US20040186670A1 - Phasor transducer apparatus and system for protection, control, and management of electricity distribution systems - Google Patents

Phasor transducer apparatus and system for protection, control, and management of electricity distribution systems Download PDF

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Publication number
US20040186670A1
US20040186670A1 US10/613,410 US61341003A US2004186670A1 US 20040186670 A1 US20040186670 A1 US 20040186670A1 US 61341003 A US61341003 A US 61341003A US 2004186670 A1 US2004186670 A1 US 2004186670A1
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Prior art keywords
device
phasor
module
digital
network
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Abandoned
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US10/613,410
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Ronald Hart
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Hart Ronald G.
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Priority to US08/369,849 priority Critical patent/US5650936A/en
Priority to US79872397A priority
Priority to US10/068,431 priority patent/US6694270B2/en
Application filed by Hart Ronald G. filed Critical Hart Ronald G.
Priority to US10/613,410 priority patent/US20040186670A1/en
Publication of US20040186670A1 publication Critical patent/US20040186670A1/en
Application status is Abandoned legal-status Critical

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    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R22/00Arrangements for measuring time integral of electric power or current, e.g. by electricity meters
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01DMEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D4/00Tariff metering apparatus
    • G01D4/002Remote reading of utility meters
    • G01D4/004Remote reading of utility meters to a fixed location
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R19/00Arrangements for measuring currents or voltages or for indicating presence or sign thereof
    • G01R19/25Arrangements for measuring currents or voltages or for indicating presence or sign thereof using digital measurement techniques
    • G01R19/2513Arrangements for monitoring electric power systems, e.g. power lines or loads; Logging
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02HEMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H1/00Details of emergency protective circuit arrangements
    • H02H1/0061Details of emergency protective circuit arrangements concerning transmission of signals
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J13/00Circuit arrangements for providing remote indication of network conditions, e.g. an instantaneous record of the open or closed condition of each circuitbreaker in the network; Circuit arrangements for providing remote control of switching means in a power distribution network, e.g. switching in and out of current consumers by using a pulse code signal carried by the network
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01RMEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R21/00Arrangements for measuring electric power or power factor
    • G01R21/133Arrangements for measuring electric power or power factor by using digital technique
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B90/00Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02B90/20Systems integrating technologies related to power network operation and communication or information technologies mediating in the improvement of the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as enabling technology in buildings sector
    • Y02B90/24Smart metering mediating in the carbon neutral operation of end-user applications in buildings
    • Y02B90/241Systems characterised by remote reading
    • Y02B90/242Systems characterised by remote reading from a fixed location
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02BCLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B90/00Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02B90/20Systems integrating technologies related to power network operation and communication or information technologies mediating in the improvement of the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as enabling technology in buildings sector
    • Y02B90/24Smart metering mediating in the carbon neutral operation of end-user applications in buildings
    • Y02B90/248Systems oriented to metering of generated energy or power
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00Enabling technologies or technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/70Systems integrating technologies related to power network operation and communication or information technologies mediating in the improvement of the carbon footprint of electrical power generation, transmission or distribution, i.e. smart grids as enabling technology in the energy generation sector
    • Y02E60/72Systems characterised by the monitored, controlled or operated power network elements or equipments
    • Y02E60/727Systems characterised by the monitored, controlled or operated power network elements or equipments the elements or equipments being or involving measuring units
    • Y02E60/728Systems characterised by the monitored, controlled or operated power network elements or equipments the elements or equipments being or involving measuring units the measuring units being or involving phasor measuring units [PMU]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S10/00Systems supporting electrical power generation, transmission or distribution
    • Y04S10/10Systems characterised by the monitored, controlled or operated power network elements or equipment
    • Y04S10/26Systems characterised by the monitored, controlled or operated power network elements or equipment the elements or equipments being or involving measuring units
    • Y04S10/265Systems characterised by the monitored, controlled or operated power network elements or equipment the elements or equipments being or involving measuring units the measuring units being or involving phasor measuring units [PMU]
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00Systems supporting the management or operation of end-user stationary applications, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y04S20/30Smart metering
    • Y04S20/32Systems characterised by remote reading
    • Y04S20/322Systems characterised by remote reading from a fixed location
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04SSYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00Systems supporting the management or operation of end-user stationary applications, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y04S20/30Smart metering
    • Y04S20/52Systems oriented to metering of generated energy or power

Abstract

A phasor monitoring system and apparatus for use with a distribution system for electricity wherein periodic three phase electricity is distributed in a plurality of circuits. The phasor monitoring apparatus comprises a phasor transducer that has an input that receives analog signals representative of parameters of electricity in a circuit of the distribution system, an analog to digital converter that receives the analog signals and outputs a digital data signal representative of the analog signals, a processor coupled to the analog to digital converter to receive the digital data signal output from the analog to digital converter, programming on the processor that computes phasor data representative of the electricity in the circuit based on the digital data received from the analog to digital converter and provides a digital output representative of the phasor data, and a network-compatible port coupled to the processor to transmit the phasor data onto a data network coupled thereto. The phasor monitoring system comprises a data network interconnecting a plurality of phasor transducers each associated with one of the circuits of an electricity distribution system. A phasor array processor is connected to the data network and receives phasor data from a plurality of the phasor transducers connected to the network. The phasor array processor computes combined phasor data for the plurality based upon the phasor data received from the plurality of phasor transducers.

Description

    RELATED APPLICATIONS
  • This application is a continuation under 37 C.F.R. § 1.53(b) of U.S. application Ser. No. 10/068,431, pending, filed Feb. 6, 2002, incorporated by reference herein, which is a continuation under 37 C.F.R. § 1.53(b) of U.S. application Ser. No. 08/798,723, filed Feb. 12, 1997, abandoned, which is a continuation-in-part of U.S. application Ser. No. 08/369,849, filed Dec. 30, 1994, now U.S. Pat. No. 5,650,936, both of which are incorporated by reference herein. U.S. application Ser. No. 08/798,923 was filed on the same day as and incorporated by reference, U.S. patent application Ser. No. 08/798,724, now U.S. Pat. No. 5,995,911, entitled “DIGITAL SENSOR APPARATUS AND SYSTEM FOR PROTECTION, CONTROL, AND MANAGEMENT OF ELECTRICITY DISTRIBUTION SYSTEMS”, filed on Feb. 12, 1997 herewith, the entire disclosure of which is incorporated by reference herein.[0001]
  • REFERENCE TO COMPUTER PROGRAM LISTINGS SUBMITTED ON COMPACT DISK
  • A compact disk appendix is included containing computer program code listings pursuant to 37 C.F.R. 1.52(e) and is hereby incorporated by reference. The compact disk contains program code files in ASCII format. The total number of compact disks is [0002] 1 and the files included on the compact disk are as follows:
    Creation Creation File Size
    Date Time (Bytes) File Name
    Jan. 28, 2003 09:42p 993,526 PROB0113.S19
  • BACKGROUND
  • The present invention relates to systems and components for the protection, control, and/or energy management of electricity distribution systems for electric utility, industrial, manufacturing, commercial, and/or institutional use. [0003]
  • Monitoring of electric parameters, such as current, voltage, energy, power, etc., particularly the measuring and calculating of electric parameters, provides valuable information for power utilities and their customers. Monitoring of electric power is important to ensure that the electric power is effectively and efficiently generated, distributed and utilized. Knowledge about power parameters such as volts, amps, watts, phase relationship between waveforms, KWH, KVAR, KVARH, KVA, KVAH, power factor, frequency, etc., is of foremost concern for utilities and industrial power users. In addition, monitoring of electricity can be used for control and protection purposes. [0004]
  • Typically, electricity from a utility is fed from a primary substation over a distribution cable to several local substations. At the substations, the supply is transformed by distribution transformers from a relatively high voltage on the distributor cable to a lower voltage at which it is supplied to the end consumer. From the substations, the power is provided to industrial users over a distributed power network that supplies power to various loads. Such loads may include, for example, various power machines. [0005]
  • In such arrangements, utilities need to measure power coming out of or into the generating station or going into a power station. It is important to minimize the phase relationship between the current and voltage waveforms of the power being transmitted to minimize losses. It is also important to minimize the amount of harmonics that are present in the voltage and current waveforms. Also, the ability to detect the presence and magnitude of faults in the power system is important. Thus, accurate measurement of these waveforms is important. [0006]
  • In industrial applications, it is important to continuously monitor the voltage, current, phase, harmonics, faults and three phase balance of the power into the machine. These parameters may vary with the machine load. With knowledge of these parameters, the industrial user can better adjust and manage the loads to control machines, determine alarm conditions and/or more efficiently use the power. [0007]
  • Many protection, control, and metering functions in a modem power distribution system require concurrent knowledge of the states of multiple circuits in the system in order to work efficiently and effectively. Examples include differential protection devices and breaker coordination schemes. Conventional devices and systems have addressed these requirements by various coordination and data sharing arrangements. Many of these approaches suffer from cost, performance, reliability, security, and scalability problems. [0008]
  • Accordingly, it is an objective of the present invention to provide a system that overcomes the disadvantages of the prior art by providing a monitoring system that can be used for protection, control, and/or metering of electricity in a electric distribution system. [0009]
  • SUMMARY
  • To achieve the foregoing and other objectives, there is provided an improved phasor monitoring system and apparatus for use with a distribution system for electricity wherein periodic three phase electricity is distributed in a plurality of circuits. The phasor monitoring apparatus comprises a phasor transducer that has an input that receives analog signals representative of parameters of electricity in a circuit of the distribution system. The phasor transducer also includes an analog to digital converter that receives the analog signals and that outputs a digital data signal representative of the analog signals and a processor coupled to the analog to digital converter to receive the digital data signal output therefrom. Programming on the processor of the phasor transducer computes phasor data representative of the electricity in the circuit based on the digital data received from the analog to digital converter and provides a digital output representative of the phasor data. The phasor transducer also includes a network-compatible port coupled to the processor to transmit the phasor data onto a digital data network. [0010]
  • According to a further aspect, there is provided a phasor monitoring system for use with an electricity distribution system having a plurality of circuits. The phasor monitoring system comprises a data network interconnecting a plurality of phasor transducers. Each phasor transducer is associated with one of the circuits of the electricity distribution system. One or more phasor array processors are connected to the data network to receive phasor data from the plurality of phasor transducers connected to the network. The phasor array processor computes combined phasor data for the plurality of circuits in the electricity distribution system based upon the phasor data received from the plurality of phasor transducers. [0011]
  • According to a further aspect, associated with each of the circuits of the electricity distribution system is a protection device. The protection device is coupled to the data network. Each of the protection devices is also connected to a circuit breaker associated with one of the circuits. The protection device operates its respective circuit breaker based upon data instructions received over the data network.[0012]
  • BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is a diagram illustrating a distribution system for electricity incorporating embodiments of the present invention. [0013]
  • FIG. 2 is a schematic diagram of a phasor transducer device in FIG. 1. [0014]
  • FIG. 3 is a block diagram illustrating the functional program modules of the phasor transducer device shown in FIG. 2. [0015]
  • FIG. 4 is a block diagram illustrating the functional program modules of one of the phasor array processors shown in FIG. 1. [0016]
  • FIG. 5 is a diagram of a plurality of electric circuits used to illustrate an exemplary embodiment of the present invention. [0017]
  • FIG. 6 is a flow chart illustrating a first exemplary method for use with the embodiments depicted in FIGS. 1-4. [0018]
  • FIG. 7 is a flow chart illustrating a second exemplary method for use with the embodiments depicted in FIGS. 1-4. [0019]
  • FIG. 8 schematically represents a preferred embodiment of a system using a power monitoring unit of the present invention. [0020]
  • FIG. 9 schematically illustrates a preferred embodiment of a physical layout of a preferred embodiment of a system of the present invention. [0021]
  • FIG. 10 schematically illustrates a preferred embodiment of the internal structure of a power monitoring unit of the present invention. [0022]
  • FIG. 11 schematically illustrates a preferred embodiment of the data acquisition module and its respective registers. [0023]
  • FIG. 11A shows a flowchart of a preferred embodiment of the logic for the client portion of the data acquisition module. [0024]
  • FIG. 12 schematically illustrates a preferred embodiment of the power meter module and its respective registers. [0025]
  • FIGS. 12A-12L show flowcharts of a preferred embodiment of the logic for the client portion of the power meter module. [0026]
  • FIG. 13 schematically illustrates a preferred embodiment of the analog input module and its respective registers. [0027]
  • FIG. 13A shows a flowchart of a preferred embodiment of the logic for the client portion of the analog input module. [0028]
  • FIG. 14 schematically illustrates a preferred embodiment of the analog output module and its respective registers. [0029]
  • FIG. 14A shows a flowchart of a preferred embodiment of the logic for the client portion of the analog output module. [0030]
  • FIG. 15 schematically illustrates a preferred embodiment of the digital input module and its respective registers. [0031]
  • FIGS. 15A and 14B show a flowchart of a preferred embodiment of the logic for the client portion of the digital input module. [0032]
  • FIG. 16 schematically illustrates a preferred embodiment of the digital output module and its respective registers. [0033]
  • FIGS. 16A-16H show a flowchart of a preferred embodiment of the logic for the client portion of the digital output module. [0034]
  • FIG. 17 schematically illustrates the inheritance of the registers and modules. [0035]
  • FIG. 17A schematically illustrates the inheritance of some of the registers. [0036]
  • FIG. 17B schematically illustrates the inheritance of some of the modules. [0037]
  • FIG. 17C illustrates a hierarchical structure. [0038]
  • FIG. 18 schematically illustrates a preferred embodiment of the properties of the modules. [0039]
  • FIG. 19 schematically illustrates a preferred embodiment of the data flow for a module. [0040]
  • FIGS. 19A-19C show a flowchart of a preferred embodiment of the logic for the module operation. [0041]
  • FIG. 20 schematically illustrates a preferred embodiment of the AND/OR module and its respective registers. [0042]
  • FIGS. 20A and 20B show a flowchart of a preferred embodiment of the logic for the client portion of the AND/OR module. [0043]
  • FIG. 21 schematically illustrates a preferred embodiment of the Setpoint module and its respective registers. [0044]
  • FIGS. 21A-21C show a flowchart of a preferred embodiment of the logic for the client portion of the setpoint module. [0045]
  • FIG. 22 schematically illustrates a preferred embodiment of the EventLog module and its respective registers. [0046]
  • FIG. 22A shows a flowchart of a preferred embodiment of the logic for the client portion of the EventLog module. [0047]
  • FIG. 23 shows an example application using the object oriented structure of this invention. [0048]
  • FIGS. 24A and 24B show the operation of the Module Flow Controller. [0049]
  • FIG. 25 schematically illustrates a preferred embodiment of the analog output manager. [0050]
  • FIGS. 25A and 2513 show a flowchart of a preferred embodiment of the logic for the application of a manager. [0051]
  • FIG. 26 schematically illustrates a preferred embodiment of the feature manager. [0052]
  • FIGS. 26A and 26B show a flowchart of a preferred embodiment of the logic for the server portion of the feature manager. [0053]
  • FIGS. 27A-27C show a flowchart of a preferred embodiment of the logic for the operation of a boolean register. [0054]
  • FIGS. 28A and 28B show a flowchart of a preferred embodiment of the logic for the operation of an enumerated register. [0055]
  • FIGS. 29A and 29B show a flowchart of a preferred embodiment of the logic for the operation of a numeric register. [0056]
  • FIGS. 30A and 30B show a flowchart of a preferred embodiment of the logic for the operation of a numeric bounded register. [0057]
  • FIGS. 31-46 depict schematic diagrams of the presently preferred embodiments.[0058]
  • DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
  • 1. General [0059]
  • Referring to FIG. 1, there is illustrated a diagram of an electricity distribution system [0060] 10. The electricity distribution system 10 represents a typical distribution system that may be used in factories or utilities, or in industrial, commercial, manufacturing and/or institutional uses. For example, the system 10 may represent a part of a typical three-phase electric switchgear or an electricity distribution substation arrangement. Such an arrangement may be located in a manufacturing facility in which electrical energy is distributed to a plurality of loads, which may be various types of machines, motors, welding equipment, furnaces, mills, etc.
