[show abstract][hide abstract] ABSTRACT: This paper deals with the development of a virtual platform for a Web-based remote application dedicated to condition monitoring and fault detection for ac electrical machines. The platform is based on several tools developed by using the LabVIEW software. Various techniques of condition monitoring and diagnosis of electrical and mechanical faults in ac electrical machines have been integrated such as the broken rotor bar, winding short circuit, bearing damage, or static/dynamic eccentricities. The main features are related to a user-friendly interface, a low-maintenance source code, and a standardized database for ac electrical machine diagnosis. The platform architecture, as well as three different test-rig configurations, has been described. The complete system can be controlled in both local and remote modes by using a simple Internet connection. Some remote experiences have been carried out between the University of Picardie “Jules Verne,” Amiens, France, and the University of Bologna, Bologna, Italy, to verify the effectiveness of the proposed system. The direct applications of this original package are based on diagnosis techniques applied to ac electrical machine faults. Some examples of rotor broken bar detection using classical techniques have been presented to show the effectiveness of the proposed platform. Further information will soon be available on the Open European Laboratory on Electrical Machines Web site: www.oelem.org.
IEEE Transactions on Industrial Electronics 11/2011; · 5.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this paper, a fuzzy PI (FPI) controller tuned using genetic algorithms (GA) is proposed for position control of six- phase induction motor (6PIM). The performance and the robustness of the control system are tested for healthy and several faulted operational modes and rotor inertia variations. The FPI controller presents many advantages such as satisfactory control performance under a wide range of operating conditions. The proposed scheme is compared to the conventional proportional-integral control and validated by simulation and experimental tests. High performance control of variable speed induction motor drives can be achieved by means of field oriented control which is based on decoupling of the torque and flux producing components of the stator current (4). The conventional controllers which are designed using the mathematical model of the system are not suitable when the load is nonlinear and uncertainties exist and robust and adaptive controllers have to be used.
[show abstract][hide abstract] ABSTRACT: In this paper, a new variable structure position control law for a Six Phase Induction Machine (6PIM) is proposed. The algorithm based on a time-varying switching line guarantees the existence of sliding mode since the beginning of the shaft motion. Indeed, the surface is initially designed to pass through the initial representative point and subsequently moved towards a predetermined desired surface via shifting. By this mean, the reaching phase is eliminated and the motor behavior is insensitive to unknown mechanical configuration changes.
Energy Conversion Congress and Exposition (ECCE), 2010 IEEE; 10/2010
[show abstract][hide abstract] ABSTRACT: This paper deals with a new variable structure position control law for a Six Phase Induction Machine (6PIM) that is based on time-rotating switching surface. This algorithm guarantees the existence of sliding mode since the beginning of the shaft motion. Indeed, the surface is initially designed to pass through the initial representative point and subsequently moved towards a predetermined desired surface via rotating. By this mean, the reaching phase is eliminated and the motor behavior is insensitive to unknown mechanical configuration changes.
Electrical Machines (ICEM), 2010 XIX International Conference on; 10/2010
[show abstract][hide abstract] ABSTRACT: The aim of this paper is to compare different experimental techniques for detecting a stator inter-turn short-circuit in a Wound rotor induction machine working as generator. Three methods using different signals such as stator or rotor current and the leakage flux will be described and experimented. The rotor currents provide interesting signatures since the stator faults introduce new harmonics in the rotor windings. Hence, in this paper, it is proved that sensing one rotor current by using a current sensor is one of possible techniques for detecting this kind of electrical fault. The leakage flux is another alternative for this kind of problems since in this paper; it is proved that a simple external leakage flux sensor is efficient to detect, in the low frequency range, the intern-turn short circuit in three-phase induction machines even in presence of power supply harmonics. Stator currents space vector is also an interesting technique since it is proved that inter-turn short circuit faults can be considered as a stator unbalance which can be detected using negative sequence of stator currents. The comparison of these three methods is performed using experiments on a 5.5kW-220V/380V-50Hz-8 poles wound-rotor induction machine working in both healthy and faulty modes at different load conditions.
Industrial Electronics (ISIE), 2010 IEEE International Symposium on; 08/2010
[show abstract][hide abstract] ABSTRACT: In this paper, a mutual model reference adaptive system (MRAS) is proposed in order to realize a speed sensorless field orientated control (FOC) of a six phase induction machine (6PIM). The efficiency of the MRAS for sensorless control of the 6PIM is realized under variations of mechanical load configuration and also in faulted mode (lost of one phase). The experimental results show the performance and the capacities of MRAS for sensorless speed control of 6PIM.
Industrial Technology (ICIT), 2010 IEEE International Conference on; 04/2010
[show abstract][hide abstract] ABSTRACT: The faulted mode of a six-phase induction machine (6PIM) denotes that the motor is working with one or more missing phases. This situation leads to torque oscillations and poor tracking behavior. Therefore, the design of a suitable robust control is a challenging task. In this way, this paper presents the application of fuzzy logic and sliding mode controls in order to obtain a high-accuracy positioning of a 6PIM rotor in both healthy and faulted modes. The two control strategies are completely different from a theoretical point of view, but the final objectives are to remove the drawbacks of the specific fault on interest. The experimental results are obtained on a dedicated setup based on a 6PIM coupled with a variable mechanical load and for which up to three phases can be removed.
