The proposed resolver works based on the sinusoidal variation of the coupling area between stator and rotor. The variable reluctance resolver is driven at a constant speed and the incremental digital values are recorded and processed to extract the fundamental through a fourier transform. It is characterized by an outer surface form that makes the fluctuation part of gap permeance very in proportion to cos. With more complex circuitry and the addition of software and specific mechanical hardware, a vr sensor can also provide measurements of linear velocity. Variable reluctance resolvers vrr variable reluctance resolvers ducommuns variable reluctance resolvers vrrs are highly reliable brushless resolvers without rotary transformers. A new technique for analysis of static eccentricity in. It can interchange rectangular and polar coordinates. Design and analysis of variable reluctance resolver for hybridelectric vehicle. Permanentmagnet, reluctance, and induction motors compared it is possible to find superefficient highhorsepower motors but, at this point, many of. Research article analysis of novel variable reluctance. Help for vr sensor signal conditioning variable reluctance. Ro solid rotor, variable reluctance, frameless, brushless resolvers for severe applications.
Development of variable reluctance resolver for position feedback greg leibovich and sara senanian abstract the variable reluctance resolver vrr is commonly used in the automotive industry as a rotor position sensor. Admotec ro series rotasyn variable reluctance frameless resolvers provide high performance in measurement and feedback applications where traditional resolvers fail. If the inline pdf is not rendering correctly, you can download the pdf file here. A variable reluctance sensor commonly called a vr sensor is a transducer that measures changes in magnetic reluctance. A new resolver to digital converter ic is also described. Performance analysis of disk type variable reluctance. This is accomplished by using a sensor which outputs a voltage as the magnetic field around it changes.
If smooth rotation is the goal, there is an electronicdriven version of the switched reluctance motor. Analysis of windings in variable reluctance resolver request pdf. Development of variable reluctance resolver for position feedback. We offer two package options to help you to improve your competitiveness. In this paper, the relationship between the numbers of stator slots, winding polarities, and rotor poles for variable reluctance resolvers is derived and verified. In this resolver the rotor core has minimum gap at one side and a maximum gap at another side of the diameter. Their platenforcer electromagnetic coupling minimizes core losses. Pdf is not rendering correctly, you can download the pdf file here. The four phases a, b, c and d are connected to the dc source with the help of a semiconductor, switches s a, s b, s c and s d respectively as shown in the above figure. Whats the difference between variablereluctance linear. The variable reluctance vr resolver is usually used to measure the shaft angle of motor. If i apply a sine wave as excitation input to the primary winding, the same will be reflecting on the secondary winding based on magnetic induction. Precision resolvertodigital converter measures angular.
Accuracy improvement in variable reluctance resolvers ieee. When combined with basic electronic circuitry, the sensor detects the change in presence or proximity of ferrous objects. A reluctance motor torque is produced due to the tendency of the rotor to align itself in the minimum reluctance position, when the speed of the motor is close to the synchronous speed. It is capable of detecting highprecision and highresolution positions for outputting optimum torque at all times. Variable reluctance motors or steppers actually use rotors like those in figure below. Description 12bit rd converter with reference oscillator. Ducommuns variable reluctance resolvers vrrs are highly reliable brushless resolvers without rotary transformers. Variable reluctance stepper motor its working circuit globe. A designtocost alternative to conventional variable reluctance resolvers for the electric drives control 2014011694 many synchronous electric motors require a very accurate position sensor compatible with a sinusoidal control. The resolver todigital converter performs two basic functions. Variable reluctance sensors full function engineering. Oct 05, 1993 a variable reluctance resolver comprises a rotor core and stator magnetic poles structured to enable reluctance in the space between the rotor core and stator magnetic poles to be changed by the positions of the rotor core and to make the fundamental wave component of the reluctance variation n cycles per revolution of the rotor core, n being an integer of 1 or more. It is also called a sinecosine generator and synchro resolver. Theory and characteristics of novel variable reluctance 1x resolver.
In the case of a variable reluctance resolver, there are no windings on the rotor, as shown in. Variablereluctance resolver design guidelines ieee. Jul 21, 2015 variable reluctance linear stepper motors are an older technology than hybrid motors. It is probably the easiest to understand from a structural point of view. Variable reluctance in electromagnetic systems matlab. The structure and the total output voltages of signal windings are. Variable reluctance vr resolvers are proposed for industrial applications due to their simple structure.
Analysis of novel variable reluctance resolver with asymmetric teeth on the stator by chengjun liu, ming qi and meng zhao no static citation data no static citation data cite. With more complex circuitry and the addition of software and specific mechanical hardware, a vr sensor. Analysis of windings in variable reluctance resolver. The fourier transform of the fundamental is compared to the original values from the variable reluctance resolver to provide a look up table of correction values. Iranian journal of electrical and electronic engineering. A variable reluctance sensor is a transducer that measures changes in magnetic reluctance. If the rotating field of a large synchronous motor with salient poles is deenergized, it will still develop 10 or 15% of synchronous torque. And unlike other variable reluctance resolvers, the rotasyn utilizes a constant air gap so it is less sensitive to eccentricity and stray magnetic fields. A variable reluctance resolver includes a rotor and a stator. A four phase or 42 pole, single stack variable reluctance stepper motor is shown below. There are two types of the variable reluctance stepper motor.