  • The distribution system [0061] 10 receives electric power over a power line 20 from an electric utility 21. In the electricity distribution system 10, three phase electric power is distributed over a plurality of three-phase electric circuits, such as electric circuits 14, 15, 16, 17, and 18. Although only five three-phase circuits are illustrated in FIG. 1, it is understood that the distribution system 10 may typically include many more such circuits.
  • As further illustrated in FIG. 1, one of the circuits, i.e. the circuit [0062] 14, is a main circuit. The main circuit 14 feeds electricity to a three-phase substation bus 19. Multiple feeder or branch circuits, such as the three-phase circuits 15, 16, 17, and 18, obtain the three-phase electric power from the substation bus 19. The feeder circuits 14, 15, 16, 17, and 18 distribute the electric power to a plurality of loads 25, 26, 27 and 28. (Note that instead of distributing electricity directly to a load, any of the feeder circuits, such as feeder circuits 15, 16, 17, and 18, may feed electricity to additional distribution feeder circuits which in turn may distribute electricity either directly to loads or to still additional feeder circuits. Also, note that the “load” for the main circuit 14 may be regarded as the combined loads of the feeder circuits 15-18.) The electricity distribution system 10 may also include numerous other components found in typical installations, such as switches and transformers.
  • Voltage sensors and current sensors are associated with each of the circuits. In one embodiment, a voltage sensor and a current sensor are associated with each of the phase conductors of each the circuits. For example, voltage sensors [0063] 29 and current sensors 30 are associated with the three phase conductors of the main circuit 14; voltage sensors 31 and current sensors 32 are associated with the three phase conductors of the feeder circuit 15, and so on. Also associated with each of the electric circuits 14, 15, 16, 17, and 18, is a circuit breaker, such as circuit breakers 44, 45, 46, 47, and 48. Although each of the circuits in the system 10 of FIG. 1 has voltage and current sensors associated with it, in alternative embodiments, the electric distribution system 10 may include additional electric circuits that do have voltage and current sensors associated with them. In one embodiment, the voltage and current sensors 29 and 30 associated with each circuit sense the power waveform for that circuit and provide an analog output representative thereof. In addition, although the embodiment of FIG. 1 shows voltage sensors and current sensors associated with each of the circuits in the installation, in alternative embodiment, some or all of the circuits may have only current sensors and no voltage sensors and similarly, some or all of the circuits may have voltage sensors and no current sensors.
  • 2. Phasor Transducer [0064]
  • Referring still to FIG. 1, associated with each of the circuits is a phasor transducer. For example, associated with the main circuit [0065] 14 is a phasor transducer 50, associated with the feeder circuit 15 is a phasor transducer 51, and so on. Each phasor transducer is connected to receive the outputs from the voltage and current sensors associated with its respective circuit. For example, the phasor transducer 50, which is associated with the main circuit 14, is connected to and receives the outputs from the voltage sensors 29 and the current sensors 30; the phasor transducer 51, which is associated with the branch circuit 15, is connected to and receives the outputs from the voltage sensors 31 and the current sensors 32; and so on. Each of the phasor transducers is connected to a digital data transmission network 60, as described in more detail below.
  • Referring to FIG. 2, the branch circuit [0066] 15 is shown to comprise three phase conductors, 15A, 15B, and 15C. The voltage sensors 31 are shown to comprise individual voltage sensors 31A, 31B, and 31C, each associated with its own respective phase conductor. The current sensors 32 are shown to comprise the three current sensors, 32A, 32B, and 32C, each associated with its own respective phase conductor, 15A, 15B, and 15C. The current sensors 32 also include the current sensor 32D which is associated with the ground or neutral conductor in the circuit 15 and which measures the ground or neutral current in the circuit 15. In one embodiment, the voltage and current sensors may be implemented using conventional technology. For example, the voltage sensors may be conventional voltage transformers (e.g. PT's) and the current sensors may be conventional current transformers (e.g. CT's). (In low voltage systems the PT's may be omitted.)
  • FIG. 2 shows a block diagram of the phasor transducer [0067] 51. The other phasor transducers, 50, 52, 53, and 54, as well as any other phasor transducers that may be associated with other circuits in the system 10, may be similar or identical in construction to the phasor transducer 51. The phasor transducer 51 has a plurality of inputs 59A-59G to which the outputs of the voltage sensors 31 and current sensors 32 are coupled. The phasor transducer S1 includes a conditioner unit 62. The conditioner unit 62 receives the voltage and current sensor signals from the inputs 59A-59G. The conditioner unit 62 comprises two parts: a voltage conditioner stage 62A and a current conditioner stage 62B. Each of the voltage signals, V1, V2, and V3, received from the voltage sensors 31A, 31B, and 31C via the inputs 59A, 59B, and 59C are separately conditioned in the voltage conditioner stage 62A to provide low level analog signals. Each of the current signals, 11, 12, 13, and 14, received from the current sensors 32A, 32B, 32C, and 32D via the inputs 59D, 59E, 59F and 59G are separately conditioned in the current conditioner stage 62B to provide low level analog signals.
  • The low level analog signals from the conditioner unit [0068] 62 are sent to a multiplexer 64. The multiplexer 64 includes two parts or stages: a first stage 64A of the multiplexer 64 receives the low level analog signals representing the voltage signals from the voltage conditioning stage 62A and a second stage 64B of the multiplexer 64 receives the low level analog signals representing the current signals from the current condition stage 62B.
  • Each stage of the multiplexer [0069] 64 operates to select in turn which of the conditioned analog signals from the conditioner unit 62 is to be output from the multiplexer 64 to an analog to digital converter 70. The analog to digital converter 70 includes two portions: a first analog to digital converter portion 70A and a second analog to digital converter portion 70B. The first analog to digital converter portion 70A receives the output of the first stage 64A of the multiplexer 64, including the selected one of the voltage signals. The second analog to digital converter portion 70B receives the output of the second stage 64B of the multiplexer 64 including the selected one of the current signals, I1, I2, I3, and I4. The analog to digital converter 70 repeatedly samples the analog signals and converts the samples to digital value outputs 76 and 78 which represent the magnitudes of the analog voltage and current signals at the instant that they were sampled. The digital value outputs 76 and 78 generated by the analog to digital converter 70 are output to buffers 82. The digital value outputs 76 and 78 are retrieved from the buffers 82 by a digital signal processor 90 which computes phasor data 92 and 94 from the digitally-sampled data, as explained further below. The digital signal processor 90 outputs the phasor data 92 and 94 to a phasor transducer local microprocessor 100.
  • The phasor transducer local microprocessor [0070] 100 is coupled to one or more communication ports 110 that connect the phasor transducer 51 to the network 60. The communication port 110 may be a conventional network-compatible port such as a 10 base T ethernet port. The phasor transducer 51 may, optionally, include a local display 112 coupled to the local microprocessor 100. The local display 112 may be used to provide a local visual display of data, including volts, amps, watts, vars, power factor, frequency, etc., as well as provide energy consumption recording of kwh, kvarh, kvah import, export and totals for each circuit, or any combination of circuits. The phasor transducer 51 may also include auxiliary local I/O ports 114 also coupled to the local microprocessor 100.
  • The phasor transducer [0071] 51 also includes a local synchronization circuit 120. In a preferred embodiment, the local synchronization circuit 120 utilizes two processes to provide a highly accurate local synchronization timing clock signal 121 internal to the phasor transducer. First, the local synchronization circuit 120 receives a network synchronization signal 122 on an input port, such as data port 110, which is connected to the network 60. This network synchronization signal 122 (which may be in a conventional UNIX time format) is generated by a network timing reference 123 coupled to the data network 60. The network synchronization signal 122 synchronizes the synchronization circuit 120 to within approximately 10 to 200 milliseconds.
  • Referring to FIGS. 1 and 2, in a preferred embodiment, the synchronization circuit [0072] 120 also receives a GPS-signal 126. The GPS-signal 126 is obtained from a GPS receiver system 127. The GPS-signal 126 is provided to each of the phasor transducers 51-54 used in the electricity distribution system 10. The GPS receiver system 127 may be a conventional type of GPS receiver that obtains GPS information and provides the GPS signal 126 as an output. In one embodiment, a single GPS receiver may be used for the entire installation containing the electricity distribution system 10. Alternatively, more than one GPS-receiver 127 may be used in the installation containing the electricity distribution system 10 and some of the phasor transducers may be coupled to receive a GPS signal from one of the GPS receivers and others of the phasor transducer may receive a GPS signal from another of the GPS receivers. A single GPS receiver may be appropriate if the installation containing the electricity distribution system 10 does not cover too large a geographic area since propagation delays from the GPS receiver to the phasor transducers should be taken into account. The GPS output signal 126 may be distributed to each of the phasor transducers by a suitable communication means, such a twisted pair, coaxial cable, wireless, and so on. In a still further embodiment, each of the phasor transducers 51-54 may have its own GPS receiver located internally thereto.
  • The GPS-signal [0073] 126 is used to fine tune the local synchronization circuit timing clock signal 121 to within approximately 1 microsecond. Using both the network synchronization signal 122 and the GPS signal 126, the local synchronization circuit 120 outputs the local synchronization timing clock signal 121 to the local microprocessor 100 and to the analog-to-digital converters 70A and 70B.
  • The local microprocessor [0074] 100 receives the phasor data 92 and 94 from the digital signal processor 90 and applies a time stamp to the data using the local synchronization signal 121 from the synchronization circuit 120. The local microprocessor 100 outputs the phasor data as digital data and transmits the phasor data output in real time via the ports 110 onto the network 60. Optionally, the local microprocessor 100 may process some or all of the phasor data prior to transmitting them in real time over the network 60, as explained below.
  • 3. The Data Network [0075]
  • As mentioned above in connection with FIG. 1, the phasor transducers [0076] 50, 51, 52, 53 and 54 are connected to the data transmission network 60. The data transmission network 60 provides real time data communication among the various components connected to the network. The data transmission network 60 may be implemented using conventional local area network (LAN) or wide area network (WAN) technology. The network 60 may use conventional communications protocols, such as point-to-point or multi-point data transmission. The network 60 should be able to sustain the data flow generated by the various devices. Data propagation times should be short, deterministic and reliable.
  • Also connected to the data transmission network [0077] 60 are at least one and preferably several phasor array processors, such as a first phasor array processor 130, a second phasor array processor 131, a third phasor array processor 132 and so on. These phasor array processors 130, 131, and 132 are connected as nodes on the network 60. It is understood that although only three phasor array processors are illustrated in FIG. 1, there may be many more phasor array processors connected to the network 60 in a typical embodiment. The structure and function of the phasor array processors are explained below.
  • The data transmission network [0078] 60 enables real time data communication between each of the phasor transducers 50, 51, 52, 53, and 54 and the phasor array processors 130, 131, and 132. In addition, in a preferred embodiment, the data transmission network 60 enables data communication between the phasor array processors 130, 131, and 132, and further, the data transmission network 60 enables communication among the phasor transducers, if desired, and between the phasor transducers and the second and third phasor array processors 131 and 132. Still further, the first phasor array processor 130 may be connected to local computers or remote computers, such as 136, 137, and 138, that are also connected to the network 60, either locally or remotely. There may also be connected to the network other equipment such as programmable logic controllers and digital control systems.
  • In one embodiment, a TCP/IP ethernet communications network is used. TCP/IP ethernet is used due to its high data throughput capabilities and its ability to be easily segmented to control data loading and propagation times. For example, if each phasor transducer computes and transmits voltages and current phasor arrays for all three phases of every cycle, and each phasor array has typically six elements for the odd harmonics, 1 to 11, the data throughput required per phasor traducer is approximately 300 kbaud including overheads. If a typical substation has sixteen circuits, then the total data throughput would be about 4800 kbaud. This is within the capabilities of LAN or WAN technology, such as 10 base T ethernet, asynchronous transfer mode (ATM), or FDDI. [0079]
  • In alternative embodiments, the network may include digital radio or fiber optic data transmission techniques to couple the data. These alternatives also provide the advantage of providing electrical isolation between the various transducers, phasor array processor, and other nodes. [0080]
  • 4. The Phasor Array Processor [0081]
  • The phasor array processors, [0082] 130, 131, and 132, are microprocessor or computer-based devices that function as nodes to receive data over the network 60 from the phasor transducers or from other phasor array processors. For example, any one or more of the phasor array processors may include the appropriate hardware and software to receive and process data from the phasor transducers, such as the data output from the phasor transducer 51 on its output ports 110 in FIG. 2.
