Power and environmental condition monitoring system and method

• US 6,598,003 B1
• Filed: 10/31/2000
• Issued: 07/22/2003
• Est. Priority Date: 10/31/2000
• Status: Expired due to Term

• Current Assignee: RX Monitoring Services, LLC
• Original Assignee: RX Monitoring Services, LLC
• Inventors: Heino, Todd V., Kindseth, Erik J., Thomas, Robert T.
• Primary Examiner(s): Wachsman, Hal
• Assistant Examiner(s): Desta, Elias
• Application Number:
  US09/703,185
• Time in Patent Office: 994 Days
• Field of Search: 702/9, 702/22, 702/52, 702/53, 702/67, 702/75, 702/83, 702/84, 702/99, 702/104, 702/116, 702/124, 702/125, 702/126, 702/130, 324/600, 324/605, 324/606, 324/607, 324/629, 324/630, 324/76.11, 324/76.39, 324/76.47, 324/76.82, 324/76.83, 324/85, 340/146.2, 340/500, 340/501, 340/502, 340/3.1, 340/825.73, 340/FOR-103, 700/9, 700/22, 700/52, 700/53, 700/67, 700/291, 700/295, 700/297, 700/299, 700/301, 708/100, 708/131, 708/132, 708/300, 708/311, 708/316
• US Class Current: 702/68
• CPC Class Codes: G01R 19/2513 Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
• CPC Class Codes: H02J 13/00001 characterised by the display of information or by user interaction, e.g. supervisory control and data acquisition systems [SCADA] or graphical user interfaces [GUI]
• CPC Class Codes: H02J 13/00002 characterised by monitoring
• CPC Class Codes: Y02E 60/00 Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y04S 10/30 State monitoring, e.g. fault, temperature monitoring, insulator monitoring, corona discharge
• CPC Class Codes: Y04S 10/40 Display of information, e.g. of data or controls
• CPC Class Codes: Y04S 10/52 Outage or fault management, e.g. fault detection or location

Abstract

The power and environmental condition monitoring system monitors the quality of power provided to a site as well as other environmental conditions that might affect the operation of electronic equipment at the site. The system detects and records power events, such as spikes, sags, surges, and other transients, records power conditions, such as voltage level, RMS volts, phase differential, A/C frequency, current, and impedance, and records environmental conditions, such as temperature, vibration, and humidity. The system includes an analog signal receiver that receives analog signals from measurement devices and converts the analog signals into digital signal data. At least some of the channels on the analog boards are high frequency channels capable of receiving and converting high frequency voltage event signals. The system also includes a digital signal processor (DSP) for reading the raw digital signal data from the analog signal receiver and for processing the raw digital signal data. The DSP processes the digital signal data by logging low frequency digital data and by detecting and logging high frequency event digital data. The high frequency event digital data is detected by classifying the data and analyzing the data based upon the class with as few data points as is needed.

Claims

1. A power and environmental condition monitoring system, for monitoring power and environmental conditions at a site, said system comprising:

at least one analog signal receiver including a plurality of analog signal channels for receiving a plurality of analog measurement signals representing power and environmental conditions, for converting said analog measurement signals into digital signals including digital signal data, and for buffering said digital signal data, wherein said analog signal channels include at least one high/low frequency voltage channel for monitoring voltage signals including high frequency voltage events and at least one configurable multi-purpose channel for monitoring low frequency analog measurement signals;

at least one digital signal processor, connected to said analog receiver, for reading said digital signal data buffered by said analog signal receiver and for processing said digital signal data, wherein digital signal processor processes said digital signal data by logging at least some of said digital signal data, and wherein digital signal processor processes said digital signal data by analyzing at least some of said digital signal data to detect a pattern consistent with an event and by logging selected values of said digital signal data sufficient to define said event; and

a post-processing system, connected to said digital signal processor, for storing and post processing processed digital signal data received from the digital signal processor.

2. The power and environmental condition monitoring system of claim 1, wherein said at least one multi-purpose channel is configurable to monitor one of a low frequency voltage signal, a current signal, and an environmental condition signal.

3. The power and environmental condition monitoring system of claim 1 wherein said post-processing system includes a communications device for communicating with a remote location and for transmitting said processed digital signal data to said remote location.

4. The power and environmental condition monitoring system of claim 1 wherein said post-processing system is implemented on a personal computer.

5. The power and environmental condition monitoring system of claim 4, wherein said at least one analog receiver includes at least one analog board connected to said personal computer, and wherein said at least one digital signal processor includes at least one digital signal processor board connected to said personal computer.

6. The power and environmental condition monitoring system of claim 4 wherein said personal computer includes software for configuring said at least one configurable multi-purpose channel.

7. The power and environmental condition monitoring system of claim 1 wherein said at least one digital signal processor includes:

a sample digital signal processor, connected to said at least one analog signal receiver, for reading said digital signal data buffered by said analog signal receiver, and for addressing and buffering said digital signal data; and

a process digital signal processor, connected to said sample digital signal processor, for receiving said digital signal data transmitted by said sample digital signal processor and for processing said digital signal data.

