Shosuke Morita

Central Research Institute of Electric Power Industry | CRIEPI · Electric Power Engineering Research Laboratory

Space charge measurement was performed on a 23-mm-thick cross-linked polyethylene (XLPE) cable at ambient and high temperatures using a newly developed high-sensitivity measurement device and a correction method for cables under temperature gradient. The space charge and electric field distribution were obtained with a spatial resolution of 0.5 mm...

The loss current method and the residual charge method had been developed as diagnosis method for water tree deterioration of XLPE cable bodies. Fundamental investigation of these method is mainly for vented trees generated from inner or outer semiconducting layers. However, bow-tie trees generated from voids or contaminants in the insulation layer...

Space charge measurement accuracy is crucial when assessing the suitability of cables for high-voltage direct current (DC) systems. This study assembled state-of-the-art analysis technologies, including time-domain deconvolution, to mark electric field estimation accuracy, which the present techniques achieve. The pulse electroacoustic method was a...

A new, very sensitive device for space charge measurements on full-size cable is proposed. The measurement employs the basis of the pulsed electro-acoustic (PEA) method, in which an acoustic signal is produced due to the interaction between the pulsed electric field and the space charge. A polymeric material was used as an acoustic coupler that als...

This paper reports that the first space charge measurement results in load cycles for a full-size 23-mm-thick XLPE cable. A pulsed electro-acoustic (PEA) method was applied using a newly proposed electrically insulating acoustic coupler to measure the space charge characteristics of thick insulation samples accurately. The space charge characterist...

The waveform immediately after the start of measurement has been used as a calibration waveform in the space charge measurement for HVDC cables. However, space charge accumulation may occur at high temperature during the acquisition of the calibration waveform, which may affect the accuracy of signal processing. In this study, we proposed a method...

Polymer insulated HVDC power cable is being implemented for submarine transmission. Since the insulation is exposed to a high temperature originating from the current in the conductor, space charge can be easily injected to the insulation which generates a distortion of electrical field. The space charge measurement for HVDC cable by Pulse Electro-...