CONTACT-FREE DC DRIVE Russian patent published in 2008 - IPC H02P6/10 H02P6/16 H02P6/22 

FIELD: electricity.

SUBSTANCE: contract-free D.C. drive consists of motor, switch, converter "code-PTM (pulse-time modulation)", digital speed signal shaper, rotation direction shaper, position transducer, position to code feedback signal converter, position error identifier, velocity error identifier, summation unit, step counter, module extractor and control code shaper for each step. Motor shaft angle of rotation signal is generated at summation unit output taking into account actuation angle of advance, which is proportional to motor speed. Switch includes serial connection of divider by constant factor, switching zone number identifier in each step, decoder, logical unit and inverter. Step counter calculates operation cycles and gives the number of step. Divider by constant factor generates signal, integral part of the said signal bearing the information about switching zone number, while fractional part deals with relative rotor position inside zone. Based on the said signals and by motor rotation and step number signal, switching zone number identifier in each step defines zone number and decoder generates code combination to control inverter switches. Logical unit provides control signals to switches for the time of PTM operation ensuring high-quality switching-over from one switching zone to another. As a consequence, resultant vector ripple of motor stator and driving torque are decreased. Control signal module extractor and control code shaper for each step increase converter "code-PTM" resolution ensuring smooth operation of electric drive at low speed rates.

EFFECT: decrease in driving torque ripple; smoother movement and improvement of power indicators.

2 cl, 4 dwg