Generator set with redundant bus sensing and automatic generator on-line control

• US 6,104,171 A
• Filed: 11/23/1998
• Issued: 08/15/2000
• Est. Priority Date: 11/23/1998
• Status: Expired due to Term

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Dvorsky, Michael A., Krahn, Darren L.
• Primary Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US09/197,657
• Time in Patent Office: 631 Days
• Field of Search: 322/7, 322/8, 322/20, 322/37, 290/40 R, 307/87
• US Class Current: 322/8
• CPC Class Codes: H02J 3/42 with automatic parallel connection when synchronisation is achieved

Abstract

A generator set controller includes a dead bus sensor producing a dead bus signal indicative of a power failure on a power bus that is an input to the controller on a digital input channel. The controller also receives a voltage signal from a phase of a power bus.

Claims

1. A generator set controller which is connected with a three-phase power bus, including:

a controller having at least one analog input and at least one digital input and at least one output, the analog input being connected with a first phase of the three-phase bus;

a dead bus sensor connected with the digital input, and a second and third phase of the bus and producing a live bus signal as a function of electrical characteristics of the second and third phase of the bus;

a breaker connected with said output and having an open and a closed position, the position of the breaker being controlled by a breaker signal produced by the controller at said output, the generator being connected with the bus when the breaker is in the closed position;

wherein the electronic controller issues a breaker signal causing the breaker to move to a closed position as said a function of signals received on said analog input and said digital input.

2. The generator set controller according to claim 1, wherein the dead bus sensor comprises a relay, said relay coil being connected between the second and third phases of the bus, and said relay contact being closed in response to a voltage potential between said second and third phases being greater than a predetermined level, and producing said live bus signal in response to the closing of the relay contact.

3. The generator set controller according to claim 1, wherein the live bus signal is produced by the dead bus sensor in response to the voltage difference between said second and third phase being greater than a predetermined value.

4. The generator set controller according to claim 1, wherein the electronic controller synchronizes the generator output to the three-phase bus and issues the breaker signal as a function of the voltage at the analog input being above a programmable value and receiving the live bus signal at said digital input.

5. The generator set controller according to claim 2, wherein the electronic controller synchronizes the generator output to the three-phase bus and issues the breaker signal as a function of the voltage at the analog input being above a programmable value and receiving the live bus signal at said digital input.

6. A method of controlling a generator connecting to a multi-phase power bus, said method including:

sensing the magnitude of the voltage of a first phase of the power bus;

determining whether a voltage difference between a second and third phase exceeds a predetermined level; and

connecting said generator to said power bus in response to said steps of sensing and determining.