Variable frequency drives (VFDs), common in robotics, tend to generate more EMI up and down the spectrum, requiring the right type of high-performance filter. In this success story, Schaffner helps a warehouse automation project with VFDs make it over the EMI compliance hurdle.
The Tricky Interference of Motor Controls
A leading e-commerce company, known for its extensive network of high-tech distribution centers, was developing an innovative warehouse system. This new setup would feature robotic arms transporting products between human-operated picking stations.
Robotic and automated factory applications require precise control over the motors that drive robotic arms and conveyors. To control these motors, designers use VFD drives, allowing the user to control motor speed and torque.
A common problem with variable drives is that since they can run through a range of operating settings, they tend to be noisy, electrically speaking. As the VFD adjusts its output to speed up or slow down the motor, electromagnetic interference (EMI) goes up and down the spectrum. At certain points of motor behavior, they may generate spikes in noise, affecting the surrounding system. VFD applications then need to be tested for electromagnetic compatibility (EMC) at various speeds.
An Ultra-Compact 3-Phase Filter with Wide Range
To get a green light for the overall automation, the client needed to perform EMI testing to ensure that the new drives would not interfere with other electronic systems in the warehouse.
Laura Roy, a rep from Norris & Associates, introduced the account to Schaffner several years ago, and the component maker’s application engineering team has since supplied several test lab kits and individual filter samples. This time, the customer’s Compliance Engineering Team was familiar with much of the Schaffner portfolio and had selected several possible 3-phase filters that could support the application.
After discussions with Tom Larkin, application engineer at Schaffner, the customer decided to test the FN3258 ultra-compact filter, a component that was ideal for robotic motor drives, with units available to support applications from 7 to 180 Amps. This filter is designed to attenuate conducted emissions from 150 kHz to 30 MHz.
Confirmation and Compliance
Schaffner’s engineering team supported the customer through compliance testing. Fortunately, the addition of the FN3258 filter helped the robotic arm to pass, and the warehouse automation project could proceed as planned.
If you have a noisy motor control in your project, look to Schaffner for filters that save space in lightweight robotics and have enough attenuation to handle the full range of EMI frequencies.
MORE POWER TO YOU!