The wind energy conversion system can deliver the maximum power when the load impedance matches with the source impedance under a given wind speed. Since the load and wind speed are varying dynamically, the maximum power point tracking (MPPT) becomes more complex. A wind-generator (WG) maximum-power-point tracking (MPPT) system is presented in the present work, consisting of a high efficiency b...

The STATCOM (Synchronous Static Compensator) based on voltage source converter (VSC) is used for voltage regulation in transmission and distribution systems. The STATCOM can rapidly supply dynamic VARs required during system faults for voltage support. The apparent impedance is influenced by the reactive power injected or absorbed by the STATCOM, which will result in the under reaching or over ...

This thesis presents a method of detecting electrical islands in low voltage distributed generator networks by measuring negative sequence impedance differences between islanded and utility connections. Extensive testing was conducted on a commercial building and 25 kV distributed generator fed network by measuring naturally occurring and artificially injected negative sequence components. Simi...

An electric railway system is a typical single-phase grid-connected converter system, and the low-frequency oscillation (LFO) phenomenon in systems has been widely reported around world. Previous research indicated that LFO small-signal instability issue caused by impedance mismatching between traction network trains. Therefore, this paper proposes an improved q-axis current control method to r...

This paper presents a buck-boost converter-based bipolar pulse generator, which is able to generate bipolar exponential pulses across a resistive load. The concept of the proposed approach depends on operating the involved buck-boost converters in discontinuous current conduction mode with high-voltage gain and enhanced efficiency. A full design of the pulse generator and its passive components...

The paper establishes a methodology to overcome the difficulty of dynamic frame alignment and system separation in impedance modeling ac grids, thereby enables impedance-based whole-system generator-converter composite power systems. is based on frame-dynamics-embedding transformation via an intermediary steady between local global frames, which yields locally defined model for each generator o...

In this paper, a direct ac-to-dc power converter is proposed for efficient energy harvesting from the low voltage inertial micro generators. The conventional power converters use diode bridge rectifiers and condition the micro generator outputs in two stages. Hence, they are inefficient and may not be a feasible option for very low voltage micro generators. Moreover, they are not conducive for ...

Most mobile equipments use battery as power source. The increasing use of low voltage portable devices and growing requirements of functionalities embedded into such devices. Thus an efficient power management technique is needed for longer battery life for them. Given the highly variable nature of batteries systems often require supply voltages to be both higher and lower than the battery. Thi...

In this paper we design the low-power CMOS limiting amplifier using negative impedance, the purpose of using negative impedance is to increase the gain of the amplifier. low-power operations are also done using all the active elements. The LA was implemented in a standard CMOS 0.18um technology. This limiting amplifier is designed for the instrumentation(bio-medical) application. Gain of the am...