Review: Different Torque Controlling Technique of DC Motor

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Review: Different Torque Controlling Technique of DC Motor

Prashant Isankar

Electrical Engineering Department

Shri Sai College of Engineering & Technology Bhadravati, Maharashtra, India

Sumit R. Punam

Assistant Professor

Electrical Engineering Department & Technology Shri Sai College of Engineering Bhadravati, Maharashtra, India


Adaptive Power System (APS) is analogous to the active filter conception whereby the active filter provides the present required to take care of the standard of the load current needed by the upstream power system. Duty cycles will vary from little to continuous and, for a few cases, the maximum (peak) power demands is capability of power system load or demand. A DC motor is any of a category of rotary electrical machines that converts DC electric power into mechanical power. The foremost common varieties accept the forces created by magnetic fields. Nearly all kinds of DC motors have some internal mechanism, either mechanical device or electronic, to sporadically amendment the direction of current flow partly of the motor. These kinds of extreme power profiles can't be supported with standard power systems.

In this paper, different methodology or techniques for providing required power profile for DC motor for dynamic loading condition are presented. This technological review of paper are very much useful for students and researcher those who are working in the field of adaptive power system designing for controlling loading condition of DC motor.

KeywordsIEEE 14 Bus, Power quality (PQ)


    In several industrial applications, dc-motors function straightforward devices for implementing rate trailing tasks. Feedback management schemes, typically, are of the proportionalintegral (PI) and proportionalintegral differential (PID)-type. Usually, the voltage for the speed controller is provided by thyristor-based section controlled rectifiers [18] operated at higher shift frequencies (above forty kHz) and are designed to supply.

    The hardiness drawback with regard to load changes on the dc-motor, is usually frequency addressed by an internet straight line force estimation through associate degree observer (see Chiasson [2] and Hagenmeyer et al.). During this temporary, we tend to use an alternate for the force estimation. This alternative could be a supposed pure mathematics estimation theme that gives correct and quick estimation results, even once subject to noise levels encountered in follow (the theoretical options, and a few of the applications, of the pure mathematics approach to parameter and signals estimation could also be found within the work of Fliess and Sira-Ramírez [4], [5]). Within the linear case, the estimation of unknown parameters is secured in an internet fashion through the analysis of a straightforward time-varying expression resorting to integrations of inputs and outputs alone.

    In applications of the technique were developed in H. Sira- Ramírez and Silva-Ortigoza in reference to ancient power physical science and, finally, for several applications addressing different fascinating mixtures of dc-power converters and dc-motors the reader is noted the works by J. Linares-Flores et al..

    The dynamic average model of the Boost-converter/dc-motor combination is shown to evolve to a special energy managing structure that is specially appropriate for the ETEDPOF controller style methodology, which, incidentally, is intimately associated with ancient static passivity-based output feedback controller style techniques. In distinction to dynamic output feedback approaches with pre-compensation (see [1]), the ETEDPOF controller, isn't solely linear however conjointly static.

    The required reference signal of the convertor is generated exploiting a partial differential flatness property of the thought of cycle system (differential flatness was introduced by Fliess et al. in [6]. the topic has undergone goodish development ever since. For a recent book, The corresponding (nominal) reference signals for the common control system and also the convertor input current area unit derived from complementary hold on energy concerns within the locality of stationary regimes. This reference expressions area unit seen to incorporate associate calculable price of the load force parameter, that is then incorporated within the feed-forward computed strategy. Consequently, the planned policy is also wont to tackle the on top of expressed strength downside. because it is common observe, a polynomial of Bezier kind is such that for a swish energy interpolation flight reminiscent of the initial and final desired angular shaft velocities. In turn, this flight fully defines in associate offline manner the reference trajectories of the convertor input current and also the average management.


    In the controlling of adjustable speed drives, the performance in of cheap digital integrated circuits is approaching the stage wherever old control system algorithms could also be displaced by new algorithms that higher exploit their speed and also the purposeful capabilities of their software. The thought of "instantaneous force control" is introduced as an objective value following within the application of such digital IC's to in drive systems [7]. Fast torque management would in essence allow the quickest potential response and also the elimination of torque ripple, at the side of several

    different blessings unfeasible with standard management algorithms, most of that area unit established to manage a time-averaged force.

