Layered Bus Bar Configuration for Induction Heating Power Supply
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High-speed switching operations in power semiconductor devices lead to rapid current changes, resulting in surge voltages due to parasitic inductance, which can damage the devices and compromise the protection of inverters in induction heating power supply systems.
Innovation Solution
The induction heating power supply apparatus incorporates a smoothing section with a pair of bus bars and capacitors arranged in a layered manner with an insulator sandwiched between them, reducing parasitic inductance and thereby suppressing surge voltages by optimizing the configuration of the bus bars and capacitors to minimize inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high speed switching operation is performed to produce high frequency AC power, then productivity is improved, but surge voltage damages the power semiconductor device
Solution Approach 1:
The patent changes the physical parameters of the bus bar configuration by arranging flat faces oppositely and reducing the distance between them, which directly reduces the parasitic inductance value. This parameter optimization allows high-speed switching to proceed with minimal surge voltage generation, resolving the contradiction between productivity and device protection.
Solution Approach 2:
The patent transitions from a conventional single-plane bus bar arrangement to a three-dimensional layered structure with oppositely arranged flat faces. This spatial reconfiguration reduces the current loop area and parasitic inductance, enabling high-frequency operation without excessive surge voltage while maintaining device safety.
2Reliability
If parasitic inductance is reduced to suppress surge voltage, then device protection is improved, but device complexity increases
Solution Approach 1:
The bus bar structure is segmented into multiple flat-faced sections arranged in specific orientations. By dividing the conductive path into segments with optimized geometries and arranging them in a layered configuration, the patent reduces overall parasitic inductance while keeping each individual segment simple in structure.
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 parasitic inductance, mitigating surge voltages and enhancing the protection of the inverter, thereby improving the reliability and longevity of the induction heating power supply system.
Implementation Method 1
a capacitor to smooth pulsating current of the DC power
Implementation Method 2
an inverter to convert the smoothed DC power back to AC power to generate high frequency AC power
Implementation Method 3
AC power is applied to a heating coil to cause the heating coil to generate a magnetic field, and a workpiece placed in the magnetic field is heated by electric current induced in the workpiece
Implementation Method 4
The current change di/dt produces surge voltage L×di/dt between terminals of the power semiconductor device due to a parasitic inductance L of a conductive path
Data Source
AI summary
An induction heating power supply apparatus includes a smoothing section to smooth pulsating current of DC power output from a DC power supply section, and an inverter to convert the DC power smoothed by the smoothing section to AC power. The smoothing section includes a pair of bus bars connected to the inverter and a capacitor connected to the pair of bus bars. Each of the bus bars has an external surface extending in a current flow direction, the external surface including a flat face having a larger surface dimension than another face of the external surface in a direction perpendicular to the current flow direction. The bus bars are arranged in a layered manner such that the flat faces of the bus bars are opposed to each other and such that an insulator is sandwiched between the flat faces of the bus bars.