projects completed and value addition. controltrix.com

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PROJECT GUIDE

Extensive experience in sensors and control pertaining to motion control and power electronics allows us to crack your tough specifications and tackle challenging problems. The following sections are a representative description of various past projects that have been undertaken and the value addition that has been possible.


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1.0.0 MOTION SENSING AND CONTROL

Extensive experience with various types of motors and electromagnetic sensors and actuators allows us to tackle a large variety of problems. Below is a small representative list of past work and where value may be added.


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1.1.0 PERMANENT MAGNET MACHINES

1.1.1 FIELD ORIENTED CONTROL / VECTOR CONTROL

Salient features (fairly common knowledge)

Precise and fast torque and speed control

Optimal motor utilization (most bang for the buck)

Useful for transient and fast changing loads such as washing machines, power tools

Low noise operation

Allows the motor to be operated beyond its rated speed

Sensored and sensor less operation possible

Traditional sensor less operation is based on estimation using sliding mode controller or

PLL type observer

Space vector modulation

Typically 2 quadrant bi directional motoring operation

More…..

Remove any performance degradation due to low grade input power supplies with large

ripple content in the input voltage. (such as front end rectifier, Power factor correction

etc)

KALMAN filter based position and speed estimation for sensor less mode for accurate

position and velocity control

16 bit computationally economical fixed point implementation of Kalman filter

4 quadrant operation. (regeneration/ braking and motoring operation) within the same

system

Dead time compensation for smoother operation

Single shunt current sense based implementation for low cost applications

Sensor less smooth and reliable startup

Operation beyond the rated speed possible with field weakening


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1.1.2 DIRECT TORQUE CONTROL

Almost identical performance as with field oriented control. (refer 1.0.2)

Much Less amount of computation. (suitable for low cost application)

Sensored and Sensor less operation

More….

Refer 1.1.1 (under value addition) same features apply


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1.2.0 BRUSH DC MOTOR

Speed control with encoder

Position control with encoder

Torque control with current sense

Regenerative and dynamic braking (4 quadrant operation)

More…..

Sensor less Speed control (without encoder/resolver) e.g. fans ,pumps etc

Sensor less Position control (without encoder/resolver) e.g. servo drives ,robots, toys

Accurate reliable and smooth position /speed estimation and control using KALMAN

filter/ Luenberger and Gopinath observer



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1.3.0 BRUSHLESS DC MOTOR

Speed control with hall effect /encoder (pumps, fans, compressors etc)

Torque control/Torque mode (electric bicycles)

Regenerative and dynamic braking (4 quadrant operation)with most energy efficient way

Speed control (open/closed) loop in sensor less mode

More…..

KALMAN filter based speed and position estimation based control


Sensored hall effect based operation with high immunity to PWM noise (useful for

electric vehicle applications, High current and Hi power drives)

Improved reliability in sensor less mode of operation using filtering

Operation beyond the rated speed of the motor

Low audible noise 6 step operation (sensored and sensor less) (e.g. fans , blowers etc )

Demonstrably lower losses


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1.4.0 THREE PHASE AC INDUCTION MACHINES

Sections 1.4.x pertains to 3 phase AC induction machines

1.4.1 V/F CONTROL

Scalar control


Low noise

Low cost

Easy to implement

More…..

Dead time compensation to ensure low distortion in current waveform



etc)

Minimize noise/harmonics due to low grade input voltage

Dynamic/regenerative braking /(4 quadrant operation)

Limiting the start current to manageable levels without significantly reducing startup

torque (white goods ,solar pumps )

1.4.2 FIELD ORIENTED CONTROL / VECTOR CONTROL

Precise and fast torque and speed control

Optimal motor utilization (most bang for the buck)

Useful for transient and fast changing loads such as washing machines, power tools

Low noise operation

Allows the motor to be operated beyond its rated speed

Sensored and sensor less operation possible

Traditional sensor less operation is based on estimation using sliding mode controller or

PLL type observer


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Typically 2 quadrant bi directional motoring operation

Operation beyond the rated speed possible with field weakening

More…..



etc)

KALMAN filter/other filter based position and speed estimation for sensor less mode for

accurate position and velocity control

Computationally inexpensive 16 bit fixed point implementation of KALMAN filter

4 quadrant operation. (regeneration/ braking and motoring operation) within the same

system

Dead time compensation for smoother operation

Single shunt current sense based implementation for low cost applications

Sensor less smooth and reliable startup

1.4.3 DIRECT TORQUE CONTROL

Almost identical performance as with field oriented control. (refer 1.0.2)

Much Less amount of computation. (suitable for low cost application)

Sensored and Sensor less operation

More…..

Refer 1.4.1 (under value addition) same features apply


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1.5.0 SERVO MOTOR CONTROL

Hi bandwidth position and velocity control (for machine tools, robots)

Hi bandwidth torque control

Reduced tracking error

Backlash error removal

Dead time compensation for reduced distortion

Repetitive control for periodic load and periodic trajectories to minimize tracking error

Smooth and low noise operation


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1.6.0 STEPPER AND SWITCHED RELUCTANCE MOTOR

Micro stepping for smooth control of stepper motor

Switched reluctance motor calculations and control


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1.7.0 SINGLE PHASE AC INDUCTION MOTOR

Inverter control of single phase AC induction motor

Limiting the start current to manageable levels without significantly reducing startup

torque (white goods ,solar pumps )

Retrofitting existing solution


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1.8.0 ELECTROMAGNETIC LINEAR ACTUATOR CONTROL

Design Control system for linear actuator (position ,speed and force control)

Sensor replacement algorithms using self sensing

Advanced filtering and sensor fusion algorithms


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1.9.0 LINEAR MEASUREMENT USING ACCELEROMETER DATA

Improved accuracy in speed and position estimation

Reduced effects of drifts using advanced filtering and sensor fusion algorithms

(Smart phone apps such as virtual measuring tape, inertial navigation system in toys,

unmanned aerial vehicles etc.)

