electro-mechanical products / technologies

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SKD

Electro-Mechanical Products / Technologies

by Rakesh Goel

S. K. Dynamics Pvt. Ltd.B-5, Industrial Estate,Roorkee - 247 667 [INDIA]℡ 91-1332-263616 Fax 91-1332-264083

Email: [email protected] URL: www.skdynamics.com

[June-2007]

1. About us ……. [6]

2. Products / Technologies ……….. [19]

3. More about Motor & Control …. [9]

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SKD

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About S K Dynamics Pvt. Ltd.About SK

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♦S K Dynamics Pvt. Ltd. (SKD) was established in 1992 with sole purpose of pursuing R&D projects in the area of Electromechanical Engineering, Digital Signal processing, Power Electronics and System engineering.

♦ SKD is 3rd party developer and was Strategic Partner of Analog Devices Inc. USA in the area of Motor Control.

♦Since 1995 SKD is recognized by Department of Scientific and Industrial Research (DSIR),India as in-house R&D unit and now approved asCommercial R&D Company.

♦ Around 2 Million Household appliances in the USA, Japan, Europe and China are working based on our Embedded Motor Control Technology.

(1) DSIR National Award 2000 for Technology Export of Motor control.

(2) EEPC Award 2000 and 2001 for Services Export. (3) ESC Award for project Services in Export in the

years 1998,1999 and 2001. (4) NSIC Award for Electric Bicycle Technology (5) ADI Award for world’s first Washing Machine using

DSP control

Awards & AchievementsAbout SKD

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SKD

1. Control System for Permanent Magnet Synchronous Motor(US Patent 5,635,810) [Granted]

2.Improved Gate Driver Circuit and Hysteresis Circuit (US Patent 5,675,276) [Granted]3.Geared Permanent Magnet Synchronous Motor

(India, Application No. 1884/cal/96) [Pending]4.Electronic Compass (India, Application No. 1011/cal/98) [Pending]5.Electrical Transmission based Flying Car (October 19, 2000) [Pending]6.Gravity motor (Aug 03,2000) [India Pending]

Patents ( Granted/ Pending)About SK

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(1) Flexible Speech/ Audio Coding published in “Signal Processing..”, Jan 1993

IISC, Bangalore, India

(2) Possible Generation of Gravitational Force (ICGA-5) Oct-2001, Russian

Gravitational Society,

(3) Universal Embedded Controller in ISPC conference, March 2003

Papers Published

SKD

About SK

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SKDAbout SK

Motors and Motor controls Digital Signal Processing & Processors Embedded hardware & softwarePower ElectronicsElectromechanical EngineeringFPGA, CPLD, Analog and Digital ElectronicsSystem Engineering /System IntegrationPrototype Manufacturing capability

Our Core CompetenceSKD

A View of SKD Team

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SKD

Products Technologies

1. Products / technologies developed

2. Products / technologies under development

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Products / TechnologieSKD

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SKDProducts / Technologie

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♦ Blackfin DSP based Controls♦ Blackfin based image processing system♦ CD Servo based on Blackfin DSP♦ Electric Car♦ Vibration Controller based on Blackfin DSP♦ Actuator Control for Missile♦ Gun Control for Tank♦ Mission Critical Motor for ISRO♦ Alternator for ISRO♦ Customized Motor for EGR of Engine

Recent Projects

DSCU for Actuator Control

SKDProducts / Technologie

Dual Blackfin based Image processing system

Motor for EGRVibration Controller

Servo Control for Missile Actuator

• Developed Digital servo control unit• for actuator control of Air defense Missile• Duration of operation – 4 Minutes• Peak power 7KW (140V, 60A)• Fitted in a compact and complicated box

(due to space limitations)• Fast dynamics for instant response

(> 15Hz for +/- 3mm on actuator)

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SKD

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Products / Technologie

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SKD

Development of 12 KW BLDC motor + Drivefor aerospace application

Requirement:Development of Brushless DC Motor for Reusable Launch vehicle application Basic specifications: 12KW, 6500 rpm, 130V, 16 minute run

(without cooling)

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Critical issues:

(a) limited size to accommodate electronics with EMI filtering(b) mechanism for cooling(c) achieving high efficiency to reduce loading of heat transfer(d) Interface with Battery & distance between Battery & Motor

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SKD

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90% (Motor + Controller)Overall EfficiencyComputed from Sensor of Motor, no external TachoVelocity feedbackIsolated RS-232 for diagnostics & commandsInterface6 segment space vector modulationCommutation methodSuitable programmable electronic controllerController17cm x 24 cm X 35 cm (Motor + Controller + Cooling Material )Size> 100 HrsLife of Motor1000 sec Max.Continuous RunBatteryPower Source130-160v DCOperating Voltage3 Hall Sensor (120o Electrical Separation)Type of Position Sensor0.14 Nm/ATorque Const Kt0.15 V/rad/secBack EMF Const Ke20 pole rotor, 30 slot statorNumber of Poles/slots18NmStarting Torque6500 rpm +/- 500Rated Speed12 kWPower RatingBrush Less DC MotorType

Specifications:

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SKD Design

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Qualification ModelTo validate design

Dummy ModelFor concept

Customized Motor for EGR Control of Engine

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SKD

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Red=vcc, black=comSensor connections (supply)13.