8. The power and environmental condition monitoring system of claim 7 wherein said sample digital signal processor reads said digital signal data representing low frequency analog measurement signals using an interrupt, and wherein said sample digital signal processor polls said analog signal receiver to read said digital signal data representing said high frequency voltage events.

9. The power and environmental condition monitoring system of claim 1 wherein said digital signal processor communicates with an internal uninterruptible power supply (UPS) for detecting power outages.

10. The power and environmental condition monitoring system of claim 1 wherein said post-processing system includes software for generating a data report, wherein said data report includes at least a summary of at least some of said processed digital signal data.

11. The power and environmental condition monitoring system of claim 1 wherein said analog signal receiver includes an isolated measurement circuit for measuring voltage signals.

12. The power and environmental condition monitoring system of claim 1 wherein said analog signal receiver includes at least one peak detect circuit for detecting said high frequency voltage signals representing said high frequency voltage events.

13. The power and environmental condition monitoring system of claim 12 wherein the sensitivity of said peak detect circuit is configurable to filter out unwanted high frequency signals.

14. An analog signal receiver for use in a power and environmental condition monitoring system that monitors power and environmental conditions at a site, said analog signal receiver comprising:

a plurality of analog signal inputs including high/low voltage signal inputs for receiving voltage signals and multi-purpose inputs for receiving low frequency analog measurement signals;

a plurality of isolated measurement circuits for measuring said voltage signals received on said high/low voltage signal inputs, wherein each of said isolated measurement circuits includes an isolating amplifier and an isolated signal transmitter connected to said isolation amplifier;

analog signal processing circuitry for processing said voltage signals and said low frequency analog measurements signals;

a multiplexer for multiplexing said voltage signals and said analog measurement signals into a multiplexed low frequency analog signal;

a low frequency A/D converter for converting said multiplexed low frequency analog signal to low frequency digital signal data;

a low frequency buffer for buffering said low frequency digital signal data;

a high frequency voltage event detector for detecting high frequency voltage events;

at least one high frequency A/D converter for converting said high frequency voltage events to high frequency voltage digital data; and

a high frequency buffer for buffering said high frequency voltage digital data.

15. The analog signal receiver of claim 14 wherein said isolated signal transmitter includes one of a linear optocoupler, a transformer coupler, and a capacitive coupler.

16. The analog signal receiver of claim 14 wherein said high/low frequency voltage inputs include voltage inputs for each phase.

17. The analog signal receiver of claim 14 wherein said multi-purpose inputs are selects from the group consisting of current inputs, low frequency voltage inputs, and environmental condition sensor inputs.

18. The analog signal receiver of claim 14 wherein said high frequency voltage event detector includes a peak detect circuit for detecting said high frequency voltage events.

23. The method of claim 18 further including the step of buffering said low frequency data and said high frequency data after receiving said high frequency data and said low frequency data.

19. A method for processing data in a power and environmental condition monitoring system, said method comprising:

receiving high frequency data and low frequency data, representing voltage signals and environmental condition signals;

generating data log entries, wherein each of said data log entries includes at least a date/time stamp and at least some of said low frequency data;

logging said data log entry in a data log;

classifying said high frequency data and said low frequency data to determine an event classification;

analyzing said high frequency data and said low frequency data based upon said event classification and selecting sufficient event data values to define said event;

generating an event data log entry; and

logging said event data log entry into an event log.

20. The method of claim 19 further including the step of generating a data report including at least a summary of processed data from said data log and said event log.

21. The method of claim 19 wherein receiving said high frequency data and said low frequency data includes polling high frequency buffers on an analog signal receiver to read high frequency event data.

22. The method of claim 19 wherein receiving said high frequency data and said low frequency data includes reading low frequency data from low frequency buffers using a programmable interrupt.

24. A method of monitoring power and environmental conditions, said method comprising:

receiving analog voltage signals over high/low frequency voltage inputs and receiving analog measurement signals over multi-purpose inputs;

converting said analog voltage signals and said analog measurement signals into low frequency digital data;

monitoring said analog voltage signals to detect high frequency voltage signals representing high frequency voltage events;

converting said high frequency voltage signals into high frequency digital data;

processing said low frequency digital data by logging selected values of said low frequency digital data into at least one data log file; and

processing said low frequency digital data and said high frequency digital data by detecting events and logging said events in an event log file.

25. The method of claim 24 wherein receiving said analog voltage signals includes taking high frequency voltage measurements and low frequency voltage measurements over an isolated measurement circuit.

26. The method of claim 24 further including the step of buffering said high frequency digital data and said low frequency digital data prior to processing.

27. The method of claim 24 further including the step of configuring at least one of said multi-purpose inputs to receive different types of analog measurement signals.

28. The method of claim 27 wherein said analog measurement signals are selected from the group consisting of current signals, low frequency voltage signals, and environmental condition signals.

29. The method of claim 24 further including the step of receiving interactive test signals from an input and an output of a device.

30. The method of claim 24 further including the step of performing line impedance tests.