The resolver is designed to provide abs variablereluctance resolver design guidelines ieee conference publication. Synchronous reluctance motordrive package for machine. This offers significant advantages in price, weight, and envelope dimensions. Due to variable air gap between stator and rotor, when rotor rotates, reluctance between stator and rotor also changes. In the case of a variable reluctance resolver, there are no windings on the rotor as shown in figure 3. The analyzed vr resolver is made by varying rotorpole shape according to a certain waveform, which can be. It discusses the theory of operation of data converter products synchro, resolver, and linear variable differential transformer lvdt, performance parameters, and design factors for typical applications. Analysis and improvement on the structure of variable reluctance resolver. More the air gap, more is the reluctance and viceversa. This type of motor consists of a soft iron multitoothed rotor and a wound stator.
The first rotor portion has n salient poles provided about a center axis at uniform angular intervals, where n is an arbitrary integer not less than 3. Analysis of novel variable reluctance resolver with asymmetric teeth on the stator chengjunliu,mingqi,andmengzhao department of electrical engineering and automation, harbin institute of technology, harbin, china correspondence should be addressed to chengjun liu. New variablereluctance resolver for rotorposition sensing ieee. Variable reluctance vr resolvers are widely used in many industrial applications.
Its use in the aerospace and defense industries has been limited due to inadequate accuracy performance. Performance analysis of linear variable reluctance resolvers based on improved winding function approach. Furthermore, due to thin copper wires that are used for signal. The rotor in this motor has four teeth and the stator has six poles, with.
The synchro resolver conversion handbookis designed as a practical reference source. Resolvers are often used to provide accurate absolute position information in highperformance motor systems. A resolver is a rotary transformer where the magnitude of the energy through the resolver windings varies sinusoidally as the shaft rotates. The paper focuses on the system functions and fault detection features added. A study for characteristics of variable reluctance resolver considering end slot leakage inductance and eccentricity zhilongwang1, kichan kim2 1. The stator has a stator yoke, a plurality of stator magnetic poles projecting from the yoke, and excitation and output windings applied to the stator. The purpose of this paper is to present a simulationbased approach capable of determining a more accurate rotor shape of variable reluctance resolver in order to cut the time and cost of its development before testing a physical prototype. Figure 1 shows the cross section of a three winding, 30 degree per step variable reluctance motor. Study of reduce harmonic and increasing positioning. Admotecs patented position sensor technology resolver technology produces a resolver with fewer parts, a solid rotor without slots, windings, or the need for a rotating transformer. For product samples, please consult the sales office jae or distributors with whom you are dealing. Ducommun variable reluctance resolvers vrrs are highly reliable brushless resolvers without rotary transformers. The magnetic field is altered by using a toothed wheel made from a ferrous material.
Variable reluctance motors variable reluctance motors also called variable switched reluctance motors have three to five windings connected to a common terminal. Jul 28, 20 the variable reluctance type resolver is widely used in an electric motor for hybrid electric vehicles as a rotor position sensor. The effect of winding arrangements on measurement accuracy. Variable reluctance vr resolvers are widely used in electric vehicles ev and hybrid electric vehicles hev to detect the rotor angle of. Vr resolvers are expected to find a wide range of applications, such as in electric powered steering, hybrid cars, electric cars, integrated starter alternaters, brake by. Therefore to support key oems we have set up a global engineering team to provide both integration and design support. Unlike conventional resolvers, the vrrs have both primary and secondary windings in the stator and no windings on the rotor. Description variable resolution, 10bit to 16bit rd converter with reference oscillator. Variable reluctance stepper motor its working circuit. The stator and rotor are designed in such a manner that the variation of the inductance of the windings is sinusoidal with respect to the rotor position. The rotor includes axially connected first and second rotor portions. Precision resolvertodigital converter measures angular position. Analysis of novel variable reluctance resolver with.
Resolvers are often used in inverterdriven permanent magnet synchronous motors as the rotor position sensors. A novel vr resolver with asymmetric teeth on the stator is proposed to achieve the minimal number of active teeth and eliminate the amplitude imbalance of the output voltages of sin and cos coils by bringing the fifth compensating tooth. A first insulator 300 is formed together with a terminal pin base 311 on which terminal pins 320 are provided. Analysis of novel variable reluctance resolver with asymmetric. A variable reluctance resolver design is described. However, their accuracy under inclined rotor fault along with different types of eccentricities includes static and dynamic eccentricities are questioned. Electrical drives and control pdf free download download books from computer to kindle, download ee electrical drives and controls edc books lecture notes syllabus click below the link download to save the bookmaterial pdf. The design of a variable reluctance resolver structure which can be integrated into brushless motors is considered. Performance analysis of disk type variable reluctance resolver under mechanical and electrical faults f. The operation of reluctance motor with diagram a media to. Electrical engineering in japan english translation of denki gakkai ronbunshi, 116 5, 1287.
