An improved method for the inrush current evaluation in single phase power transformers

Magnetising inrush current of low-voltage iron core three phase power reactors

“…The high-value magnetizing inrush current surged by iron core three phase power reactors at the energizing moment is mainly caused by the H-B nonlinear characteristic of the ferromagnetic core [16,17]. That could also be express in terms of the strong nonlinear phase inductance dependence of the absolute value of the current intensity.…”

“…The main features of this magnetizing inrush current (amplitude and duration) are influenced by the following factors [4,5,16]:…”

“…Due to its generation principle it is being also known as magnetizing inrush current [14][15][16]. Relying on the circuit model of the ferromagnetic coils, their time domain transient state characterization is performed.…”

Transient State Characterization of Asynchronous Motors in Modern Low-Voltage Electric Installations

“…For motors with higher power units, one may apply, depending on power level the machine and its operating mode, the following classical procedures [1][2][3][4][5]: star-delta starter, rheostat starters, series stator coils, autotransformer starter, or more recently, the usage of static power converters [8][9][10][11][12]. For motors driven by variable-frequency drive, energising is performed implicitly with a voltage-frequency control [9][10][11][12][13][14][15].…”

“…In this particular transient state, the basic electrical and mechanical machine parameters changes as the rotor accelerates. The inrush currents associated with the motor connection to the network have values that could exceed the motor rated currents and exhibit special distorted waveforms [7][8][9][10][11][12][13]. These features of these inrush currents additionally stress up both the motor by increasing the losses within the motor and the supply network by adversely affecting the other loads or receptacles, connected at the common coupling point [14][15][16][17].…”