    Some of the basic principles of fast torque controlling area unit developed for the switched reluctance motor, that is employed as associate example as a result of, just like the brushless dc permanent-magnet motor with targeted windings, it's the potential for speedy response, however it will have considerable torque ripple with unfavorable firing angles. A organization transformation that may eliminate the rotor position from the voltage and torsion equations isn't acknowledged for either of those machines. This exposes variety of attention-grabbing queries on the generality of fast torque management algorithms, and whether or not they are often incorporated into the final or unified theory of electrical machines.

    Fig.1. Controller block diagram, linear case [7]

    The idea of fast torque control management for motor drives has been introduced and explored for the actual case of the switched reluctance motor, that is chosen as Associate in Nursing example owing to the simplicity of its elementary torque production theory and since it's a decent vehicle for exploring the likelihood of generalizing the thought of fast force management to a wider category of motor drives.

    The controlling algorithm drawback related to brushless dc motors (BLDCM) for direct-drive robotic applications is taken into account [8]. So as to ensure the superior operation of BLDCMs in such applications, the consequences of reluctance variations and magnetic saturation square measure accounted for within the model. Such a BLDCM model constitutes a extremely coupled and nonlinear dynamic system. Exploitation the transformation theory of nonlinear systems, a feedback management law, that is shown to make amends for the system nonlinearities, is derived. Conditions below that such an impression law are feasible square measure given. What is more, the necessity for the derivation of express commutaion ways is eliminated, leading to the reduction of the computations concerned. to ensure the high performance operation of the system subject to substantial uncertainties, a strong management law comes and appended to the general management structure. The inclusion of the strong controller leads to sensible trailing performance once

    there square measure modeling and measure errors and payload uncertainties. The efficaciousness of the general management law is investigated by considering a single-link direct-drive arm motivated by a BLDCM.

    Fig.2. Typical configuration for a BLDCM and its commutation [8]

    The complete dynamics of the motor and also the arm are combined in investigation the trailing management downside related to the system. To ensure the superior operation of the system, the results of magnetic saturation and reluctance variations are accounted for within the BLDCM mathematical model. Some experimental information was given to demonstrate the validity of the model. A nonlinear management law was derived and was shown to behave well even once there have been vital modeling and payload inertia uncertainties. The behavior of this management law, however, was shown to deteriorate once correct measurements weren't on the market. To alleviate this downside, a correction term was derived and appended to the nonlinear controller to boost the hardiness of the system. It absolutely was incontestable that by fitly selecting most bounds on the uncertainties within the system, favorable results square measure accomplished. Additional investigation through computer simulations indicated that it's attainable to make undesirable oscillations within the system if the controller law isn't properly outlined.

    The method was projected for direct torque management of ac machines victimization separate pulse-modulated electrical converters like the resonant -dc link inverter [9]. A novel feature of the management technique bestowed is that only 1 current sensing element within the dc link is needed. The theme is of specific importance for the conclusion of traction drives rated within the 10-100 kW power vary for electrical cars still as a possible replacement for typical open-loop constant V / f drives. wonderful management of torsion, mechanical device flux, and motor current wave shapes is seen to be obtained while not poignant the high dynamic performance related to direct self management (DSC) of machines. By process an impression that doesn't use the zero voltage vector, Associate in Nursing observer is purposed for estimation of the motor current victimization only 1 current

    sensing element within the dc link. An on the spot bang-bang (sliding mode) torque controller is then derived on the premise of this current observer. Experimental verification of simulation results area unit enclosed on a resonant dc link electrical converter drive with a shift frequency of twenty seven kHz. The electrical converter shift theme is enforced employing a time period Motorola DSP56000 digital signal processor-based controller.

    Fig.3. Block schematic of direct self-controlled inverter using a resonant dc link inverter [9]

    These include the absence of speed or position sensors and a single current sensor in the dc link. In addition, load parameters other than the stator resistance need not be known or estimated since the control scheme is not based on an inner current regulator loop. The sliding-mode control scheme presented is intended for use in discrete pulse-modulated resonant link inverters or other high-frequency inverters. This type of torque control scheme is particularly well suited to electric vehicle applications where torque is the reference quantity and where high quality waveforms and low acoustic noise is required.

