Condition monitoring for predictive maintenance
21/02/2020
Nord Drivesystems has launched condition monitoring for predictive maintenance (PdM) concepts.The system records drive and status data, either regularly or permanently, in order to optimise the operational safety and efficiency of machines and plants. Based on this information, concepts for predictive maintenance may also be developed. Fast, efficient and comprehensive evaluation of analogue and digital data (measurements, signals and operating parameters) by the intelligent programmable logic controllers (PLCs) in the drive electronics forms the basis.
The objective of predictive maintenance is to maintain machines and plants proactively and to detect changes at an early stage, reducing downtime and increasing the efficiency of the entire plant.
A status-orientated maintenance approach replaces that of traditional time-based maintenance. The detection and avoidance of impermissible operating states at an early stage allows unplanned downtime and machine failures to be avoided. Predictive maintenance enables plannable machinery and plant downtime based on real drive and process data.
For plant and machinery operators using drive technology from Nord Drivesystems, this results in a reduction of service and material costs as well as increased plant availability. Further advantages are increased service life of components and machinery, as well as plannable and cost-optimised maintenance.
Nord Drivesystems uses a drive-based approach in which intelligent algorithms and virtual sensors transfer information from condition monitoring to predictive maintenance. An example is the sensorless determination of the optimum oil change time based on oil temperature. This derives from the fact that the oil temperature is a key factor for oil ageing in gear units. This information, in combination with available gear unit parameters and specific operational parameters, makes it possible to precisely calculate the oil change time. A physical temperature sensor is not required. The preprocessing of drive data using intelligent algorithms takes place in the Nord frequency inverter’s integrated PLC, which is used as an evaluation unit. The customer can access the calculated data via all common interfaces.
The drive equipment can be optionally extended and adjusted to the respective automation task. Customers can select what tasks (drive monitoring, drive control, process control) they want to directly shift into the drive. In smaller production areas, this scalability offers the possibility of gaining initial experience before reorganising the plant.
There are three configuration levels available. At the first level, the drive unit PLC only performs the drive monitoring. The drive parameters are preprocessed in the PLC and communicated to the higher-level control system, which is responsible for drive and process control.
At the medium level, the PLC integrates the drive control and also runs drive-related functions.
At the higher configuration level, the inverter PLC completely replaces the higher-level control system. Alongside communication to a control unit, a local data management system without an Internet connection can optionally apply the data.
