Ville Sarkimaki

Applicability of ZigBee technology to electric motor rotor measurements

The purpose of this work is to determine the applicability of the ZigBee technology to electric motor rotor measurements. Requirements for data transmission, electrical structure and powering of a sensor are discussed. A prototype wireless ZigBee-based torque sensor is built and tested. The results of the tests are analyzed

Design considerations for current transformer based energy harvesting for electronics attached to electric motor

Energy harvesting or scavenging from environment is being researched intensively. The main motivation of the research is to develop a maintenance free energy source for ubiquitous electronics, such as wireless sensors or sensor networks. The on-line condition monitoring of electric motors requires also sensors that are installed at the motor. In this case, the energy required by sensors could be harvested from a magnetic field. In this article, current transformer based energy harvesting is considered. A switch-mode power supply utilizing current transformer is designed. It is tested in laboratory with the mains supply and variable speed drive. According to the tests carried out, the current transformer based power sources are a feasible alternative to supply the electronics attached to an electric motor.

Estimation of the data transfer requirements of vibration and temperature measurements in induction motor condition monitoring

Continuous condition monitoring requires data transmission from the sensors to a higher level where the analyses and decisions are made. In this paper, the amounts of data produced by vibration and temperature measurements of the condition monitoring of induction machines are estimated. The effect of communication protocols to the data transmission capacity requirements is analysed

Motor feedback speed control by utilizing the motor feeder cable as a communication channel

A feedback loop is used in the motor speed control in order to transmit the measured motor rotational speed information to the controller. The implementation of the feedback loop requires cabling between the motor and the frequency converter both for signalling and powering. However, the motor power cables could be also used for data transmission. The possibility of using the same motor feeder cable for supplying power to the motor and for transferring the motor rotational speed information to the controller is researched in this article. The data transmission utilizes a PLC (power line communication) method that forms an Ethernet connection over the motor feeder cable

Utilization possibilities of frequency converter in electric motor diagnostics

In this article, we investigate the possibilities of utilizing the frequency converter to supplement the diagnostics of the electric motor it supplies. Available measurements and data are studied, and requirements for a frequency converter functioning as a data-collecting unit are defined. Communication structures in the drive are compared

Wireless technologies in condition monitoring and remote diagnostics of electric drives; requirements and applications

This paper concentrates on utilization of wireless technologies on the data transfer needs of condition monitoring, maintenance and remote diagnostics of electric drives. A short introduction to typical short-range radio technologies is given. Requirements for wireless technologies in condition monitoring are discussed. The main focus is the introduction of different applications that the use of short-range wireless technologies makes possible

A wireless ZigBee-based torque sensor for an underwater power generator

A prototype of a wireless ZigBee-based torque sensor for underwater power generator was built and installed. The torque measurement is implemented using strain gages. A measuring unit and strain gages are rotating with the rotor and sending measurements over wireless ZigBee link to the receiver unit located at the stator. The measurements are sent over RS485 to a computer. In this article, design challenges and solutions are discussed, focusing on wireless data transmission.

Current measurement-based detection of load torque changes in a variable speed VSI induction motor drive to support motor diagnostics

Most spectrum analysis methods used to extract features from the vibration signal measured at the motor frame require the motor to be in the stationary state during the whole measurement. In this paper, the possibility to detect transient states based on the data available in an inverter is studied. The theoretical background is introduced, and practical measurements are carried out. The sensors that exist in the inverter are utilized, and the data is retrieved using ModbusTCP. No modifications to the inverter are required.