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This paper presents design and analysis of a coupling device which is used for measurement of PD signal and AC voltage as the conventional partial discharge testing according to IEC 60270. The remarkable feature of the developed coupling device is the accuracy in PD signal measuring and the ability in eliminating noise signal Therefore, In the AC signal measuring part, the proper impedance was chosen...
This paper presents the analysis of an AC-AC converter used in partial discharge test. In this paper, the analysis of the frequency converter is separated into two parts. Firstly, the converter models are simulated by a circuit simulation program for comparing noise signals generated by the 2-level SFC and 5-level SFC. The frequency of the converter was set to be 200 Hz. With the help of the simulator,...
This paper presents the usage of multilevel frequency converters for partial discharge tests and an approach for noise reduction. The comparison of the background noise generated by square wave (2-level) and 5-level frequency converters with the frequency of 200 Hz is presented. The testing frequency of 200 Hz is necessary for partial discharge test of transformers because of avoiding saturation effect...
This paper presents design and construction of a quad-pole coupling device which is used for measurement of PD signal and AC voltage as the conventional partial discharge testing according to IEC 60270[1]. The developed coupling device is capable to measure AC voltage at frequencies of 50 Hz and 200 Hz. Lower limit and Upper limit frequencies of the developed coupling device are 30 kHz and 20 MHz,...
Mineral-oil based nanofluids are proved that the addition of suitable nanoparticles can increases the AC breakdown voltage and Partial Discharge Inception Voltage (PDIV) compared with those of the unmodified mineral oil. In this paper, a standard impulse breakdown voltage of the mineral oil and the mineral-oil based nanofluids is investigated. Three types of nanoparticle, i.e., Zinc oxide (ZnO), Barium...
Undamped power and voltage swings of synchronous generators due to severe disturbances may make power systems unstable. To tackle this problem, this paper proposes a control scheme of active and reactive power outputs of a photovoltaic (PV) generator equipped with power oscillation dampers (PODs). The PODs with second-order lead/lag structure are installed in the active and reactive power control...
This paper presents a soft starting control scheme of a three-phase induction motor using a PWM AC chopper technique to reduce the magnitude of currents during a start up process. To control bidirectional power switches in the PWM AC chopper, a PWM signal is generated by a single voltage signal, and compared with a single carrier signal. By this approach, the PWM signal is independent since the PWM...
This paper presents a soft starting control scheme of a capacitor start and run type single-phase induction motor(SPIM) using a PWM AC Chopper control technique to control an amplitude of the motor starting current. The actual current of the motor during start up is used as a feedback signal for comparing with a setting value. The error, then, is sent to a PI controller. The output of the PI controller...
This paper presents control schemes for energy saving of a capacitor start and run type single-phase induction motor using a PWM AC Chopper to adjust the appropriate motor voltage under various load levels. MATLAB/Simulink is used for the simulation. The main winding stator current is used to feedback for minus with the appropriate current obtained from the multiple of the auxiliary winding stator...
This paper presents the studies of breakdown characteristics of a 12-kVarcing horn under a lighting impulse superimposed on an AC power frequency voltage at various angles. The lightning impulse is superimposed on the AC power frequency voltage at a phase angle varied from 0° to 360. The 12-kV arcing horn under test has dimension and configuration according to DIN 42531 standard. The critical breakdown...
This paper presents a novel fuzzy logic control technique tuned by particle swarm optimization (PSO-FLC) for maximum power point tracking (MPPT) for a photovoltaic (PV) system. The proposed PV system composes of a current-mode boost converter (CMBC) with bifurcation control. An optimal slope compensation technique is used in the CMBC to keep the system adequately remote from the first bifurcation...
This paper presents the design of a fuzzy logic controller for switching current-mode DC/DC boost converters. The proposed simple fuzzy logic controller, with nine rules, provides an optimal slope compensation to keep the system adequately remote from the first bifurcation point by means of reducing the current spectrum peak. In spite of nonlinear characteristics and instabilities of the converter,...
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