Power Conversion Device Active Noise Canceler Inductor Size
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Solution Overview
Problem
Existing power conversion devices that reduce normal mode and common mode noise either require increasing the size of inductors, leading to larger device sizes, or face inefficiencies in noise reduction.
Innovation Solution
A power conversion device incorporating both active and passive filters, where the active noise canceler reduces low-frequency common mode noise and the passive filter reduces normal mode noise and high-frequency common mode noise, allowing for efficient noise reduction without increasing the device size by optimizing the inductor size and component layout.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the amount of inductance of an inductor is increased to reduce normal mode noise and common mode noise, then the noise reduction effectiveness is improved, but the power conversion device itself is increased in size
Solution Approach 1:
The filter unit is segmented into multiple functional components: a passive filter for normal mode noise, an active noise canceler for common mode noise, and a choke coil for additional filtering. This segmentation allows each component to be optimized independently, reducing the need for oversized inductors while achieving comprehensive noise reduction across different frequency ranges.
Solution Approach 2:
The invention changes the operating parameters by introducing an active noise canceler that operates in the frequency domain rather than relying solely on passive inductive filtering. The active noise canceler uses operational amplifiers and filtering circuits to target specific frequency ranges, allowing for smaller inductor values while maintaining effective noise reduction.
2Device complexity
If only one of an active noise canceler or passive filter is used to reduce noise, then the device complexity is reduced, but the inductor size must be increased to achieve effective noise reduction
Solution Approach 1:
The invention merges both passive filtering (for normal mode noise) and active noise cancellation (for common mode noise) into a unified filter unit. This combination allows the system to leverage the strengths of both approaches: passive filters handle broadband noise efficiently, while active circuits target specific frequency ranges, eliminating the need for oversized inductors that would be required if only one approach were used.
Solution Approach 2:
The filter unit is designed with multi-functionality to handle both normal mode and common mode noise through different mechanisms. The passive filter component addresses normal mode noise while the active noise canceler addresses common mode noise, creating a universal filtering solution that covers multiple noise types without requiring separate systems or oversized components.
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
This configuration effectively reduces normal mode and common mode noise without enlarging the power conversion device, improving efficiency and reducing costs by minimizing the size and weight of inductive components, thus enhancing performance and reducing heat generation.
Implementation Method 1
a choke coil having a primary winding wound around a conductor to which the first alternating current power is supplied and a secondary winding configured to output a current depending on a magnetic flux generated by the primary winding
Data Source
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AI summary
A power conversion device includes a filter unit including an active noise canceler including an active element reducing low frequency components contained in common mode noise of noise and lower than a predetermined threshold frequency, and a passive filter including a passive element reducing normal mode noise of the noise and high frequency components contained in the common mode noise of the noise and equal to or higher than the threshold frequency. The active noise canceler includes a choke coil having a primary winding wound around a conductor to which a first alternating current power is supplied and a secondary winding outputting a current depending on a magnetic flux generated by the primary winding, a filter circuit reducing at least a high frequency region of the current of the secondary winding, an amplifier circuit amplifying output of the filter circuit and securing a required amount of the current, and a current injection circuit provided between the choke coil and an inverter unit, and injecting output of the amplifier circuit to each phase of the first alternating current power.