IEEE Transactions on Industrial Electronics 02/2010; · 5.17 Impact Factor
[show abstract][hide abstract] ABSTRACT: In this work, a duty ratio control scheme for inverter fed six-phase induction machines using the direct torque control method based on a fuzzy inference system is presented. A six-phase induction machine has six windings spatially phase shifted by sixty electrical degrees. An improved steady state torque response has been achieved by using the duty ratio control and it has shown less torque ripple compared to the conventional direct torque control. A fuzzy inference system has been used to implement the duty ratio during each switching cycle using the torque and flux errors as inputs. The main advantage of the proposed algorithm is the improvement of torque and flux ripple characteristics in the low speed mode. This feature provides an opportunity for motor operation under minimum switching loss and low noise.
[show abstract][hide abstract] ABSTRACT: The aim of this paper is to develop a technique for detecting a real rotor inter-turn short-circuit fault in a wound rotor induction machine working as generator by using the spectral and the bispectral analysis. The stator currents provide interesting signatures since the rotor inter-turn short-circuit fault introduces new harmonics in the stator windings. Hence, in this paper, it is proved that sensing one stator current by using a current sensor is possible techniques for detecting this kind of electrical fault. This technique is based on mmf, flux and emf computation for both healthy and faulty machines during any operating condition. Then, by using the spectral and the bispectral analysis, the computed harmonics of stator currents are experimentally verified on a 5.5kW-220V/380V-50Hz-8 poles wound-rotor induction machine working in both healthy and faulty modes at different load conditions.
[show abstract][hide abstract] ABSTRACT: This paper presents the simulation and experimental results of a 42 V fault-tolerant six-phase induction machine (6PIM) with opened stator phases. The 6PIM has symmetrical 60 degrees displacement winding allowing fault-tolerant modes for an electric power steering (EPS) application. A voltage source inverter (VSI) in closed-loop using a vector control feeds its. The 6PIM model is derived from the stator winding distribution on a conductor-by-conductor basis and the geometrical dimensions of the different slots. A case study by simulation and experimental tests on a six-phase squirrel-cage induction machine rating 90 W, 14 V, 50 Hz, 2 poles is described and analyzed to validate the system performance in faulted modes. This paper presents also the torque ripple estimation in degraded mode using the dq0 components.
Diagnostics for Electric Machines, Power Electronics and Drives, 2009. SDEMPED 2009. IEEE International Symposium on; 10/2009
[show abstract][hide abstract] ABSTRACT: In this paper, sliding mode control (SMC) is applied to regulate the dq axis currents of a 6 phase induction machine (6PIM). This strategy presents a good alternative in power electronics for electrical drives because of its dynamic properties and its high robustness. The design of the sliding mode control law, defined from the healthy mode model, is based on the linear feedback with switched gains approach. With this strategy, the control voltages are smooth and guarantee the stability of the control loop regarding the faulted condition of the 6PIM. Experimental results assess the robustness of the proposed sliding mode control compared to traditional Proportional-Integral algorithm.
Electric Machines and Drives Conference, 2009. IEMDC '09. IEEE International; 06/2009
[show abstract][hide abstract] ABSTRACT: A sensorless vector control strategy for induction machine (IM) operating in variable
speed systems is presented. The sensorless control is based on a reduced-order linear observer
based on terminal voltage and current as input signals. An estimation algorithm based on this
observer is proposed to compute speed. It is shown that the proposed sensorless control is more
sensitive to the stator resistance than to the rotor resistance. In order to tune the observer and to
compensate for the parameter variations and the uncertainties, a separate estimation of the stator
resistance is introduced. The equations to estimate the stator resistance are derived from the
machine differential equations. For certain operating regions of the machine, it is verified that the
stator resistance can be accurately estimated regardless of wide stator resistance variation. It is
shown that design and hardware implementation of this method is simpler than the previous works.
The simulation and experimental results demonstrate the good performance of the proposed
observer and estimation algorithm and of the overall indirect-field-oriented-controlled system.
Iranian journal of science and technology, Transaction B: Engineering. 04/2009; 33(B2):133-147.
[show abstract][hide abstract] ABSTRACT: In this paper, a new direct torque control (DTC) algorithm for six phase induction machines (6PIM) will be introduced. The machine has two sets of three phase windings spatially shifted by 60 electrical degrees. This approach is based on deriving the voltage vectors in a synchronous frame rotating with the stator flux. It leads to a fixed switching frequency and low torque ripples. Simulation and experimental results show satisfactory performances and validate the proposed method.
[show abstract][hide abstract] ABSTRACT: The main goal of increasing the number of phases in an induction machine is to ensure its performance in all the operating modes such as normal, disturbed and faulted settings. The faulted mode of a Six Phase Induction Motor (SPIM) denotes that the SPIM is working with one or more missing phases. This situation leads to high torque ripples and bad tracking behaviour. A suitable robust control law has then to be applied to cope with these effects. Therefore, this paper presents the design and implementation of fuzzy logic control associated with indirect field oriented control method for high precision positioning of the shaft rotor of the SPIM in healthy and faulted modes. The proposed fuzzy controller has been first tested in simulation and then implemented on an advanced test bed built up in our laboratory. Simulation results have been validated experimentally.
[show abstract][hide abstract] ABSTRACT: This paper presents the design and application of the fuzzy logic and the sliding mode controls associated with field oriented control in order to obtain a high precision positioning of a six phases induction machine (6PIM). The two techniques are first presented. Then, to validate experimentally the efficiency of the two methods, an advanced test bed is used.
Electrical Machines, 2008. ICEM 2008. 18th International Conference on; 10/2008