Developing a new SVPWM control strategy for open-winding brushless doubly fed reluctance generators

In this paper, a new open-winding control strategy is proposed for a brushless doubly fed reluctance generator (BDFRG) used for stand-alone wind turbine or ship generators. The BDFRG is characterized with two windings on the stator: a power winding and a control winding. The control winding is fed with dual two-level three-phase converters, and a vector control scheme based on space vector pulsewidth modulation is designed. Compared with traditional three-level inverter systems, the dc-link voltage and the voltage rating of power devices in the proposed system are reduced by 50% while still greatly improving the reliability, redundancy, and fault tolerance of the proposed system by increasing the switching modes. Its performance is evaluated by simulation in MATLAB/Simulink and an experimental study on a 42-kW prototype machine

Active and Reactive Power Control of Wound Rotor Induction Generators by Using the Computer and Driver

In this chapter, a power control system for a wound rotor induction generator has been explained. This power control system has realized a control method using a rotating reference frame fixed on the air-gap flux of the generator. Application of such a system allows control of the active and reactive power of generators independently and stably. So, a two-step process is presented here. The first step is to acquire the complex power expression (and thus the active and reactive power expressions) for an induction machine in space vector notation and in two-axes system. Then, a computer aided circuit is given to realize the power and current control by analyzing them. Also, the results of an experiment given in literature are shown to be able to compare the results

Investigation and development of new concepts for improvement of aircraft electrical power systems Quarterly progress report

Electrical loads analysis and parametric data of aircraft utilization component

Electronic/electric technology benefits study

The benefits and payoffs of advanced electronic/electric technologies were investigated for three types of aircraft. The technologies, evaluated in each of the three airplanes, included advanced flight controls, advanced secondary power, advanced avionic complements, new cockpit displays, and advanced air traffic control techniques. For the advanced flight controls, the near term considered relaxed static stability (RSS) with mechanical backup. The far term considered an advanced fly by wire system for a longitudinally unstable airplane. In the case of the secondary power systems, trades were made in two steps: in the near term, engine bleed was eliminated; in the far term bleed air, air plus hydraulics were eliminated. Using three commercial aircraft, in the 150, 350, and 700 passenger range, the technology value and pay-offs were quantified, with emphasis on the fiscal benefits. Weight reductions deriving from fuel saving and other system improvements were identified and the weight savings were cycled for their impact on TOGW (takeoff gross weight) and upon the performance of the airframes/engines. Maintenance, reliability, and logistic support were the other criteria

Aircraft Electric Secondary Power

Technologies resulted to aircraft power systems and aircraft in which all secondary power is supplied electrically are discussed. A high-voltage dc power generating system for fighter aircraft, permanent magnet motors and generators for aircraft, lightweight transformers, and the installation of electric generators on turbine engines are among the topics discussed

Comparison of doubly-fed induction generator and brushless doubly-fed reluctance generator for wind energy applications

Phd ThesisThe Doubly-fed Induction Generator (DFIG) is the dominant technology for variable-speed wind power generation due in part to its cost-effective partially-rated power converter. However, the maintenance requirements and potential failure of brushes and slip rings is a significant disadvantage of DFIG. This has led to increased interest in brushless doubly-fed generators. In this thesis a Brushless Doubly-Fed Reluctance Generator (BDFRG) is compared with DFIG from a control performance point of view. To compare the performance of the two generators a flexible 7.5kW test facility has been constructed. Initially, a classical cascade vector controller is applied to both generators. This controller is based on the stator voltage field orientation method with an inner rotor (secondary stator) current control loop and an outer active and reactive power control loop. The dynamic and steady state performance of two generators are examined experimentally. The results confirm that the BDFRG has a slower dynamic response when compared to the DFIG due to the larger and variable inductance. Finally a sensorless Direct Power Control (DPC) scheme is applied to both the DFIG and BDFRG. The performance of this scheme is demonstrated with both simulation and experimental results.Engineering and Physical Sciences Research Council (EPSRC) and Overseas Researcher Scholarship (ORS

Current Control of Self-Excited Induction Generator using Shunt Active Filter

Self-energized impelling generators are great applicants for wind controlled power era, particularly in remote territories, in light of the fact that they needn't bother with an outside force supply to process the excitation attractive field. A three-stage actuation machine could be made to fill in as a self-energized instigation generator where a three-stage capacitor bank is joined over the stator terminals to supply the touchy force necessity of a heap and generator. A standout amongst the most well-known issues when uniting little renewable vitality frameworks to the electric burden is it can infuse symphonious parts that may fall apart the force quality. In the late decades, the world has seen a development in the utilization of non-direct loads. The sounds causes issues in force frameworks and in customer items, for example, gear overheating, capacitor blowing, engine vibration, unnecessary nonpartisan momentums and low power variable. Shunt active power filter compensates current harmonics by injecting equal-but-opposite harmonic compensating currents into the grid. This paper presents a new control strategy based on shunt active power filter for controlling the current of self-excited induction generator when generator is connected to a nonlinear load. This paper also represents the analysis and modelling of dynamic model of SEIG in MATLAB/ SIMULINK. Basically a strategy based on an active power filter (APF) for controlling the current and power quality of the self-excited induction generator (SEIG) have been presented in this paper. The shunt active power filter was implemented using a three phase PWM current controlled voltage source inverter (VSI) and connected to the wind generator and loads in order to compensate the current harmonics and reactive power

Modeling, Control and Characterization of Aircraft Electric Power Systems

A study model of advanced aircraft electric power system (AAEPS) corresponding to B767 Aircraft is developed in the PSIM9 software environment. The performance characteristics of the system under consideration for large sharing of non-linear loads are studied. A comprehensive mathematical model describing system dynamics is derived where the GSSA technique is applied for reduced-order system approximation. The transient and steady-state performance of the hybrid PEM-FC/battery APU integrated to the aircraft electric network is analyzed while different loading scenarios are taken into account. In addition, dynamic bifurcation analysis is employed to characterize the systems stability performance under multi-parameters condition. Also, the power quality of the system is assessed under various loading configurations, and the effect of installing active/passive power filters (APF/PPF) on power quality of the system is investigated for a wide range of operating frequencies