A control method for stand alone mode operation of doubly fed induction generator is presented. The method bases on the stator voltage vector control represented in the synchronously rotated polar coordinates. The generated stator voltage is controlled by rotor currents. Amplitude of stator voltage and its frequency are controlled independently. The output… (More)
The following paper presents bidirectional switch neutral point clamped three-level inverter topology, which is intended for low voltage applications. The inverter schematic and its principles of operation are presented. Then conduction and switching losses model derivation is proposed. According to obtained model equations, proposed concept is compared… (More)
The paper presents variable speed generation system producing standardised 400 V/230 V/50 Hz voltage. An internal combustion engine (diesel engine) is driving a permanent magnet axial flux generator. An AC/AC power electronic system converts variable frequency and amplitude the permanent magnet generator AC voltage to the standardised AC voltage. The axial… (More)
The paper describes a new holistic approach to the modeling of integrated renewable energy systems. Energy Resource (DER) hybrid systems.
The following paper presents the method of poles position identification of the axial flux permanent magnet machine at zero and low speed. The identification is used for starting the motor in the demanded direction. The axial flux motor possesses a large number of poles which results in a small mechanical angle for magnet sector. The derived poles position… (More)
Neutral current and neutral voltage in three-phase four-wire distribution system is a big concern in power system. Various non-linear loads specially the switch mode power supply types loads inject harmonic current in neutral. The variations of neutral current and neutral voltage are analysed. Measurements taken from Electrical Machine lab of National… (More)
We show that frequency bands of interaction as well as dynamics of energy flow to the point of common coupling (PCC) lead to hybrid system design keys. Related to each power source and storage device, segmentation of frequency domain of the hybrid system is achieved by control strategy in time domain.
This paper presents a novel method for parallel operation of adjustable speed power-electronic generation systems. The proposed method is based on the well known droop scheme and therefore does not require any additional interconnections between units operating in parallel. Modifications and extensions to the conventional droop scheme are introduced to… (More)