  • Each of the phasor array processors may be implemented using a general purpose computer platform, such as an IBM-compatible personal computer. Alternatively, the phasor array processors may be implemented using a custom-designed computing device. A custom-designed computing device may be used for higher performance for specific tasks. Custom-designed devices may include multiple processors or digital signal processors for very fast computational capabilities. A task-specific hardware platform, such as a 7700 ION, manufactured by Power Measurement Ltd., of Victoria, BC, may be used. [0083]
  • The phasor array processor is preferably equipped with suitable hardware, such as RS-232, RS-485, ethernet or other industry standard communications ports, so that it is network-compatible with the network [0084] 60. The phasor array processor 130 may also be equipped With multiple communication ports which would allow it to connect to multiple phasor transducer devices or multiple central computers, or to allow multiple phasor array processors to be connected to a remote computer.
  • 5. Protection Devices on the Data Network [0085]
  • Also connected to the data transmission network [0086] 60 are one or more protection devices (also referred to as protection device nodes). In one embodiment, a protection device is associated with each of the circuits. For example, a first protection device 184 is associated with the first circuit 14, a second protection device node 185 is associated with the second circuit 15, and so on. Alternatively, there may be more or fewer protection devices than circuits. The protection devices are microprocessor or computer-based devices or nodes that can receive data over the network 60 from the phasor transducers 50-54 or the phasor array processors 130-132, as well as from other devices on the network 60. In a preferred embodiment, the protection devices process data using object-oriented program modules, as explained in more detail below.
  • The protection devices may be implemented using a general purpose computer platform. For example, the protection device node may implemented on an IBM-compatible personal computer or on a task-specific hardware platform. Each protection device is preferably equipped with suitable hardware, such as RS-232, RS-485, ethernet or other industry standard communications ports, so that it is network-compatible with the network [0087] 60. Each of the protection devices has one or more outputs that are connected to the circuit breakers associated with the circuit. In the embodiment wherein there is one protection device for each circuit, each of the protection devices may have a single output coupled to its respective circuit breaker for its respective circuit. For example, the output of the first protection device 184 is connected to the circuit breaker 44 associated with the main circuit 14, the output of the protection device 185 is connected to the circuit breaker 45 associated with the branch circuit 15, and so on. In the alternative embodiment where there are fewer protection devices than circuits, at least one of the protection devices has more than one output and is coupled to more than one of the circuit breakers.
  • The protection devices may be coupled directly to the circuit breakers, or alternatively, each of the protection devices may have a data output that is coupled to the data network [0088] 60. In this latter embodiment, the circuit breakers 44-48 each have a port coupled to the network 60 to receive data addressed thereto from the one or more protection devices.
  • In one embodiment, a first protection device operates to provide outputs to some or all of the circuit breakers in the distribution system. Another protection device operates to back up the first protection device. According to this embodiment, the second protection device is configured similar to the first protection device so that its operation follows that of the first protection device. The second protection device takes over for the operation of the first protection device if the first protection device fails. [0089]
  • 6. Operations and Program Objects [0090]
  • The phasor array processors have four principle functions: protection, control, energy management, and systems diagnostics. An individual phasor array processor can provide any combination of these functions depending on the hardware, software, and/or software/firmware and the requirements of the user. [0091]
  • According to a present embodiment, the phasor transducers and phasor array processor(s) include appropriate software, such as programming and logic, to implement the desired functions, features, and operations. The software may be implemented in alternative ways including various programming languages, scripts, and architectures, and combinations of software and firmware, etc. In one preferred embodiment, the phasor transducers, phasor array processors, and other components on the network [0092] 60 interact internally and with each other using an object-oriented programming architecture. One preferred object-oriented programming approach is disclosed in the copending patent application Ser. No. 08/369,849, now U.S. Pat. No. 5,650,936, the entire disclosure of which, including the microfiche appendix, is incorporated by reference herein and the text of which is replicated below.
  • If a phasor array processor is implemented using an IBM-compatible personal computer, the personal computer may run the Virtual ION Processor software developed by Power Measurement Ltd. of Victoria, BC. This software allows standard ION modules to be implemented on an IBM-compatible personal computer. The ION communication architecture allows the inputs or outputs of any ION module on the phasor array processor to be linked to the inputs or outputs of any ION module on the phasor transducers via standard communications networks. [0093]
  • ION Architectural Description (Incorporated from U.S. Pat. No. 5,650,936) [0094]
  • An object oriented architecture is used within individual monitoring units. The monitoring devices include circuitry which receives an electrical signal and generates at least one digital signal representing the electrical signal. Objects within such individual monitoring units include modules which perform a function and registers which contain the inputs, outputs and setup information for the modules. Methods can be invoked on all objects to change or query the operation or configuration of the device. At least one of the modules receives the digital signal as an input and uses the signal to generate measured parameters. Additional modules take measured parameters as input and generate additional parameters therefrom. The module may be linked in an arbitrary manner to form arbitrary functional blocks. [0095]
  • The present embodiments relate generally to digital power monitoring. More specifically, the embodiments relate to a digital power monitoring system using an object oriented structure. The present embodiments also generally relate to an improved object oriented structure. [0096]
  • Monitoring of electrical power, particularly the measuring and calculating of electrical parameters, provides valuable information for power utilities and their customers. Monitoring of electrical power is important to ensure that the electrical power is effectively and efficiently generated. distributed and utilized. As described in more detail below, knowledge about power parameters such as volts, amps, watts, phase relationship between waveforms, KWH, KVAR, KVARH, KVA, KVAH, power factor, frequency, etc. is of foremost concern for utilities and industrial power users. [0097]
  • Typically, electricity from a utility is fed from a primary substation over a distribution cable to several local substations. At the substations, the supply is transformed by distribution transformers from a relatively high voltage on the distributor cable to the lower voltage at which it is supplied to the end consumer. From the substations, the power is provided to industrial users over a distributed power network which supplies power to various loads. Such loads may be, for example, various power machines. [0098]
  • In such arrangements, utilities need to measure power coming out of the generating station or going into a power station. It is also important to minimize the phase relationship between the current and voltage waveforms of the power being transmitted to minimize losses. Thus, accurate measurement of these waveforms is important. [0099]
  • In industrial applications, it is important to continuously monitor the voltage, current and phase of the power into the machine. These parameters may vary with the machine load. With knowledge of these parameters the industrial user can better adjust, and control the loads to control machines, determine alarm conditions and/or to more efficiently use the power. [0100]
  • Various different arrangements are presently available for monitoring, measuring, and controlling power parameters. Typically, an individual power measuring device which measures specific power system parameters is placed on a given branch or line proximate one of the loads. Such power monitoring devices measure electrical power parameters, such as those described above. [0101]
  • An example of such a system is disclosed in U.S. Pat. No. 5,151,866. In the system disclosed in this patent, a power analyzer system uses discrete analog transducers to convert AC voltage and current signals from a power system to DC output signals. The values from the voltage and the current transducers are then used to calculate the various other desired power parameters. [0102]
  • In addition to monitoring power parameters of a certain load, power monitoring devices have a variety of other applications. For example, power monitoring devices can be used in supervisory control and data acquisition systems (SCADA), process controllers (PLC), etc. [0103]
  • As discussed briefly above, in industrial applications, a plurality of the power monitoring units are placed on the branches of a power distribution system near the loads. The monitoring units are connected through a communication network to at least one central computer. An example of such system is disclosed in Siemens Power Engineering & Automation VII (1085) No. 3, Pg. 169, Microprocessor—Based Station Control System For New And Existing Switchgear, Muller et al. [0104]
  • In fact, many other applications also use a network of devices interconnected through some sort of communication media. Often, the network is composed of a large number of slave devices with a much smaller number of master devices. A master device is any device that can query another device or change the configuration of another device. A slave device is a device that performs a function, and produces results that can be accessed by another device. It is possible for a single device to act as a master and a slave. In the power monitoring system described above, the central computer is the master device and the individual power monitoring units are the slave devices. [0105]
  • The architecture of the slave devices is such that they contain a large number of registers. Some of these registers contain output values from the slave device which can be read by the master and some of these registers contain setup information for the slave device which the master can read or write. The master device must know which registers contain which information for every different slave device. For instance the master device would know that a certain device measures volts and it would know that volts are stored in a particular register. Therefore, in order for the master to retrieve a reading of volts from the slave device it must send a request (communications packet) to the slave device indicating that it requires a packet containing the number in the respective register. [0106]
  • With this approach, the master device(s) must have a large amount of knowledge about the configuration of the remote devices. This requires large amounts of storage space on the master device(s). Also, if the characteristics of a slave device are changed, or a new type of slave device is added, the master device(s) must be reprogrammed. If the slave devices go through a large number of changes, the master device(s) must retain information about the slave devices for all intermediate versions to retain backward compatibility. This further increases the memory and processing power requirement for the master device(s). [0107]
  • In the configuration where the slave device is field programmable, the master device(s) must have some means of determining the slave device's current configuration. In addition the master device(s) must be able to change the slave device's configuration. This invariably means that the master device(s) must know all the possible configurations of the remote device which again increases the memory and processing power required for the master device. [0108]
  • Further, if there are multiple masters changing the configuration of the same slave device, it is difficult for the masters to keep track of the current configuration of the device. Each master has its own local copy of the current configuration of the slave device. When another master changes the configuration of the device, the first master's local copy is not updated. Thus, the first master may think the device is executing a function it no longer is. [0109]
  • If the configuration of a slave device is not configurable or if the slave device has limited configurability, the slave device may be using its available resources (memory and processing power) to perform functions that the user has no interest in. Therefore, the slave device may perform many functions that are not required, but may be missing some functions that are required by a certain user. [0110]
  • Systems are available which use an object oriented approach to program a computer to connect the outputs of a number of remote devices to local functions on the computer and to the inputs of other devices. US. Pat. Nos. 4,901,221, 4,914,568 and 5,155,836 disclose such systems where a central digital computer is connected to a number of remote devices. In the systems disclosed in these patents, however, the object oriented structure resides on the central digital computer and all information must travel through the central computer. Therefore, the speed of the system is limited to the speed of the communications channels between the computer and the remote devices and the speed of the computer. Further, although the structure on the computer can be modified through the object oriented architecture the slave devices cannot be easily modified or updated. [0111]
  • Systems are also available which allow reprogramming of a slave device. For example, such a system is disclosed in U.S. Pat. No. 5,155,836. The controlling logic within these devices, however, does not allow the reconfiguration of the device while other functions within the device continue to operate. The user must compile and download firmware in order to implement a different control program. The downloading process interrupts the operation of the device. [0112]
  • Therefore, in view of the above it is a primary object of the present embodiments to provide a power monitor which can be readily configured to exactly match a user's unique requirements. [0113]
  • It is a further object of the present embodiments to provide a power monitoring system where it is not necessary to change the software on a master device when a slave device is upgraded. [0114]
  • It is a further object of the present embodiments to provide a power monitoring system where the storage space memory and/or processing power required for master device(s) is minimized. [0115]
  • It is still a further object of the present embodiments to provide a power monitoring system where master device(s) can accurately and easily track changes or modifications in the configuration of individual monitoring units devices. [0116]
  • To achieve these and other objectives, the present embodiments use an object oriented architecture within individual digital devices, such as monitoring devices. The monitoring devices include circuitry which receives an electrical signal and generates at least one digital signal representing the electrical signal. Objects within such individual monitoring units include modules which perform a function and preferably registers which contain the inputs, outputs and setup information for the modules. Methods can be invoked on all objects to change or query the operation or configuration of the device. At least one of the modules receives the digital signal as an input and uses the signal to generate measured parameters. Additional modules take measured parameters as input and generate additional parameters therefrom. [0117]
  • In one preferred embodiment, the monitoring device includes transducers which measure voltage and current from a power line. [0118]
  • In another preferred embodiment, a flow controller is used to control the operation of the modules. A feature manager provides a means for accessing the entire device. [0119]
  • Since, the objects reside inside the individual slave devices the communication between the different objects is limited only by the processing speed of the individual monitoring units and not by the speed of the communications media between the devices. With this arrangement the number of slave devices connected to a single master is virtually unlimited since no communication between the devices is required unless a specific request from the user is made. [0120]
  • The operations that the monitoring unit performs are configured by a master device executing methods which instruct the monitoring unit to connect modules to registers. The objects can be programmed and linked in totally arbitrary ways, enabling the user to build arbitrary functional blocks consisting of networks of objects. [0121]
  • Many modifications to the preferred embodiment will be apparent to those skilled in the art. It is the intention of this description to provide an example system using the disclosed embodiments. [0122]
  • The present embodiments comprise a novel system with an object oriented structure. The novel system and architecture are particularly useful for configuring a power monitoring unit to perform given functions and causing the unit to execute those functions. [0123]
  • FIG. 8 schematically illustrates how a power monitoring unit [0124] 900 using the present embodiments is connectable to a three wire power line. Three current transducers (CTs) 902A, 902B and 902C are connected to wires 901A, 901B and 901C of the power line, respectively. Potential transducers (PTs) 904A and 904B are connected between lines 901A, 901B and 901B, 901C, respectively. A plurality of fuses 906 are disposed between the lines 901A-901C and Pts 904A and 904B. Fuses 910 are connected between Pts 904A and 904B and unit 900.
  • The CTs [0125] 902A-902C are connected through a shorting switch or test block 908 to the power monitoring unit 900. The CTs 902A-902C provide the power monitoring unit 900 with current inputs 111-132. The PTs 904A and 904B provide the power monitoring unit 900 with voltage inputs V1-V3. Current inputs I41 and I42, chassis ground 912 and voltage input VREF are connected to ground potential. The unit 900 is connected to a power supply, such as a standard 120 V AC supply, through power leads L and N.
