Adaptive Ripple Reduced Control of SRM Drives

Nowadays s witched reluctance m o to r (SRM) drives h ave been w idel y used i n t h e fi el d of c ont rol l e d el ect ri c m o t o r dri v es. The paper proposes a m odel reference adapt i v e cont rol m e t hod for SR M dri v es. The m a i n goal of t he d r iv e co n t ro l is t o i m prove dy n am i cal perform ance by com pensat i ng for t h e m o t o r non lin earities. Th e ripple free operation can b e rea lize only with a n current w avef orm dependi ng on t h e angl e, s peed a nd t o rque. The proposed r i ppl e reduced m et hod c hanges onl y t h e t u rn-on and t h e t u rn-off angl e i n f unct i on of t he s peed a nd cur rent r eference. O ne of t he a dvant ages o f usi ng t h e ri ppl e reduced m et hod t h at i t do es not n eed t he r eal- tim e calcu latio n o r m easu r in g th e m o to r to rq u e . So it can b e im pl em ent e d on a cheap m i c rocont rol l e r. T he t est of t hi s cont rol m e t hod was perf orm e d i n a n experi m e nt al d ri ve s y s t e m . A S R M o f 6/ 8 pol e and 4 kW r at ed pow er w as u sed. Si m u l a t i on and experi m e nt al resul t s are present ed

Model Reference Adaptive Control of SRM Drives

The paper proposes a m odel reference adaptive control m e thod fo r SRM drives. T he m ain goal of t he drive control is t o im prove d y n am ical p erform ance by c om pensati ng for the m o tor nonlinearities. T he proposed r ipple reduced m ethod changes only the turn-on and the t urn-off angle in f unction of t he speed a nd current r eference. O ne o ff the advantages of u sing th is m ethod that it do es not need the real- tim e calculation or m easuring the m o tor torque. Sim ulation and experim e ntal results are presented

Convergence Test of of Model Reference Parameter Adaptive SRM Drives

Nowadays switched reluctance motor (SRM) drives have been widel y used in the field of controlled electric motor drives. The paper proposes a model reference par ameter adaptive control method for SRM drives. The main goal of the drive control is to improve dynami cal performance by compensating for the motor nonlinearities. The adaptation practically works only in a relatively narrow speed error track (adaptation range) which is equa l to approximately 20-100 revol ution/min absolute value of speed error. The drawback of this limitation is the relatively short time fo r the algorithm to operate. But the convergence of the algorithm is extremely fast which significan tly reduces the effect of this drawback. Two more important advantages emerge when adaptation works only with small speed errors. First of all the controller at changing drive parameters adapts to parameter s around the value specified by speed reference signal which also assists to speed the adaptation. Th e other significant positive effect is the disappearing of the problem coming from nonlinear systems that the response of the system can even differ in its character when the value, amplitude of the refere nce signal is changed. The convergence test of this control method was performed in an experimental drive s ystem. A SRM of 6/8 pole and 4 kW rated power was used. Simulation and e xperimental results are present ed

Adaptive PF Speed Control of SRM Drives

This paper proposes two model reference adaptive PF speed control m ethods for SRM drives. Following from the structure of model reference parameter adaptive PF control it makes it easier to reach overshootless as well as fast speed changing compensation caused by jump in load. The approaching block diagram of the model reference signal adaptive contr ol can be seen as an extended version of the PF controller, so one of the adaptation factors (which is the free parameter of the adaptive control) is given. Both model reference adaptive controls drawn up can be easily implemented because the adaptation algorithms do not need acceleration measuring

Investigation of Model Reference Parameter Adaptive SRM Drives

Nowadays switched re luctance motor (SRM) drives have been widely used in the field of controlled electric motor drives. The paper proposes a m odel reference adaptive control method for SRM drives. The main goal of the drive control is to improve dynamical performance by compensating for the motor nonlinearities. The r ipple free operation can be realize only w ith an current waveform depending on the angle, speed and torque. The proposed ripple reduced meth od changes only the turn-on and the turn-off angle in functio n of the speed and current reference. One of the advantages of using the ripple –reduced method that it does not need the real-time calculation or measuring the motor torque. So it can be implemented on a cheap microcontroller. The test of this control method was performed in an experimental d rive system. A SRM of 6/8 pole and 4 kW rated power was used. Simulation and experimental results are presented

