Basically there are two major types of permanent magnet-type machines like sinusoidal back EMF type & trapezoidal back EMF type. With that trapezoidal motor have a higher torque ratio compared to other types. The back EMFs induced in the stator windings has trapezoidal type and its phases must be supplied with quasi-square wave currents for ripple free operation . The proposed trapezoidal type motor drives are more attractive for industrial applications because of simplicity, lower price, and high efficient operation compared to sinusoidal type, this may require complex hardware & software tools for sensing the rotor position. BLDC drives exist in many more configurations but the three phased fourswitch type motor is most valuable type due to affordable features. Offers a good interaction between precise control and reduced number of switching devices are required to control over the stator currents. Detection of rotor position is usually implemented by utilizing three hall sensing devices that detects the presence of small magnets are distributed to the rotor shaft.
The selection of mode of operation is a tradeoff between the allowed stresses on PFC switch and cost of the around system during the operating mode of front-end converter. The two different modes of operation are depending on design parameters; either continuous or discontinuous conduction mode approach may lead the converter. In this design, a BLDC motor drivefed by a PFC BL-SEPIC operates in four modes. At the time of starting or overloading inrush current is created. The inrush current occurring at start-up or overload was eliminated by operating the PFC in discontinuous conduction mode (DCM), it also gives natural protection for switches, low input ripple, and less electromagnetic interference (EMI) . In this paper a fuzzy controlled BL-SEPIC is analysed in terms of harmonic reduction.
A logic of an approximate reasoning continues to grow in importance, as it provides an in expensive solution for controlling know complicate systems. Fuzzy logic con- trollers are already used in appliances, washing machine, refrigerator and vacuum cleaner etc. Computer subsys- tems (disk drivecontroller, power management) consum- er electronics (video, camera and battery charger) C.D. Player etc. and so on in last decade, fuzzy controllers have convert adequate attention in motion control systems. As the later possess non-linear characteristics and a precise model is most often unknown. Remote controllers are in- creasingly being used to control a system from a distant place due to inaccessibility of the system or for comfort reasons. In this work a fuzzy remote controllers is devel- oped for speed control of a converter fed dc motor. The performance of the fuzzycontroller is compared with conventional P-I controller.
ABSTRACT: Nowadays efficiency and cost are the major concerns in designing and developing low-power applications. Due the several advantages of brushless direct current motors (BLDC). These features are high efficiency, high flux density per unit volume, low electromagnetic interference, silent operation and low maintenance requirements. However, the use of BLDC motors is not limited to domestic applications only.This paper presents a power factor corrected (PFC) bridgeless (BL) buck boost converter fed brushless direct current (BLDC) motor drive as a cost effective solution for low power applications. An approach of speed control of the BLDC motor by controlling the dc link voltage of voltage source inverter (VSI). This helps the operation of VSI at fundamental frequency switching by using the electronic commutation of the BLDC motor which offers reduced switching losses. The diode bridge is eliminated using bridgeless configuration thus reducing the conduction losses associated with it. A PFC BL buck boost converter is designed to operate in Discontinuous Current Mode (DCM) to provide a better PFC at ac mains. This drive is compared with the conventional PFC scheme and without PFC scheme and shows satisfactory performance. The performance of the proposed drive is simulated in MATLAB/Simulink.
The ripple contents of stator current, electromagnetic torque and rotor speed are minimized with FLC method. . The advantage of Fuzzy Logic Controller is that it does not require any mathematical model and only based on the linguistic rules. The use of the d-q-0 reference frame for BLDCM is based on the fact that, in a three-phase Y-connected motor with non- sinusoidal air gap flux distribution, the d-q-0 transformation of the three line-to-line back EMF’s results in the finding of the d- and q- components identical to those of three phase back EMF’s transformation.