  • FIG. 9 shows a preferred embodiment of the physical layout of a plurality of monitoring units [0126] 900 in a system using the present embodiments. The system comprises one or more personal computers (PCs) 914 which are used as master devices. A plurality of monitoring units 900 configured as intelligent electronic devices (IEDs) are used as slave devices. Virtual intelligent electronic devices (VIEDs) 915 which reside in software on the personal computer 914 can also serve as slave devices. All devices in the system are interconnected through a communication network 916. The network may be directly connected to devices or may connect through other communications devices such as modems 912. Preferably, the IEDs, PCs and VIEDs all have an object oriented architecture as described in detail below.
  • To fully appreciate the present embodiments, an understanding of the principals of basic object oriented structures is necessary. Therefore, a brief description of the type of architecture is given here. (A more detailed discussion of the principles of object oriented structures is given in “SMALLTALK-80 The Language And Its Implementation,” Goldberg and Robson, 1983 (from which some of the following definitions are taken)). An object consists of some private memory and a set of operations. An object has state, behavior and identity. The nature of the object's operations depends on the type of component it represents. For example, objects representing numbers compute arithmetic functions, and objects representing data structures store and retrieve information. A key component of object oriented architecture is encapsulation. Encapsulation is the process of hiding all of the details of an object, as well as the implementation of its methods. In an object oriented system, in order for an object to carry out one of its operations, a request must be made which specifies which operation is desired. The request is called a “message”. Importantly, because of encapsulation in object oriented architecture, the message does not specify how that operation is to be carried out. The “receiver”, the object to which the message was sent, determines how to carry out the requested operation. The set of messages to which an object can respond is called its “interface” with the rest of the system. The only way to interact with an object is through its interface. A crucial property of an object is that its private memory can be manipulated only by its own operations. Messages are the only way to invoke an object's operations. These properties ensure that the implementation of one object cannot depend on the internal details of other objects, only on the messages to which they respond. [0127]
  • Messages ensure the modularity of the system because they specify the type of operation desired, but not how the operation should be accomplished. [0128]
  • Other important components of object oriented architecture are “classes” and “instances”. A class describes the implementation of a set of objects that all represent the same kind of component. The individual objects described by a class are called its instances. A class describes the form of its instances' private memories and it describes how they carry out their operations. Even an object that represents a unique component is implemented as a single instance of a class. The instances of a class are similar in both their public and private properties. An object's public properties are the messages that make up its interface. All instances of a class have the same message interface since they represent the same kind of component. An object's private properties are a set of instance variables that make up its private memory and a set of methods that describe how to carry out its operations. The instance variables and methods are not directly available to other objects. The instances of a class all use the same set of methods to describe their operation. [0129]
  • Each method in a class tells how to perform the operation requested by a particular type of message. When that type of message is sent to any instance of the class, the method is executed. A class includes a method for each type of operation its instances can perform. The method may specify some changes to the object's private memory and/or some other messages to be sent. A method also specifies a value that should be returned. An object's methods can access the object's own instance variables, but not those of any other objects. [0130]
  • Another important aspect of the objects within the device is that they are independent or autonomous. In other words, any change in the configuration of one object on a slave by a master device does not affect the operation of the other objects on the slave device (or and objects on the master device). [0131]
  • Referring now to FIG. 10, a preferred embodiment of the internal structure of an IED [0132] 900 is illustrated. As described in more detail below, the IED's 900 are run by an object oriented structure. The electrical signals (i.e. the voltage and current) from the power lines are used by a detector to generate digital signals which represent the electrical signals. In the illustrated embodiment, the detector is comprised of the CTs 902, PTs 904, conditioning circuitry and A/D converters, as described more fully below. Three-phase voltage and current input signals V1-V3 and I1-I4 from electric power lines enter the motherboard 825 and are converted to voltage levels compatible with the analog to digital converters (A/Ds) 829 and 830 by signal conditioning circuitry 823. In an exemplary embodiment a suitable A/D convertor is a 13 bit, 7 input one available from National Semiconductor as model No. LM12458. A suitable voltage to the A/D's 829 and 830 ranges from 0 to 5 Volts depending on what part of the AC signal the sample is taken at and the level of the AC signal.
  • In the illustrated embodiment, the signal conditioning circuitry comprises operational amplifiers (op amps) [0133] 860, 862 and 864 and associated circuitry which amplify V1, V2 and V3 respectively. The currents I1, I2, and I3 are amplified by two different scales to provide greater dynamic range. The amplification to the two different scales is implemented using the conditioning circuitry 823. Op amps 866A, 866B and 866C amplify input current signals I1, I2 and I3, respectively, to a first scale. For example, a current of 5 Amperes AC creates a voltage of 4 Volts AC to the A/D converter. Op amps 868A, 868B and 868C amplify input current signals I1, I2 and I3, respectively to a second scale. For example, a current of 100 Amperes AC creates a voltage of 4 Volts AC to the A/D converter. The voltage and current signals enter separate A/Ds 829 and 830 so that the voltage and current on a particular phase can be simultaneously sampled. Auxiliary Input Signals 820 on the AUX board 824 also pass through signal conditioning circuitry 822 and to A/D 829. Auxiliary inputs allow the user to sample additional signals in addition to the three-phase voltage and current. For example, the auxiliary inputs may be 0 to 10 Volts DC outputs from a temperature transducer.
  • A digital signal processor (DSP) [0134] 828 reads the samples from the A/D converters 829, 830 through the A/D Bus 831. The signals are preferably sampled at the rate of 128 samples per line frequency cycle. The DSP performs a Fast Fourier Transform (FFT) on the samples to determine the frequency components of the signal in a manner known in the art. It also calculates Root Mean Square (RMS) voltage and/or current for each input signal. This data is then transferred through dual port RAM 827 to the microcontroller 835. A suitable DSP is a 4 K byte RAM available as a TMS320C25 available from Texas Instruments.
  • The microcontroller [0135] 835 performs many functions within the IED. The fundamental frequency to square wave converter 843 provides a square wave at the fundamental frequency of the incoming voltage signals. A suitable fundamental frequency to square wave converter is an LM311D available from National Semiconductor configured in a manner known in the art. A time processing unit (TPU) within the microcontroller 835 measures this frequency and multiplies it by a predetermined value, such as 128. The TPU creates an A/D sample clock 842 at this new frequency so that the A/Ds sample at 128 samples per cycle. A suitable microcontroller is a MC68332ACFC16 available from Motorola.
  • Different AUX boards [0136] 824 and motherboards 825 can be exchanged with different CPU Boards 846. This, however presents a calibration problem. In the system of the present embodiments, the calibration information for the circuitry 822, 823 of each AUX or motherboard is preferably stored on the individual board. A suitable EEPROM in a 93LC56 available from Microchip. This is implemented by storing the information in calibration constants EEPROM 839, 840 on each individual board. The microcontroller 835 then reads the information using the synchronous serial communications bus 838 before performing calculations on the values received through the dual port RAM 827 from the DSP 828. The synchronous serial communications bus 838 is also used to communicate with the display 851. Results of all calculations and control functions of the microcontroller 835 can be displayed on the display.
  • The IED [0137] 900 connects to the network 916 through the communications board 848. The microcontroller 835 sends and receives information over the serial communications bus 847.
  • A further description of a preferred embodiment of the present embodiments and its operation is given in U.S. patent application Ser. No. 08/367,534, now U.S. Pat. No. 5,736,847, filed Dec. 30, 1994 and entitled “High Accuracy Power Monitor and Method” which is incorporated herein by reference. [0138]
  • FIGS. 11, 12, [0139] 13, 14, 15 and 16 show how the auxiliary input signals 820, the voltage and current input signals 821, and the digital I/O signals 844 may be represented in the object oriented structure of this embodiments. In an exemplary embodiment, in the IED 900 the logic or code is implemented in firmware and in the PC the code is implemented in software. It will, of course, be recognized by those skilled in the art that the logic for the IED 900 can also be implemented in software and that the logic in the PC can be implemented in firmware. In the present embodiment, the firmware is implemented using a 512 K byte flash EEPROM 834 available from Intel as a 28F010 EEPROM. In an exemplary embodiment, the software is written in the C programming language. An exemplary embodiment of the logic for the object oriented architecture of the present embodiments in object code is given in CD-ROM Appendix which is incorporated herein by reference and which corresponds to the code included in the microfiche appendix of U.S. Pat. No. 5,650,936, referred to above. The object code is presented in Srecord format which is defined in the M68332BUG Debug Monitor User's Manual (Motorola 1990) which is incorporated herein by reference. More detailed schematics for the presently preferred embodiment are given in FIGS. 31-46.
  • In the system of the present embodiments, two fundamental classes exist for objects: 1) registers and 2) modules. Both the registers and modules are derived from a common base class (class=1). The registers are passive data storage objects containing a single value, an array or structure. Registers behave only as “servers” in the architecture. A “server” is defined as an entity which can respond to method invocations. A “client”, on the other hand, is an entity which can invoke a method on a server. Modules behave both as client and server. The client portion of the module contains the active components that perform the various tasks within the device. The inheritance of the registers and modules is shown in FIG. 17. An inheritance diagram for some of the registers is shown in FIG. 17A. An inheritance diagram for some of the modules is shown in FIG. 17B. Data passing between objects is accomplished using method invocation using “types,” where types define the semantics for passing data between objects. A method is invoked by a “client” sending a message to another object. This message contains a “method” and may contain a “value”. Every method in an object has a security level. Any methods which are invoked with a level less than the security level for that method will fail. The system also has the following set of rules of operation which must be followed by objects: [0140]
  • 1. All data passed to or from an object must have a Type. [0141]
  • 2. Modules must be owned by a module, with the exception of the root module, which has no owner. [0142]
  • 3. Registers must be owned by a module. [0143]
  • 4. Behavior of servers will be consistent for multiple clients. [0144]
  • 5. A server portion of a object cannot access the server portion of another object. [0145]
  • 6. A client portion of an object cannot access the client portion of another object. [0146]
  • 7. Any register or module cannot be destroyed if it is owned by any module. [0147]
  • The system also has a hierarchy. As used herein a hierarchy means that every manager, module and register can be accessed by starting at the top of the hierarchy. This concept can be seen pictorially by referring to FIG. 17C. In this figure modules or registers that appear as setup registers are connected to the bottom of the modules or managers with a line. Registers that appear as output registers are connected with lines to the right side of the modules and registers that appear as input registers are connected with lines to the left of the modules. [0148]
  • Certain semantics are needed for passing information to and from modules and registers. Here these semantics are defined by “Types”. Table A provides the Types defined in the presently preferred embodiment. [0149]
    TABLE A
    The Types describe the semantics for passing information to and from modules and registers.
    Type Name Type equivalence Restrictions Description
    VoidType fundamental Type Has no semantic
    value.
    SignedType fundamental Type Maximum size = Defines a signed
    32 bits. value.
    UnsignedType fundamental Type Maximum size = Defines an
    32 bits unsigned value.
    CharType fundamental Type Maximum size = Defines a
    32 bits. character value.
    Supports wide
    characters as
    well as ASCII.
    BooleanType fundamental Type Size = 1 bit. Defines a
    Boolean value.
    Value may be
    TRUE or FALSE.
    FixedPointType fundamental Type Maximum size = Defines a fixed
    64 bits. point value.
    FloatType fundamental Type Size = 32, 64, or Defines a floating
    80 bits. point value.
    ComplexType fundamental Type Maximum size = Defines a
    TBA. complex value.
    DeltaType fundamental Type Size = 0 bits. The value
    represents a
    delta-function
    pulse.
    RealType define union RealType = Defines a real
    SignedType.linevert split. value.
    UnsignedType.linevert split.
    CharType.linevert split.
    BooleanType.linevert split.
    FloatType.linevert split.
    FixedPointType.
    NumericType define union Defines a
    NumericType = numeric value.
    RealType.linevert split.
    ComplexType.
    SignedArrayType define array Defines an array of
    SignedArrayType = signed values.
    {SignedType
    {grave over ( )}value.sub.i {grave over ( )}}.
    UnsignedArrayType define array Defines an array of
    UnsignedArrayType = unsigned values.
    {UnsignedType {grave over ( )}value.sub.i {grave over ( )}}.
    CharArrayType define array CharArrayType = Defines an array of
    {CharType {grave over ( )}char.sub.i {grave over ( )}}. characters.
    BooleanArrayType define array Defines an array of
    BooleanArrayType = Boolean values.
    {BooleanType {grave over ( )}value.sub.i {grave over ( )}}.
    FixedPointArrayType define array Defines an array of
    FixedPointArrayType = fixed point values.
    {FixedPointType {grave over ( )}value.sub.i {grave over ( )}}.
    FloatArrayType define array FloatArrayType = Defines an array of
    {FloatType {grave over ( )}value.sub.i {grave over ( )}}. floating point values.
    ComplexArrayType define array Defines an array of
    ComplexArrayType = complex values.
    {ComplexType {grave over ( )}value.sub.i {grave over ( )}}.
    NumericArrayType define union Defines an array of
    NumericArrayType = numeric values.
    SignedArrayType.linevert split.
    UnsignedArrayType.linevert split.
    CharArrayType.linevert split.
    BooleanArrayType.linevert split.
    FixedPointArrayType.linevert split.
    FloatPointArrayType.linevert split.
    ComplexArrayType.
    ArrayUnsignedArray define structure Structure defines an
    Type ArrayUnsignedArrayType = array of
    {UnsignedArrayType UnsignedArrayTypes.
    {grave over ( )}us.sub.-- array.sub.i {grave over ( )}}.
    StringType define StringType = must be null Defines a character
    CharArrayType. terminated. string (null-terminated).
    StringArrayType define structure Defines an array of
    StringArrayType = strings.
    {CharArrayType {grave over ( )}string.sub.i {grave over ( )}}.
