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Full-Text Articles in Power and Energy
New Three-Phase Multilevel Inverter With Reduced Number Of Power Electronic Components, Saad Mekhilef
New Three-Phase Multilevel Inverter With Reduced Number Of Power Electronic Components, Saad Mekhilef
Saad Mekhilef
In this paper, a new configuration of a three-phase five-level multilevel voltage-source inverter is introduced. The proposed topology constitutes the conventional three-phase two-level bridge with three bidirectional switches. A multilevel dc link using fixed dc voltage supply and cascaded half-bridge is connected in such a way that the proposed inverter outputs the required output voltage levels. The fundamental frequency staircase modulation technique is easily used to generate the appropriate switching gate signals. For the purpose of increasing the number of voltage levels with fewer number of power electronic components, the structure of the proposed inverter is extended and different methods …
Simulation Of Z-Source Inverter Using Maximum Boost Control Pwm Technique, Suresh L
Simulation Of Z-Source Inverter Using Maximum Boost Control Pwm Technique, Suresh L
suresh L
Z – source inverters have been recently proposed as an alternative power conversion concept as they have both voltage buck and boost capabilities. These inverters use a unique impedance network, coupled between the power source and converter circuit, to provide both voltage buck and boost properties, which cannot be achieved with conventional voltage source and current source inverters. To facilitate understanding of Z – source inverter, this paper presents a detailed analysis, showing design of impedance network, implementation of Maximum Boost control (MBC) PWM technique and simulation of Z – source inverter.
Direct Power Control Of Dfigs Based Wind Energy Generation Systems Under Distorted Grid Voltage Conditions, Emad Gameil Shehata E. G. Shehata
Direct Power Control Of Dfigs Based Wind Energy Generation Systems Under Distorted Grid Voltage Conditions, Emad Gameil Shehata E. G. Shehata
Emad Gameil Shehata E. G. Shehata
This paper presents an improved direct power control (DPC) strategy of a wind turbine driven doubly fed induction generators (DFIGs) connected to distorted grid voltage conditions. A coordinate control strategy of the grid side converter (GSC) and rotor side converter (RSC) of the DFIG is designed to improve the overall scheme performance. The RSC is controlled based on a DPC principle to eliminate the electromagnetic torque and stator reactive power oscillations. The total active and reactive power oscillations are compensated by the GSC control to achieve constant active and reactive powers from the overall DFIG system. A current control scheme …
Direct Power Control Of Wind-Turbine-Driven Dfig During Transient Grid Voltage Unbalance, Emad Gameil Shehata E. G. Shehata
Direct Power Control Of Wind-Turbine-Driven Dfig During Transient Grid Voltage Unbalance, Emad Gameil Shehata E. G. Shehata
Emad Gameil Shehata E. G. Shehata
In this paper, a direct power control (DPC) of a wind-turbine-driven doubly fed induction generators (DFIGs) under unbalanced network voltage conditions is studied. Variations of the stator output active, reactive and electromagnetic powers are fully deduced in the presence of negative sequence supply voltage. The rotor side converter is controlled on the basis of DPC to eliminate the electromagnetic torque oscillations at double supply frequency under unbalanced stator supply. The rotor voltage references estimation requires only simple calculations without any integral operation. The proposed control scheme removes rotor current regulators and the decomposition processing of positive and negative sequence rotor …
At89c51 Microcontroller Based Control Model For Hybrid Assistive Limb (Knee ), Suresh L
At89c51 Microcontroller Based Control Model For Hybrid Assistive Limb (Knee ), Suresh L
suresh L
In this paper, a controlling system is implemented for a wearable walking supporting device so called as Hybrid Assistive Limb. The control circuit is implemented without considering the biological signals of the human body for the knee part, which is based on the knee joint moment from the human body model. The control and a driving circuit s are implemented to assistive the knee as for the requir ement of knee joint dynamics.
Effect Of Renewable Distributed Generators On The Fault Current Level Of The Power Distribution Systems, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Masoud Farhoodnea, Marjan Mohammadjafari
Effect Of Renewable Distributed Generators On The Fault Current Level Of The Power Distribution Systems, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Masoud Farhoodnea, Marjan Mohammadjafari
Dr. Hadi Zayandehroodi
The presence of renewable distributed generator (RDG) in a distribution system will have unfavorable impact on the operating system because the distribution system is no longer radial in nature and is not supplied by a single main power source. With RDGs in a distribution network, it brings about a change in the fault current level of the system and causes many problems in the protection system, such as false tripping of protective devices, protection blinding, an increase and decrease in short-circuit levels. This paper presents the effect of RDGs on the fault current level of the system. The operating protection …