dg communication – development of object models and related standards

DG Communication – Development of Object Models and Related Standards

Clemson, SC, March 10, 2005

Dr. Alexander Apostolov

AREVA T&D Automation

> DER IEC61850 Object Models2

Introduction

IEC 61850 is now an approved international standard

It allows the extension of the modelling concept to cover different domains and applications

The successful implementation requires good understanding of the principles of the standard and the specifics of the domain


Distributed Energy Resources


Objects An object is “.. a thing that can be seen and touched;

material thing that occupies space .. “.

Webster New World Dictionary of the American Language

In object-oriented design (OOD) an object is an abstraction of real world entities and functions in a problem domain.

Problem Domain is the application or process that is being modeled by Object Oriented representation (Classes and Objects) – power system protection and control.

Objects are encapsulated — that is, they contain both their code and their data, making them more easier to maintain


Classes and Objects

A class is a template for the creation of objects, the description of one or more objects with the same definitions for information and behavior.

An object is defined as an instance of a class Objects represent information and behavior :

properties (or components, attributes) Data that describe an object

services (or methods, and events) Methods are things you can tell the object to do Events are things the object does


Classes and Objects


Substation Communications Architecture

Substation Computer

IED IED IED

Switch

Substation HMI

Router

IED IED IED IED

Switch

SCADA Master

WAN


DER System Communications Architecture

IED

Switch

Analysts

WAN

Substation 1

Substation 2

Substation i

Substation j

SubstationGateway

EMS

SCADA ServerISD

EMS

Traders

IED IED

IED

DERDER

DER

DER

DER


Function Definitions

Functions in the substation are performed by the protection, control, monitoring and recording system.

A function can be divided into sub-functions and functional elements.

The functional elements are the smallest parts of a function that can exchange data.

These functional elements in IEC 61850 are called Logical Nodes


Logical Node Groups

System Logical Nodes LN Group: L

Logical Nodes for protection functions LN Group: P

Logical Nodes for protection related functions LN Group: R

Logical Nodes for control LN Group: C

Logical nodes for generic references LN Group: G

Logical Nodes for interfacing and archiving LN Group: I

Logical Nodes for automatic control LN Group: A


Logical Node Groups

Logical Nodes for metering and measurement LN Group: M

Logical Nodes for sensors and monitoring LN Group: S

Logical Nodes for switchgear LN Group: X

Logical Nodes for instrument transformers LN Group: T

Logical Nodes for power transformers LN Group: Y

Logical Nodes for further power system equipment LN Group: Z

Logical Nodes for Distributed Energy Resources LN Group: D


Logical Nodes Group D

DER Controller DRCT

DER generator Ratings DRAT

DER Generator DRGN

Synchronization DSYN

Inverter DINV

Diesel Engine DIES

Fuel cell DFCL

Photovoltaics DRPV


Logical Nodes Group D

Fuel Systems DFUL

Battery Systems DBAT

Environmental Conditions ENVR

Heat System DHET

Contractual Parameters DCCT


Logical Nodes Information Categories


Functional Constraints

The property of DataAttribute that shows its use is a Functional Constraint (FC).

Some more commonly used are:

CO – control

SP – set point

CF – configuration

DC – description

SG – setting group

MX – measurements


Object Hierarchy

Server

Logical Device

Logical Device

Logical Device

Logical Node

Logical Node

Logical Node

Data Data Data

Data Attribute

Data Attribute

Data Attribute


Nested DataAttributes

DATAInstance

DataAttr

DataAttr

DAComp

DAComp

DAComp

DAComp


Data path example

MMXU1.A.phsB.cVal.mag.f

MMXU1: instance of LN class MMXU defined in Part 7-4

A: instantiation of the Composite DATA class WYE (defined in 7-3)

phsB: value of the current in phase B as a Simple Common DATA class of

type CMV (defined in 7-3 )

cVal: is the complex value of the current in phase B (of the Common

DataAttribute type Vector)

mag: this object represents the magnitude of the complex value (type

AnalogValue - defined in 7-3)

f is a DataAttributeComponent which is of the basic type FLOATING POINT

(defined in 7-2)


Common data classes for measurand information

Measured value (MV)

Complex measured value (CMV)

Sampled value (SAV)

WYE

Delta (DEL)

Sequence (SEQ)

Harmonic value (HMV)

Harmonic value for WYE (HWYE)

Harmonic value for Delta (HDEL)


Metering and Measurement Logical Nodes

Differential measurements Name: MDIF Harmonics or interharmonics Name: MHAI Non phase related harmonics or interharmonics

Name: MHAN Metering Name: MMTR Non phase related Measurement Name: MMXN Measurement Name: MMXU Sequence & imbalance Name: MSQI

