Parameters affecting the turn insulation lifetime and durability

Moghadam, Davoud Esmaeil; Speck, Joachim; Großmann, S.; Stähl, Jutta

doi:10.1109/tdei.2017.006905

Cited by 11 publications

(2 citation statements)

References 26 publications

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“…The types of partial discharge, equipment for substantiating the maintenance schedule and the need for repair are considered. The issue of detecting partial discharges and reducing their negative consequences is discussed in works [8][9][10].…”

Section: Abstract: Diagnostics Mathematical Model Electrical Insulati...mentioning

confidence: 99%

Justification of choice of methods for diagnostics of insulation condition of electrical machines of electric railway stock

Dubravin,

Shostak,

Bakhonya

et al. 2024

TST

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The object of the study is the process of monitoring the technical condition of electrical insulation of traction electric machines in order to determine the need for their maintenance or repair. Diagnostics of electric machines is an important aspect of supporting the operation of electric drives. Failure of the windings is one of the main reasons for failure of electric motors. Therefore, the task of developing operational methods for diagnosing the insulation of windings of traction electric motors is urgent. A study of the negative impact of operating conditions on the technical condition of electrical insulation of motors was carried out. The analysis of the existing methods of diagnosis of insulation systems of electric machines was carried out. Special attention was paid to the selection of predictive parameters of the insulation state. A mathematical model was developed to study the frequency characteristics of the stator insulation system of the traction electric motor model AD914. Refined dependences of the effect of changes in the insulation parameters of the motor stator winding on its frequency characteristics were obtained. It was concluded that the method of monitoring the insulation state of electric motor windings based on the assessment of electrical resistance relative to the stator core and amplitude-frequency characteristics is the most effective. The field of practical application of the obtained results is the system for monitoring the condition of electrical insulation of traction electric machines to determine the schedule of their maintenance and repair. The conducted research is a scientific justification for the choice of methods and devices for diagnosing the insulation state of electric motors of railway traction rolling stock.

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Section: Abstract: Diagnostics Mathematical Model Electrical Insulati...mentioning

confidence: 99%

Justification of choice of methods for diagnostics of insulation condition of electrical machines of electric railway stock

Dubravin,

Shostak,

Bakhonya

et al. 2024

TST

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“…Fast rise/fall time produces higher frequency harmonics, resulting in electrical stress on the winding insulation [24]. In addition, these higher frequency harmonics cause heating of the insulation system which makes PD even worse [25]. To eliminate the high frequency harmonics, employing filters is necessary.…”

Section: Section III Partial Dischargementioning

confidence: 99%

Survey of Insulation Systems in Electrical Machines

Hemmati

El-Refaie

2019

2019 IEEE International Electric Machines &Amp; Drives Conference (IEMDC)

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Insulating materials and insulation systems design have been gaining more attentions as more electrical machines tend to operate in harsher environments for various applications. Harsh environments include high temperature, humidity, erosion, low air pressure, etc. This paper discusses recent advances in insulation systems for electrical machines. Insulation tests as well as test standards that have been used to evaluate insulation systems and detect insulation failures will be discussed. Insulating materials used for a wide range of industrial applications such as wind turbine generators, aerospace hybrid/electric powertrain, and hydro generators have been summarized. For the emerging high-altitude, highvoltage aerospace applications, partial discharge and its impact on insulation systems will be discussed. Finally, polymer nanocomposite materials with excellent thermal conductivity and dielectric strength are highlighted as an outlook. SECTION I. Introduction Due to the continued growth of renewable energys, the number of electrical machines used worldwide has significantly increased. Insulation system is a very critical component of electrical machines. Insulation breakdown can lead to failures, which eventually result unpredicted downtime and negative financial impacts and in some applications can be a safety hazard. For some specific industries where uninterruptible operation is required, the unpredicted downtime is unacceptable. The unpredicted downtime for an offshore oil plant would be $25,000/h [1]. The dielectric strength of electrical insulation materials has been gradually improved over the years. By introducing new materials in the past 20 years for instance, the dielectric strength of ground-wall insulation nearly doubled [2]. Electrical, mechanical, thermal, and ambient stresses can cause insulation degradation which consequently leads to insulation failure [3], [4]. Insulation failure causes short circuits in the stator winding and consequently high currents could pass through the defected stator winding [5]. A survey on 1141 induction motors with power ratings above 200 hp shows that around 30% of motor failures are due to insulation failures [6]. With advances in sensors, digital signal processing, diagnosis methods and test standards, insulation failures can be detected [7], [8]. Through online estimation of material degradation and lifetime in early stages, insulation systems of electric machines can be protected from further aging while unpredicted downtime could be avoided through scheduled maintenance. Even though insulation system is a passive component in an electrical machine which does not produce torque, insulation build/thickness (which represents the key thermal resistance in electrical machine)can have significant impact on the machine cooling and hence electrical loading and torque production. There have been several efforts to minimize insulation thickness for design compactness, low manufacturing cost and high efficiency [3]. The two main functions of insulation systems in electr...

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