5, +0.2mmMounting Hole Dimension12.

67..5 PCD x 4 holesmmMounting Hole 11.

6 dia x 30 lengthmmShaft extension10.

40degSensor Shift- Mechanical Angle9.

57 x 57 x 40mmHousing size8.

Motor Housing

4.3V/k rpmBack EMF Constant (KE)7.

0.04Nm/ATorque Constant (Kt)6.

9No. of slots5.

6No. of Poles4.

2500RPMSpeed3.

0.22NmTorque 2.

S22P6V2 BModel No.1.

General

parametersUnitsTechnical DetailsS.N.

SKDImage Processing Solutions

In recent years DSP power has reached to significantly high level and image processing is almost feasible on single DSP. Security is a world wide issue and intelligent image processing will be required in future.

Our different hardware for Image Processing are:

1. BF533 based network camera board

2. BF533 based multi-purpose development board

3. BF533 dual DSP based image recorder board

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SKDBofors Gun Control Project-

• Bofors Gun control unit was developed by SKD, for its sister concern Saraswati Dynamics Pvt. Ltd. working for the Indian Military.

• It was a challenging project as the control unit was the only electronic part in the complete Gun unit, while rest of the Gun contains electromechanical and hydraulic equipments.

• Original unit was developed by Philips Holland.

• SKD used DSP and FPGA technology to design more efficient and reliable control unit. We developed and our associate company SaraswatiDynamics supplied 28 control units to Indian Military.

• Joint National award was received from DSIR, Government of India for the same.

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SKDElectrodynamic Vibration System

• Electrodynamic Vibration systems were developed between 1982 to 1999 at our associate company “Saraswati Dynamics Pvt Ltd.”

• SKD provided required support to the Indian defense forces by supplying vibration system to various departments of Indian space researchOrganization and Indian Military.

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SKDTypical Induction Motor Control

(for Washing Machine)

• Optimized processor for motor control application • Wide range Speed Control 200 to 16000 rpm of a 4 pole motor to give efficient washing control during Tumble/ Spin• Timer Motor Control• Data Recovery during Power Failure• Weight unbalance detection and re- distribution

• Over 2 Million washing machines based on this design were sold in US market

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SKD

2ACIM based Washing Machine


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SKDTypical PMSM Sensorless Control

(for Refrigerators)

• The control Solution for a Sensorless PMSM was developed in 1996 which was modified and tuned for a refrigerator compressor control by 1998.• The Sensorless PMSM control technique is implemented, in which only two windings are excited at a time and third phase isused to measure back EMF for Rotor position detection.•This solution was transferred and used by Sharp - Japan for their refrigerator compressor control. • Over 0.5 Million refrigerators were sold in the Japanese market alone based on this technology.

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SKD

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PMSM based Refrigerator Control


SKD

Tracking Camera:(Mixing of Image Processing with Motor Control)

Developing a BF531/BF533 based Ethernet Camera with image recognition and Tracking Servo System.

This is a very challenging project for demonstrating the R&D capabilities in motion control and image processing.

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More about Motors & Control

• Motor Control solutions• Technologies and performance

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SKD

SKDMotor Control Solutions

In recent years market size and acceptance of motor control is increased.

Our different platforms for Motor Control are

ADMC326 / ADMC341 / ADMC340 based on ADSP2171 core

ADuC7024 based on ARM7 core

ADSP21992 based on 219x core

BF532 Blackfin DSP core

Non DSP based (UC2625 Control) and CPLD+ADC based motor control

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Motor & Control

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SKD

Types of Motors• DC Brush Motor • Induction Motor • Permanent Magnet Synchronous Motor (PMSM)• Brushless DC Motor (BLDC)• Switched Reluctance Motor (SRM)• Stepper Motor

About Motors & ControlsMotor ConfigurationsConventional Configuration(Outer Stator)

• Outer Rotor Configuration• Pancake / HUB Motor • Linear Motor • Low Inertia / Coreless Motor• High Inertia / Gyro Motor • Motor with Internal Planetary Gear Assembly

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Motor & Control

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SKD General Range of Motors (developed)• Capacity: 10 W to 16 HP (12KW)• No. of Poles: 2 to 100• No. of Phases: 2, 3, 4• Type: DC /Induction Motor /PMSM /BLDC /SRM /Stepper • Configuration: Outer Stator /Outer Rotor /HUB /Inertia• Weight to Power Ratio: up to 1 Kg/ HP• Type of Gearbox: Internal / ExternalRange of Controllers (developed)• Control Dynamics: Two Quadrant / Four Quadrant • Breaking: Regenerative / Dissipative • Electrical Frequency: up to 1000 Hz• Interface: Analog, Digital (TTL), Communication • Control Parameters: Position, Velocity, Acceleration • Control Technique: Sensorless or 1 or 3 Sensor(s) • Multi-Drive Control: 1 to 62 Drives from 1 Master• Power Source: 6V to 350V DC, 110V / 220V AC

