Motor Controller LC Filter Layout for Pump Noise Suppression
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Solution Overview
Problem
Current motor noise suppression technologies in pump devices are insufficient, especially when used in precision applications or on-vehicle systems, as they fail to effectively reduce noise without compromising motor performance.
Innovation Solution
A motor controller with a specific capacitor configuration, including an inductor and capacitors connected in series and parallel, is used to smooth drive voltages and neutral point voltages, along with additional capacitors in control and output signal lines to eliminate noise, while maintaining optimal motor rotation characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a motor with noise countermeasure (single capacitor between neutral point and reference potential) is used, then noise generated from the motor is suppressed, but the noise suppression is insufficient for precision apparatus and on-vehicle pump applications
Solution Approach 1:
The single capacitor in the neutral point is segmented into multiple capacitors (first capacitor connected to drive voltage line, second capacitor connected to common line, third capacitor connected between second capacitor and ground). This segmentation allows each capacitor to perform specific noise suppression functions at different locations in the circuit, achieving comprehensive noise suppression that satisfies precision apparatus and on-vehicle pump requirements
Solution Approach 2:
An inductor is introduced as an intermediary component connected in series with the drive voltage line. The inductor works together with the capacitors to form an LC filter circuit, providing enhanced noise filtering capability. The inductor acts as a mediator that blocks high-frequency noise while allowing the drive voltage to pass through, thereby improving overall noise suppression performance
2Object-affected harmful factors
If multiple capacitors and an inductor are added to suppress noise, then noise suppression performance is improved, but the device complexity increases
Solution Approach 1:
The multiple capacitors and inductor are merged into a unified noise suppression circuit structure where the first capacitor is connected between the drive voltage line and ground, the second capacitor is connected between the common line and ground, and the third capacitor connects the second capacitor to ground. This merging creates a coordinated noise filtering system that achieves superior noise suppression without requiring separate independent circuits, thereby managing complexity effectively
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 solution effectively suppresses noise in the motor and pump device, ensuring that precision apparatuses are not affected by motor-generated noise and maintaining the motor's performance by optimizing capacitor values within specific capacitance ranges.
Implementation Method 1
an inductor which is electrically connected in series with the drive voltage line
Implementation Method 2
a first capacitor which is electrically connected between a portion between the inverter and the inductor in the drive voltage line and the ground, a second capacitor which is electrically connected between a portion on an input side with respect to the first capacitor in the drive voltage line and the ground, and a third capacitor which is electrically connected between the second capacitor and the ground
Data Source
AI summary
A motor controller includes a motor control part controlling a motor having a three-phase coil by a control signal, an inverter applying a drive voltage supplied from a power source to the three-phase coil based on an output signal from the motor control part, a drive voltage line supplying the drive voltage to the inverter, a common line electrically connected with a neutral point of the three-phase coil, an inductor electrically connected in series with the drive voltage line, a first capacitor between a portion between the inverter and the inductor in the drive voltage line and a ground, a second capacitor between a portion on an input side with respect to the first capacitor in the drive voltage line and the ground, and a third capacitor between the second capacitor and the ground. The common line is electrically connected between the second capacitor and the third capacitor.