This paper presents an improved model of uniform transformer winding for frequency response analysis (FRA), based on traveling wave theory. The accurate representation of the losses and detailed consideration of measurement chains are the main features of the model. The transfer function expression of the transformer winding and equivalent distributed-parameter circuit for FRA have been derived...

In this paper, a review of PV inverters is reported based on converter characteristics as the number of energy processing stages, the presence of a transformer (high-frequency or 50Hz transformer), and the adopted configuration of the PV field. In particular, the considered solutions have been evaluated depending on efficiency, input current ripple and life-time of the capacitors coupling with ...

This paper describes the design of a middle-frequency power transformer, its material composition and magnetic circuit windings, operating in frequency range 800 to 2000Hz, with capacity 200kVA, air-cooled, be fed from suitable converter, characterized by reduced noise. The proposed solution allows implementation galvanically isolated DC-DC converters for auxiliary traction drives other convert...

Abstruct-This paper proposes a transformer assisted PWM zero voltage switching Neutral-Point-Clamped (NPC) inverter. With the assistance of a transformer assisted small rating lossless auxiliary circuit, the main switches work with zero voltage switching without suffering from any voltage/current spikes, under simple explicit control. The technique allows for higher operating frequency and bett...

| A recent frequency-domain, subspace-based algorithm is used in the identiication of two power transformers. The results indicate that the subspace-based identiica-tion algorithms can be used without modiication even when the dynamic range of frequency response data is large.

The more sophisticated a protection algorithm, the more information on both steady-state and transient behavior of a protected element required for proper designing, setting and testing of a given relay. In the case of a power transformer, the most important phenomena to be modeled from the standpoint of protective relaying are: magnetizing inrush including initial, recovery and sympathetic inr...