    SizeType define SizeType = An unsigned integral
    UnsignedType. value which is used for
    defining a size
    parameter (e.g. size of
    array, #records).
    CounterType define CounterType = An unsigned integral
    UnsignedType. value which can be
    incremented (by 1 or
    more), decremented (by
    1 or more), and cleared
    to 0.
    IndexType define IndexType = An unsigned integral
    UnsignedType. value which is used to
    index arrays.
    TimeType define TimeType = Universal Time (GMT) in
    NumericType. seconds.
    ReasonType define ReasonType = The reason for an
    CharArrayType. exception.
    ExceptionType define structure ExceptionType = An exception returns a
    UnsignedType code and value. A
    {grave over ( )}exception.sub.-- cause. reason string is
    Type opitonal.
    {grave over ( )}exception.sub.-- value{grave over ( )} The valid codes are:
    [ReasonType {grave over ( )}reason{grave over ( )}]. 0 = underflow
    1 = overflow
    2 = not.sub.-- valid
    3 = not.sub.-- supported
    4 = not.sub.-- available
    5 = invalid.sub.-- method
    6 = loss.sub.-- of.sub.--
    precision.
    7 = internal.sub.-- error
    MethodType define The value represents
    MethodType = UnsignedType. (numerically) the
    particular method of an
    Object.
    ClassType define ClassType = The value represents
    UnsignedType. (numerically) a particular
    class (such as Numeric
    Register of PowerMeter
    Module).
    NodeHandleType define union NodeHandleType = An address to a remote
    StringType.linevert split. IED site.
    UnsignedType.
    ExtendedHandleType define structure Defines a handle used
    ExtendedHandleType = to a reference an object
    [NodeHandleType {grave over ( )}node{grave over ( )}] on another IED.
    UnsignedType {grave over ( )}handle{grave over ( )}.
    HandleType define union HandleType = The value represents
    UnsignedType.linevert split. the address of an
    ExtendedHandleType. object.
    ExtendedHandle define structure array The value is an array of
    ArrayType ExtendedHandleArrayType = Extended Handles.
    {ExtendedHandle {grave over ( )}value.sub.i {grave over ( )}}.
    HandleArrayType define union HandleArrayType = The value is an array of
    ExtendedHandleArrayType.linevert split. handle values.
    UnsignedArrayType.
    PriorityType define Priorities range from 0 The value represents an
    PriorityType = UnsignedType. to 255 priority. Guidelines for
    priorities are as follows:
    Urgent
    192 to 255
    High
    128 to 191
    Medium 64 to 127
    Low 0
    to 63
    RangeType define structure RangeType = defines a range of
    IndexType values that starts at
    {grave over ( )}range.sub.-- start{grave over ( )} index range.sub.-- start and
    IndexType ends at index
    {grave over ( )}range.sub.-- end{grave over ( )}. range.sub.-- end. This is
    useful in log situations.
    EventType define structure EventType = Defines a structure for
    PriorityType {grave over ( )}priority{grave over ( )} an event.
    UnsignedType Values for event.sub.--state
    {grave over ( )}event.sub.-- state{grave over ( )} are:
    HandleType 0 = unary state event.
    {grave over ( )}cause.sub.-- handle{grave over ( )} 1 = Active transition
    IONType for bi-state event.
    {grave over ( )}cause.sub.-- value{grave over ( )} 2 = Inactive transition
    HandleType for bi-state event.
    {grave over ( )}effect.sub.-- handle{grave over ( )} 3 = Label change
    IONType event.
    {grave over ( )}effect.sub.-- value{grave over ( )}.
    LogHeaderType define Structure defines the
    LogHeaderType = header for a general
    HandleArrayType purpose log record.
    LogRecordType define structure LogRecordType = Structure defines the
    IndexType {grave over ( )}position{grave over ( )} data values in a general
    TimeType purpose log record.
    {grave over ( )}timestamp{grave over ( )}
    {Type {grave over ( )}value.sub.i {grave over ( )}}.
    LogArrayType define structure.sub.-- array Array of log records.
    LogArrayType =
    {LogRecordType {grave over ( )}logrec.sub.i {grave over ( )}}.
    WaveformType define structure Defines a structure for
    WaveformType = a waveform.
    NumericType Note:
    {grave over ( )}sampling.sub.-- frequency{grave over ( )} plotted value =
    NumericType {grave over ( )}offset{grave over ( )} (data point +
    NumericType {grave over ( )}scale{grave over ( )} offset) * scale.
    TimeType
    {grave over ( )}time.sub.-- of.sub.-- first.sub.-- point{grave over ( )}.
    NumericArray {grave over ( )}points{grave over ( )}.
    AlarmType define structure AlarmType = Structure for alarms:
    HandleType When parameter
    {grave over ( )}effect.sub.-- handle{grave over ( )} Transitions is odd the
    CounterType alarm is active.
    {grave over ( )}transitions{grave over ( )}.
    PriorityType {grave over ( )}priority{grave over ( )}.
    AlarmArrayType define structure.sub.-- array Array of alarms.
    AlarmArrayType =
    {AlarmType {grave over ( )}alarm.sub.i {grave over ( )}}.
    SecurityType define Value represents a
    SecurityType = UnsignedTypes. security level.
    The following security
    levels are defined:
     1 = no access
    16 = user (R/O)
    32 = user (R/W)
    48 = configure (can
    create/destroy
    modules)
    64 = system
    administration (can
    change secruity
    levels).
    80 = highest level
    (factory - i.e. cal
    constants)
    MehtodSecurityType define structure Assigns a security level
    MethodSecurityType = to a method.
    MethodType {grave over ( )}method{grave over ( )}
    SecurityType {grave over ( )}security{grave over ( )}.
    MethodSecurityArray define structure.sub.-- array Array of method-
    Type MethodSecurityArrayType = security.
    {MethodSecurityType
    {grave over ( )}methsec.sub.i {grave over ( )}}.
    CompositeLogRecord define structure This is the complete
    CompositeLogRecord = description of a log
    UnsignedType record.
    {grave over ( )}record.sub.-- type{grave over ( )} Note:-the position field
    HandleType {grave over ( )}handle{grave over ( )} of the log record type is
    LogHeaderType {grave over ( )}header{grave over ( )} the record ID.
    [StringArrayType {grave over ( )}labels{grave over ( )}] RecordType is currently
    LogArrayType {grave over ( )}records{grave over ( )}. always zero.
    CompositeLogArray define structure.sub.-- array An array of
    CompositeLogArray = CompositeLogRecords
    {CompositeLogRecord
    {grave over ( )}record.sub.i {grave over ( )}}.
    CompositeEventRecord define structure This is a complete
    CompositeEventRecord = description of a single
    UnsignedType event (either unary
    {grave over ( )}record.sub.-- type{grave over ( )} event or half of a
    HandleType {grave over ( )}handle{grave over ( )} binary event). The
    LogHeaderType {grave over ( )}header{grave over ( )} header consists of two
    [StringArrayType {grave over ( )}labels{grave over ( )}] handles cause.sub.-- handle
    LogArrayType {grave over ( )}records{grave over ( )} and effect.sub.-- handle (in
    TimeType this order).
    {grave over ( )}achmowledge.sub.-- time{grave over ( )} The records field
    PriorityType {grave over ( )}priority{grave over ( )}. always has two
    elements, cause.sub.-- value
    and effect.sub.-- value.
    RecordType is 0 for
    unary events, 1 for
    binary active events, 2
    for binary inactive
    events, and 3 for label
    change events.
    CompositeEventArray define structure An array of
    CompositeEventArray = CompositeEventRecords
    {CompositeEventRecord
    {grave over ( )}record.sub.i {grave over ( )}}.
    PredicateOperator define PredicateOperatorType = Defines some SQL
    Type UnsignedType {grave over ( )}operator{grave over ( )}. predicate operators
    0 = AND
    3 = OR
    1 = IN
    4 = XOR
    2 = BETWEEN
    PredicateOperand define PredicateOperandType = A predicate for an SQL-
    Type Type {grave over ( )}operand{grave over ( )} type query is formed
    from a list of
    PredicateOperandType
    (see SearchCriteria
    type).
    SortOrderType define structure
    UnsignedType {grave over ( )}order{grave over ( )} SortOrderType order is:
    StringType {grave over ( )}key{grave over ( )}. 0 = Ascending order
    1 = Descending order.
    key names a key field
    of a table.
    SortOrderArray define structure.sub.-- array
    SortOrderArray =
    {Sort OrderType
    {grave over ( )}order.sub.i {grave over ( )}}.
    SearchCriteria define structure SearchCriteria = Defines a query on a
    {PredicateOperandType LogSchemeRegister
    {grave over ( )}operand.sub.i } The list of operands
    SortOrderArray {grave over ( )}order{grave over ( )}. form a predicate in
    postfix (reverse Polish)
    notation.
    Type define union Type = All Types.
    /* type all types here */
  • Table 1 lists a set of methods which are presently defined for the base class. All of these base class methods are inherited by the registers and modules. [0150]
    TABLE 1
    # Method Return-type Description
    1 read.sub.-- class( ) Class Type Causes a manager, module or register to return a
    number indicating what type of manager, module
    or register it is.
    2 read.sub.-- name ( ) StringType Causes a manager, module or register to return a
    string containing the name of the manager,
    module or register.
    3 read.sub.-- label ( ) StringType Causes a manager, module or register to return a
    string containing the label for the manager,
    module or register.
    A label differs from a name in that
    it can be programmed by executing a
    Write Label method on the manager,
    module or register. If no label is
    programmed the object name will be returned.
    128 write.sub.-- label(StringType) BooleanType Write the programmable object label. If a
    null-string is
    written, the Label is destroyed.
    129 read.sub.-- security.sub.-- SecurityType Is executed to determine whether a method can
    level(MethodType) be executed on a particular manager, module or
    register.
    Not all methods are available on all devices.
    The master device can determine whether it will
    receive a
    valid result by first executing this method.
    Another method, Read All Security Levels
    returns a list which
    corresponds to the security levels of all the
    methods that can be executed on a manager
    or module.
    130 read.sub.-- all.sub.-- MethodSecurity Read the security levels for all methods of a
    security.sub.-- levels( ) ArrayType given
    object. Only methods valid for the object's
    class are included.
    131 read.sub.-- parent.sub.-- handle HandleType Returns a handle of the parent of a manager,
    module or register. For instance, executing this
    method on an
    analog output module will return the handle of
    the analog output manager. Executing this method
    on the
    analog output manager will return a handle to
    the feature manager. Executing this method on an
    analog output's output register returns the analog
    output module.
    132 read.sub.-- owners( ) HandleArray Returns a list of handles for all the modluels
    Type that own
    the object this method is executed on. This
    will include a list of modules if the method is
    invoked on a
    register or a manager if it is invoked on a
    module.
    133 IsA(ClassType) BooleanType Returns a value indicating whether or not and
    object is
    derived from the class given as an argument.
    134 check.sub.-- sanity( ) BooleanType Checks to see if the manager, module or
    Register is
    operating correctly. i.e., determines whether
    the software that implements the object is
    operating correctly. Returns True if object is
    sane.
  • If a method invocation is unsuccessful, an ExceptionType will be returned rather than the normal Return-type. [0151]
  • In the current implementation a module performs a function using registers. Input registers provide the information a module is operating on. Setup registers permit modification of the operation of the module. Output registers contain the results of the module's operation. The output registers of one module can be used as input registers for another. The module keeps track of which registers are to be used for its input, output and setup. The links to the input registers can be modified, but those to the output and setup registers are fixed. A module is said to “own” all the registers it is linked to. Methods may also be executed on registers once the handle to a register is known. The handle of a register or module is a number which is unique for each register and module on a device. When a method is invoked, a handle is supplied which indicates which module or register the method is to be invoked upon. [0152]
  • In most instances, the methods that can be invoked on the different types of registers depend on what type of register is involved. Table 2 lists a set of methods which are presently defined for all registers (all register classes are inherited from the register class). [0153]
    TABLE 2
    Register Class (R) - class = 20
    # Method Return-type Description
    20 read.sub.-- time( ) TimeType Read the time of last
    update.
    21 read.sub.-- value( ) VoidType Read the value of the
    object
    22 write.sub.-- value(VoidType) BooleanType Write the value of the
    object
  • TABLES 3-19 list methods which are supported for the indicated register classes. (In Tables 3-19, “*” indicates that the method is inherited from the parent class and “+” indicates that the method is re-defined from the parent class.) [0154]
    TABLE 3
    BooleanVariableRegister (BVR) - class = 21
    This class defines a Boolean variable storage location.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of last update
    21 read.sub.-- value( )+ BooleanType Read the value of the register.
    22 write. sub.-- value(BooleanType)+ BooleanType Write the value of the register
    30 read.sub.-- ON.sub.-- label( ) StringType Read the ON label.
    500 write.sub.-- ON.sub.-- label(StringType) BooleanType Write the ON label.
    31 read.sub.-- OFF.sub.-- label( ) StringType Read the OFF label.
    501 write.sub.-- OFF.sub.-- label(StringType) BooleanType Write the OFF label.
    32 read.sub.-- current.sub.-- state.sub.-- StringType Returns the ON label if register value =
    label( ) True and OFF label if register value =
    False.
  • [0155]
    TABLE 4
    EnumeratedRegister (ENR) - class = 22
    This class defines a register that can store one instance of an enumerated list.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of last update
    21 read.sub.-- value( )+ StringType Read the value of the register.
    22 write.sub.-- value(StringType)+ BooleanType Write the value of the register. The string must
    be one of the strings provided by the
    read.sub.-- unumerations( ) method - otherwise
    the method will fail.
    520 read.sub.-- enumerations( ) StringArrayType Read the enumeration list. This list contains
    ALL possible register values.
  • [0156]
    TABLE 5
    NumericRegister (NR) - class = 24
    This is the parent class for Numeric Registers.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time
    of last update
    21 read.sub.-- value( )+ NumericType Read the value
    of the register
    22 write.sub.-- value(NumericType)+ Boolean Type Write the value
    of the register
  • [0157]
    TABLE 6
    NumericBoundedRegister (NBR) - class = 23
    This defines a numeric value bounded by two values.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of last update
    21 read.sub.-- value( )* NumericType Read the value of the register
    22 write.sub.-- value(NumericType)* BooleanType Write the value of the register. If the value
    is outside
    the prescribed bounds, no value will be
    written and an excepeition will be returned.
