Motor Control Device Shared Capacitor Parasitic Inductance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing motor control devices require multiple capacitors for voltage smoothing, leading to increased size and inefficiency, as they do not adequately consider the parasitic inductance between voltage boosting and inverter circuits.
Innovation Solution
A motor control device with a voltage boosting circuit, a shared capacitor for smoothing voltages, and an inverter circuit, where the distance between the voltage boosting circuit and inverter is optimized to minimize parasitic inductance, allowing the capacitor to serve both circuits and reduce overall device size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple capacitors are used for voltage smoothing in voltage boosting circuit and inverter circuit, then voltage smoothing performance is improved, but device size increases
Solution Approach 1:
The patent combines the capacitor for the voltage boosting circuit and the capacitor for the inverter circuit into a single shared capacitor. This capacitor is configured to smooth voltages from both circuits simultaneously, eliminating the need for separate capacitors and thereby reducing overall device size while maintaining voltage smoothing performance
Solution Approach 2:
The shared capacitor serves multiple functions: it acts as the smoothing capacitor for the voltage boosting circuit, the smoothing capacitor for the inverter circuit, and provides common voltage stabilization for the entire system. This multi-functionality allows a single component to replace what would traditionally require multiple separate components
2Adaptability or versatility
If distance between voltage boosting circuit and inverter circuit is increased, then layout flexibility is improved, but parasitic inductance increases
Solution Approach 1:
The patent applies different spatial arrangements to different parts of the circuit: the voltage boosting circuit and inverter circuit are positioned close to each other to minimize parasitic inductance in the high-current path, while the control unit is positioned separately to provide layout flexibility. This localized optimization ensures that critical high-frequency paths have minimal inductance while the overall layout remains flexible
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 reduces the number of capacitors needed, minimizing the motor control device's size while maintaining effective voltage smoothing and reducing heat generation and parasitic inductance-related issues.
Implementation Method 1
a condenser that smooths a voltage output by the voltage boosting circuit
Implementation Method 2
a voltage boosting circuit that boosts a power source voltage supplied from outside
Data Source
AI summary
A motor control device includes: a voltage boosting circuit that boosts a power source voltage supplied from an outside; a condenser that smooths a voltage output by the voltage boosting circuit; an inverter circuit that generates a drive voltage of a motor by switching a voltage output by the voltage boosting circuit and smoothed by the condenser; and a control part that causes the voltage boosting circuit to bypass and causes the power source voltage to be supplied to the inverter circuit, and a distance between the voltage boosting circuit and the inverter circuit is a distance with which a parasitic inductance is equal to or less than a predetermined value.