Sensorless Vector Control and Implementatio - Why and How (1)

Sensorless Vector Control and Implementation: Why and How Renesas Electronics America Inc © 2012 Renesas Electronics America Inc All rights reserved Renesas Technology & Solution Portfolio © 2012 Renesas Electronics America Inc All rights reserved Microcontroller and Microprocessor Line-up 2010 2013 1200 DMIPS, Superscalar 32-bit  Automotive & Industrial, 65nm  600µA/MHz, 1.5µA standby 1200 DMIPS, Performance  Automotive, 40nm  500µA/MHz, 35µA deep standby 500 DMIPS, Low Power  Automotive & Industrial, 90nm  600µA/MHz, 1.5µA standby 165 DMIPS, FPU, DSC  Industrial, 40nm  242µA/MHz, 0.2µA standby 165 DMIPS, FPU, DSC  Industrial, 90nm  242µA/MHz, 0.2µA standby 8/16-bit 25 DMIPS, Low Power  Industrial, 90nm  1mA/MHz, 100µA standby  Industrial & Automotive, 150nm  190µA/MHz, 0.3µA standby 44 DMIPS, True Low Power 10 DMIPS, Capacitive Touch  Industrial & Automotive, 130nm  144µA/MHz, 0.2µA standby  Format Automotive, 130nm WideIndustrial &LCDs  350µA/MHz, 1àA standby Embedded Security, ASSP â 2012 Renesas Electronics America Inc All rights reserved ‘Enabling The Smart Society’  Challenge: Sensorless vector control increases the energy efficiency of motor control systems that drive the smart society However, understanding and implementing sensorless vector control is a herculean task MCU  Solution: This class will help you understand key challenges associated with sensorless vector control and how to implement it using Renesas microcontrollers © 2012 Renesas Electronics America Inc All rights reserved Agenda  Need for vector control  Theory behind vector control  Challenges in implementing sensorless vector control  RX62T MCU family for sensorless vector control  Renesas motor control solutions © 2012 Renesas Electronics America Inc All rights reserved Macro Factors Driving Need for Energy Efficiency Global Environmental Concerns Energy Efficiency Policies New Initiatives © 2012 Renesas Electronics America Inc All rights reserved Realizing Energy Efficiency in Motor Control Industrial 44% Residential 26% Others 30% Motors (45%) Electronic Control Energy Efficient Motors  Variable speed drives  Motor Design  Vector control  Motor Type  Direct torque control  Power factor correction 15% 20% Up to ~30% savings © 2012 Renesas Electronics America Inc All rights reserved Sensorless Vector Control Theory © 2012 Renesas Electronics America Inc All rights reserved Permanent Magnet AC Motor  Complex Control  Sinusoidal stator current produces rotating field  Rotor mounted magnetic field is rotating Γ = k λs × λr  Maintain stator field orthogonal to rotor field A X C’ B X B’ θ X C A’ © 2012 Renesas Electronics America Inc All rights reserved A B C Vector Control Challenge  Maintain orthogonality  Error correction feedback loop – In-phase current = – Orthogonal current set per torque requirements  What parameters to adjust  Voltage magnitude (PWM duty cycle)  Need to transform current vectors to rotor frame Stator Field 900 Rotor Field 10 © 2012 Renesas Electronics America Inc All rights reserved ωr Code Size Floating-point code size is 45% lower Current Measurement Position Estimation Floating Point Clarke and Park Fixed point PI Loop B 43 © 2012 Renesas Electronics America Inc All rights reserved 50 100 150 200 250 Driving Two 3-Phase BLDC Motors  Sensorless Vector Control www.renesas.com/rxmotorkit  Floating point math  CPU BW used (α,β) ->(d,q) Current Reconstruction PWM Interrupt2 Last θ Actual Current Reference Current Last ω & Reference ω Speed PI Current PI Voltage (d,q) New Speed Estimation New θ Estimation V(u,v,w) -> PWM Duty (d,q) -> (α,β) (u,v,w)