Abstract- A PFC based BL-Luo converter-fedBLDC motor drive has been proposed for a wide range of speeds and supply voltages. A single voltage sensor-based speed control of the BLDC motor using a concept of variable dc-link voltage has been used. The PFC BL-Luo converter has been designed to operate in DICM and to act as an inherent power factor pre-regulator. An electronic commutation of the BLDC motor has been used which utilizes a low-frequency operation of VSI for reduced switching losses. The speed of the BLDC motor is controlled by an approach of variable dc- link voltage, which allows a low-frequency switching of the voltage source inverter for the electronic commutation of the BLDC motor, thus offering reduced switching losses. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power quality at ac mains. Fuzzy logic controller, in most instances, provides a superior performance to PI controller. However, it needs to be trained properly; anything that doesn't pertain to the behavior of intended system will fail you. Fuzzy is more forgiving than PI when the system deviates from its expected operating state. Fuzzy logic is widely used in machine control. The term "fuzzy" refers to the fact that the logic involved can deal with concepts that cannot be expressed as the "true" or "false" but rather as "partially true". Although alternative approaches such as genetic algorithms and neural networks can perform just as well as fuzzy logic in many cases, fuzzy logic has the advantage that the solution to the problem can be cast in terms that human operators can
To overcome these issues and drawbacks, a basic, cost- effective and efficient water pumping system based on SPV array fedBLDC motor is proposed, by altering the existing topology (Fig. 1) to as appeared in Fig. 2. A zeta converter is used with a specific end goal to remove the maximum power available from a SPV array, delicate beginning and speed control of BLDC motor coupled to a water pump. Because of a single switch, this converter has great effectiveness and offers boundless region for MPPT. This converter is worked in continuous conduction mode (CCM) bringing about a decreased stress on its power devices and components. Moreover, the switching loss of VSI is reduced by adopting fundamental frequency switching bringing about an extra power saving and hence an enhanced efficiency. The phase currents and also the DC link voltage sensors are completely eliminated, offering straight forward and efficient system without scarifying its execution. The speed of BLDC motor is controlled, with no extra control, through a variable DC link voltage of VSI. Besides, a delicate beginning of BLDC motor is accomplished by appropriate introduction of MPPT calculation of SPV cluster. These elements offer an expanded effortlessness of proposed system.
This paper deals with a power factor improvement using PFC-based Cuk converter-for speed control of brushless dc motor (BLDC) drive as a cost-effective solution for low-power applications. The speed of the BLDC motor is controlled by varying the dc-bus voltage of a voltage source inverter (VSI) which uses a low frequency switching of VSI (electronic commutation of the BLDC motor) for low switching losses. A diode bridge rectifier followed by a Cuk converter working in a discontinuous conduction mode (DCM) is used for control of dc-link voltage with unity power factor at ac mains using fuzzycontroller. The performance of the BLDC motor is simulated in a MATLAB/Simulink environment.
A new speed management strategy of a PMBLDCM drive is valid for a mechanical device load of associate degree cooling that uses the reference speed as the same reference voltage at DC link. “The speed management is directly proportional to the voltage management at DC link. the speed electric circuit introduced within the reference voltage at DC link effectively limits the motor current among the required price throughout the transient condition (starting and speed control). the extra fluorocarbon feature to the planned drive ensures nearly unity PF in big selection of speed and input AC voltage. Moreover, power quality parameters of the planned PMBLDCM drive area unit in conformity to a world customary IEC 61000-3-2. The proposed drive has incontestable smart speed management with energy economical operation of the drive system within the wide range of speed and input AC voltage. The planned drive has been found as a promising candidate for a PMBLDCM driving Air-Con load in 1-2 kW power vary.Through this project work we've created an effort to research Power Factor” Correction convertor with the assistance of simulations. In future the hardware implementation of the fluorocarbon circuit will be done and its results obtained in real – time things may be compared with the simulation results.
Abstract- A PFC based BL-Luo converter-fedBLDC motor drive has been proposed for a wide range of speeds and supply voltages. A single voltage sensor-based speed control of the BLDC motor using a concept of variable dc-link voltage has been used. The PFC BL-Luo converter has been designed to operate in DICM and to act as an inherent power factor pre-regulator. An electronic commutation of the BLDC motor has been used which utilizes a low-frequency operation of VSI for reduced switching losses. The speed of the BLDC motor is controlled by an approach of variable dc-link voltage, which allows a low-frequency switching of the voltage source inverter for the electronic commutation of the BLDC motor, thus offering reduced switching losses. The proposed BLDC motor drive is designed to operate over a wide range of speed control with an improved power quality at ac mains. Fuzzy logic controller, in most instances, provides a superior performance to PI controller. However, it needs to be trained properly; anything that doesn't pertain to the behavior of intended system will fail you. Fuzzy is more forgiving than PI when the system deviates from its expected operating state. Fuzzy logic is widely used in machine control. The term "fuzzy" refers to the fact that the logic involved can deal with concepts that cannot be expressed as the "true" or "false" but rather as "partially true". Although alternative approaches such as genetic algorithms and neural networks can perform just as well as fuzzy logic in many cases, fuzzy logic has the advantage that the solution to the problem can be cast in terms that human operators can understand, so that their experience can be used in the design of the controller. The proposed concept can be implemented to fuzzy based torque ripple minimization MATLAB/SIMULINK software.
