Method and apparatus to control input to AC induction motors

• US 20040174134A1
• Filed: 03/18/2004
• Published: 09/09/2004
• Est. Priority Date: 04/10/2001
• Status: Active Grant

• Current Assignee: Enviro World Systems, Inc.
• Original Assignee: Enviro World Systems, Inc.
• Inventors: Cashatt, Jerry D.
• Granted Patent: US 6,954,046 B2
• Time in Patent Office: Days
• US Class Current: 318/727
• CPC Class Codes: H02P 23/26 Power factor control [PFC]
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier

Abstract

One embodiment of the present invention is a method to control input to an alternating current (AC) induction motor from a power supply that includes steps of: (a) determining a measure of reactive power (VAR) in two input lines to the motor during a time period; and (b) maintaining an SSR (solid state relay) connected in series between the power supply and the motor in a non-conducting state for a subsequent time period, the length of which subsequent time period is determined by analyzing the measure of VAR.

Claims

1. A method to control input to an alternating current (AC) induction motor from a power supply that comprises steps of:

determining a measure of reactive power (VAR) in two input lines to the motor during a time period; and

maintaining an SSR (solid state relay) connected in series between the power supply and the motor in a non-conducting state for a subsequent time period, the length of which subsequent time period is determined by analyzing the measure of VAR.

2. The method of claim 1 further comprising a step of driving the SSR to be conducting after the subsequent time period.