Harmonic Filter for Magnetic Amplifier Attenuating Even-Ordered Harmonics
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Solution Overview
Problem
Magnetic amplifiers generate unwanted harmonics due to nonlinearity at saturation points, leading to overheating and potential destruction of dc circuits as these harmonics induce high voltages and currents, which existing technologies fail to effectively mitigate.
Innovation Solution
A harmonic filter is integrated into the magnetic amplifier, comprising coils with a symmetrical configuration and positioned adjacent to the control circuit windings, short-circuited to isolate and attenuate even-ordered harmonics through mutual induction, providing a low-impedance connection that cancels out currents induced by ac flux harmonics, thereby dampening them.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If magnetic amplifier operates at saturation point to achieve high power control, then power control capability is improved, but harmonics are generated causing overheating and circuit damage
Solution Approach 1:
A harmonic filter is introduced as an intermediary component between the magnetic amplifier and the circuit it controls. This filter contains control windings and filter windings that work together to detect and eliminate harmonics. The filter windings are short-circuited to provide a low-impedance path for harmonic currents, effectively removing them before they can cause overheating or damage to the circuit.
Solution Approach 2:
The harmful harmonics are extracted and separated from the main power signal using the harmonic filter. The filter windings are specifically designed to isolate even-ordered harmonics through mutual induction with the control windings, allowing these harmful frequency components to be removed while preserving the useful power transmission.
2Object-affected harmful factors
If harmonic filter with short-circuited windings is added to mitigate harmonics, then harmonics are attenuated, but device complexity increases
Solution Approach 1:
The harmonic filter is integrated with the magnetic amplifier by positioning the control windings and filter windings adjacently on the same magnetic core. This merging of functions allows the filter to utilize the existing magnetic path and structure of the amplifier, reducing the need for separate, complex filtering components while effectively attenuating harmonics.
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 harmonic filter effectively minimizes and dampens even-ordered harmonics, preventing overheating and circuit damage, while being energy-efficient and compatible with varying power loads, ensuring the stability and longevity of magnetic amplifiers.
Implementation Method 1
coils with a symmetrical configuration and positioned adjacent to the control circuit windings, short-circuited to isolate and attenuate even-ordered harmonics through mutual induction
Implementation Method 2
The disclosed magnetic amplifiers use saturation in magnetic permeable cores to change the equivalent impedance of power lines and/or circuits
Data Source
AI summary
A magnetic amplifier includes a permeable core having multiple legs. Control windings wound around separate legs are spaced apart and connected in series in an anti-symmetric relation. Harmonic filters are positioned adjacent to the control windings to attenuate even-ordered harmonics generated by alternating load current passing through a portion of the legs. The control windings bias magnetic flux arising from control current flowing through one of the control windings which is substantially equal to the biasing magnetic flux flowing into a second control winding. The flow of the control current through each of the control windings changes the reactance of the permeable core reactor by driving those portions of the permeable core that convey the biasing magnetic flux 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 permeable core.