Damped Filter Windings for TT-Filter Resonance Suppression
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Solution Overview
Problem
In high-voltage systems of electric vehicles, the TT-type filter can experience resonance due to the differential mode ripple current matching the resonant frequency, leading to excessive current flow into the auxiliary smoothing capacitor and potential faults.
Innovation Solution
A filter component is designed with a magnetic core, first to fourth windings, and resistive elements connected in parallel with the windings, which suppresses resonance in the filter circuit by converting a portion of the differential mode current into Joule heat.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the TT-type filter is used to suppress differential mode ripple current, then electromagnetic interference is reduced, but resonance occurs when the ripple current frequency matches the resonant frequency, causing excessive current flow and potential faults
Solution Approach 1:
The patent introduces a resistive element that converts the harmful resonance energy into Joule heat, transforming the harmful resonant oscillation into a dissipative process. The resistive element provides damping that converts the excessive current energy at resonant frequency into thermal energy, thereby eliminating the harmful resonance effect while maintaining the filter's electromagnetic interference suppression capability
Solution Approach 2:
The resistive element acts as an intermediary component between the inductive and capacitive elements of the filter circuit. It provides a controlled energy dissipation path that mediates the resonance condition by introducing damping, preventing the uncontrolled oscillation that would otherwise occur between the filter inductors and capacitors at resonant frequencies
2Volume of moving object
If the filter component size is reduced for miniaturization, then space is saved, but heat dissipation becomes more difficult
Solution Approach 1:
The patent changes the electrical parameters of the filter by introducing the resistive element, which modifies the overall impedance characteristics and Q-factor of the circuit. This parameter change allows for reduced component values and smaller physical dimensions while the resistive element simultaneously provides a heat dissipation mechanism that manages the thermal effects of the resonance suppression function
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 solution effectively suppresses resonance in the TT-type filter, reducing the ripple current flowing through the smoothing capacitor and preventing potential faults, while also allowing for the miniaturization of the filter component due to reduced heat generation.
Implementation Method 1
resistive elements connected in parallel with the windings, which suppresses resonance in the filter circuit by converting a portion of the differential mode current into Joule heat
Implementation Method 2
first to fourth windings wound around the magnetic core... The first and third windings form a common-mode inductor... The first winding, the second winding, the third winding, and the fourth winding form a differential-mode inductor
Data Source
AI summary
A filter component is adapted to an electrical system having first and second electric apparatuses. The filter component has a resistive element and first, second, third and fourth windings. The first electric apparatus has a power terminal being a first power terminal and another power terminal being a second power terminal. The second electric apparatus has a power terminal being a third power terminal and another power terminal being a fourth power terminal. The first and second windings are connected in series, and the third and fourth windings are connected in series. The first and third windings form a common-mode inductor suppressing a common-mode noise current. The first to fourth windings form a differential-mode inductor suppressing a differential-mode noise current. The resistive element is connected in parallel across at least one of the first to fourth windings.