ABSTRACT: This paper deals with a power factor correction (PFC)-based Cuk converter-fed brushless dc motor (BLDC) drive as a cost-effective solution for low-power applications. The speed of the BLDC motor is controlled by varying the dc-bus voltage of a voltage source inverter (VSI) which uses a low frequency switching of VSI (electronic commutation of the BLDC motor) for low switching losses. A diode bridge rectifier followed by a Cuk converter working in a discontinuous conduction mode (DCM) is used for control of dc-link voltage with unity power factor at ac mains. Performance of the PFC Cuk converter is evaluated under four different operating conditions of discontinuous and continuous conduction modes (CCM) and a comparison is made to select a best suited mode of operation. The performance of the proposed system is simulated in a MATLAB/Simulink environment and a hardware prototype of the proposed drive is developed to validate its performance over a wide range of speed with unity power factor at ac mains.
ABSTRACT: The induction motor drives with B4 inverter is used to balance the three phase currents in order to maintain low dc link voltages offset suppression. The three phase B4 inverter controls both stator flux and torque. Whereas in B6 inverter stator flux and torque are not controlled and three phase currents are collapsed due to fluctuations. In B4 inverter Stator flux will controls the three phase currents and it forces the three phase currents to stay in balance condition and on the other side torque will control voltage, amplitude and magnitude. Induction motor with three phase B4 inverter fed uses predictive torque control scheme for voltage vectors of B4 inverter to minimize open and short circuit fluctuations in two dc link capacitor voltages .In fault tolerant conditions of induction motor with three phase B4 inverter in open and short circuits it derives precise predictions by controlling its pi controller and fuzzy logic controller. Three phase induction motor drives operate under four switches in order to maintain low cost function. KEYWORDS: Cost function, current unbalance, four-switch inverter, induction motor (IM) drives, model predictive control (MPC).
Fuzzy logic controller is a rule-based logic controller. Fuzzy logic controller designs the general behaviors of the control system in a linguistic manner by forming IF-THEN rules . The fuzzy rules are in the form of no of statements. The general structure of fuzzy logic controller consists of four functional parts as shown in Figure-3. They are given as fuzzification, fuzzy rule- base, fuzzy inference engine and defuzzification. The design steps in fuzzy logic controller are i) Define the inputs and output variables ii) Define universe of discourse iii) Define fuzzy membership functions and fuzzy set rules. In this fuzzy logic controller structure, E (error) and IE (integrative error) are taken as two inputs and gives controlled output (u) to the BLDC motor. A fuzzy logic controller with a fuzzy rule viewer block is used to control the output of BLDC motor. Different membership functions for fuzzy variables are selected to control the output. Fuzzy Interference System (FIS) file is saved which includes all input and output membership functions and fuzzy rules.
A BLDC Motor is a permanent synchronous motor that uses position detectors and an inverter to control the armature currents. Its armature is in the stator and the magnets are on the rotor and its operating characteristic resembles those of a DC motor. Instead of using a mechanical commutator as in the conventional DC Motor, the BLDC motor employs electronic commutation which makes it a virtually maintenance free. The BLDC motor isdriven by DC voltage but current commutation is done by solid-state switches. The commutation instants are determined by the rotor position and the position of the rotor is determined either by position sensors like Hallsensor, position encoder and resolver etc. or by sensorless techniques. There are two main types of BLDC Motors:Trapezoidal type and Sinusoidal type. The trapezoidal motor is a more attractive alternative for most applications due to its simplicity, lower price and higher efficiency. Here State-Space based trapezoidal motor has been taken for modeling and simulation in MATLAB\SIMULINK. Overall block diagram is shown.
