Break Through Industry Testing Bottlenecks with Independently Developed FFT Waveform Analysis System

In the field of traction machine performance testing, conventional methods mainly include vibration testing, noise testing, etc. However, accurately capturing voltage waveforms and analyzing operational data is the core of judging motor status. After extensive refinement, the NIDEC Elevator Motor Team has independently developed an FFT waveform analysis system based on the back electromotive force principle of traction machines — without the need for complex external sensors, it can generate sine waves only through signal conversion, providing a more efficient and accurate solution for traction machine testing.

Multiple Algorithms to Strengthen the Fault Detection Line of Defense

The Fast Fourier Transform (FFT) algorithm, the core of NVH analysis tools, is a classic tool for fault detection. It can accurately convert the time-domain signals of induced electromotive force collected during motor operation into frequency-domain signals. In the actual operation of permanent magnet synchronous motors, faults such as misalignment, reverse pasting, and offset pasting of permanent magnets will be reflected in subtle changes in induced electromotive force, which will generate abnormal signals at specific frequencies. With its powerful signal analysis capability, the FFT algorithm can keenly capture these subtle changes and provide important clues for fault diagnosis.

Dual Cores of NIDEC Elevator Motor Testing Solution

Hardware Core: High-Sampling-Rate Data Acquisition Card

To avoid signal "distortion", we select high-sampling-rate and high-resolution data acquisition cards as the hardware foundation. It can real-time capture tiny voltage changes of back electromotive force during motor operation, convert analog signals into precise digital signals, and provide "high-quality raw data" for subsequent analysis.

To ensure that the selected data acquisition card meets the requirements, the ME team tested it. The analysis shows that the selected data acquisition card has excellent stability, with a GRR of approximately 0.072% among three measurers A, B, and C.

Software Core: Independently Developed FFT Waveform Analysis System

The core advantage of this system lies in converting "professional data" into "visible, analyzable, and usable" test results. Its three core functions cover full-dimensional analysis from time domain to frequency domain:

• Induced Voltage Time-Domain Chart: Real-time displays the change curve of voltage signals over time, intuitively showing voltage fluctuations and peak occurrence nodes, making instantaneous signal changes clear at a glance;

• Lissajous Figure Analysis: Generates Lissajous figures through the phase relationship of different signals, quickly judges the operational stability of the traction machine, and identifies abnormal phase deviations at a glance;

• In-depth Spectrum Analysis: Converts time-domain signals into frequency-domain data, clearly shows the proportion of each frequency component, and easily locates potential problems such as harmonic interference.

Beyond "viewing data", the system focuses more on "delivering results". Three key test indicators safeguard traction machine performance:

1. Peak Distribution Rate: Counts the distribution of voltage peaks, judges whether peaks are within a reasonable range, and avoids motor loss caused by abnormal peaks;

2. Waveform Non-Coincidence Degree: Compares the difference between the actual waveform and the standard sine wave, quantifies waveform distortion, and provides precise basis for motor commissioning;

3. Waveform THD Analysis: Calculates total harmonic distortion, intuitively reflects the impact of harmonics on voltage waveforms, and helps optimize the product quality of traction machines.

Achievement Display

Through the independently developed FFT waveform analysis system, multi-dimensional testing of motor NVH performance has been carried out, significantly reducing product quality issues and ensuring motor quality before delivery. From December 2024 to the present, approximately tens of thousands of motors have been tested, with the first-pass yield of tested motors maintained above 99.5%. The collection and analysis of these data fully demonstrate the reliability of NIDEC elevator motor quality and the significance of developing this motor FFT performance testing software.

Finally, from NVH principle interpretation, innovation introduction, high-speed data acquisition, multi-dimensional parameter analysis to full-scale mass product testing, this FFT waveform analysis system breaks the limitations of traditional testing. Whether for motor factory quality inspection, daily operation and maintenance monitoring, or fault diagnosis, it can provide detailed and comprehensive testing support, injecting new momentum into the efficient, safe, and reliable testing of motor performance in the elevator traction machine industry!