The motor drive: A key player in predictive maintenance?

15 June 2021

Predictive maintenance is fast becoming recognised as one of the more easily exploited applications of digitalisation, says Blake Griffin, a senior analyst at Interact Analysis. 

Predictive maintenance can offer cost savings by reducing production losses due to unexpected downtimes. A predictive maintenance report from Interact Analysis put a focus on the ability of motor drives to perform predictive maintenance diagnostics not only on themselves, but also on the equipment they control. This technology, while still in its early days, is expected to be a key enabler of predictive maintenance initiatives as it opens up a new stream of data for both machine builders and end-users.

Motor drives can be sophisticated pieces of equipment, capable of performing diagnostics on themselves, and giving signals to alert engineers when maintenance is necessary, thereby avoiding breakdowns and subsequent costly machinery downtime. Companies such as Siemens have recognised the potential of this predictive maintenance technology and offer it as a service to end-users through their digitalisation platform called Analyze MyDrives. 

However, drives can do more than diagnostics on themselves. For example, they can monitor the status of the motor they are controlling by measuring the voltage and current the motor requires to perform a task in real-time. This data is used to control torque and motor speed, but it can also be used to identify the imminent failure of a component in a motor - drives vendors will argue that voltage and current measures give more sophisticated insights into motor failure than the standard monitoring of vibration and some vendors are developing software for their products which are aimed at making the process of gathering, organising, and monitoring trends in this data easier. 

When it comes to the kind of data captured, a lot depends on whether the drive acts as a sensor, collecting and analysing data, or as a gateway passing data on to an external network. A motor drive acting as a sensor will monitor voltage and current and flag up potential malfunctions in the motor-driven equipment. It has been suggested that 70% of motor problems could be diagnosed by the drive in this way. However, for reasons of cost, not all drives have voltage and current sensors, so this is not an across-the-board solution. 

If the drive could act both as a current and voltage sensor and a gateway to send more sophisticated data from smart sensors elsewhere to be analysed, it is most likely the vast majority of motor failure issues would be pre-empted. We believe this will be one solution offered by drive manufacturers in the future, but will probably not be useable technology on smaller, cheaper drives.

So, what is the best solution? Where should data be analysed? And how can it be done most cost-effectively – on the drive or on the cloud? The problem with sensors is that they can produce a vast amount of data. If we only want to send key analytics of motor and drive performance to the network, all that information will have to be processed on the drive. The drive would need to be able to store this data, while simultaneously collecting new information, requiring both hardware and software modifications. In all likelihood, we expect drives as a sensor to be a premium feature within drives in the short term, and to gradually become the standard offering as demand for data from smart devices heightens.

As a general rule, the bigger the motor, the greater the financial loss when it stands idle for repair. We believe the industries that will be first in the queue for motor drives offering predictive maintenance capabilities will be those using the largest and most expensive machinery. Additionally, process industries in which downtime could represent the loss of a batch being manufactured are expected to adopt predictive maintenance early. 

Smaller-scale industries may be slower to adopt predictive maintenance owing to cost issues, but we can expect these operations to increase their demand for drives that can diagnose issues on the spot, on the motors they are controlling.

Predictive maintenance in motor drives is a technology on the move. We expect to see this industry flourish as the cost benefits become more evident in an industrial environment where efficiency is key. Suppliers have already started working on the next generation of drives which incorporate predictive maintenance. These drives will not only identify an issue with a motor; they will also adjust its performance so it will keep running until an engineer can fix it. For industrial drives, it really is a brave new world out there.

Contact Details and Archive...

Related Articles...

Print this page | E-mail this page