From: Pavel Pisa Date: Tue, 11 Oct 2016 00:56:21 +0000 (+0200) Subject: Raspberry Pi PMSM Motor Control - initial page version added. X-Git-Url: https://rtime.felk.cvut.cz/gitweb/ert_linux_web.git/commitdiff_plain/351fd545f90563d274b4aba96d56e1e8308c33f1?hp=756b3f75955ccb0f72700ec3e7c8975986e6914f Raspberry Pi PMSM Motor Control - initial page version added. Signed-off-by: Pavel Pisa --- diff --git a/rpi-pmsm-control/index.html b/rpi-pmsm-control/index.html new file mode 100644 index 0000000..4f2f152 --- /dev/null +++ b/rpi-pmsm-control/index.html @@ -0,0 +1,64 @@ + + + + [[!meta title="Raspberry Pi Permanent Magnet Synchronous Motor (PMSM) Control"]] + + + + + +
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+[[!rpi_pmsm_motor_control.png size="300x" align=right alt="Simulink connected to RPi running PMSM control model"]] +Raspberry Pi is often +used for education and many hobbyists tasks but it is not equipped with hardware +peripherals required for a quite complex vector electric motor control task. +This project sumplements bare Raspberry Pi board by two other boards to implement +complete educational BLDC/PMSM motor control system. One board uses small +Microsemi IGL00 FPGA to implement missing peripherals and the second board +implements 3-phase power stage with current sensing, ADC and galvanic +isolation which can be used in this project or even connected +to Altera DE2 education kits. +

+ +

Three-pases PMSM Control Basics

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+The differences between Voltages connected to the three stator windings +terminals cause current flow which forms rotating magnetic field. +The direction and magnitude of this field drive permanent magnet +rotor which is to align with the direction of the magnetic field vector. +North pole is attracted to the south and vice versa. For constant speed +and torque, the waveforms of the phase Voltages (the same for currents) +are sinusoidal with an equidistant phase shift of 120 deg. The three phases +system is in some respect redundant, in the case of Voltages (uA, +uB, uC) only differences count, i.e. one can be +fixed to zero. A sum of the three currents (iA, iB, +iC) has to be zero by the Kirchhoff's current law. As a consequence, +only two independent quantities/scalars are needed to describe the currents +or Voltages which are in the fact vector in the 2D space. The polar coordinates +system can be used but a rectangular system of alpha, beta components is equivalent +and easier for transformations computation. This transformation of the three phase +system to the two orthogonal components vector is named according to its +inventor Clark transformation. The waveforms in this 2D system are sine +and cosine for steady speed state. Because realization of a controller +in this altering components system is not feasible, another transformation +was invented which convert the quantities to the coordinates fixed to +the revolving rotor. A base formed by direct (D) component aligned to North, +South pole direction of the rotor and orthogonal quadrature (Q) has been +introduced by Robert H. Park and the transformation is named according to him. +The control in the D-Q coordinates is (almost) independent of actual rotor +position and (in simplified outlook) separates reactive current (iD) +from the active current (iQ) resulting in torque affecting rotor +movement. +

+[[!img pxmc-pmsm-block.png size="300x" align=right alt="Basic PMSM control setup diagram from PXMC library documentation"]] + +
+ + + + \ No newline at end of file diff --git a/rpi-pmsm-control/pxmc-pmsm-block.png b/rpi-pmsm-control/pxmc-pmsm-block.png new file mode 100644 index 0000000..be8768d Binary files /dev/null and b/rpi-pmsm-control/pxmc-pmsm-block.png differ