Control system for stand-by electrical generator

• US 6,657,416 B2
• Filed: 06/15/2001
• Issued: 12/02/2003
• Est. Priority Date: 06/15/2001
• Status: Expired

• Current Assignee: Generac Power Systems Incorporated (Generac Holdings Incorporated)
• Original Assignee: Generac Power Systems Incorporated (Generac Holdings Incorporated)
• Inventors: Harrison, Phillip, Wilcox, Steven J., Zhou, Hongping, Wedel, Francis X., Kern, Robert D., Ruehlow, Gerald C., McLean, Graham
• Primary Examiner(s): Ramirez, Nestor
• Assistant Examiner(s): SAN MARTIN, JAYDI A
• Application Number:
  US09/882,745
• Publication Number:
  US 20020190526A1
• Time in Patent Office: 900 Days
• Field of Search: 322/8, 322/7, 322/29, 322/32, 290/40.B, 307/57, 307/64
• US Class Current: 322/29
• CPC Class Codes: H02J 9/066 characterised by the use of dynamo-electric machines H02J9/08 takes precedence
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator
• CPC Class Codes: H02P 9/305 controlling voltage H02P9/302 takes precedence
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y04S 20/20 End-user application control systems

Abstract

A generator structure is provided for generating an AC power for a load. The generator structure includes a generator connectable to a load and an engine operatively connected to the generator for driving the same. A generator controller is operatively connected to the engine for controlling operation thereof and operatively connected to a generator for controlling the AC power generated thereby. A communications link connects the generator control to a network.

Claims

1. A control system for controlling operation of an engine-driven, electrical generator which generates AC power and AC voltage having a magnitude and a frequency for a load, the load being operatively connected to a utility source which provides AC power having a magnitude and power factor and AC voltage having a magnitude and a frequency thereto, and the engine having an adjustable engine speed, comprising:

a generator control operatively connected to the engine for controlling operation thereof and operatively connected to the generator for controlling the AC power generated thereby;

a synchronizer operatively connected to a generator control, the synchronizer monitoring the magnitude and frequency of the AC voltage of the utility source and the magnitude and frequency of the AC voltage generated by the generator; and

a communications link for operatively connecting the generator control to a network;

wherein the generator control adjusts the magnitude of the AC voltage generated by the generator and adjusts the engine speed of the engine to vary the frequency of the AC voltage generated by the generator such that the magnitude and frequency of the AC voltage generated by the generation matches the magnitude and frequency of the AC voltage of the utility source.

2. The control system of claim 1 further comprising a user interface operatively connected to the network, the user interface allowing a user to communicate with generator control so as to set predetermined operating parameters of the engine and the generator.

3. The control system of claim 1 further comprising a transfer switch having a first input connectable to the utility source for providing AC power, a second input operatively connected to the generator, and an output connectable to an alternate load, the transfer switch is selectively movable between a first position connecting the utility source to the alternate load and a second position connecting the generator to the alternate load.

4. The control system of claim 3 wherein the transfer switch is operatively connected to the generator control such that the generator control controls movement of the transfer switch between the first and second positions.

5. The control system of claim 1 further comprising a switch operatively connected to the generator control and being movable between a first closed position for interconnecting the generator and the load and a second open position, the generator control moving the switch to the closed position in response to the magnitude and frequency of the AC voltage generated by the generator being generally equal to the magnitude and frequency of the AC voltage provided by the utility source.

6. The control system of claim 1 wherein the generator control includes a digital governor connectable to the engine for controlling the engine speed of the engine.

7. The control system of claim 6 wherein the digital governor includes a throttle valve, the throttle valve movable between a first open position wherein the engine generates maximum AC power and a second closed position wherein the engine generates minimum AC power.

8. The control system of claim 1 wherein the generator control includes a voltage regulator for controlling the magnitude of the AC voltage generated by the generator.

9. The control system of claim 1 further comprising an alarm system connectable to the engine for monitoring various engine parameters, the alarm system communicating with the generator control and generating an alarm signal in response to a predetermined condition on the engine.

10. A generator structure for generating AC power for a load, the load including a utility source which provides AC power having a magnitude and power factor and AC voltage having a magnitude and frequency, comprising:

a generator connectable to the load, the generator generating AC power having a magnitude and a power factor and AC voltage having a magnitude and a frequency;

an engine operatively connected to the generator for driving the generator, the engine having an adjustable engine speed;

a generator control operatively connected to the engine for controlling operation thereof and operatively connected to the generator for controlling the AC power generated thereby, the generator control including a synchronizer for monitoring the magnitude and frequency of the AC voltage provided by the utility source and the magnitude and frequency of the AC voltage generated by the generator wherein the generator control adjusts the magnitude of the AC voltage generated by the generator and adjusts the engine speed of the engine to vary the frequency of the AC voltage generated by the generator such that the magnitude and frequency of the AC voltage generated by the generator the magnitude and frequency of the AC voltage of the utility source; and

a communications link for operatively connecting the generator control to a network.