Compensate effect of gravitation on the fly

Gesture recognition (smart phone apps)


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1.10.0 ROTATIONAL MEASUREMENT USING GYROSCOPIC DATA

Improved accuracy in angular speed and angular position estimation

Reduced effects of drifts using advanced filtering and sensor fusion algorithms (Smart

phone apps such as virtual measuring tape, inertial navigation system in toys,

unmanned aerial vehicles etc.)

Gesture recognition (smart phone apps)

Handling cross coupled states

Compensation for curvature and rotation of earth in inertial navigation systems

Estimation of radius of circular motion (gyroscopic + accelerometer data)

Advanced Filtering to ensure accurate estimate of radius


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2.0.0 POWER CONTROL

Extensive experience in power conversion allows us to tackle a wide array of problems to meet your stringent performance requirements. The following is a representative list of various past projects and value addition. In general

1. Meeting performance specs

2. Simulation for visulati

3. Code generation for fixed point DSP implementation

4. Problem solving


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2.1.0 DC-DC DIGITAL PWM SWITCHED MODE CONVERTERS

Optimal performance

Stability analysis

Large number of topologies

Excellent line and load regulation


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2.2.0 SINGLE PHASE DIGITAL POWER FACTOR CORRECTION

Near unity power factor for Continuous conduction mode operation

Improved voltage response to fast changing load

Achieving low THD and high PF @ Low load (discontinuous conduction mode) (ever

stringent specs) e.g. 10% THD @ 10% load

Advanced non linear techniques to improve THD in discontinuous mode

Consistent performance across a wide input and output voltage range

Single phase and interleaved operation

Fixed on-time hysteresis PFC control


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2.3.0 THREE PHASE DIGITAL POWER FACTOR CORRECTION

Bidirectional power flow

Near unity power factor for Continuous conduction mode operation

Improved voltage response to fast changing load

Unbalanced voltage source handling

Voltage following

Sine table look up with PLL for low THD


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2.4.0 SINGLE CYCLE CONTROL PFC SW IMPLEMENTATION

Emulate in software single cycle control PFC

Lower number of ADC required

Phase Voltage measurement not required

Only unidirectional operation

Unbalanced voltage source handling

Voltage follower operation


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2.5.0 PURE SINE WAVE INVERTER (HOME UPS,BACKUP)

Low distortion sine wave under all types of load ( rectifier, inductive, capacitive)

Low overshoot and undershoot

Dead time compensation

Inductor saturation

Syncing with AC source and switchover

Sine table lookup ,variable frequency ,amplitude and phase

Low tracking error


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2.6.0 DC-DC CONVERTER/BATTERY CHARGERS

Various topologies full bridge, push pull, buck, boost, buck boost , fly back, forwardly

resonant series/parallel

Low overshoot/undershoot

Current source and voltage source

Current sink and voltage sink

Controlled regulation operation

Voltage mode control, current mode control, peak current mode control

Remote sense

Paralleling/load sharing

Optimizing thermal stress by load sharing based on temperature

Ideal diode software implementation

Charge profiling, charge termination and state of charge control


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2.7.0 POWER LED CONTROL

Digital dimming ~ 400 hz led is turned on and off

Fast current rise

Almost any DC –DC converter topologies

Almost perfect square wave current wave shape

Minimal spikes/overshoots/undershoots @ start and stop of the on –time


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2.8.0 HID LAMP BALLAST CONTROL/WELDING

Constant current control for negative resistance load


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2.9.0 HYBRID OFF GRID/ GRID CONNECTED INVERTER

MPPT solar PV inverter for feeding into the grid

SCR/thryristor based inversion

PLL and synching with the AC grid

Current source topology

Lower computation


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2.10.0 MICRO GRID/ DISTRIBUTED GENERATION

Synchronization of multiple AC sources

Black start

Limiting current based on power electronic devices

Protection schemes


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2.11.0 DIGITAL SLOPE COMPENSATION

For peak current mode control

Dynamic Slope compensation using digital calculations instead of a constant ramp

addition

Optimal choice of slope for any given operating conditions

Best convergence

Minimal degradation to voltage mode control (contrast traditional slope compensation)

Useful for wider range input and output voltage systems


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2.12.0 THRYRISTOR/SCR BASED 3PHASE / 1PHASE POWER CONTROL

Motor drives

3phase and 1phase SCR/Thryristor phase angle control

Validation of conditions

Starters for motor

Light dimming

Harmonic analysis


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2.13.0 TEMPERATURE CONTROL AND THERMAL MANAGEMENT

Minimum overshoot/undershoot

Smooth continuous control emulated through on off

Modeling using MATLAB and obtaining predictable results

projects completed and value addition. controltrix.com

Technology

motion control

mode of operation

control pertaining

velocity control

encoder torque control

encoder position control

direct torque control

step operation