Metering Statistics Name: MSTA


Measured values attributes in MMXU

Name Type DescriptionPPV DEL Phase to phase voltagesPhV WYE Phase to ground voltagesA WYE Phase currentsW WYE Phase active power (P)VAr WYE Phase reactive power (Q)VA WYE Phase apparent power (S)TotW MV Total Active Power (Total P)TotVAr MV Total Reactive Power (Total Q)TotVA MV Total Apparent Power (Total S)TotPF MV Average Power factor (Total PF)Hz MV FrequencyPF WYE Phase power factorZ WYE Phase Impedance


Measurements Object MMXU


Logical Nodes Data


Setting Data


Overcurrent Protection LN PTOC


Setting Attributes


Services


Services

control devices (Operate service or by multicast trip signals) (1)

fast and reliable peer-to-peer exchange of status information (tripping or blocking) (2)

reporting of any set of data (data attributes), SoE – cyclic and event triggered (3)

logging and retrieving of any set of data (data attributes) – cyclic and event triggered (4)

substitution (5)


Services

handling and setting of parameter setting groups

transmission of sampled values from sensors,

time synchronisation,

file transfer,

online configuration (6), and

retrieving the selfdescription of a device (7)


IED Functional Hierarchy

Multifunctional

IED

DeviceIdentit

y

Over-current

Ground Definite time #1

Pickup Value

Function

Function

Phase

Negat. Seq.

Inverse time

Instant.

Time delay

Directio-nality

Minimum

Maximum

Step

Function

Control

Sub-FunctionControl



Substation Functional Hierarchy

PD2

LNn

LD1

F2

PD1

LN4

LNn

LD1

F1

F3

LN1

LN2

LN3

LN4

LN1

LN2

LN3



Substation Computer

IED IED IED IED

CT VT CT VT

Station Bus

Process Bus

Station Bus Mappings (8-1)

Layered Mapping (TCP/IP)

GOOSE/GSSE (Link)

Time Sync (SNTP)

Process Bus Mappings (9-1,9-2)

Sampled Values (Link)

GOOSE/GSSE (Link)

Time Sync (SNTP)


Logical Interfaces

Technical Services

Remote control (NCC)

CONTR. PROT.

FCT. A FCT. B

PROT. CONTR.

Sensors Actuators

BAY/UNIT LEVEL

STATION LEVEL

PROCESS LEVEL

HV Equipment

Remote protection

Process Interface

1,6

3 3

9

8

1,6

2 2

4,54,5

710

Remote protection


Logical Interfaces

IF1: protection-data exchange between bay and station level

IF2: protection-data exchange between bay level and remote protection

IF3: data exchange within bay level

IF4: CT and VT instantaneous data exchange (especially samples) between process and bay level

IF5: control-data exchange between process and bay level


Logical Interfaces

IF6: control-data exchange between bay and station level

IF7: data exchange between substation (level) and a remote engineer’s workplace

IF8: direct data exchange between the bays especially for fast functions like interlocking

IF9: data exchange within station level

IF10: control-data exchange between substation (devices) and a remote control center


High-Speed Peer-to-Peer Communications

Generic Substation Event (GSE)

Based upon the asynchronous reporting of an IED’s functional elements status to other peer devices enrolled to receive it during the configuration stages of the substation integration process

Used to replace the hard wired control signal exchange between IED’s for interlocking and protection purposes

Mission sensitive, time critical and must be highly reliable.


GSE Messages:

GSSE and GOOSE

Status/State Oriented

Event ID

Event Time

Higher Reliability

Periodic Refresh

Automatic Reset

Sequence Count


Addressing Modes

Unicast communication takes place over the network between a single sending IED and a single receiving IED. The Destination Address identifies a unique device that will receive the Ethernet frame.

Multicast is the addressing mode in which a given frame is targeted to a group of logically related IEDs. In this case the Destination Address is the Multicast Address, also called a "group" address.


Addressing Modes

Broadcast is the mode when an IED is sending a frame to all devices connected to the substation network.

The Destination Address in this case is a Broadcast Address - a multicast address identifying the group of all devices on a network - all 1 bits.

The Broadcast Domain includes all network segments joined together by bridges.


Measuring Functions Decomposition

IARC IHMI

MMTR MMXU

TVTR TCTR

SubstationLevel

BayLevel

ProcessLevel


Multifunctional IED Object Model

Server

LD1

LD2

LD3

LD4

LD5

LD6



Server

LN1

LN2

LN3

LN4

LNn

LD1



PQM IED

LN(i)

MMXU1

LD1

MMTR1

MMHI1

MSTA1

MMXU2

MMHI2

MSTA2

HV

MV

hv

mv


Configuration File

dg communication – development of object models and related standards

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