Analysis of Torque and Speed Controller for Five Phase Switched Reluctance Motor

Abstract-The electric drives play a vital role on the productivity to any industry. The application of Switched Reluctance Motor (SRMs) in high performance industry is due to the progress in the motor design and power electronic control technology. The electromagnetic operation of an SRM is achieved by the proper excitation and control. A SRM is characterized by simple features like simple construction, high reliability and low cost. It can be used in the high temperature and hazardous environment applications. Most switched reluctance motors are either 3 phase or 4 phase types with unipolar or half wave electronic drives. The torque ripple must be carefully minimized with proper commutation of the power to each of the stator phase winding. The design of control system for five phase SRM is very complex since it has large torque ripples and non uniform torque at its output. The reduction in torque ripples and speed control requires an effective controller. In this paper the output obtained using PI controller is shown clearly.Here, simulation of the PI based controller for SRM is performed by using MATLAB/simulink. Keywords-switched reluctance motor, proportional integral controller (PI), torque ripple. I.INTRODUCTION A switched reluctance motor is a brushless AC motor which has simple construction and does not require permanent magnet for its operation. Hence it has many advantages over other dc or ac machines. The stator and rotor in SRM have salient poles and the number of poles depends on the number of phases. Normally two stator poles at opposite ends are configured to form one phase. The number of stator poles is always different from that of rotor poles. SR motor has the phase winding on its stator and concentrated windings are used. The windings are inserted into the stator poles and connected in series to form one phase of the motor. SR motor has the phase winding on its stator only and concentrated windings are used. The windings are inserted into the stator poles and connected in series to form one phase of the motor. In a five phase SRM there are five pairs of concentrated windings and each pair of the winding is connected in series to form each phase respectively. The flux linkage, inductance and torque characteristics vary with rotor position (i.e. the relative position of the rotor pole with the stator pole). The flux linkage, inductance and torque characteristics of a SR motor are highly non-linear. Positive torque in a SR motor is available at half the rotor pole pitch. Torque production in an SR motor can be explained based on energy conversion process. When one phase of the motor is energized, energy from the power supply is transferred to the phase winding. Part of the energy, which is also known as the co-energy, is used to produce mechanical movement. Torque produced in this movement is defined as the ratio of change in co-energy to the change in rotor position. In mathematical expression, the torque production process can be expressed as Torque = ΔW′̸ Δθ where W′ is co-energy, θ is rotor position

Velocity Regulation in Switched Reluctance Motors under Magnetic Flux Saturation Conditions

We propose a controller for velocity regulation in switched reluctance motors under magnetic flux saturation conditions. Both hysteresis and proportional control are employed in the internal electric current loops. A classical PI velocity controller is employed in the external loop. Our control law is the simplest one proposed in the literature but provided with a formal stability proof. We prove that the state is bounded having an ultimate bound which can be rendered arbitrarily small by a suitable selection of controller gains. Furthermore, this result stands when starting from any initial condition within a radius which can be arbitrarily enlarged using suitable controller gains. We present a simulation study where even convergence to zero of velocity error is observed as well as a good performance when regulating velocity in the presence of unknown step changes in external torque disturbances

Commande directe du couple appliquée à une machine à reluctance commutée à trois phases

