Results from experiments on a tap transformer based grid connection system for a variable speed vertical axis wind turbine are presented. The tap transformer based system topology consists of a passive diode rectifier, DC-link, IGBT inverter, LCL-filter, and tap transformer. Full range variable speed operation is enabled by using the different step-up ratios of a tap transformer. Simulations us...

The Transformer based Z-Source inverter is an enhanced series inductance Z-Source impedance network. This proposed inverter is used to combine the main circuit and the power source. This configuration delivers a strong boost capacity to overcome the barriers of the series inductance Z-source inverter. Further, with the usage of low voltage capacitors and the transformer, the capacitor voltage s...

This paper takes a typical 220 kV three-phase three-limb oil-immersed transformer as an example, this paper building transient field-circuit coupled model and 3D coupled magneto -fluid-thermal model. Considering a nonlinear B–H curve, the magneto model uses the field-circuit coupled finite element method (FEM) to calculate the magnetic flux distribution of the core and the current distribution ...

This paper presents the analysis of a new multi-oscillated current resonant type DC-DC converter. Current resonant converters have several remarkable features such as high efficiency, small size, low cost and low noise, and are frequently employed in many portable electronic systems such as personal computers, cellular phones and flat panel displays. The current resonant type converter generall...

This paper presents a nonisolated, high boost ratio hy-brid transformer dc–dc converter with applications for low-voltage renewable energy sources. The proposed converter utilizes a hy-brid transformer to transfer the inductive and capacitive energy simultaneously, achieving a high boost ratio with a smaller sized magnetic component. As a result of incorporating the resonant operation mode into...

A6s t~ac t A flyback dc-dc converter is obtained from t h e conventional buck-boost converter by replacing t h e inductor with an isolation transformer. A transformer in the flyback converter is used to achieve a d c isolation between t h e input and the o u t p u t of t h e converter. This paper presents dc and small-signal circuit models for t h e flyback converter for continuous conduction m...

A new passive Power Factor Corrector (PFC) based on Valley Fill (VF) is proposed for an off-line Flyback converter. By adding an extra winding which is magnetically coupled to the Flyback transformer and electrically coupled to the VF, higher Power Factor (PF) and lower Total Harmonic Distortion (THD) can be achieved. The proposed circuit uses a high frequency inductor, low voltage capacitors t...

The flyback-flyback single stage converter operated in DCM+DCM is easy to control bus voltage, but it hard to control stress of switch. We propose a new converter having low voltage stress on its switch. The flyback converter is simplified into buck-boost form. Then the PFC flyback transformer is replaced by an inductor The switch of both PFC and DC/DC stages are merged, and a diode is used to ...

This paper introduces the use of the voltage multiplier technique and passive absorption circuit applied to the non-isolated dc-dc converter in order to obtain high efficiency and high voltage gain. A passive absorption circuit is inserted in the interleaved flyback converter to transfer the leakage energy to load. The operation principle of the circuit is explained. This paper also deals with ...