    A current observer that estimates the input line current by reflective the dc link current through the electrical converter shift perform has been derived. With this observer, it's been shown that torsion and flux management is satisfactorily accomplished victimization solely dc link current feedback. The observer- based mostly theme of torsion management has been by experimentation shown to control quite satisfactorily since the shift frequency is sort of high. the sole issue in victimization the dc link current feedback considerations the enhanced susceptibleness to noise once sampling the dc link current. Strategies to spot the parameters describe for required to attain that system [10]. What is more, the improved theme during this paper presents a way to pick the stiffness of the torsion detector to attain the correct torsion system. The fundamental plan is cceleration controller, supported a disturbance observer, rather than position controller projected within the past. The advantage is that the

    consequences of your time delays because of the system dynamics and also the effects of Coulomb friction square measure eliminated by observer.

    The method additionally delineated that the system victimization same structure provides associate degree correct torsion management capability once the system parameter is intended within the manner simply conferred. The analysis tell North American country that the acceleration controller, the acceleration signal of the link (arm), a and one in all the reference torsion, Tref, ar essentially necessary. The choosing the lower stiffness torsion sensor makes additional correct torsion system. The effectiveness of the planned technique was incontestable employing a single axis back-geared DC motor system.

    New controlling technique for the strong position controlling of brushless DC (BLDC) motor is given [11]. The linear quadratic controller and load force observer is utilized to get the strong BLDC motor system around linear exploitation the field-orientation methodology for associate degree ac servo.

    Fig.4. A Geared DC Motor with a Torque Sensing Elementand Feedback Control System [10]

    And also the gains are obtained consistently from the separate state area analysis. Additionally, the hardiness is additionally obtained while not touching the system response. The load disturbance is detected by a 0-observer of the unknown and inaccessible input, and is salaried by the feed-forward while not requiring the yelling current info. Of these styles are done merely within the state area. Finally, the system is management led by exploitation the micro chip and also the performance of every control formula is compared with each the simulation and also the experimental results for the 2 styles of the machines, i.e., a BLDC motor and a brushless direct drive (BLDD) motor. a scientific approach is finished for the strong position management of a BLDD motor linearized by a vector management methodology supported the sector orientation. The LQC and load force observer is complete within the digital system and also the separate state area analysis is finished to get the gains. Considering the load force because the unknown and inaccessible input, the strong digital position system is enforced supported the observer theory while not current info. Therefore, the load force compensator supported the observer theory isn't full of the

    present noise. and also the feed-forward will wipe out apace the steady state and also the transient position error thanks to the external disturbances like a numerous friction and a load force. However these phenomena are completely different from those of the disturbance compensation employing a high gain impact, that to boot ends up in the matter of influencing the system response. During this projected controller, the system response isn't full of the disturbance compensator.

    The total system is completed by a digital controller wherever the gain is obtained in z-domain mistreatment the best control theory. And also the performance of every management formula is compared to each the simulation and also the experimental results of the 2 kinds of the machines, i.e., a BLDC motor and a brushless direct drive (BLDD) motor.

    A metod of the torque management attenuating the unsought torsion pulsation for brushless dc motor with nonideal quadrangle back electromotive force is presented [12]. Its the direct torsion management technique during which the applied output voltage is calculated from the reference torsion and therefore the torsion of the previous step within the two- phase conducting amount and within the commutation amount considering the rear electromotive force undulation. The time delay thanks to the calculation is salaried by the one step ahead current prediction. to live the instant torsion ripple, a torsion observer is built employing a high preciseness encoder of 50000 pulse per revolution. The simulation and experimental results show that the projected technique reduces the torsion ripple considerably which it keeps the torsion management dynamics furthermore.

    Fig.5. Block diagram of the proposed controller [12]

    In the planned methodology, the applied output voltage is calculated from the reference torsion and also the torsion of the previous step considering the non-ideal back electromotive force wave form. The planned methodology was verified with the simulation and also the experiments. A torsion observer was made exploitation the high exactness encoder to live the fast torsion. 'The results show that the planned methodology attenuates the torsion ripple considerably which it keeps the torsion management

    dynamics yet in BLDCM with the non-ideal quadrilateral back electromotive force.

