Effect of power quality on windings temperature of marine induction motors. Part II: Results of investigations and recommendations for related regulations

Case Study—Based Overview of Some Contemporary Challenges to Power Quality in Ship Systems

“…It was shown, that taking into account two various limit values for both: momentary 200-ms aggregated values and aggregated 10-min values of distortion factors are reasonable. The second aggregation time would be appropriate for assessment of waveform distortions impact on heating of electric motors [45] and this should concern other power quality indices as well. The main ambiguities related to the measurement methods of quantities characterizing electrical power quality in the wake of appropriate ship standards and rules, can be formulated as follows [29]:…”

“…It should be taken into account when evaluating electric power quality. For example, the temperature rises of electric motor winding caused by voltage and frequency deviations have been significantly increased if supply voltage waveform and/or unbalance have occurred concurrently [45,46]. Taking into account present state of the art, to overcome the above appointed disadvantages concerning the applied methods of signal processing and hardware structure of existing solutions, some research oriented to dedicated devices complying with marine environment requirements and needs have been undertaken, among others, at Gdynia Maritime University [41,42,47,48].…”

Power Quality and Energy-Efficient Operation of Marine Induction Motors

“…Such a recommendation could be the value of the coefficient of voltage energy efficiency cvee ≤ 1.05. Further, for values cvee greater than 1.05, analysis of the effect of PQ disturbances on heating of induction motors could be recommended, for example with the method presented in [13], [15]. The appropriate curves cvee = 1.05 and cvee = 1.2 are shown in Fig.…”

“…16, 17) and the maximal permitted frequency is merely about 103% of frat. It is also worth mentioning that in previous works [13], [14], [15], the authors formulated a proposal for limitation of PQ disturbances to protect induction motors against excessive heating. The proposal is based on a synthetic power quality factor-a temperature coefficient of power quality (cpqs) [15].…”

“…As a result, even PQ disturbances within the limit prescribed by [9]- [12] exert a deleterious effect on various elements of ship power systems, including induction motors. In induction motors, they cause, among other things, an increase in power losses and overheating [13]- [16]. According to the authors' investigations, PQ disturbances may even result in about a 50% increase in power losses in comparison to the nominal supply.…”