On-site measurement of load and no-load losses of GSU transformer
Present development and production of power transformers with lower losses in addition to replacement of outdated transformers assume regular measurement of losses in both load and no-load regime. These measurements are very demanding especially in the case of on-situ measurements. The complexity of the measurements grows with the size of transformer. This paper presents one typical test of losses measuring in load and no-load regime of power transformer with nominal power of 40 MVA in HPP Perucica.
No-load loss measurements of power transformers under distorted supply voltage waveform conditions
The problem of correcting the results of no-load loss measurements of power transformers for the effect of distorted supply voltage waveform on the magnetic flux in the core and hence on both the hysteresis and eddy current loss components of core losses is presented. The instrumentation requirements for no-load loss measurements to ensure proper application of the correction formula are described.
Laminar heat or mass transfer in rectangular channels and in cylindrical tubes for fully developed flow: comparison of solutions obtained for various boundary conditions
Abstract A comparison is made of results obtained with various boundary conditions at the wall of the channels. By comparing blood Sherwood numbers for finite wall resistance with those for constant concentration boundary condition only a small variation is found for various points along the blood channel.