Opposing Bus Bar Structure for Power Conversion Noise Attenuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Power conversion apparatuses in electric vehicles generate significant electromagnetic noise in the AM broadcast and short wave frequency bands due to switching element fluctuations, which are not effectively mitigated by existing technologies.
Innovation Solution
A bus bar structure with opposing portions and strategically placed capacitance units and inductors forms an LCL (or LCLC) filter to reduce normal mode noise current, utilizing capacitance elements connected between bus bars and frame ground, and inductors to enhance noise attenuation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If switching elements are used to convert DC voltage to AC voltage, then power conversion function is improved, but electromagnetic noise in AM broadcast and short wave frequency bands is generated
Solution Approach 1:
A bus bar structure with specific geometric configuration (opposing portions with current flowing in opposite directions) is introduced as an intermediary element between the switching elements and the power source terminals. This structure generates magnetic fields that oppose each other, creating a shielding effect that attenuates electromagnetic noise in the AM broadcast and short wave frequency bands while allowing power conversion to proceed normally
Solution Approach 2:
The invention changes the physical parameters of the bus bar structure by creating opposing portions where current flows in opposite directions. This geometric and current-direction parameter change causes the magnetic fields generated by each portion to oppose each other, resulting in noise attenuation in specific frequency bands without affecting the power conversion function
2Object-generated harmful factors
If bus bar structure is designed to reduce noise, then electromagnetic noise attenuation is improved, but device complexity increases
Solution Approach 1:
The noise reduction function is merged into the bus bar structure itself rather than being a separate component. The opposing portions are integrated directly into the bus bar geometry, combining the power transmission and noise shielding functions into a single unified structure, thereby avoiding additional device complexity
Solution Approach 2:
The bus bar structure serves multiple functions simultaneously: it transmits power from the power source to the switching elements and also provides electromagnetic noise shielding in the AM broadcast and short wave frequency bands. This multi-functionality eliminates the need for separate noise filtering 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
The proposed bus bar structure effectively reduces noise in the AM broadcast and short wave frequency bands, enhancing noise attenuation while maintaining miniaturization and cost efficiency.
Implementation Method 1
a first capacitance unit connected between a positive terminal and a negative terminal of a power source and configured to smooth noise (voltage change) superimposed on a direct current (DC) voltage
Implementation Method 2
the first bus bar and the second bus bar have portions opposing each other (opposing portions), and are arranged so that the current flows in the same direction in the opposing portions
Implementation Method 3
the first bus bar and the second bus bar have portions opposing each other (opposing portions), and are arranged so that the current flows in the same direction in the opposing portions
Implementation Method 4
A bus bar structure with opposing portions and strategically placed capacitance units and inductors forms an LCL (or LCLC) filter to reduce normal mode noise current
Data Source
AI summary
A power conversion apparatus PWCS includes a smoothing capacitance element Cxp connected between a positive terminal and a negative terminal of a power source and configured to smooth a voltage change superimposed on a DC voltage, a switching circuit SWC converting the DC voltage into an AC voltage, a first bus bar BSB1 configured to electrically connect between the positive terminal of the power source and a terminal TCx1 of the smoothing capacitance element Cxp, a second bus bar BSB2 configured to electrically connect between the negative terminal of the power source and a terminal TCx2 of the smoothing capacitance element Cxp, and a filtering capacitance elements C1 and C2 electrically connected between the first bus bar BSB1 and the second bus bar BSB2. The first bus bar BSB1 and the second bus bar BSB2 include opposing portions and are disposed to allow the current to flow through the opposing portions in the same direction.