The fuzzy inputs are combined based on these rules and the degree of membership in each function set. The output membership functions are then manipulated based on the controller for each rule. All of the output member functions are then combined into one aggregate topology. The defuzzification process then chooses the desired finite output from this aggregate fuzzy set. There are several ways to do this such as weighted averages, centroids, or bisectors. This produces the desired result for the output. FLC is the combination of various different processes which are shown above in the Fig.4.It means a fuzzy logic controller comprises of numbers of methods  which are described below in stepwise form. Here the processes are explained in general format as explained above are described in detail below:
For as long as two decades a few Asian nations, for example, Japan, which have been under weight from high energy costs, have actualized variable pace PM motor drives for energy sparing applications, for example, aeration and cooling systems and iceboxes . Then again, the U.S.A. has continued utilizing modest actuation motor drives, which have around 10% lower productivity than customizable PM motor drives for energy sparing applications. Hence as of late, the expansion in energy costs goads higher requests of variable rate PM motor drives. Likewise, late fast multiplication of motor crashes into the car business, in view of half and half drives, produces a genuine interest for high effective PM motor drives, and this was the start of enthusiasm for BLDC motors. BLDC motors, additionally called Permanent Magnet DC Synchronous motors, are one of the motor sorts that have all the more quickly picked up prominence, basically as a result of their better attributes and execution . These motors are utilized as a part of an incredible measure of mechanical segments on the grounds that their engineering is appropriate for any wellbeing basic applications. The brushless DC motor is a synchronous electric motor that, from a demonstrating point of view, looks precisely like a DC motor, having a straight relationship amongst current and torque, voltage and rpm. It is an electronically controlled replacement framework, rather than having a mechanical compensation, which is commonplace of brushed motors. Also, the electromagnets don't move, the perpetual magnets pivot and the armature stays static. This gets around the issue of how to exchange current to a moving armature. With a specific end goal to do this, the brush-framework/commutator gathering is supplanted by an astute electronic controller, which plays out the same force dispersion as a brushed DC motor . BLDC
ABSTRACT: This paper presents a power factor corrected (PFC) variable DC converter fed brushless dc motor (BLDCM) drive as a cost effective solution for low-power household applications. The variable DC converter operation is based on canonical switching cell (CSC) topology. The speed of BLDCM is controlled by varying the dc- bus voltage of voltage source inverter (VSI). The BLDCM is electronically commutated for reduced switching losses in VSI due to low-frequency switching. A front-end CSC converter operating in discontinuous inductor current mode (DICM) is used for dc-bus voltage control with unity power factor at ac mains. A single sensor for dc-bus voltage sensing is used for the development of the proposed drive, which makes it a cost-effective solution. The performance of the proposed drive is evaluated over a wide range of speed control and variable loading conditions with improved power quality at ac mains. The performance of the proposed drive is simulated in MATLAB/Simulink environment . KEYWORDS: Brushless dc motor, canonical switching cell converter, discontinuous inductor current mode, power factor correction, power quality.
Electric drives are rapidly used in the modern world for various applications. The reliable operation of a typical electrical drive is essential for proper functioning of the entire system. A typical electric drive must be operating even in case of occurrence of the fault -. Fault-tolerant control (FTC) strategy is the fault diagnostic method to evaluation of the condition of fault including detection and necessary remedial measures to be taken to minimize the effect of the fault. The fault diagnostic methods include both online as well as offline. In case of BLDCdrive system, the FTC is incorporated on the power inverter side -. FTC is gaining prominence in case of massive flow of current during fault in case of short circuit and voltage interruption in case of open circuit. Advancements in the FTC technology ranges in usage of time as well as frequency domain to update signal processing algorithm, although time domain is commonly used-.
Fig. 1 illustrates the transverse section structure of a brushless DC motor. The stator windings of BLDC are similar to those in a polyphase AC motor, and the rotor is composed of one or more permanent magnets. Brushless DC motors (BLDC) contain a powerful permanent magnet rotor and fixed stator windings. The stationary stator windings are usually three phases, which means that three separate voltages are supplied to the three different sets of windings . Brushless DC motors are different from AC synchronous motors in that the former incorporates some means to detect the rotor position (or magnetic poles) to produce signals to control the electronic switches as shown in fig. 2.
The revolution of the BLDC engine is in light of the criticism of rotor position which is gotten from the corridor sensors . BLDC engine ordinarily employments three lobby sensors for deciding the recompense Grouping. In BLDC engine the force misfortunes are in the stator where warmth can be effectively exchanged through the edge or cooling frameworks are utilized as a part of expansive machines [7-8]. BLDC engines have numerous focal points over DC engines and prompting engines. A percentage of the favorable circumstances are better speed versus torque qualities, high element reaction, high proficiency, long working life, quiet operation; higher pace ranges . Up to now, more than 80% of the controllers are PI (Relative and vital) controllers on the grounds that they are effortless and straightforward.