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This paper presents the implementation of a decentralized modulation for the control of multilevel converters requiring phase-shifted carriers. Contrary to the principle using a “master” controller providing a set of interleaved carriers, the proposed method uses local interconnections between different independent elementary controllers allowing them to self-align their own carrier regardless the...
This paper proposes a DC–DC converter dedicated to high efficiency and high voltage conversion ratio, which is well suited for fuel cell applications. At high voltage conversion ratio the proposed converter, named here mirror boost converter, has a better ratio of active/freewheeling times which, compared with conventional structures, reduces the penalty on efficiency induced by the high conversion...
Connecting legs in parallel in a buck convertor is a way to increase the output current by improving the output's waveforms. By coupling these legs, it is possible to reduce the current ripple and thus the coil volume; however this coupling adds internal variables which must be controlled in order to prevent saturation of the iron core in the couplers and keep the linearity of the system. This paper...
The parallel association of classical commutation cells is a good solution for increasing the output current driven by the converters while the classical semiconductors technology are used. The control strategies used with this type of connection must be able to ensure good distribution of the output current among the different legs. This paper applies two control strategies based on the Model Predictive...
In this work we propose a control strategy based on Model Predictive Control (MPC) with variable commutation instants at constant frequency. Two stages are used by association of a reduced cost function and a state machine which selects the optimum state. The strategy is applied to flying capacitor converters connected in parallel, which requires the development of strategies capable to control the...
Interleaving techniques applied to the parallel association of converters provide the reduction of the output current ripple and the increase of its frequency, leading to a reduction of the associated filters. The best way of paralleling commutation cells is by means of InterCell Transformers (ICT). The design of such special magnetic components strongly depends on the magnetic flux flowing through...
This paper presents a reconfigurable parallel interleaved inverter connected through InterCell Transformers (ICT) and driving two separate and identical AC loads. The proposed system can be connected to both 270V and 540V bus DC available in aeronautical applications, without any difference in the system operation and with no need of oversizing switches, filters and passive components. This feature...
In the paper a new five-level (5L) inverter based on unidirectional Flying-Capacitor switching cells is presented. It is named 5L-Flying-Capacitor with Coupled-Inductor (5L-FC-CI) and consists in parallel connection of two unidirectional (P and N) three-level (3L) Flying-Capacitor switching cells with a coupled-inductor. The PWM output voltage is vastly improved and the switch control dead times is...
The multilevel topologies allow the power transfer for applications in the range of medium voltage with switching frequencies less than one kHz. For many years, many structures were proposed to increase the number of levels. A new three-phases topology with 4 levels is proposed in this paper using the concept of both SMC (Stacked Multicell Converter) and ANPC (Active Neutral Point Clamp). To increase...
This paper reports a compact, robust distance-only sensor for networked small robotic platforms. Two methods of sensing distance (neglecting heading) between robots are discussed: Received Signal Strength Indicator (RSSI) and Time Difference of Arrival (TDOA). Both implementations make use of a commercially available wireless sensor network board for communication and processing. Although RSSI requires...
Multilevel structures are becoming more and more common in the industry because they can convert a DC voltage into an AC voltage for high-power and medium voltage condition. However there are limitations in some topologies where the DC Bus is divided by capacitors. With 3 or more DC bus capacitors, it is difficult to ensure the voltages balance across each capacitor. This paper proposes a 5-level...
In this paper, small-signal stability issues of low-voltage parallel-connected voltage source inverters without control interconnections are addressed by means of dynamic analysis and experimentations. The studies performed showed that the parallel system damping is severely reduced when the traditional droop method is employed and the cabling is long. This paper proposes the application of the PSS...
The paper is focused on the numerical calculation of total losses in each power device of 3L-ANPC (Active-NPC) and 3L-ASNPC (Active-Stacked-NPC) multilevel converters in a STATCOM application. Due to the symmetry of the structures the conduction and switching losses are calculated only for half of power devices. The modulation functions and the conduction/switching intervals are elaborated in order...
The principle of an automatic VHDL code generator dedicated to the control of the electric systems is presented in this paper. From the definition of classic regulator, it is possible to envisage a direct integration of the digital regulator in a FPGA component. The advantage of using a FPGA rather than a micro-controller lies in the fact of reaching very high sampling frequencies, allowing to obtain...
In this paper, small-signal stability issues of parallel-connected voltage source inverters without control interconnections are addressed. The dynamic analysis performed showed that the system stability margin is reduced when the composition of the inverter connection impedance is neither purely inductive nor purely resistive, which are two common approximations found in the literature. Based on...
The multilevel topologies allow the power transfer for applications in the range of medium voltage drive with switching frequency of about kHz. In the three phases applications, some of these topologies have many switches. In order to reduce this number of switches, it is possible to share some of them between several phases and thus reduce the total number of switches. Based on a known topology of...
A new 5-level non-differential PFC topology with fault tolerant capability is presented and compared to known structures. It is derived from a 3-level double-boost PFC. The series-connection of the two low-voltage switching-cells decoupled by a single flying capacitor provides a fault-tolerant capability and a post failure operation increasing the availability of converter. The most important features...
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...
The efficiency of power conversion is an important factor to design static converters. The paper is focused on the calculus of total losses of 3L-NPC and 3L-active-NPC converters for different PWM strategies. The calculus was made in the most critical operating points when certain switches have the biggest total losses. Different modulation functions have been elaborated to calculate conduction losses...
In the paper the operation and the features of a new three-level (3L) converter for industrial medium-voltage application are presented. The proposed topology was named 3L-ASNPC (Active-Stacked-NPC). The main advantage of 3L-ASNPC converter 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...
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