    540 read.sub.-- bounds( ) NumeriArray Read the bounds of the register. The numeric
    Type array will have two elements.
    541 write.sub.-- bounds(NumericArrayType) BooleanType Write the bounds of the register. The first
    array element will be the low bound and the
    second will be the hight bound.
  • [0158]
    TABLE 7
    NumericVariableRegister (NVR) - class = 25
    This defines a numeric storage location.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time
    of the last
    update
    21 read.sub.-- value( )* NumericType Read the value
    of the register
    22 write.sub.-- value(NumericType)* BooleanType Write the value
    of the register
  • [0159]
    TABLE 8
    DeltaRegister (DR) - class = 26
    This defines a delta-function value.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of
    last update
    21 read.sub.-- value( )+ VoidType Read the delta value
    22 write.sub.-- value(VoidType)* Boolean Type Output a delta-pulse
  • [0160]
    TABLE 9
    Arrayregister (AR) - class = 27
    This is the parent class for all registers containing arrays.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of last update
    21 read.sub.-- value(RangeType)+ VoidType Read a range of values.
    22 write.sub.-- value(IndexType, VoidType)+ BooleanType Write values at index
    35 read.sub.-- depth( ) SizeType Read the depthe of the array
    36 write.sub.-- depth(SizeType) BooleanType Write the depth of the array
    37 read.sub.-- rollover( ) UnsignedType Read rollover value - value is the
    highest count that can be reached
    before rollover to 0.
  • [0161]
    TABLE 10
    BooleanArrayRegister (BAR) - class = 28
    This class defines a non-circular array of Boolean values.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of
    last update
    21 read.sub.-- value(RangeType)+ BooleanArray Read a range of
    Type values.
    22 write.sub.-- value(IndexType, BooleanType Write values at
    BooleanArrayType)+ index
    35 read.sub.-- depth( )* SizeType Read the depth of
    the array
    36 write.sub.-- depth(SizeType)* BooleanType Write the depth of
    the array
    37 read.sub.-- rollover( )* UnsignedType Read rollover
    value.
  • [0162]
    TABLE 11
    NumericArrayRegister (NAR) - class = 29
    This class defines a non-circular array of numeric values.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of
    last update
    21 read.sub.-- value(RangeType)+ NumericArray Read a range of
    Type values.
    22 write.sub.-- value(IndexType, BooleanType Write values at
    NumericArrayType)+ index
    35 read.sub.-- depth( )* SizeType Read the depth of
    the array
    36 write.sub.-- depth(SizeType)* BooleanType Write the depth of
    the array
    37 read.sub.-- rollover( )* UnsignedType Read rollover
    value.
  • [0163]
    TABLE 12
    LogRegister (LR) - class = 30
    This class defines a circular array of log-type
    structures. This class is intended for the
    implenemtation of any kind of historic log.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of last update
    21 read.sub.-- value(RangeType)+ LogArrayType Read a range of records.
    22 write.sub.-- value(IndexType, BooleanType Write the records at index
    LogArrayType)+
    35 read.sub.-- depth( )+ BooleanType NotSupported
    36 write.sub.-- depth( )+ BooleanType NotSupported
    37 read.sub.-- rollover( )* UnsignedType Read rollover value.
    40 read.sub.-- position( ) IndexType Read the present position. Note: Upon leaving
    the factory, the position = 0 (i.e. the first
    record will be written into position 0). The
    position always indicates where the next record
    will be written.
    41 write.sub.-- position(IndexType) BooleanType Write the present position
  • [0164]
    TABLE 13
    EventLogRegister (ELR) - class = 31
    This class defines a circular array of event structures
    and a non-circular array of alarms. It is derived from
    the LogRegister class. The following methods are supported.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of the last update
    21 read.sub.-- value(RangeType)* LogArrayType Read range of events
    22 write.sub.-- value(IndexType, BooleanType Write range of events
    LogArrayType)*
    35 read.sub.-- depth( )+ BooleanType NotSupported
    36 write.sub.-- depth( )+ BooleanType NotSupported
    37 read.sub.-- rollover( )* UnsignedType Read rollover value.
    40 read.sub.-- position( )* IndexType Read the present position.
    41 write.sub.-- position(IndexType)* BooleanType Write the present position
    45 read.sub.-- alarms( ) AlarmArrayType Read entire alarm array.
    46 write.sub.-- alarms(AlarmArrayType) BooleanType Write entire alarm array.
    560 read.sub.-- alarm.sub.-- count.sub.-- rollover( ) UnsignedType Read rollover value of alarm counters
    in the AlarmArray - value is the
    highest count that can be reached
    before rollover to 0.
  • [0165]
    TABLE 14
    SchemaRegister (DSR) - class = 39
    This is derived from TableRegister. A SchemaRegister
    loosely represents of a database schema, a collection
    of related database tables. In the current embodiment,
    the tables are not accessible via methods. These
    registers are used primarily as inputs to specialized
    modules that allow indirect access to the tables.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of the last
    update.
    21 read.sub.-- value( )+ BooleanType NotSupported.
    22 write.sub.-- value( )+ BooleanType NotSupported.
  • [0166]
    TABLE 15
    Log View Register (LVR) - class = 40
    The Log View Register class is derived from Register.
    In database terminology, a view is a database table
    that is derived from queries on other database tables.
    Here a “view” is extended to mean a specialized
    representation of table or group of tables. A log View
    Register is used to access data stored in the Table
    Registers associated with the creator module (see Log
    View Module). Data retrieved from the tables is
    reformatted and returened as Composite Log Records.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of the last update.
    21 read.sub.-- value(SearchCriteria)+. CompositeLogArray Returns all records that match
    SearchCriteria.
    22 write.sub.-- value( )+ BooleanType Not supported.
    583 read.sub.-- updates(SearchCriteria) CompositeLogArray The first time this method is invoked (for
    a particular program), all records that
    match the SearchCriteria are returned.
    Subsequently, only the newest matching
    records are returned.
  • [0167]
    TABLE 16
    EventViewRegister (EVR) - class = 41
    The EventViewRegister class is a LogViewRegister that
    specializes the in storage of CompositeEventRecords.
    It also allows these records to be marked as
    acknowledged and sends prioritized alarm messages to
    registered clients.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of the last update.
    21 read.sub.-- value(SearchCriteria)+ CompositeEventArray Returns all records that match
    SearchCriteria.
    22 write.sub.-- value( )* BooleanType Not supported.
    583 read.sub.-- updates(SearchCriteria)+ CompositeEventArray See LogViewRegister
    584 acknowledge(UnsignedArrayType) Boolean Type Marks the specified event records as
    acknowledged. The argument is an array of
    recordIDs.
  • [0168]
    TABLE 17
    WaveformRegister (WR) - class = 32
    This class defines an array of points defining a waveform.
    # Method Return-type Descripiton
    20 read.sub.-- time( )* TimeType Read the time of last update
    21 read.sub.-- value( )+ WaveformType Read the present value of the register
    22 write.sub.-- value(WaveformType)+ BooleanType Write the present value of the register
  • [0169]
    TABLE 18
    EventRegister (ER) - class = 33
    This class defines a register which holds an evet.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of
    last update
    21 read.sub.-- value( )+ EventType Read the present
    value of the register
    22 write.sub.-- value(EventType)+ BooleanType Write the present
    value of the register
  • [0170]
    TABLE 19
    TimeRegister (TR) - class = 34
    This class defines a register which holds unformatted time.
    # Method Return-type Description
    20 read.sub.-- time( )* TimeType Read the time of
    last update
    21 read.sub.-- value( )+ TimeType Read the present
    value of the register
    22 write.sub.-- value(TimeType)+ Boolean Write the present
    Type value of the register
  • It is also contemplated that a TableRegisterClass will be defined. The TableRegisterClass represents a database table, rows of data organized into distinct columns. It is presently envisioned that the database tables will not be accessible using methods. These registers may be used permanently as inputs to specialized modules that allow indirect access to the tables. [0171]
  • Registers operate only as servers in the architecture. In other words they only respond to method invocations. Some of the most commonly used registers in the preferred embodiment are boolean registers, enumerated registers, numeric registers and numeric bounded registers. A flow chart for the server operation of a boolean register is shown in FIGS. 27A-27C. A flow chart for the server operation of an enumerated register is shown in FIGS. 28A-28B. A flow chart for the server operation of a numeric register is shown in FIGS. 29A-29B. A flow chart for the server operation of a numeric bounded register is shown in FIGS. 30A-30B. [0172]
  • It will be recognized by those skilled in the art that the registers' functionality can be embedded within the modules. [0173]
  • The modules provide the IED the functionality in the architecture. FIG. 18 schematically illustrates a preferred embodiment of the properties of the modules. The modules can be considered as “black boxes” that read data at the inputs, manipulate the data in some fashion, and write the result to outputs. Input data is read from registers and output data is written to registers. For all types of modules, the links to input registers can be programmed, but the links to output registers are fixed. Most modules have links to registers which contain setup information—these links are also fixed, and the module can only read them. FIG. 19 illustrates the data flow for a module. A module [0174] 861 is linked to input registers 863 a-863 n through programmable links 869 a-869 n. Setup registers 867 a-867 n are linked to module 861 through links 872 a-872 n which are not programmable. Output registers 864 a-864 n are linked to module 861 through links 870 a-870 n which also are not programmable.
  • In the preferred embodiment, the modules have the following properties [0175] 1001531 An array of handles (input handles) point to the input registers. The module has shared ownership of these registers. Thc module reads a register using the Read.sub.—Value method.
  • Module setup data (such as scaling information) is stored in registers. An array of handles (setup handles) point to these Registers. There is one exception. For a manager module these Handles point to other modules rather than registers. The module has shared ownership of these objects. [0176]
  • The module uses the input data and setup data to produce output data according to the function of the module which is described by the module behavior. [0177]
  • An array of handles (output handles) point to the output registers. The module has shared ownership of these registers. A module writes these registers using the Write.sub.—Value method. [0178]
  • UpdatePeriod contains the period at which the module updates the output registers. [0179]
  • ModuleSecurity contains the security level which the module uses when invoking methods on other objects. [0180]
  • The module has a class which is unique to that type of module. (e.g. All setpoint modules would have the same class). [0181]
  • The module has a name. This name is fixed (read only) and is different in every module. [0182]
  • The module has a label which can be programmed. [0183]
  • A method security level is defined for every method which can be invoked on a module. Thus, there is a security parameter for every method which can be invoked on the module. [0184]
  • The module has owners which are listed in an array of Handles. This array lists all the module(s) that have shared ownership of the module. [0185]
  • A module is created by a manager using the Create.sub.—Module( ) method. When the module is created all output registers and setup registers arc also created. However, input registers are not created when a module is created. Often, a manager will have a fixed number of modules and the Create.sub.—Module( ) method will not be supported. [0186]
  • The module class (class=500) is derived from the base class. The methods listed below in Table 20 are common to all module classes (all module classes are inherited from this module class). [0187]
    TABLE 20
    # Method Return-type Description
    1000 read.sub.-- input.sub.-- handles( ) HandleArray Returns a list of the handles to the
    Type registers that are connected as inputs to the manager
    or module. (In the current embodiment,
    managers do not have inputs.)
    1001 write.sub.-- input.sub.-- handles(HandleArrayType) BooleanType Accepts a list of handles and attempts to
    link a module or manager to these input
    registers.
    (In the current embodiment, managers do not
    have inputs.) The handle order is defined
    in the module definitions. If one of the
    handles is incorrect the method will fail and NO
    handles will be written (i.e. all or nothing).
    1002 read.sub.-- input.sub.-- classes( ) ArrayUnsigned Reads the allowed register classes for the
    ArrayType write.sub.-- input.sub.-- handles method.
    The returned
    array has the same number of elements as
    the HandleArray used in the
    write.sub.-- input.sub.-- handles method.
    If the returned
    array has an element that contains a Null
    rather than a class this indicates that
    this input element cannot be programmed.
    1003 read.sub.-- output.sub.-- handles( ) HandleArray Returns a list of handles to the output
    Type registers of a module or manager. (In the
    current embodiment, managers do not have
    outputs.) The handle order is defined in
    the module definitions.
    1004 read.sub.-- setup.sub.-- handles( ) HandleArray Returns a list of handles to the setup
    Type register
    of a module or a list of handles to modules
    for a manager. The handle order is defined
    in the module definitions.
    80 read.sub.-- setup.sub.-- counter( ) CounterType Returns a number indicating how many times
    the module or manager has had its
    configuration changed. A master device can
    keep a local copy of this number. If
    another master device changes the setup of
    the slave device, the first manager can
    detect the change by comparing its count
    with the current count.
    81 read.sub.-- update.sub.-- counter( ) CounterType Returns a number indicating how many times
    the module or manager has successfully
    invoked a method to write a new value to
    its output registers. A master device can
    then determine if it is necessary to read
    the output
    from the module or manager. (In the current
    embodiment, managers have no outputs.)
    1005 read.sub.-- update.sub.-- period( ) StringType Returns a number indicating the minimum
    amount of time there will between the
    module or manager updating its output
    registers. (In
    the current embodiment, managers have no
    outputs.)
    Typical response is one of:
    “one cycle”
    “one second”
    “two cycles”
    1006 read.sub.-- module.sub.-- security( ) SecurityType Returns a numbers indicating the security
    access a module has. Other modules or
    registers may refuse to execute a method
    invoked by a module which does not have a
    high enough security level.
  • Table 21 below lists the behavior details for the module parameters. [0188]
    TABLE 21
    Module
    Parameter Behavior
    update. will be incremented every time a write.sub.-- value( )
    sub.-- counter method is successfully invoked on one of the
    registers identified by the output handles.
