This paper presents a comparative study of three Predictive Current Control (PCC) schemes for Permanent Magnet Synchronous Machines (PMSM) drives. The first control scheme predicts the future evolution of the currents for each possible configuration of the inverter legs. Then the switching state which minimizes a given cost function is selected and applied during the next sampling time. The second control scheme uses a modulator to apply two configurations of the inverter legs during a computation period. Among these configurations, one leads to null voltages. The duration of the other configuration is calculated in order to minimize the distance between the obtained state vector and the desired one. The third control scheme uses a model of the PMSM in order to predict the stator voltages which allows to reach the desired currents after one modulation period. An algebraic method is presented to compute the duty cycle of each leg of the inverter in a direct manner. These control schemes are detailed and tested using the same switching frequency on the same test-bench (1.6kW PMSM drive). A simulation study is performed in order to compare sensitivity to parameters of each control schemes. Experiments confirm the simulation results.

High temperature power electronics has become possible with the recent availability of silicon carbide devices. This material, as other wide-bandgap semiconductors, can operate at temperatures above 500°C, whereas silicon is limited to 150-200°C. Applications such as transportation or a deep oil and gas wells drilling can benefit. A few converters operating above 200°C have been demonstrated, but work is still ongoing to design and build a power system able to operate in harsh environment (high temperature and deep thermal cycling).

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This paper discusses the estimation of possible device destructions inside converters in order to predict failures by mean of simulation. The study of insulated gate bipolar transistor (IGBT) thermal destruction under short circuit is investigated. An easy experimental method is presented to estimate the temperature decay in the device from the saturation current response at low gate-to-source voltage during cooling phase. A comparison with other classical experimental methods is given. Three one-dimensional (1-D) thermal models are also studied. The first one is a thermal equivalent circuit represented by series of resistance-capacitance (RC) cells, the second model treats the discretized heat-diffusion equation (HDE), and the third model is an analytical model developed by building an internal approximation (IA) of the heat-diffusion problem. It is shown that the critical temperature of the device just before destruction is larger than the intrinsic temperature, which is the temperature at which the semiconductor becomes intrinsic. The estimated critical temperature is above 1050 K, so it is much higher than the intrinsic temperature ( 550 K). The latter value is underestimated when multidimensional phenomena are not taken into account. The study is completed by results showing the threshold voltage and the saturation current degradation when the IGBT is submitted to a stress (repetitive short circuit).

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Abstract-This paper presents the implementation of a hybridcontrol strategy applied to a permanent-magnet synchronousmotor (PMSM) drive. Hybrid control is a general approach for control of a switching-based hybrid system (HS). This class of HS includes a continuous process controlled by a discrete controller with a finite number of states. In the case of ac motor drives, in contrast to conventional vector control like proportional-integral control or predictive control, where the inverter is not taken into account by the controller, hybrid control integrates the inverter model and considers the state of the inverter as a control variable. It allows to obtain faster torque dynamics than vector-control algorithms. The hybrid control algorithm requires both computing velocity for real-time implementation and code flexibility for management of low-performance functions and analog-digital interfaces. Codesign appears as a promising methodology for partitioning hybrid-control algorithm between software (flexible) and hardware (velocity) while taking care of overall time constrains. In this paper, the implementation of hybrid-control algorithm for a PMSM drive is performed through a codesign approach on an Excalibur board, embedding a CPU-core (Nios-2 by Altera) inside an APEX20KE200EFC484-2X field-programmable gate array. The partitioning of software and hardware parts is explained. Experimental results show the effectiveness of the implementation. Performances, advantages, and limitations are discussed.Index Terms-AC motor drives, control, dynamic hybrid system (HS), field-programmable gate array (FPGA), hardware-software codesign.

In order to reduce production costs of RF devices, it is important to remove bad circuits very early in the production flow. It is all the more true for dies designed to be integrated in complex systems. Thus highly efficient RF wafer testing is mandatory for those applications to prevent the loss of assembled systems due to defective RF dies. The problem is that current RF probing technologies hardly fulfill the industrial test requirements in terms of accuracy, reliability and cost. The proposed method proves to be a very interesting alternative to validate RF parameters with no need of expensive RF equipments (RF probes and RF automated test equipments (ATE)). A new test strategy based on DC or very low frequency (LF) measurements, which allows the elimination of expensive RF tests, is presented. The main idea is to insert some simple design for test (DfT) circuitry within the chip.This DfT provides relevant information on the structural behavior of the device blocks. The internal node data are additional to standard DC test measurements like power supply current or advanced DC test signatures (e.g. Vdd ramping), and LF measurements like gain in loopback mode.Since RF performance of each block is directly related to such structural data, it is possible to predict the RF characteristics of the blocks without time consuming RF measurements. RF parameters estimation is performed using nonlinear Artificial Neural Networks.

An efficient rectenna based on a dual Schottky diodes converter has been designed at 2.45 GHz. The proposed rectifying circuit is well suitable for wireless sensor applications because no input lowpass filter and no via-hole connections are required, resulting in a more simple structure. A simulation mixing an electromagnetic and circuit analysis has been first used to optimise the rectifier. In addition, the performances of the rectenna has been correctly predicted and characterised using an FDTD formulation extended to lumped circuit elements. The realised rectenna exhibits 83% efficiency over a 1050 V resistive load at a power density of 0.31 mW/cm 2 .Introduction: The rectenna is an important component for converting RF or microwave power into DC power. These techniques are of great interest to supply actuators [1] or wireless sensors [2] through free space without wire connections or a battery. A rectenna usually contains a receiving antenna, a combination of one or several Schottky diodes in series [3] or shunt [4], in voltage doubler configurations [5] or in a modified bridge converter [6], an input lowpass filter (LPF), an output DC pass filter and a resistive load. The input (LPF) rejects harmonics created by the diodes and provides matching between the antenna and the rectifier. It can be directly included on the radiating element by using harmonic-rejecting antennas [7].We propose an efficient rectenna design based on a dual diodes converter. In this configuration, the LPF between the antenna and diodes can be eliminated, reducing the insertion losses of the rectifier. The structure has been optimised and characterised using advanced design system (ADS) commercial software and the 3D-FDTD algorithm extended to lumped element circuits. Finally, simulated results are compared with the measured ones and show good agreement.