The variable reluctance motor is based on the principle that an unrestrained piece of iron will move to complete a magnetic flux path with minimum reluctance, the magnetic analog of electrical resistance synchronous reluctance. A variable reluctance resolver according to the present invention includes m resolver units disposed in tandem, each comprising a rotor and a stator, where m is an integer not less than 2. Disk type variable reluctance dtvr resolvers have distinguished performance under run out fault comparing to conventional sinusoidal rotor resolvers. Design and analysis of variable reluctance resolver for. Us20050168091a1 variable reluctance resolver and method. But i am not able to understand the role of rotor here. Resolver is a synchro whose rotor is mechanically driven to translate rotor angle into electrical information corresponding to the sine and cosine of rotor angle. Performance analysis of disk type variable reluctance resolver. In the case of a variable reluctance resolver, there are no. The ratio of the magnetomotive force mmf across the component to the resulting flux that flows through the component is defined as the reluctance, and is dependent on the value of the input physical signal. Variable reluctance resolver and method and apparatus for.
The most popular method of performing these functions is called ratiometric tracking conversion. Us20050168091a1 variable reluctance resolver and method and. Like rotary variable reluctance stepper motors, variable reluctance linear steppers can be noisy and are usually only run in fullstep mode. Variable reluctance resolvers, on the other hand, have no windings on the rotor. Thin resolver using the easy magnetization axis of the grainoriented. Request pdf a novel variable reluctance resolver for hevev applications in order to simplify the manufacturing process of variable reluctance vr. Unlike conventional resolvers, vrrs have both primary and secondary windings in the stator assembly and no windings in the rotor. Analysis and improvement on the structure of variable. A variable reluctance resolver wherein the sine and cosine values are processed to obtain digital values for position with an accuracy similar to that of a conventional resolver. Recognizing product cost constraints, we have already. In order to realize the high precision control in the motor and drive system of hybridelectric vehicle, it is necessary to test the rotor position and motor speed in realtime. A variable reluctance motor intended to move in discrete steps, stop, and start is a variable reluctance stepper motor.
Although accuracy of encoders is among different magnetic sensors, the encoder and resolver are commonly used as the position and speed sensors for an inverterdriven electric motors and motion. Development of variable reluctance resolver for position. Minebea has begun delivering highperformance vr resolver. A novel vr resolver with asymmetric teeth on the stator is proposed to. The stator and the rotor of the motor are aligned in such a way that the magnetic reluctance is minimum. The existed multiturn resolvers are woundrotor wr resolvers, while the variable reluctance vr resolvers are expected to be more cost. Their primary and secondary windings are all on the stator, but the saliency exposed poles of the rotor couples the sinusoidal variation in the secondary with the angular position. Ad2s1210 datasheet1536 pages ad variable resolution, 10. I was trying to understand the working of variable reluctance resolver. In this paper the effect of different stator windings on position accuracy of the sinusoidal rotor vr resolver under different fault conditions is studied. This offers significant advantages in price, weight, and. A study for characteristics of variable reluctance.
If you do not have any window for dealings, please contact jae by telephone, fax or form we will inform you of the distributors. The effect of winding arrangements on measurement accuracy of. Vr resolvers, an angle sensor based on a variable reluctance method, have a promising future mainly for use in controlling motors in automobilerelated applications. Theory and characteristics of novel variable reluctance 1x. Angular position error detection of variable reluctance. Due to the variable air gap between stator and rotor, when the rotor rotates, reluctance between stator and rotor also changes. Ep1557644a1 redundant variable reluctance resolver. A variable reluctance resolver according to claim 4, wherein the bulge assumes a platelike shape. The principle of variable reluctance stepper motor is based on the property of the flux lines which capture the low reluctance path.
The variable reluctance block models a variable reluctance, that is, a component that resists flux flow. I have attached the image of the same which i am trying to understand. In a variable reluctance resolver having terminal pins at an insulator, a technique for preventing deformation of the terminal pins, shorting between the terminal pins, and contact failure at portions of the terminal pins is provided. Request pdf analysis of windings in variable reluctance resolver in this paper, the relationship between the numbers of stator slots, winding polarities, and rotor poles for variable. Ad2s1210 datasheet1536 pages ad variable resolution. Variable reluctance sensors engine control computers ecu require an input to determine angular position of the crank andor camshaft. A resolver control transmitter has one primary winding, the reference winding, and two secondary windings, the sin and cos windings. Performance evaluation of disk type variable reluctance. Pdf performance analysis of linear variable reluctance. Variable reluctance resolver, accuracy, physical parameters, time steps, finite element method. Vr resolver rotation angle sensor the vr resolver variable reluctance type resolver is an angle sensor that detects the magnetic pole position of the motor. Variable reluctance vr this type of stepper motor has been around for a long time.
Here, 42 pole means that the stator has four poles and the rotor has two poles. In this study, a new disk type variable reluctance dtvr resolver is introduced. The second rotor portion has n1 salient poles provided about the center axis at uniform angular intervals. Lvdts find uses in modern machinetool, robotics, avionics, and computerized manufacturing. The proposed resolver directly utilized the salient pole effects with only.