    Note: by default the update counter will be incremented
    every time an module writes an event
    register.
    setup. will be incremented every time a write.sub.-- value( )
    sub.-- counter method is successfully invoked on one of the system
    registers identified by the setup handles and
    every time the write.sub.-- input.sub.-- handles( )
    method is successfully invoked.
  • Table 22 below provides a list of the modules (including the corresponding input, output and setup registers) presently supported by the presently preferred embodiment. [0189]
    TABLE 22
    # Module Name Input Registers Output Registers Setup Registers Module Description
    501 Power Meter V1 (NAR) Vabc*(NVR).sup.1 ode(ENR) Basic 3-phase power met
    V2 (NAR) Vllabc*(NVR) PT Pri Volts(NBR) met meter.
    V3 (NAR) labc*(NVR) PT Sec Volts(NBR) PhaseOrder:
    l1 (NAR) KWabc*(NVR) CT Pri (NMR) “ABC”
    l2 (NAR) KVARabc*(NVR) CT Sec l(NBR) “ACB”
    l3 (NAR) KVAabe*(NVR) 14 CT Pri l(NBR) NormFreq:
    l4 (NAR) PFSIGNabc*(NVR) 14 CT Sec l(NBR) “50”
    PFLEADabc*(NVR) l1 Polarity(ENR) “60”
    PFLAGabc*) NVR) l2 Polarity(ENR) “400”
    Vunbal(NVR) l3 Polarity(ENR) PhaseLabels:
    lunbal(NVR) PhaseOrder(ENR) “ABC”
    l4(NVR) NormFreq(ENR) “RST”
    Iresidual(NVR) PhaseLabels “XYZ”
    PhaseRev(BVR) (ENR) “RYB”
    LineFreq(NVR)
    Event(ER)
    502 Analog Input ScaledAnalog(NVR) Zero Scale(NBR) Analog Input function.
    Event(ER) Full Scale(NBR) Port indicates H/W Input
    Port(ENR) port.
    503 Analog Output Source(NVR) State(NVR) Zero Scale(NBR) Analog Output function.
    Event(ER) Full Scale(NBR) OutputState gives present
    OutputMode output value as a % of
    (ENR) output full scale.
    Port(ENR)
    OutputMode:
    “0-20 ma”
    “4-20 ma”
    note: OutputMode is not
    supported for all devices.
    Port indicates H/W output
    port.
    504 Digital Input State(BVR) InputMode (ENR) Processes raw digital
    Trigger(DR) EvLogMode signals received from H/W
    Event(ER) (ENR) digital input channel.
    InPolarity(ENR) Trigger on valid state
    Debounce(NBR) changes.
    Port(ENR) InputMode:
    “Pulse”
    “KYZ”
    EvLogMode:
    “Log Off”
    “Log On”
    InPolarity:
    “non-inverting”
    “inverting”
    Debounce in ms.
    Port indicates H/W input
    port.
    505 Digital Output Source(BVR) State(BVR) EvLogMode Provides raw bit pattern
    ForceOn(DR) Mode(BVR) (ENR) for H/W digital output
    ForceOff(DR) Event(ER) OutPolarity(ENR) channel.
    Normal(DR) PulseWidth(NBR) EvLogMode:
    Port(ENR) “Log Off”
    “Log On”
    OutPolarity:
    “non-inverting”
    “inverting”
    PulseWidth:
    0 = continuous output.
    not 0 = pulse width in
    ms.
    Port indicates H/W output
    port.
    506 Pulser Source(DR) Event(ER) PulseWidth(NBR) Proves pulse output (e.g.
    OutputMode for Kwh pulsing). Output
    (ENR) Port is pulsed every time
    OutPolarity(ENR) a pulse is received at the
    Port(ENR) Source input.
    PulseWidth specified in
    ms.
    OutputMode:
    “Pulse”
    “KYZ”
    OutPolarity:
    “non-inverting”
    “inverting”
    Port indicates H/W output
    port.
    508 SWD Source(NVR) SWD(NVR) Period(NBR) Provides SWD on source
    Sync(DR) Prediction(NVR) #Periods(NBR) input.
    Reset(DR) Event(ER) SyncMode(ENR) Period in minutes.
    PredictSpeed SyncMode:
    (NBR) “internal”
    “external”
    Sync input is used in
    external sync mode,
    otherwise un-used.
    PredictSpeed from 0-99
    (99 = fast response).
    509 TD Source(NVR) TD(NVR) Period(NBR) Provides Thermal Demand
    Reset(DR) Event(ER) TimeConstant calculation on a single
    (NBR) source input.
    Period in minutes.
    TimeConstant is a
    percentage of the Period.
    510 Integrator Integrand(NVR) Result(NVR) Divisor(NBR) Provides integration
    Enable(BVR) Pulse(DR) IntMode(ENR) function.
    Reset(DR) Event(ER) PulseSize(NBR) Enable allows gating
    Divisor in seconds (for
    Kwh the Divisor would be
    3600)
    IntMode:
    “forward”
    “reverse”
    “absolute”
    “net”
    The Pulse output will be
    pulsed when the Result
    output changes by the
    amount specified in
    PulseSize setup . . .
    511 Min Source(NVR) Min(NVR) Event(ER) Scans Source register for
    Enable(BVR) Trigger(DR) new minimum values.
    Reset(DR) Enable allows gating for
    every new minimum the
    Min and Trigger registers
    are updated.
    512 Max Source(NVR) Max(NVR) Scans Source register for
    Enable(BVR) Trigger(DR) Event(ER) new maximum values.
    Reset(DR) Enable allows gating for
    every new maximum the
    Max and Trigger registers
    are updated.
    513 Setpoint Source(NVR/BVR) Status(BVR) HiLim(NBR) Provides hysteric
    Enable(BVR) Trigger(DR) LoLim(NBR) setpoint function on
    Reset(DR) Event(ER) TDOperate(NBR) numberic of loolean value.
    TDRelease(NBR) Enable allows gating.
    InputMode(ENR) Trigger on setpoint going
    EvaluateMode ACTIVE.
    (ENR) TDOperate and TDRelease
    EventPri(NBR) in ms.
    InputMode:
    “Signed”
    “Absolute”
    EvaluateMode:
    “GreaterThan”
    “LessThan”
    514 FFT Source(NAR) FFT(NAR) Performs FFT calculations
    Enable(BVR) Event(ER) on input source array and
    generates an array of
    complex numbers.
    515 Harmonics Source(NAR) HD1(NVR) Performs harmonics
    Analyzer Enable(BVR) . . . HDN(NVR) calculations on an N-size
    THD(NVR) array of complex numbers
    TEHD(NVR) (i.e. from an FFT module).
    TOHD(NVR)
    KFactor(NVR)
    Event(ER)
    516 Recorder Source1 RecLog(LR) Depth(NBR) Provides a snapshot of the
    (NVR/BVR/NAR/ Event(ER) RecMode(ENR) input source registers
    BAR/WR) EvLogMode when trigger register is
    . . . SourceN (ENR) pulsed. Can record
    (NVR/BVR/NAR/ waveforms, arrays, and
    BAR/WR) single value registers.
    Enable(BVR) Enable allows gating
    Trigger(DR) RecMode:
    “Circular”
    “Stop-when-full”
    EvLogMode:
    “Log Off”
    “Log On”.
    517 Wave form RawWF(NAR/BAR) FormattedWF(WR) Format(ENR) Formats waveform data.
    Formatter Event(ER) Format (#sampls/cyc x
    #cycles)
    “128.times.12”
    “64.times.28”
    etc . . .
    518 Periodic Enable(BVR) Trigger(DR) Period(NBR) Pulses the Trigger output
    Timer Initialize(DR) Event(ER) TimingMode whenever the timer value
    (ENR) reaches zero.
    ResetMode(ENR) Period in ms.
    TimingMode:
    “Sync to UNIX”
    “Sync to Init”
    ResetMode:
    “init to Period”
    “init to zero”
    519 One-shot Enable(BVR) State(BVR) Period(NBR) Provides a one-shot timer.
    Timer TriggerIn(DR) TriggerOut(DR) State:
    Event(ER) 1 when timer is running
    0 after time out
    The Trigger Out activates
    at the end of the timing
    interval.
    Period in ms.
    520 Counter Trigger(DR) Count(NVR) Multiplier(NBR) Increment/Decrement
    Initialize(DR) Event(ER) UpDown(ENR) Count register by the
    amount specified in the
    Multiplier register each
    time the counter is
    triggered.
    UpDown:
    “Count Down”
    “Count Up”
    521 LogicalAndOr Source1(BVR) Results(BVR) Mode(ENR) Performs either Logical
    . . . SourceN(BVR) Event(ER) EvLogMode AND, NAND or function on
    (ENR) the source inputs.
    Mode:
    “AND”
    “NAND”
    “OR”
    EvLogMode:
    “Log Off”
    “Log On”
    522 Event Log Event1(ER) EventLog(ELR) EvLogDepth Logs all event records in
    Controller . . . EventN(ER) (NBR) EventLog regardless of
    AlarmPriority priority.
    (NBR) Keeps track of previous
    and presently active
    alarms in EventLog. Any
    event with a priority equal
    to or above AlarmPriority
    is an alarm.
    528 LogSchema LogInout1 (LR) LogSchema(DSR) Uploads log records from
    . . . LogInputN (LR) the remote LogRegister
    inputs and stores them in
    a database schema.
    529 EventSchema EventInput1 (ELR) EventSchema(DSR) Combines event records
    . . . EventInputN (ELR) and alarm information
    from each IED and stores
    the data in a database
    schema.
    532 Label EventLog1 (ELR) LableTable (DTR) Maintains a historic list of
    . . . EventLogN (ELR) all labels that exist on
    each IED. The remote
    EventLogRegister inputs
    can be used to track label
    changes. Initially all labels
    are read by accessing the
    feature manager.
    533 LogView LogSchema (DSR) LogView (LVR) Acts as a bridge between
    LabelTable (DTR) the input database tables
    and the output
    LogViewRegister. The
    input tables are joined to
    produce detaild log
    records.
    534 EventView EventSchema (DSR) EventView (EVR) Acts as a bridge between
    LabelTable (DTR) the input database tables
    and the output
    EventViewRegister. The
    input tables are combined
    to produce detailed event
    records.
    524 Comm Reset (DR) Event (ER) CommMode Communications Interface.
    (ENR) CommMode:
    Baudrate(ENR) “RS232”
    HandshakeMode “RS485”
    (ENR) BaudRate:
    RTSLevel(ENR) “300”
    CTSLevel(ENR) “1200”
    RTSDelay(NBR) etc . . .
    UnitD(NBR) HandshakeMode:
    “RTS with level”
    “CTS with level”
    RTSLevel:
    “active low”
    “active high”
    CTSLevel:
    “active low”
    “active high”
    RTSDelay:
    specifies transmission
    delay time (in ms) after
    RTS has been raised.
    523 Data Acquisition Output1(NAR) Provides sampled data
    . . . OutputN(NAR) from the waveforms of a
    power system.
    530 External Control Numeric1(NVR) Provides registers that can
    . . . NumericN(NVR) be controlled externally.
    Trigger1(DR)
    . . . TriggerN(DR)
    Switch1(BVR)
    . . . SwitchN(BVR)
    525 Diagnostics Reset(DR) Output1(BVR/NVR) Output registers provide
    . . . OutputN(BVR/NVR) diagnostic features . . .
    Event(ER)
    526 Real-time Clock Time(TR) Provides real-time clock
    facility.
    Time register in universal
    (GMT) seconds.
    527 Factory Event(ER) Setup1 Used for Factory
    (ENR/NBR) Purposes.
    . . . SetupN All other uses violate the
    (ENR/NBR) architecture.
    It has no owner and
    cannot be created or
    dewtroyed (“it merely
    exists”)
    It can be accessed only
    with the factory security
    level.
    531 Symmetrical Source1(NAR) ZeroSeqMag(NVR) Harmonic(NBR) Calculates the magnitude
    Components Source2(NAR) ZeroSeqPhase(NVR) and phase for each
    Source3(NAR) PosSeqMag(NVR) sequence component for a
    Enable(BVR) PosSeqPhase(NVR) particular harmonic.
    NegSeqMag(NVR) Typically, FFT Modules is
    NeqSeqPhase(NVR) used to produce the
    Event(ER) Numeric Array Registers
    inputs.
  • In the following description reference is made to “managers”. It will be noted that managers are just a specific type of module which have additional functionality. The purpose of the managers is to manage modules. One manager is needed for each practical group of modules, such as setpoint modules and min modules. [0190]
  • Table 23 below provides a list of the methods which are added specifically for the manager class. (All class and module class methods are inherited by the manager class but are not shown here for reasons of brevity.) [0191]
    TABLE 23
    # Method Return-type Description
    100 read.sub.-- module.sub.-- setups.sub.-- counter( ) CounterType Returns a number indicating how many times
    the setup registers of the modules below a
    manager have been changed. The master
    device can keep a local count of this number
    in order to determine if another master device
    has successfully invoked a method to change
    the setup of the device. For instance, if a
    master device keeps this count for the feature
    manager, it can tell if any setup register on
    the deivce has been changed without going to
    each individual module.
    101 read.sub.-- module.sub.-- updates.sub.-- CounterType Returns a number indicating how many times
    counter( ) the output registers of the modules and
    managers beneath a certain manager have
    been updated. Used in the same fashion as
    Read Module Setups Counter, the Read
    Module Updates Counter is used to determine
    if any of the modules beneath the manager
    have successfully invoked a method to update
    their output registers. (In the current
    embodiment, managers have no outputs.)
    1500 create.sub.-- module(Class Type) HandleType Creates a module and stores the module
    handle in the setup handles array; return
    handle to module. The method
    read.sub.-- managed.sub.-- class indicates
    which class of
    module can be created.
    1501 destroy.sub.-- module(HandleType) BooleanType Destroys a module. Handle must be one of
    setup handles or an exception will be returned
    and the method will fail. The resources for
    that module are then available to perform
    other functions on the device.
    1502 read.sub.-- managed.sub.-- class( ) ClassType Returns the class of module which can be
    created with the create.sub.-- module
    method.
