Voltage control using engine speed

• US 6,226,998 B1
• Filed: 03/26/1999
• Issued: 05/08/2001
• Est. Priority Date: 03/26/1999
• Status: Expired due to Term

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Reason, John Robert, Navarro de Andrade, Joao Eduardo
• Primary Examiner(s): Tanner, Harry B.
• Application Number:
  US09/277,507
• Time in Patent Office: 774 Days
• Field of Search: 62/230, 62/228.4, 62/228.1, 62/323.1, 62/323.3, 62/323.4
• US Class Current: 62/230
• CPC Class Codes: B60H 1/3208 Vehicle drive related control of the compressor drive means, e.g. for fuel saving purposes
• CPC Class Codes: F02D 29/04 peculiar to engines driving pumps

Abstract

An process and method for monitoring and limiting high voltage conditions in a transport refrigeration unit is disclosed. The system provides a microprocessor control which monitors the load, generator temperature and engine speed and compares it to an algorithm or map programmed into a controller for the unit. The map or algorithm preferably predicts voltage based upon load (amperage), generator temperature and engine speed. If the result of the monitored features predicts a voltage above preselected acceptable levels which are programmed into the controller, then the controller will drop the engine into low speed.

Claims

1. A process for monitoring and limiting high voltage conditions in an electrically powered transport refrigeration unit, said electrically powered transport refrigeration unit including at least an engine and a generator, said process comprising the steps of:

i monitoring an drive parameter of said transport refrigeration unit;

ii comparing said drive parameter to an operating parameter model within the microprocessor of said transport refrigeration unit;

iii selectively decreasing the speed of the engine in response to drive parameters which exceed predetermined limits of the operating parameter model.

2. The process of claim 1, wherein the drive parameters being monitored are selected from the group consisting of current draw, engine speed, and the temperature of the generator.

3. The process of claim 1, wherein the drive parameter being measured is the temperature of the generator.

4. The process of claim 1, wherein the step of selectively decreasing speed comprises lowering a two speed engine from high speed to low speed.

5. A process for monitoring and variable controlling voltage conditions in a electrically powered transport refrigeration units, said process comprising the steps of:

i monitoring a generator for generator current and generator temperature levels, said generator being located within said transport refrigeration unit;

ii comparing said generator current and generator temperature to an operating parameter model within the microprocessor of said transport refrigeration unit;

iii selectively varying the speed of the engine in response to operating parameters which vary from predetermined limits of the operating parameter model.