Moisture Measurement of Transformer by Time Methods

The first part of the paper deals with the base information about base measuring methods of transformer insulating system. The second part of paper deals use of time methods - the method of return voltage measurement (RVM) and method of polarization depolarization current (PDC) for distribution transformer. These methods are used in the analysis of the insulating condition of power transformer with a system of oil-paper. In the other part, the paper presents experimental results of the moisture measurement for a real transformer 22/0.4 kV using time method RVM.