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In the area of natural gas industry, there is a large interest in converters for driving high speed, medium voltage induction motors. High-speed drive systems are capable of directly driving turbo-compressors at speeds of up to 20,000 rpm / 8 MW. In high speed motor drive applications, the motor fundamental frequency can vary from 100 Hz to 300 Hz, which requires a high switching frequency. However,...
This work investigates the influence of the choice of the operation point (Deltai @ fs) under the final volume of PFC boost converter. Boost inductor, EMI filter and thermal heatsink are the elements which main influences in the converter volume. These elements are strongly influenced by the chosen operation point, showing a direct relationship among them. With the increase of switch frequency and...
The forthcoming scenario of the wireless sensor network and the so called pervasive computing would greatly boost if all electronic systems involved in their deployment could feature some sort of energy self-sufficiency. In this application an aggressive power management solution is required in order to collect a sufficient amount of energy in storage elements in general from different power sources...
This paper presents a comparison study between the operation of a back-to-back and a matrix converter induction motor drive under the presence of faults in the power switches of these converters. These two topologies are functionally equivalent in terms of input power quality and energy regeneration capabilities but need to be compared in terms of performance under faulty conditions as well due to...
This paper presents a modulation scheme in order to reduce conducted electromagnetic interference (EMI) generated by modular power converters with parallel topology. The proposed scheme is based on a combination of interleaving and Switching Frequency Modulation (SFM) techniques. The objective of this modulation scheme is to cancel certain harmonics of EMI and to reduce the amplitude of the remaining...
A new self-controlled and self-protected integrated power switch dedicated to self-switching mode power converters is presented. To achieve this function, two original topologies based on a thyristor and an IGBT are proposed. Their operating modes are analyzed with 2D physical simulation and the obtained results are discussed in order to compare the two topologies. The two architectures validate the...
The strategy of conventional space vector modulation (SVM) is based on the assumption of ideal power commutations. In reality, the power commutations are under switching disturbances that leads to the appearance of distortions into the output current. The reduction of the current distortions is available due to obtaining the robustness of SVM based on redundancy. The robust SVM with minimum distortions...
A novel technique for conducted-noise reduction has been proposed in this paper. The proposed technique uses three randomized parameters for generating the switching signals. These parameters are carrier frequency, duty-ratio, and the pulse position. This triple-hybrid spread-spectrum technique has been designed and implemented using field-programmable gate array (FPGA) technology. Moreover, the effect...
A maximum speed of response control of switches-based system described by a second-order difference equation is proposed. A feedback is produced as a linear combination of the differences of system variables. The equation is transformed to the form with nilpotent matrix. The solution of the transformed difference equation converges into a fixed point after two steps. The equation is transformed with...
This paper describes improvement of Z-source inverter (ZSI) properties possible due to advanced PWM methods. Switching conditions and distribution of semiconductor power losses in the ZSI are analyzed. Two new PWM methods are proposed, including Asymmetric Optimized Switching Type (AOST) with efficiency improvement by 2,7%. Considerations are illustrated with datasheet based calculations, simulation...
This paper proposes a digital predictive current controller applied to a power factor correction boost converter rated to a wide range of output power, operating in mixed conduction mode with fixed switching frequency. The current controller comprises two predictive model based control laws (one for the continuous and another for the discontinuous conduction mode) and an operation mode selection algorithm,...
This paper presents a new class of pulsewidth modulation (PWM) DC-to-DC converters with quadratic conversion ratios for photovoltaic applications without a transformer. The aim of these structures is to obtain at the same time high conversion ratio and excellent efficiency for a wide source voltage range. The DC voltage conversion ratios of these converters have a quadratic dependence on duty cycle...
A graphical method, easy to understand and easy to implement, has been developed for two-level and multi-level space vector modulation. Switching sequences can be computed with no need of solving neither multi-variable inverse problems nor expensive trigonometric functions. Proposed method has been validated through simulations and physical implementations.
Decades of research have seen single-phase boost-type PWM converters be employed as front-end PFC rectifiers in commercial power supplies. The benefits of employing this technology to comply with power quality standards while assuring high efficiency and low volume and weight have been observed. However, this work shows that further efforts can be driven into new topologies. In this context, a new...
In the paper a new three-level converter is presented. The proposed topology was named 3L-ASNPC (Active-Stacked-NPC) and its main advantage is the reducing of the average switching frequency for all power devices. In the same time, the apparent switching frequency of the output voltage is naturally doubled. Experimental results are shown in the paper in order to validate the proposed topology and...
This paper presents a novel design methodology for the tank circuit of LLC resonant converters, based on a simplified yet accurate model of the steady-state operation in the ldquobelow-resonancerdquo region. This model is used in a design strategy that aims to design a converter capable of operating with soft-switching in the specified input voltage range, with a load varying from zero up to the maximum...
A switched-capacitor programmable filter is proposed as educational tool for the feedback compensation of power converters. The transfer function of the external feedback network, expressed in the Z-transform domain, can be assigned by means of Multiplying DACs. The cancellation of poles and zeros of switching power cells is precisely implemented even in the case they are complex. An ideal final single...
A novel dodecagonal space vector structure for induction motor drive is presented in this paper. It consists of two dodecagons, with the radius of the outer one twice the inner one. Compared to existing dodecagonal space vector structures, to achieve the same PWM output voltage quality, the proposed topology lowers the switching frequency of the inverters and reduces the device ratings to half. At...
A step-up ZVS full-bridge (FB) converter with a primary-side energy recovery circuit (PERC) is proposed. The PERC means can recover the power loss due to high spike current hiding in primary inductance when the phase-shift switching activates. High ringing currents occurring at the beginning of the two resonances each half-period can then be smoothly transferred to DC bus and restrain the resonant...
In this paper the circulating energy of an integrated auxiliary commutation circuit applied to a double-conversion uninterruptible power supply is analyzed. This analysis is based on a comparison between the circulating energy of Zero Voltage Transition (ZVT) and integrated Zero Voltage Transition (iZVT) in Auxiliary Commutation Circuits (ACC), both attached to the same double-conversion UPS. Two...
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