Active Common-Mode Noise Compensation With EMI Data Feedback
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Solution Overview
Problem
Existing passive EMI filters for high-power systems are inefficient in noise reduction due to magnetic saturation, leading to increased size and cost, and lack the ability to collect noise data after cancellation.
Innovation Solution
An active compensation device with a sensing unit, integrated circuit (IC) unit, and compensation unit that converts common-mode noise signals into digital data and generates compensation currents or voltages, allowing for noise data collection and external monitoring.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the size or number of common mode chokes is increased to prevent magnetic saturation and maintain noise reduction performance in high-power systems, then noise reduction performance is maintained, but the size and price of EMI filters are greatly increased
Solution Approach 1:
The patent replaces the passive mechanical/common-mode-choke-based noise suppression system with an active electronic compensation system using operational amplifiers and feedback circuits. This substitution allows noise cancellation through electronic means rather than relying on the physical size and magnetic properties of common mode chokes, thereby reducing the overall filter size while maintaining noise reduction performance in high-power systems
Solution Approach 2:
The invention changes the operating parameters of the noise compensation system by using active electronic components with adjustable gain and bandwidth characteristics. The operational amplifiers allow dynamic adjustment of compensation parameters, enabling effective noise suppression without requiring large physical components, thus resolving the contradiction between noise reduction performance and filter size
2Reliability
If passive common mode chokes are used to suppress CM noise current, then noise reduction is achieved, but information about the noise cannot be collected after cancellation
Solution Approach 1:
The patent implements a feedback mechanism where the noise signal is sensed, converted to digital data, and used to generate a compensation signal that is fed back to cancel the original noise. This feedback loop not only achieves noise reduction but also preserves and provides access to the noise information in digital form, eliminating the information loss inherent in passive suppression systems
Solution Approach 2:
The invention introduces an intermediary device (the active compensation circuit with ADC and DAC) that mediates between the noise source and the cancellation mechanism. This intermediary converts the analog noise signal to digital data for information preservation while simultaneously generating the compensation signal needed for noise suppression, thus achieving both noise reduction and data collection
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
Enables effective noise cancellation and data collection for monitoring and big data processing, reducing the need for larger passive filters and enhancing noise management in high-power systems.
Implementation Method 1
a sensing unit configured to generate an output signal corresponding to a common-mode noise signal on the high-current path
Implementation Method 2
an integrated circuit (IC) unit that receives the output signal and converts the same into a digital signal
Implementation Method 3
amplify the analog signal to generate the amplified signal
Implementation Method 4
a compensation unit configured to draw a compensation current out of the high-current path or generate a compensation voltage on the high-current path, based on the amplified signal
Data Source
AI summary
The present disclosure provides an active compensation device for actively compensating for noise generated in a common mode in each of at least two high-current paths. The active compensation device includes: a sensing unit configured to generate an output signal corresponding to a common-mode noise signal on the high-current path, an IC unit that receives the output signal and converts the same into a digital signal, generates noise data and an amplified signal at least based on the digital signal, and outputs the noise data and the amplified signal, and a compensation unit that draws a compensation current from the high current path or generates a compensation voltage on the high current path, based on the amplified signal. The noise data is provided to an external device.