11. The generator structure of claim 10 further comprising a transfer switch having a first input connectable to a utility source for providing AC power, a second input operatively connected to the generator, and an output connectable to an alternate load, the transfer switch selectively movable between a first position for connecting the utility source to the alternate load and a second position for connecting the generator to the alternate load.

12. The generator structure of claim 11 wherein the transfer switch is operatively connected to the generator control such that the generator control controls movement of the transfer switch between the first and second positions in response to the AC power supplied by the utility source.

13. The generator structure of claim 10 further comprising a switch operatively connected to the generator control and being movable between a first closed position wherein the generator is connected to the utility source and a second open position, the generator control moving the switch to the closed position in response to the magnitude and frequency of the AC voltage generated by the generator being generally equal to the magnitude and frequency of the AC voltage provided by the utility source.

14. The generator structure of claim 10 wherein the generator control includes a digital governor connectable to the engine for controlling the engine speed of the engine.

15. The generator structure of claim 14 wherein the digital governor includes a throttle valve, the throttle valve movable between a first open position wherein the engine generates maximum AC power and second closed position wherein the engine generates minimum AC power.

16. The generator structure of claim 10 wherein the generator control includes a voltage regulator for regulating the magnitude of the AC voltage generated by the generator.

17. A control system for controlling operation of an engine-driven, electrical generator which generates AC power and AC voltage having a magnitude and a frequency for a load, the load being operatively connected to a utility source which provides AC power having a magnitude and power factor and AC voltage having a magnitude and a frequency thereto, and the engine having an adjustable engine speed, comprising:

a generator control operatively connected to the engine for controlling operation thereof and operatively connected to the generator for controlling the AC power generated thereby, the generator control including a volt-ampere-reactive (VAR) control for varying the power factor of the AC power generated by the generator to a predetermined value;

a synchronizer operatively connected to a generator control, the synchronizer monitoring the magnitude and frequency of the AC voltage of the utility source and the magnitude and frequency of the AC voltage generated by the generator; and

a communications link for operatively connecting the generator control to a network;

wherein the generator control varies the magnitude and frequency of the AC voltage generated by the generator to match the magnitude and frequency of the AC voltage of the utility source.

18. A generator structure for generating AC power for a load, the load including a utility source which provides AC power having a magnitude and power factor and AC voltage having a magnitude and frequency, comprising:

a generator connectable to the load, the generator generating AC power having a magnitude and a power factor and AC voltage having a magnitude and a frequency;

an engine operatively connected to the generator for driving the generator, the engine having an adjustable engine speed;

a generator control operatively connected to the engine for controlling operation thereof and operatively connected to the generator for controlling the AC power generated thereby, the generator control including a volt-ampere-reactive (VAR) control for varying the power factor of the AC power generated by the generator;

the generator control including a synchronizer for monitoring the magnitude and frequency of the AC voltage provided by the utility source and the magnitude and frequency of the AC voltage generated by the generator such that the generator control the magnitude and frequency of the AC voltage generated by the generator the magnitude and frequency of the AC voltage of the utility source; and

a communications link for operatively connecting the generator control to a network.

19. A method of providing AC power to a load, the load including a utility source which provides AC power having a magnitude and a power factor and an AC voltage having a magnitudes and a frequency, comprising the steps of:

setting various operating parameters for a generator structure and transmitting the same to the generator structure over a network; and

generating AC power and AC voltage with a generator structure in response to the various operating parameters set, the AC power having a magnitude and a power factor and the AC voltage having a magnitude and a frequency;

monitoring the magnitude and the frequency of the AC voltage provided by the utility source and the magnitude and the frequency of the AC voltage generated by the generator structure;

varying the magnitude and the frequency of the AC voltage generated by the generator structure to match the magnitude and the frequency of the AC voltage provided by the utility source, and

interconnecting the generator structure to the utility source in response to the magnitude and the frequency of the AC voltage generated by the generator structure being generally equal to the magnitude and the frequency of the AC voltage provided by the utility source.

20. The method of claim 19 comprising the additional step of varying the power factor of the AC power generated by the generator structure to a predetermined value.

21. The method of claim 19 comprising the additional step of adjusting the magnitude of the AC voltage generated by the generator structure to a user selected magnitude.