JPS6227637B

• Main Authors: IIJIMA KAZUHIKO, SUZUKI SHUICHI, OGAWA TAKESHI, NIIMURA YOSHIHISA
• Format: Patent
• Language: English
• Published: 16.06.1987
• Subjects: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORSOR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER; ELECTRICITY; GENERATION

PURPOSE:To peform a highly accurate and smooth speed control on the subject motor by a method wherein a current feedback signal, having the polarity reverse to a comparison speed signal, is maintained at all times even under the condition where the winding current of each phase of the brushless motor is an alternate current. CONSTITUTION:Using the positional signals A-C sent from a position detector 15 as an input, a current selection signal forming circuit 20 outputs a current selecting signals S(-IR')-S(IT') at the suitable timing at which a current feedback signal Icomp, with the polarity reverse to a comparison speed signal S3, is composed of the galvanic current IR'-IT' sent from winding current detectors 17-19 are reverse- polarized winding detecting current -IR-IT'. Currents -TR'-IT' are formed by a current feedback signal forming circuit 21 using currents IR'-IT' as inputs and at the same time, the current satisfying the prescribed conditions is picked out from the currents IR'-IT' and IR'-IT' based on signals S(-IR')-S(IT'), and the signal Icomp having a low percentage of ripple content is outputted by composing the above-mentioned signals.