Le moteur à reluctance commutée (SRM) est connu pour sa conception simple, sans aimants permanents, bobinage au rotor et son bas cout de production et une bonne robustesse qui lui confère conception, même sous la perte d’une phase ou de plus et d’opérer dans un environnement industriel très contraignant. Néanmoins ce moteur présente de nombreux inconvénients due à sa double saillance polaire, ses caractéristiques magnétiques et un couple de sortie hautement non linéaires très instable et qui présente de fortes perturbations. La double saillance du moteur ne permettant pas d’exciter ce dernier par une alimentation CA conventionnelle et de commander ce moteur utilisant la théorie des champs tournants. En outre, en raison des caractéristiques de sortie de couple non linéaires du moteur, une ondulation à couple élevé est inhérente au moteur, sauf si une stratégie de réduction de l’ondulation de couple est utilisée. Afin de parer à la non linéarité du couple de sortie et de diminuer les fortes perturbations de couple, plusieurs techniques ont été utilisées. La technique de contrôle du couple direct (DTC) est une excellente technique qui a donné de bons résultats pour ce type de moteur, et pour ce faire notre travail peut être considérée comme une contribution à l’amélioration de la DTC. Nous considérons spécifiquement le remplacement des régulateurs à hystérésis par ceux utilisant les techniques d’intelligence artificielle (logique floue, réseaux de neurones et neuro-flou), avec une concentration plus prononcée pour la technique de régulation par logique floue avec une structure Takagi-Sugeno comme le cœur de notre travail. Pour finir, nous avons utilisé la commande adaptative pour varier les paramètres du régulateur flou en temps réel lors de perturbations paramétriques du SRM et notamment pour parer à la variation de la résistance statorique. La loi de contrôle et la loi adaptative développées, garantissent que tous les signaux dans le système en boucle fermée sont limités en amplitude, alors que la conception du contrôleur est basée sur la synthèse de Lyapunov.Switched Reluctance (RS) Motors have an intrinsic simplicity and low cost that makethem well suited to many applications. Furthermore, the motors have a high robustness due to the ability to operate with the loss of one or more motor phases and are thus well suited to operate in harsh industrial environments. However, the motor has many drawbacks due to the motor’s doubly salient structure as well as highly non-linear torque output and magnetization characteristics. The double salient structure leads to the inability to excite the motor using conventional ac motor rotating field theory to the motor. Furthermore, due to the motor’s non-linear torque output characteristics, a hightorque ripple is inherent in the motor unless a torque ripple reduction strategy is employed. to overcome the non-linearity of the output torque and reduce torque ripple,several techniques have been developed. Direct torque control (DTC) is an excellent technique which has had good results for this type of motor. our work, is a contribution to the improvement of the DTC by the substitution of the hysteresis regulators by thoseusing artificial intelligence techniques (fuzzy logic, neural networks and neuro-fuzzy), with a more pronounced concentration in our study for fuzzy logic regulation technique with Takagi-Sugeno structure. Finally, we used the adaptive control to vary the fuzzy regulator parameters in real time during parametric disturbance of the SRM and especially during stator resistance variation. The control law and the adaptive law developed guarantee the delimitation of all the signals in the closed-loop system and the controller design is made according to Lyapunov's synthesi

A new switching technique for minimisation of DC-link capacitance in switched reluctance machine drives.

In a switched reluctance (SR) drive, the transfer of the de-fluxing energy in stator windings back to the dc-link results in a large dc-link capacitance. This limits its applications where weight and size of the drive are restricted. This thesis describes a control technique for the dc-link capacitance minimisation in an SR drive. The proposed control technique maintains the constant power transfer between the de supply and the H-bridge converter. The average dc-link current over a switching period is kept constant. When the output of the integrator, i.e., the average dc-link current, reaches a predefined value proportional to the torque demand, appropriate switching takes place. This is achieved by integrating the dc-link current in each switching period. This technique is called dc-link current integration control (DLCIC). The de-fluxing current from the outgoing phase is not fed back to the dc-link capacitor. Instead, it is transferred to the incoming phase to prevent a negative dc-link current, which causes a fluctuation in the capacitor voltage. Extensive simulation studies of the DLCIC and other techniques reported in literature have been performed and the simulation results from DLCIC are compared with those from other techniques such as Hysteresis Current Control (HCC) and Pulse Width Modulation Current Control (PWMCC). It has been shown that the peak-to-peak voltages across the dc-link capacitor from DLCIC are the lowest amongst other techniques. The operational speed range of the DLCIC is determined and the optimal turn-on and turn-off angles are proposed. Filter components under the DLCIC operation has been designed and compared with the filter for HCC. It is shown that the weight of the filter for DLCIC is far lower than that for HCC. The proposed control technique have been validated by experiments. The experimental results show that at the dc-link voltage ripple which results from DLCIC is much lower than that from HCC. This demonstrates that DLCIC can minimise the dc-link capacitance in an SR machine drive