Control system and circuits for distributed electrical-power generating stations

• US 5,754,033 A
• Filed: 03/13/1996
• Issued: 05/19/1998
• Est. Priority Date: 03/13/1996
• Status: Expired due to Fees

• Current Assignee: Alaska Science and Technology Foundation
• Original Assignee: Alaska Power Systems, Inc.
• Inventors: Thomson, William R.
• Primary Examiner(s): Laballe, Clayton E.
• Assistant Examiner(s): Ponomarenko, Nicholas
• Application Number:
  US08/615,688
• Time in Patent Office: 797 Days
• Field of Search: 322/47, 322/22, 322/25, 290/40 B, 290/40 C, 290/52
• US Class Current: 322/45
• CPC Class Codes: H02J 3/38 Arrangements for parallely feeding a single network by two or more generators, converters or transformers
• CPC Class Codes: H02P 2101/45 for motor vehicles, e.g. car alternators
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator

Abstract

A system (30) for providing electrical-power to remote communities (34) widely distributed over an extended geographical area (38) includes a generating station (32) located proximate each of the communities, each generating station supplying only that community to which it is proximate. The generating stations are in electronic communication with a central computer (40). Each generating station includes a plurality of generators (54-56). Each of the generators is controlled by a microprocessor based controller (64). Each controller is arranged to operate the generating station cooperatively with the other controllers associated with other generators in the station, and to assume a supervisory role in doing so by a mutual arbitration procedure among the controllers. Each controller is also arranged to monitor important generator operating parameters and to communicate these parameters to the central computer. Any controller may be reprogrammed by instructions communicated from the central computer, and functions of any controller may be overridden by instructions communicated from the central computer. The controllers include novel signal processing circuits (90 and 85) and logic for improved voltage and frequency regulation. The controllers also include novel circuits (92) and logic for monitoring generator fuel consumption and calculating generator fuel-efficiency therefrom.

Claims

1. In an engine driven electrical power generator arrangement, a method for determining fuel efficiency of electrical energy generation, comprising the steps of:

(a) from a magnetic rotary vane flowmeter providing first and second current pulse signals representing respectively fuel flow to and fuel flow from the engine, said current pulse signals having a frequency representative of volume fuel flow, and having a magnitude representative of fuel temperature;

(b) converting said first and second current pulse signals to first and second voltage pulse signals;

(c) determining from said first and second voltage pulse signals respectively first and second values of fuel volume flow and first and second values of fuel temperature;

(d) from said first and second values of fuel volume flow, said first and second values of fuel temperature and from a predetermined standard temperature, standardizing said first and second fuel volume flows to a density corresponding to said standard temperature; and

(e) subtracting said standardized second fuel volume flow from said first standardized fuel volume flow thereby determining a fuel consumption value;

(f) receiving a signal from the generator that the generator has generated a predetermined amount of electrical energy; and

(g) calculating the fuel efficiency of electrical energy generation from the fuel consumption value and the predetermined amount of electrical energy.

2. The method of claim 1, wherein any one of said fuel volume flow rates is determined by the steps of (h) recording a highest and a lowest value of said voltage pulses (i) averaging said highest and lowest values of said voltage pulses thereby providing an average voltage value (j) counting a frequency with which said voltage pulses cross said average voltage value, and (k) determining said fuel volume flow from said frequency.

3. The method of claim 2, wherein any one of said first and second fuel temperatures is determined by the step of (l) subtracting said lowest recorded voltage value from said highest recorded voltage value.