Motors and generators manufacturer ABB is offering a new condition monitoring service for large induction motors, ABB MACHsense-P, that acts like a skilled doctor with a stethoscope, detecting trouble before it can lead to crisis. The key to its early-warning capabilities is ABB's intelligent software, which analyzes vibrations and other data collected from the motor with remarkable accuracy.
“No one in the past has looked at data the way we do,” explains Cajetan Pinto, R&D Manager for ABB Motors and Generators, Service and Vice President for ABB in Mumbai, India. “We recently filed three patents for our methodology.”
According to Pinto, older monitoring systems generated too many errors – both false positives and false negatives. In part, that's because noises from non-essential parts of the motor tended to confuse the readings.
Picking-up right signals
ABB MACHsense-P, based on years-long intensive research, represents a major leap forward. "ABB's analysis system uses algorithms that pick out specific signals," says Pinto. "If you're concerned about bearings, our system can isolate the signals coming from the bearings itself."
Since May 2010, customers can order the ABB MACHsense-P service in one of two ways: ‘Standard’ service comes as part of a regular six-month maintenance plan, while ‘advanced’ service refers to a one-time intervention to troubleshoot a specific problem. Next year, ABB plans to expand the service from large induction motors to synchronous motors and wind generators.
How does it work?
An ABB technician, arriving at the work site, attaches sensors to the motor being tested. Certain sensors, using accelerometers, convert vibrations into electrical signals. Others measure electrical data. The signals are picked up by a data collector, which is in turn connected to a laptop. During the course of a day, a technician can usually test between four and six motors.
Immediately, the customer receives an on-site summary of the motor’s performance, which is presented as a color-coded report rating four key areas: anti-friction bearings, cage rotor, installation and power supply. Later, following extensive analysis by experts, the customer receives a more detailed report.
ABB MACHsense-P can save a customer from major headaches. Pinto recalls, “At a power plant recently, the in-house maintenance team did not detect any defects in its motor bearings – but we picked up defects, and they were verified.”
In fact, more than 60 percent of failures in squirrel-cage motors occur in the bearings. When bearings develop faults, said Pinto, "they can lead to catastrophic failure.”
Besides trouble with bearings, ABB MACHsense-P also detects a wide range of other problems, including rotor winding defects, imbalance, looseness, internal misalignments and voltage abnormalities.
Technicians at ABB service centers in 35 countries are now being trained to use ABB MACHsense-P. “We have gotten very positive responses from our customers so far,” said Pinto. “This service could extend the working life of thousands of motors, running in critical applications worldwide.”
|ABB Motors and Generators|
ABB manufactures a comprehensive range of reliable and highly efficient motors and generators, from a 0.06 kW LV motor to a 70 MVA synchronous generator. The extensive range comprises AC and DC motors, as well as induction and synchronous motors and generators.
ABB MACHsense-P is only one example from a complete portfolio of services for motors and generators offered by ABB. The service organization has long experience in electrical motors and generators and their applications, enabling it to deliver improved operational availability and life-cycle profitability to ABB’s
Developing ABB MACHsense-P was a global effort. Over the past three years, ABB corporate research centers in Poland and Sweden made significant breakthroughs in intelligent software for detecting motor faults.
They sent their results to Cajetan Pinto, who heads the team at R&D Center for ABB Motors and Generators, Service. The team’s job was, in turn, to turn those discoveries into a marketable product.
• Provides accurate diagnosis
• Reports quickly, with a summary delivered on-site
• Includes integrated analysis for current, voltage and vibration
• Rates defects clearly, by severity
• Recommends specific repairs
• Considers machine design in judging defect severity
• Reduces unplanned downtime
• Issues early warnings, allowing time for planning maintenance