DC resistance is usually in power systems or electrical components, refers to the resistance presented by the DC signal in the electrical components, that is, the inherent resistance of the component, also known as the static resistance, the unit is ohms (Ω), the measurement process is to apply a constant, high-precision current to the external load to be measured, and then, the obtained data is processed to obtain the actual resistance value.
In the power system, it is commonly used to measure whether the coil of the transformer has a phase short circuit, a short circuit between turns, and whether the connection condition of the coil and the lead is false welding, loosening and other abnormal conditions, which is one of the routine actions to check the internal conditions of the transformer and one of the important means to prevent transformer failure. Usually, in the case of constant rated current, the larger the measured DC resistance, the greater the copper loss, the more serious the heating of the surface transformer, and once the specified range value is overflowed, the transformer core is easy to burn.
The DC resistance data is normally measured by the corresponding DC resistance measuring instrument, e.g. KRI 9310 winding resistance tester;JYR 10S winding resistance tester.etc..