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Motor & Control

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SKD BLDC Motor

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Motor & Control

1515 K5K3024168 X 168 X 150S66

25.08 K + 8 K1.2 K125 CW +125 CCW

50225 X 225 X 150Twin RotorCoaxial

.5.6 K8 K.751256 φ x 60O_Rotor A

7.512.0 K6.5 K1818140 X 140 X 130S55

6.57.5 K5 K1524112 X 112 X 140S44 B

6.57.5 K10 K7.512112 X 112 X 140S44 A

3.52.0 K10 K2.51284 X 84 X 110S33

1.240020 K0.3656 X 56 X 90S22

0.815020 K0.15642 X 42 X 80S15 X

0.45030 K0.05428 X 28 X 70S11

Estimated Weight kg

Max. PowerW

SPEEDRPM

TORQUE Nm

# POLESDIMENSIONSMm

SIZE CODE

Range of Motors (Under Development / Developed)

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SKD

Factors Affecting Performance of a BLDC MotorHigher number of poles and operation at 1 KHz electrical frequency is the main factor for high performance BLDC motors. However, there are certain limitations while increasing # of poles

BLDC Motor design is a complicated process, but a shortcut isPower = .03 x f x D2 x L Watt , Speed = f x 120 / (No of poles) rpmWhere f= frequency (Hz), D = air gap diameter (cm), L= stack length (cm)Example: Poles=12, f=1 KHz, Dimensions= 8 cm dia x 8 cm length, D=4 cm, L=5.5 cm, speed=10000 rpm, power= 2.5KW, Weight= 3 Kg

Motor performance is described by power to weight ratio. A typical value is 1 hp/kg achievable for high performance motors above 1 hp.

BLDC Motor

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Motor & Control

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SKD1. Electrical losses including iron and copper losses

2. Alignment of sensors

3. Heat transfer limitations

4. Managing additional space required by sensors.

5. Non-linearity in Torque Constant due to Armature Reaction

Critical Issues in High performance BLDC Motor

•To solve the problem of heat transfer, the motors are partially filled with oil. The main advantage of oil filling is to reduce the thermal resistance and to cool rotor magnets also. This helps in heat transfer and peak current rating.

Sacrificing 6 slots for 10 mm Depth accommodates 3 hall sensors. Sensors alignment is good by this method with minimum space utilization.

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Motor & Control

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SKD

1. Third Harmonic Injection and Space Vector Modulation was used in induction motor control for washing machine.

2. Single Point Discrete Fourier Transform was used in sensorlessVector Control of induction motor based compressor control

3. Digital Angular Filter with Phase advance was used in BLDC control.

4. Nonlinear controls were used in speed and servo controls.

5. Maxima of cross-correlation/ Auto-correlation for rotor position estimation was used in PMSM sensorless control of refrigerator compressor and submersible pump.

Advanced Techniques used in DSP control

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Motor & Control

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SKDProblems Due to Sensor Misalignment

There are Mechanical limitations in sensor alignment and certain mechanical alignment error is present in BLDC motors.

Electrical error of sensor Alignment increases with increase in# of poles.If.. Mechanical Alignment Error = θ1Electrical Alignment Error θ2 = θ1 * N/2(Where N is no. of Poles) Example: Assume θ1 = +1• to +2 •

θ2 = +6 • to +12 • for 12 pole motorθ2 = +12 • to +24 • for 24 pole motor

This problem is handled by Digital Angular Filter

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Motor & Control

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SKDProblems in Control:• Integral control continuously disturbs the loop• Differential control introduces high frequency noise• Higher proportional control gain makes loop unstable while low gain gives slow response. • Separate PID control is required for Velocity and Position Control.• Control output is only MI (Modulation Index) while control inputs are many. Therefore, all control elements are closely inter-linked.

Modifications in PID Control:• Use of dead band in error input of integral control • Use of second order equation in proportional control• Use of FIR filter in differential control• Mask / Clip errors and individual control outputs. In addition to limiting overflow, Mask function makes dynamic gain zero during clipping and makes loop more stable. • Use of priority handling in control loops (current,velocity, Position)

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Control TechniquesMotor & Control

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S.K. Dynamics Pvt. Ltd.B-5, Industrial Estate,Roorkee - 247 667 [INDIA]℡ 91-1332-263616 Fax 91-1332-264083

Email: [email protected] URL: www.skdynamics.com

SKD S.K. Dynamics Pvt. Ltd. Roorkee [INDIA]

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