Energy economizer for polyphase induction motors

Patent · Tue Dec 30 04:00:00 EST 1980

OSTI ID:6466103

Hedges, R W

A standard three phase induction motor starts with all three of its input connections connected to the three phase power line. Two of these connections are through triacs which remain continously conducting below said motor's particular most energyefficient speed, which is above about 95% of synchronous speed. This assures full starting torque and undiminished overload handling capability. The triacs, in response to a control signal, may open the circuits over a sufficiently wide portion of the sine wave input voltage to substantially maintain said particular efficient speed under all rated load conditions. To assure smooth operation and maximum energy savings, the two triacs conduct differently at very light motor loads. The dc control voltage which determines the operation of the triacs is generated by a frequency discriminator circuit which receives its information from a load detecting device that is frequency modulated by load/speed related properties inherent to induction motors.

• Assignee: IFI; EDB-81-092345
• Patent Number(s): US 4242625
• OSTI ID: 6466103
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
320303* -- Energy Conservation
Consumption
& Utilization-- Industrial & Agricultural Processes-- Equipment & Processes
AC SYSTEMS
CONTROL SYSTEMS
ECONOMIZERS
EFFICIENCY
ELECTRIC MOTORS
ELECTRONIC CIRCUITS
ENERGY EFFICIENCY
ENERGY SYSTEMS
INDUCTION
MOTORS
POWER SYSTEMS