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The nonlinear beam with vertical combined excitations is proposed as an energy harvester. The system is modelled as a cantilever beam with included a tip mass and piezoelectric patches which transduce the bending strains induced by both, the harmonic and as an additive stochastic forces. The excitation affects in vertical directions by kinematic forcing into electrical charge. The main goal is to...
This paper presents a unified power quality conditioner (UPQC) and its control strategy for assisting the fault ride-through operation of large-scale photovoltaic (PV) power station. The output voltage of PV station can be controlled to its rated value with UPQC under high grid voltage fault condition. Moreover, it can absorb reactive power from the grid under high voltage condition to support the...
Due to the presence of the low-order background voltage harmonics in the grid, it will cause higher current harmonics in the AC side of the grid inverter with Selective Harmonic Elimination PWM (SHEPWM). Therefore the grid inverter with traditional SHEPWM has not prevailed since it is unable to overcome the background harmonics of the utility and satisfy the power quality requirement. In this paper,...
This paper focuses on the currents supply waveforms of a non-conventional electrical machine - Doubly Salient Permanent Magnet Generator (DSPMG) (10 kW, 50 tr/min), which is dedicated to marine tidal current applications. A dynamical dq model is firstly developed. Then, classical sinusoidal and quasi sinusoidal current waveforms are all applied for DSPMG to minimize the torque ripples and to analyze...
The work presented in this paper aims to propose a control strategy being able to extract efficiently energy from a fixed-pitch marine current turbine associated with a 5-phase Permanent Magnet Synchronous Generator (PMSG) in healthy mode and in faulty mode. The considered faults are opened phases. For each tidal current speed, the control strategy aims to extract the maximum power with respect of...
The paper investigates the feasibility of an approach to design effective cloaking devices by means of a joint exploitation of available degree of freedom in synthesis strategies and the physical mechanism underlying cloaking. A different point of view in the design of dielectric covers that minimize the scattering cross section of dielectric objects is introduced and new opportunities are outlined...
This paper presents a global fast terminal sliding mode (GFTSM) control based on backstepping design for active power filter(APF). Power system is a typical nonlinear system. Its mathematic model can be reduced order by backstepping method. Power system is decomposed into low-level subsystems until finalizing the design of the control law. The System's stability is ensured by Lyapunov framework. The...
Several fixed frequency applications of multilevel converters require a very low level of distortion factor of the output voltage. Bringing the output voltage to a form as close as possible to a sine wave is usually done through linearization methods of the Newton-Raphson algebraic equations. The method proposed in section III uses for the waveforms optimization a genetic algorithm, having a positive...
A new concept based on the injection of a periodically repeated oscillations train into an oscillator is presented. It is based on a phenomenon named pseudo-locking, leading to a novel programmable harmonic selection technique. Theoretical description of the concept is presented, in particular an analytical condition is carried out, paving the way of design rules. For a proof of concept, an oscillator...
The problem of controlling three-phase series active power filters (series APF) is addressed in presence of nonlinear loads. An oriented control model for Series APF-load system is developed in (α, β) coordinates. The control objective is twofold: (i) compensating for the harmonic and disturbed voltages components at the PCC, this objective is referred to voltage quality (ii) Regulating the inverter...
Processes requiring a variable applied voltage often use power electronic devices. This causes reduced power factor and higher levels of current harmonic injection. Although power quality issues are typically rendered after the fact, by careful consideration during the design phase, equipment and/or processes can often be designed to achieve a better performance. This paper deals with methods for...
Three-phase four-leg neutral point clamped (NPC) inverter is more suitable in dealing with all sort of the loads especially unbalanced/nonlinear due to harmonics issues. Most control strategies applied on four-leg NPC are classified as high switching frequency lead to high power losses and low efficiency. In this paper, selective harmonic elimination pulse width amplitude modulation (SHE-PWAM) technique...
The use of proportional resonant (PR) current controller in grid side wind power converters instead of the traditional proportional integral (PI) controller has gained a large popularity. Particularly its capability for compensating harmonics in the current waveforms is an essential feature. Due to the replacing of the generator side converter by a simple diode rectifier, harmonics with variable frequencies...
This paper presents suppression control of the module capacitor voltage fluctuation for the Cascade Static Synchronous Compensator (STATCOM). In the control of the reactive current of the cascade STATCOM, the instantaneous power of the each module fluctuates by twice the source frequency. Therefore, the module capacitor voltage of the cascade STATCOM fluctuates by twice the source frequency. If the...
The plant bandwidth plays a vital role in the design of any feedback controller. Its importance is more for repetitive controller (RC) based systems because it is required to provide higher gains at desired frequencies. This paper discusses design of the repetitive controller (RC) for a LCL filter based grid connected inverter with special emphasis on plant's bandwidth. The relation between plant...
Polar transmitters suffer from the problem of having high out-of-band noise. To solve this problem, most of the proposed solutions rely on increasing the sampling rate of the phase branch. In this paper, we present a novel method based on processing the digital radius signal in order to reduce the out-of-band noise. The proposed method modifies the output of the Digital-to-Analog Converter (DAC) in...
In the present work an analytical investigation of the behavior of the subsynchronous cascade drive at certain slip values is carried out, specifically at the multiples of 1/6. The drive behavior at these slip values has caused controversy among the researchers in the past. With the help of the space vector theory an analytical investigation is carried out which shows a specific synchronization of...
In permanent magnet machines, the primary cause of pulsation torque, which is the sum of the cogging torque and the pulsating components of magnet torque, is space harmonics contained in the magnetomotive force due to the armature current and in the air gap flux density due to the rotor permanent magnets. The pulsation torque causes vibration and acoustic noise and reduces the performance of the machine...
Applying the selective harmonic elimination (SHE) technique to grid connected cascaded modular multilevel inverters has been widely discussed in literature. However, due to the difficulties of solving high-order non-linear transcendental equations, the SHE technique cannot be implemented in real time so its applications are limited. This paper presents a technique to convert the non-linear equations...
Microwave acoustic filters operated at high power levels generate nonlinear mixing products necessitating improved nonlinear modeling. The latest communications protocols place strict limits on such mixing products including the generation of intermodulation distortion products, which desensitize a receiver, as well as second harmonic emissions. We extend the conventional nonlinear acoustic theory...
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