    One of the strategy describes force controller with Associate in Nursing observer for a Brushless DC (BLDC) motor [13]. The force management strategy wants correct position and speed info. however the BLDC motor incorporates a low resolution internal encoder to work out switch position. therefore the speed and also the intermediate position square measure obtained from a stable expert which might be derived from nonlinear modeling. The force management formula springs for the motor of capricious back-EMF wave with considering the freewheeling current. it'd be potential to own correct speed management for big selection of speed while not force ripple. The projected system is straightforward to be enforced and scale back computation time by new motor modeling. within the experiment, the controller is completed by DSP TMS320C31. The effectiveness of the controller square measure shown by simulation and experiment.

    A new controlling technique for the sturdy position management of a brushless DC (BLQC) motor victimization the reconciling load torsion observer is bestowed [14]. For the BWC motor system close to linearized victimization the field-orientation technique, it's shown that the increased state variable feedback are often applicable to the present system. To beat the matter of the unknown parameter or the parameter variation like a flux linkage, a model following reconciling management mechanism is utilized for the load torsion observer. And stability analysis is distributed victimization Liapunov stability theorem. As a result, the lustiness are often obtained while not poignant the system response. The load disturbance detected by the reconciling 0- observer is salaried by feed-forwarding the equivalent current having the quick response.

    Fig.6. Block diagram of the proposed digital position control system [14]

    A load force observer exploitation the model reference adjustive system is utilized to get the higher performance from the BLDC motor during a position management. Conjointly the increased state variable feedback is utilized

    within the digital system with associate optimum gain. The system response comparison between the mounted gain observer and also the adjective observer has been done. The load force compensator supported the adjective observer and also the feed-forward may be accustomed wipe out the steady state and also the transient position error thanks to the external disturbances like a varied friction and a load force. During this projected theme, the general system response isn't suffering from the disturbance compensator, and also the rotor position error caused by the non-exact parameter is decreased linearly. And also the total system may be complete by a digital controller wherever the gain is obtained in z-domain exploitation the optimum theory.

    One of the strategy introduces a senseless nonlinear management scheme for dominant the speed of a magnet electric motor (PMSM) driving associate degree unknown load force [15]. The states of the motor associate degreed disturbance force are calculable via an extended nonlinear observer avoiding the employment of mechanical sensors. The management strategy is an explicit feedback linearization strategy, with flight following evaluated on calculable values of the PMSM states and also the disturbance force. The system performance is evaluated by simulations.

    Fig.7. sensor less nonlinear control scheme for controlling the speed of a permanent magnet synchronous motor (PMSM) [15]

    The planned controlling was tested by simulations, presenting a really satisfactory performance within the whole speed vary, with slowly variable load torsion and uncertainties within the mechanical parameters. The dynamics of the theme will become unstable as a result of electrical parameters variations; however a considered choice of the nominal values reduces the importance of this drawback. In this controlling conjointly delivers associate degree estimate of motor speed that becomes inaccurate within the presence of electrical parameters variations. These inaccuracies and therefore the overall performance may still be improved victimization for example, the next order extended nonlinear observer.

    A new variable-structure position controlling scheme for a dc motor is planned [16]. The formula supported a time variable change line guarantees the existence of a slips mode from the start of the shaft motion. Indeed, the surface is at the start designed to suffer the initial representative purpose and later on touched toward a preset desired surface via shifting. By this implies, the reaching part is eliminated and therefore the motor behavior is insensitive to unknown mechanical configuration changes. The formula has been tested in simulation and therefore the experiment has been performed employing a cheap 16-bit microcontroller. Then, a sophisticated work is employed so as to judge the pursuit properties and therefore the strength capacities of the variable-structure management law with variations of the mechanical configuration.

