Frequency inverting apparatus

US5237494A · kind A · utility

Assignee

• Barmag AG · DE

Inventors

• Uwe Baader · Wuppertal, DE
• Gerhard Martens · Henstedt-Ulzburg, DE
• Karl-Ludwig Rafflenbeul · Ennepetal, DE

Key dates

• Filing date: Sep 10, 1991
• Grant date: Aug 17, 1993
• Expiry date: Sep 10, 2011

Classification

• Technology area (CPC H): Electricity
• CPC primary: H02M5/44
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

An apparatus for driving a plurality of motors at different variable speeds. The apparatus includes a rectifier for supplying direct current power to a dc bus circuit. A plurality of inverters are connected to the dc bus circuit and each inverter drives a respective motor. Each inverter is controlled by an individual controller connected thereto for controlling the frequency of the output of the inverter to thereby control the speed of the associated motor. The inverters are preferably mounted on a common heat sink to reduce electrical and mechanical complexity. The apparatus permits the rectifier and the dc bus circuit to be sized to handle a maximum rating of less than the sum total of maximum loads of each of the motors. The dc bus circuit also serves to distribute energy generated by a slowing motor, for example, to other motors driven from the bus circuit. A chopper resistor may be included and switched across the dc bus circuit to provide braking to the motors.