  • Every system has a “root” manager module called the feature manager. The feature manager has setup handles to all the other managers. Importantly, the feature manager handle is identical for all systems. The handle for the feature manager is 2. Starting with this handle, it is possible to determine the entire system configuration. [0192]
  • As was mentioned previously, modules act as both clients and servers in the object oriented architecture. In the present embodiment, the client and server portion of the modules operate separately. The server portion of the modules respond to method invocations. The server portion follows the same logic for all modules (except the managers) on the device. A flow chart of the logic for the server portion of a module is shown in FIGS. 19A-19C. [0193]
  • A description is now given of how the modules described above are used in the system of FIGS. 8-10. In the preferred embodiment the output registers from the data acquisition module [0194] 952 (FIG. 11) (which are digital signals representing the samples of the voltage and current) are permanently connected as input registers 120 of a module called the power meter module 926 (FIG. 12). Conceptually, the data acquisition module encompasses signal conditioning circuitry 860, 862, 864, 866A, 866B, 866C, 868A, 868B, 868C, 870, the A/D converters 829, 830 and software in the DSP 828. The interface between the data acquisition module and the power meter module includes the dual port RAM 827. A flow chart for the logic of the client portion of the data acquisition module 952 is shown in FIG. 11A. The power meter module 926 owns setup registers 922 which modify the operation of the power meter module 926 and output registers 924 which contain the results of the calculations that the power meter module does and can be connected to other modules. A flow chart of the logic for the power meter module 926 is shown in FIGS. 12A-12L.
  • The module called the analog input module is an example of a module which connects to a physical signal in a different way. A-preferred embodiment of the analog input module [0195] 928 is illustrated schematically in FIG. 13. An exemplary embodiment of the logic for the client portion of the analog input module of FIG. 13 is illustrated in flowchart form in FIG. 13A. The analog input module 928 owns a port setup register 930 which defines which of the auxiliary input signals 820 the module is associated with. Analog input modules can also be connected to digital I/O signals 844 (FIG. 9). In this configuration, the Digital I/O transceiver 849 operates in input mode and the analog input module converts the frequency of the digital signal into a number. In this embodiment, an external voltage to frequency converter is connected to the digital input signal line.
  • Analog output modules can also be connected to the Digital I/O Signals [0196] 844. In this configuration, an external device is connected to the I/O line which converts the digital signals coming form the analog output module 930 to an analog signal. A preferred embodiment of the analog output module 930 is illustrated schematically in FIG. 14. An exemplary embodiment of the logic for the client portion of the analog output module 930 is illustrated in FIG. 14A in flowchart form.
  • The digital input module [0197] 940 transforms a digital I/O signal 844 into a form that can be used as an input to other modules. A preferred embodiment of the digital input module 940 is illustrated schematically in FIG. 15. An exemplary embodiment of the logic for the client portion of the digital input module 940 is illustrated in FIGS. 15A-15B in flowchart form.
  • The digital output module [0198] 950 transforms the output from another module into a signal on a digital I/O signal line 8. A preferred embodiment of the digital output module 950 is illustrated schematically in FIG. 16. An exemplary embodiment of the logic for the client portion of the digital output module 950 is illustrated in FIGS. 16A-16H in flowchart form.
  • Additional modules that operate only on the results of other modules are also possible. An example of one of these modules is the AND/OR module [0199] 960 illustrated schematically in FIG. 20. The AND/OR module 960 takes a number of boolean variable register inputs and performs a logical AND or OR on them to create a result. The CalcMode setup register 961 determines which AND or OR function is being executed. The EvLogMode setup register 962 determines whether events will be generated in the Event output register 963 when the Result 964 register changes. The logic for a preferred embodiment of the client portion of the AND/OR module 960 is illustrated in FIGS. 20A-20B in flowchart form. The setpoint module 972 is shown schematically in FIG. 21. The logic for a preferred embodiment of the client portion of the setpoint module 972 is shown in FIGS. 21A-21C. These modules do not interface to the outside world.
  • Another module of note is the EventLog module [0200] 970. The EventLog module is shown schematically in FIG. 22. A flowchart of a preferred embodiment for the client portion of the EventLog module is shown in FIG. 22A. Nearly all other modules within the device are connected to an event output register. When an unusual state arises within a module, it may send an event message to the event register. The EventLog module 970 takes event registers as an input and invokes a method to write the “event” into its event log output register. The result is that the Event Log register then contains a list of all the significant occurrences that have happened on the device. In this manner, the time as well as the effects which occur in the IED may be recorded.
  • An example of the events that may be generated on the power meter of the present embodiments can be seen in Table 24. [0201]
    TABLE 24
    Event # Time Cause Label Cause Value Effect Label Effect Value
    1 Dec. 15/94 @ 800 None External Motor 4 Powdered Down
    2 Dec. 15/94 @ 800 Motor 4 Powdered Down Cooler 7 Shutdown
    3 Dec. 15/94 @ 923 kW Phase A 1000 Over kWa True
    4 Dec. 15/94 @ 923 Over kWa True Relay 6 Closed
  • In table 24 a number of events in the system are shown. Event #1 is an event that a digital input module might create if its hardware changed state. In this case, the digital input is connected to the status output of a motor. There is no cause label in this case since the cause is external to the meter. Event #2 shows an event that a digital output module might create. The source input of this digital output module is connected as the state output of the digital input module. Event #3 is an event that a setpoint module might create. The setpoint module has detected that the amount of power being consumed is too great so its status output register is set to true. This status output register is connected as the source input register to another digital output module. In Event #4 the digital output module is shown to close a relay. Therefore, the fact that kW Phase A has exceeded a certain bounds has caused an external relay to close (hopefully rectifying the problem). [0202]
  • A significant feature of the disclosed architecture is that the modules can be linked in arbitrary fashions to form arbitrary functional blocks comprised of networked objects. [0203]
  • An example application using the architecture of this embodiments is shown in FIG. 23. In this example, a setpoint module [0204] 972 is used to monitor Phase A current from the power meter module 926. The setpoint is enabled using a digital input module 940 which is driven by the manual switch 941. The setpoint setup registers are configured so that the setpoint goes ON when the current exceeds 100 Amps. The setpoint status output controls the digital output module 950, which drives a relay 951 which could control a motor (not shown). Whenever the phase A current exceeds 100 Amps and the manual switch 941 is closed, the relay 951 will be closed causing the motor to turn off. (Note: in this example setup registers and other registers that are not needed for the example are not shown.) It will be appreciated by those skilled in the art that the number and variety of possible additional modules and applications is unlimited.
  • The operation of most of the modules in the IED is governed by the client portion of the module flow controller. A flow chart for the execution of the client portion of the module flow controller is shown in FIG. 24A. The module flow controller causes different modules within the device to execute. The module flow controller only triggers modules to execute that have valid input registers. Therefore, any modules that do not meet this requirement do not use any of the processing power available to the device. The server portion of the module flow controller is executed when a module has the write input handles method invoked on it. A flow chart for the operation of the server portion of the module flow controller is shown in FIG. 24B. The server portion of the module flow controller records whether the input handles being written are valid or not. The client portion then uses this information when it makes its decision on whether to execute the module or not. [0205]
  • FIG. 25 schematically illustrates a preferred embodiment of a manager, the analog output manager [0206] 1100. A flow chart for the logic for the server portion of a manager is shown in FIGS. 25A-25B. In the present embodiment, managers have no client portion. There is one resource manager 1100 for each type of module. Each resource manager 1100 may have many modules below it.
  • Every manager [0207] 1100 in an IED resides beneath the feature manager for the device. A preferred embodiment of feature manager 1200 is schematically shown in FIG. 26. A flow chart for the logic of the server portion of the feature manager is show in FIGS. 26A-26B. All the managers on the device appear as setup registers 1201 to the feature manager 1200. The feature manager 1200 controls access to the entire device 900. Starting from the feature manager 1200, a master device, such as PC 914, can determine all input, output and setup registers for every module on the IED device 900.
  • Each manager is said to own all the modules that appear as its setup registers. The feature manager is said to own the resource managers that appear as setup registers to it. Therefore, a hierarchy of modules exists with the feature manager on top. [0208]
  • In order for a master device, such as PC [0209] 914, to access the information in a slave device, such as the IED 900, it invokes methods on the managers, modules or registers. In order for a master to execute a method on a slave, it must have a handle. The handle indicates which manager, module or register the method is to be acted on. For example, the handle for the feature manager for any type of slave device is 2 in the current embodiment. This is the only thing that is fixed in the architecture and every type of device has a feature manager with a handle of 2. From this handle, the entire configuration of the device can be determined.
  • With the configuration of the present embodiments, the slave device, such as the IED's [0210] 900 may have the capability to execute many different objects, but only a limited number of objects can be executed at any one time due to processing power constraints. The flow control client controls the operation of modules. Therefore, only the modules that have valid input, output and setup registers connected to them are executed.
  • In order for a master device, such as a PC [0211] 914, to determine the configuration of a slave device without the master device having any previous knowledge of the configuration, the master device invokes certain methods on the feature manager. These methods are fixed in the architecture. In other words, every feature manager for every different type of slave device will interpret these methods in the same way. For instance, the master device may invoke the method Read Setup Handles on the feature manager which requests a list of the managers that reside beneath it. From this list, the master device can then go to each individual manager and request the operating modules beneath them by again executing the method Read Setup Handles. Once the master device knows which modules are operating, it can request of each module its currently connected input, output and setup registers using the appropriate methods and thus determine the entire configuration of the device. Thus, without any prior knowledge of the slave device, or its configuration, the master device can determine all characteristics of the device. The master device can then invoke other methods to change the configuration of the device. The slave devices, however can operate autonomously without the involvement of the master devices.
  • Thus, the slave devices, such as power monitors, can be readily configured to exactly match a user's unique requirements and to provide the ability to do so without interrupting the operation of the rest of the functions the device is performing. The slave devices, such as the IEDs, can be networked to one or more computers and the slave devices can be configured or reconfigured via the communications network. [0212]
  • Further, with the present embodiments, it is not necessary to change the software on a master device when a slave device is upgraded. [0213]
  • The modules are independent or autonomous. Thus, when a module is modified, there is no need to modify the other modules. As used herein the term “independent modules” means that modifications or changes can be made to one or more modules without a need to modify the remaining modules (i.e. a modification to one module has no effect on the operation or functionality of the other modules. [0214]
  • The feature manager keeps a count of how many times the configuration of the device has been changed. A master can invoke a the method Read Module setups counter on the feature manager to request this count. If there are multiple masters changing the configuration of the device, each master need only request this count from the feature manager to determine if the configuration of the device has been changed, [0215]
  • The feature manager also contains a count of how many times the modules below it have updated their output registers. Each individual manager has a count of how many times the modules below it have updated their output registers and each individual module has a count as well. Therefore, if a master device executes the method Read Module Updates Counter and finds that none of the modules under a certain manager have updated their output registers since the last time the master read the values in the registers, the master does not need to waste communications bandwidth reading the same values again. [0216]
  • Methods and Modules are preferably assigned a security level. This permits the system to be configured such that certain users have access to all of the system functions while other users have access to only selected functions. [0217]
  • The Read Security Level, Read All Security Levels and Read Module Security methods can be used to determine what level of authorization is necessary to access the various methods and modules in the system. [0218]
  • The foregoing description of the preferred embodiments of the present embodiments has been presented for purposes of illustration and description. The described embodiments are not intended to be exhaustive or to limit the embodiments to the precise forms disclosed. Obviously many modifications and variations are possible in light of the above teachings. The embodiments which were described were chosen in order to best explain the principles of the embodiments and its practical applications. [0219]
  • Referring back to FIG. 3 is a diagram using the object-oriented architecture disclosed in the copending application Ser. No. 08/369,849, now U.S. Pat. No. 5,650,936. The diagram of FIG. 3 shows modules which represent program objects. A “module” may be regarded to be an active object in the program architecture. Modules behave as both a client and a server. The client portion of a module contains the active components which perform the various tasks within the device. Modules act as “black boxes” that read data in at the inputs, manipulate the data in some fashion, and write the result to outputs. The inputs are read from registers and the outputs are written to registers. [0220]
  • The diagram of FIG. 3 shows a functional relationship between the program objects that may be used in a preferred embodiment of the system. The objects shown in FIG. 3 include objects that may be physically located (or that may be regarded as “running”) on the phasor transducers and/or the phasor array processors, or both. In a preferred embodiment, the modules shown in FIG. 3 are located on a single phasor transducer, such as the phasor transducer [0221] 51. The other phasor modules, 50, 52, 53, and 54, would include similar phasor modules.
  • (1). Phasor Power Modules [0222]
  • As shown in FIG. 3, running on the phasor transducer [0223] 51 (specifically on the phasor transducer local microprocessor 100) are a plurality of phasor modules 200. In the embodiment shown, the plurality of phasor modules 200 includes a phasor module for each voltage and current channel. The plurality of phasor modules 200 receive the digitized values of the voltage and current signals V1, V2, V3, I1, I2, I3, and I4, that are output from the analog to digital converter 70 in FIG. 2. (Each of the other phasor transducers 50, 52, 53, and 54 of FIG. 1 would likewise include its own plurality of phasor modules for the digitized values of the voltage and currents channels sensed by its corresponding voltage and current sensors associated with its corresponding circuit.) In the embodiment shown in FIG. 3, the plurality 200 of phasor modules includes seven phasor modules, 200A-200G. Each of these phasor modules receives as an input one of the digitized voltage or current signals, V1, V2, V3, I1, I2, I3, and I4. In addition, each of these modules includes an “enable” input, such as input 202A on module 200A. The “enable” input enables operation of the module. The “enable” input is received from another module with a Boolean output. In an alternative embodiment, the module 200A may defaulted to “enable” and will provide an output unless a negative signal is received on its “enable” input.
  • Each of the phasor modules [0224] 200 provides an output in the form of a phasor array output register and an event register. For example, phasor modules 200A-200G output phasor array output registers 206A-206G, respectively, and event registers 208A-208G, respectively. Each of the phasor module output registers 206 contains an array of phasors computed by it