    It has been shown that the chattering downside round the switch surface that involves excessive management effort may be eased mistreatment the VSC approach with linear feedback and switched gains. Mistreatment this algorithmic rule, the delays because of the sampling amount of the digital system are taken into consideration and precisely salaried. The simulation results show that the switch frequency is decreased round the switch surface however they conjointly unconcealed that the system dynamics stay insensitive to the mechanical configuration changes solely once the system reaches the slips surface. Then, to impose the dynamic behavior of the drive since the start of the motion, a time- varying switch line has been introduced within the VSC algorithmic rule with linear feedback and switched gains. The switch line is rapt mistreatment constant speed in a very means that the physical limitation of this is glad, that the integral of absolutely the worth of the motor shaft position is decreased , which the switch frequency is decreased round the final switch line. The analysis shows that, mistreatment this approach, the sliding mode happens from the terribly starting of the motion and also the behavior of the drive is insensitive to mechanical configuration changes. Moreover, this time-varying slippy line algorithmic rule doesn't need an oversized quantity of computation since it's been enforced on a low-priced single-chip 16-bit microcontroller.

    Indeed, the osition, the speed, and also the output management computations want solely 350 s victimization this microcontroller. Then, the sampling amount can be reduced so as to attenuate the magnitude of oscillations between 2 change periods.

    The application of direct force management (DTC) to brushless ac drives has been investigated extensively. Technique describes its application to brushless dc drives [17], and highlights the essential variations in its implementation, as regards force estimation and also the illustration of the electrical converter voltage area vectors. Simulated and experimental results ar bestowed, and it's shown that, compared with typical current management, DTC ends up in reduced force ripple and a quicker dynamic response.

    Fig.8. Schematic of BLDC drive system [17]

    DTC has been applied to a BLDC drive, and its utility has been valid by simulations and measurements on 2 BLDC motors that have terribly completely different back-EMF waveforms. the most distinction between the implementation of DTC to BLAC and BLDC drives is within the estimation of torsion and therefore the illustration of the electrical converter voltage vectors. Its been shown that DTC is capable of instant torque management and, thereby, of reducing torque pulsations.

    The projected DTC provides a world minimum torsion ripple that satisfies the root-mean-square (rms) criteria of torque ripple [18]. Such a world minimum torsion ripple DTC has not been derived before. The projected world minimum torsion ripple DTC may be a two steps design style. The primary step drives the torque error to zero at the tip of the controlling amount. Then, the second step reduces the torsion bias and rms ripple by modifying the spatial property shift patterns of the applied voltage vectors of the primary step into symmetry ones. Theoretical analysis is provided to indicate that the torsion ripple of the projected DTC may be a world minimum rms ripple.

    Fig.9. Block diagram of DTC of an induction motor [18]

    This technique has projected a straightforward and effective torque ripple reduction technique for DTC of induction motor drives. If compared with the previous studies, the projected technique has the advantage of worldwide minimum rms torsion ripple.

    The practicable of the study during this method has additionally been verified by building a fixed-point TMS320F240 DSP-based induction motor DTC drive system. The simulation and experimental results have incontestable that the projected technique effectively reduces a lot of rms torsion ripples compared with the tactic of a previous study. Moreover, the connected current ripple is additionally reduced. As a result of the torsion ripple is reduced, a doable application is going to be that the case desires a lot of precise speed management. The most downside left here is that the drift of machine, which ends up within the machine device flux estimation error.

    An pure mathematics approach was given for the quick feed- forward adaptation of the angular velocity flight following task in a very Boost-converter driven dc-motor system [19]. For the variation, the load torque perturbations area unit assumed piecewise constant and area unit, non- asymptotically, on-line calculable victimization the on the market blatant measurements of the state variables. The controller may be a linear controller supported the precise following error dynamics passive output feedback (ETEDPOF) controller style methodology as well as appropriate accommodative feed-forward pre-compensation relying expressly on the exactly calculable torsion. The reference flight needed by the controller is generated in associate degree approximate manner, resorting to the hold on energy within the boost-converter. For robustness, the reference trajectories receive associate degree update for the nominal load torque parameter whenever the online- generated estimate of the load torque changes.


    This paper is representing the different methodology for controlling the DC motor and other electric motor load torque.

    In this paper, different methodology or techniques for providing required power profile for DC motor for dynamic loading condition are presented. This technological review of paper are very much useful for students and researcher those who are working in the field of adaptive power system designing for controlling loading condition of DC motor.


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