AN2357 Freescale Semiconductor / Motorola, AN2357 Datasheet
AN2357
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AN2357 Summary of contents
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... Freescale Semiconductor, Inc. Application Note AN2357 11/2002 Sine Voltage Powered 3-Phase Permanent Magnet Motor with Hall Sensor By Jiri Ryba Roznov System Application Laboratory Roznov, Czech Republic Introduction This application note describes the control of a 3-phase PM (permanent magnet) motor with a Hall sensor powered by a sine voltage based on Motorola’ ...
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... Freescale Semiconductor, Inc. AN2357/D MC68HC908MR8 Features The Motorola MR8 Family members are well suited for digital motor control. These microcontroller units (MCUs) offer many dedicated peripherals such as a pulse width modulation (PWM) module, analog-to-digital converter (ADC), timers, serial communication interface (SCI), on-board FLASH, and random- access memory (RAM) ...
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... Space vector of rotor magnetic flux evoked by the r permanent magnet — Electrical torque T e ∠ , ψ — Angle between vectors of stator current and rotor magnetic flux Go to: www.freescale.com AN2357/D Target Motor Theory Stator Stator Winding (in slots) Shaft Rotor Air gap Permanent Magnets Equation 1 Equation 2 ⋅ ( ∠ , ψ ...
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... Freescale Semiconductor, Inc. AN2357/D Motor speed can be controlled by the amplitude of the voltage vector, while the direction of the voltage vector depends on the rotor position. Several methods can be used to control the voltage vector direction. The three basic method are: 1. Vector of stator voltage is placed 90° relative to the vector of rotor 2. Vector of stator current is kept 90° ...
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... E Ψ 90° Figure 3. Stator Current is 90° Relative to Rotor Flux Figure 4. This control strategy keeps the current ω Ψ to: www.freescale.com AN2357/D Target Motor Theory Equation 3 the Ψ Ψ r Ψ Ψ ...
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... Freescale Semiconductor, Inc. AN2357/D System Concept The control strategy is designed to optimally utilize features of the MC68HC908MR8. The application provides the following properties: • • • • • • • • • • • • • • • • Figure 5 application was designed to control a ventilator PM motor. Speed of the motor is controlled by the amplitude of the voltage vector, while the direction of the voltage vector depends on the rotor position ...
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... Voltage Ripple Cancellation Voltage Torque to Limitation Voltage Conversion Speed PI Torque Controller Limitation Required Deceleration Speed - - Limitation Actual Speed Commutation Period 1/T Figure 5. System Concept Go to: www.freescale.com AN2357/D System Concept 3-ph 3-ph PM Inverter Motor PWM 3-ph Sine Wave Generator Required Angle PLL Period, Position Recognition 68HC908MRx 7 ...
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... Freescale Semiconductor, Inc. AN2357/D Hardware Design The motor control system is designed to drive the 3-phase PM motor in a speed closed loop using a MC68HC908MR8 microcontroller. The system configuration is shown in • • • Controller Board The controller board, shown in 1. Main board switches 2. Emulator / MC68HC908MR32 socket enabling conection ...
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... For More Information On This Product, Figure 7. Control Board Elements Table 1. The JP2 jumper must be connected. Table 1. MCHC908MR32 MC Board Jumper Settings Jumper Group Comment JP1 Tacho JP2 Encoder/Hall sensor JP3 BEMF_z_c JP4 PFC_z_c JP5 PFC_PWM JP7 GND_Connection Go to: www.freescale.com AN2357/D Hardware Design Connections NC 1 1-2 9 ...
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... Freescale Semiconductor, Inc. AN2357/D Power Stage Motorola’s embedded motion control series low-voltage (LV) BLDC power stage is designed to run 3-phase BLDC and PM synchronous motors. It operates from a nominal 12-volt motor supply. It delivers rms motor current from a dc bus that can deliver peak currents combination with one of Motorola’ ...
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... Control PC master process Period Calculation period_hall_sensor Speed Calculation omega_measured Torque Limitation v_phase_limit Voltage Limitation Ripple Cancellation v_phase_amplitude Figure 8. Main Data Flow Go to: www.freescale.com AN2357/D Software Design Hall Sensor Sensor Edge Detection PLL phase_increment phase_measured Field Weakening Calculation fieldWeakening torque_limit Sine Wave ...
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... Freescale Semiconductor, Inc. AN2357/D Period Calculation To eliminate the difference between the rotor poles, the edges from same poles are used for period calculation. The motor used has three pole pairs. The principle of period calculation is shown in each signal edge, but the time from same edge and same pole is used for the period calculation in the current time ...
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... constant representing the omega scale and the number of pole ω pairs T is the Hall sensor period h Go to: www.freescale.com AN2357/D Software Design 240 300 360 Position Signal from Hall sensor ∆T – position difference between expected and real position Equation 5 ...
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... Freescale Semiconductor, Inc. AN2357/D Speed Controller The scaled PI controller is used for the speed closed loop. The controller is called every 5 ms. The controller constants were tuned experimentally. Because the speed update depends on actual motor speed, the speed controller constants have to be changed according to the measured speed to achieve the best result ...
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... C depend on motor parameters. In the designed Φ G and C Φ G 12). motor speed [rpm] Figure 12. Constants for Torque Limitation Go to: www.freescale.com AN2357/D Software Design Equation 9 can be replaced by a constant, which Equation 9 can be simplified to: Equation 10 Equation 11 are changed according to the motor *ω ...
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... Freescale Semiconductor, Inc. AN2357/D Voltage Ripple The voltage ripple cancellation recalculates the absolute required voltage into Cancellation a relative voltage, so that output voltage amplitude does not depend on the dc- bus voltage. where: • • • The function has two main purposes: 1. Change in dc-bus voltage does not effect torque limitation algorithm 2 ...
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... Figure 14. Measured Reactive Power for Different Torque and Speed δ = 101° base δ = 122° max Go to: www.freescale.com AN2357/D Software Design Equation 13 Equation 14 w2_T3 w1_T3 w2_T2 w1_T2 w2_T1 w1_T1 120 130 17 ...
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... Freescale Semiconductor, Inc. AN2357/D Sine Wave The sine wave generation is calculated with each PWM reload interrupt, which is every 64 µs. The function Generation gets the sinus of the actual phase for all three phases from the table, and multiplies it by the phase amplitude. Resolution of the sinus is 1024 points per period and 256 points per amplitude. The function is written in assembly language to minimize execution time. The execution time is about 20 µ ...
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... PCIM 2002. Design of Brushless Permanent-Magnet Motors, J.R. Hendershot and T.J.E. Miller, Magna Physics Publishing and Clarendon Press, 1994 AN1917, 3-Phase Synchronous PM Motor Control with Quadrature Encoder Using DSP56F80x, P.Grasblum, Motorola 2002 AN2292, 8-Bit Software Development Kit, J. Ryba, Motorola 2002 Go to: www.freescale.com AN2357/D References 19 ...
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... Motorola and the Stylized M Logo are registered in the U.S. Patent and Trademark Office. digital dna is a trademark of Motorola, Inc. All other product or service names are the property of their respective owners. Motorola, Inc Equal Opportunity/Affirmative Action Employer. © Motorola, Inc. 2002 AN2357/D Rev. 0 11/2002 Go to: www.freescale.com ...