovation Solution
A magnetic amplifier with a saturable core and anti-symmetric control windings that use a biasing magnetic flux to drive specific portions of the core into saturation, reducing reactance and impedance, allowing for controlled power flow without the need for superconductive windings by simulating an air core.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If significant biasing current is applied to saturate the core, then the reactance and impedance are reduced, but the power consumption increases and superconductive windings are required
Solution Approach 1:
The core is divided into multiple segments or regions, each with its own control winding. This allows selective saturation of specific core portions rather than requiring complete core saturation, significantly reducing the biasing current needed while maintaining effective reactance control for power flow management.
Solution Approach 2:
Different portions of the core are given different magnetic properties through localized control windings. By applying biasing current only to specific control windings, only certain core regions are saturated, creating local variations in permeability that achieve the desired reactance reduction without requiring system-wide high current.
2Loss of energy
If a saturable core is used to control power flow, then the reactance can be reduced, but the device complexity increases due to cryogenic equipment requirements
Solution Approach 1:
The patent extracts and eliminates the cryogenic equipment requirement from the system by using distributed control windings that operate at standard temperatures. The core saturation is achieved through localized magnetic fields from control windings rather than requiring superconductive materials and cryogenic infrastructure.
Solution Approach 2:
Control windings serve as intermediaries between the power circuit and the core. These windings generate localized magnetic fields that selectively saturate core portions, acting as mediators that achieve reactance control without requiring direct application of high currents or cryogenic conditions to the entire system.
3Measurement precision
If control windings are placed close together, then the magnetic flux control is improved, but the voltage induced in control windings from load current increases
Solution Approach 1:
The control windings are arranged in an asymmetric configuration where windings on opposite sides of the core have different numbers of turns or different positions. This asymmetric arrangement causes the voltages induced in opposite windings to be unequal, allowing them to partially cancel each other out and reducing the net harmful voltage while maintaining effective magnetic flux control.
Solution Approach 2:
Instead of trying to minimize the induced voltage through symmetric cancellation, the patent inverts the approach by using asymmetric winding configurations that deliberately create unequal induced voltages. This inversion of the conventional symmetric design allows the control windings to be placed closer together for better flux control while the asymmetric arrangement naturally limits the harmful voltage through differential cancellation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The magnetic amplifier effectively controls high-voltage power flow with reduced reactance and impedance, enabling efficient power transmission and distribution across various voltage levels, including high voltage, extra high voltage, and ultra-high voltage systems, while minimizing power consumption and equipment complexity.
Implementation Method 1
The control windings are configured in such a way that a biasing magnetic flux arising from a control current flowing through one of the control windings is substantially equal to the biasing magnetic flux flowing into a second control windings
Implementation Method 2
Some saturable reactors control current flow through changing reluctance (magnetic resistance). The core of these reactors may be magnetically saturated in which the magnetic domains of the core are lined up with a magnetizing force. Before reaching saturation, the reactor's magnetic permeability and impedance to a winding with an alternating current may be large, limiting alternating current flow. As the core reaches saturation, its reactance (impedance) may be significantly smaller.
Data Source
AI summary
A magnetic amplifier includes a saturable core having a plurality of legs. Control windings wound around separate legs are spaced apart from each other and connected in series in an anti-symmetric relation. The control windings are configured in such a way that a biasing magnetic flux arising from a control current flowing through one of the plurality of control windings is substantially equal to the biasing magnetic flux flowing into a second of the plurality of control windings. The flow of the control current through each of the plurality of control windings changes the reactance of the saturable core reactor by driving those portions of the saturable core that convey the biasing magnetic flux in the saturable core into saturation. The phasing of the control winding limits a voltage induced in the plurality of control windings caused by a magnetic flux passing around a portion of the saturable core.