NZQA registered unit standard
26020 version 4
Page 1 of 7
Title
Demonstrate knowledge of intermediate concepts in power system
protection
Level
5
Credits
10
Purpose
People credited with this unit standard are able to: demonstrate
knowledge of the coordination of low and high voltage
protective schemes; demonstrate knowledge of protection
terminology, feeder protection and IEC and DIN standards
relating to advanced power system protection schemes;
demonstrate knowledge of components in protection schemes;
demonstrate knowledge of High Voltage (HV) protection;
describe the principles of circuit and busbar protection in the
electricity supply industry; demonstrate knowledge of System
Control and Data Acquisition (SCADA) Systems; demonstrate
knowledge of communications; demonstrate knowledge of ‘as
built’ diagrams and system documentation procedures; and
demonstrate knowledge of safety and safe working practices
when operating in a HV environment.
Classification
Electricity Supply > Electricity Supply - Power System
Maintenance
Available grade
Achieved
Entry information
Critical health and
safety prerequisites
Unit 26019, Demonstrate knowledge of introductory concepts
in power system protection, or demonstrate equivalent
knowledge and skills.
Explanatory notes
1
This unit standard is intended for, but not restricted to, workplace assessment. The
range statements across the unit standard can be applied according to industryspecific equipment, procedures, and processes.
2
Protection systems may include those associated with prime movers, generators,
transformers, bus work and distribution networks including: fault detection systems,
shutdown and alarm initiation systems, electrical protective relays, voltage and
current transformers, field devices, transducers, programmable logic controllers,
computers, and alarm annunciation systems.
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011
NZQA registered unit standard
26020 version 4
Page 2 of 7
3
Sources of information include but are not limited to the International Electrotechnical
Commission (IEC), the Institution of Engineering and Technology (IET), the American
National Standards Institute (ANSI), and the Deutsches Institut für Normung e. V. (DIN).
4
Performance and work practices in relation to the outcomes and evidence
requirements must comply with all current legislation, especially the Electricity Act
1992, and any regulations and codes of practice recognised under that statute; the
Health and Safety in Employment Act 1992; and the Resource Management Act
1991. Electricity supply industry codes of practice and documented industry
procedures include the Safety Manual – Electricity Industry (SM-EI) (Wellington:
Electricity Engineers’ Association, 2010). A full list of current legislation and industry
codes of practice is available from the Electricity Supply Industry Training
Organisation, PO Box 1245, Hamilton 3240.
5
The phrase in accordance with industry requirements is implicit in all outcomes and
evidence requirements in this unit standard.
6
Industry requirements include all asset owner requirements; manufacturers’
specifications; and enterprise requirements which cover the documented workplace
policies, procedures, specifications, and business and quality management
requirements relevant to the workplace in which assessment is carried out.
7
The outcomes of this unit standard are equivalent to the learning outcomes of the
New Zealand Board of Engineering Diplomas (NZBED) course component DE5413
Power Protection Systems 1 Level 5. If a candidate has completed the NZBED
course component related to this standard then they can apply to the ITO for
Recognised Prior Learning (RPL). Further information about this process may be
obtained from the Electricity Supply Industry Training Organisation, PO Box 1245,
Hamilton 3240.
Outcomes and evidence requirements
Outcome 1
Demonstrate knowledge of the coordination of low and high voltage protective schemes.
Range
fuse to fuse, circuit breaker to fuse, time lag fuses, limitation of fault current,
discrimination, back-up protection, protective devices used in 11kV to 220kV AC
and 350kV DC.
Evidence requirements
1.1
Terms used to describe protection schemes are explained.
Range
includes but is not limited to – reliability, selectivity, discrimination,
setting calculations, speed of operation, sensitivity, stability, unit
protection, prospective short circuit currents (PSCC), primary
protection, backup protection, relay pickup current, instantaneous
relays, inverse time relays, inverse definite minimum time relays,
definite time relays, Translay systems (pilot).
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011
NZQA registered unit standard
1.2
The type of protection required and the reason for the type is explained for each
point of connection in the total system, from generation to low voltage
distribution, using a diagram.
Range
1.3
26020 version 4
Page 3 of 7
includes but is not limited to – switchyards, high voltage and low
voltage transmission, earth fault (instantaneous, inverse, and
definite time), differential, overall differential, overcurrent
(instantaneous, inverse, and definite time), distance, bus zone,
discrimination.
Function and use of each type of protection relay are explained with reference
to test specifications and performance characteristics.
Range
includes but is not limited to – earth fault (instantaneous, inverse,
and definite time), differential, under voltage, over voltage,
overcurrent (instantaneous, inverse, and definite time), bus zone,
frequency, fuse failure, diode fuse failure, directional, Translay
systems (pilot), Inverse Definite Minimum Time Lag (IDMTL) relay,
static protection relay;
performance characteristics – pick up, drop off, polar plots; for
digital, electro-mechanical, solid state types.
Outcome 2
Demonstrate knowledge of protection terminology, feeder protection and IEC and DIN
standards relating to advanced power system protection schemes.
Range
protection terminology, ANSI and IET relay codes and symbols, protection
schemes of feeder both radial and parallel, low set, high set and inverse time
elements (directionality), earth fault, auto reclosing relays, discrimination,
testing, both electro-mechanical and digital microprocessor based relays, pilot
wire/live differential, isolation requirements, oscillation, inverse time curve.
Evidence requirements
2.1
Naming schemes as they apply to the IEC and DIN standards, and the
relationship between the two standards, are identified and described.
2.2
Naming schemes as they apply to the IEC and DIN standards are coded and
the significance of each flag is explained.
Range
includes but is not limited to – instantaneous overcurrent,
instantaneous earth fault, definite time, tripping auxiliary, inverse
time overcurrent, inverse time earth fault, pilot wire, distance,
positive sequence, negative sequence, differential, directional
(other than earth fault), temperature, change over, directional
earth fault, differential earth fault, under voltage, over voltage,
unidirectional (protection signalling), frequency, reverse power,
oscillator lockout, bus zone A, bus zone B, bus check, bus super.
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011
NZQA registered unit standard
26020 version 4
Page 4 of 7
Outcome 3
Demonstrate knowledge of components in protection schemes.
Range
basic concepts of overcurrent relay Definite Minimum Time (DMT), Inverse
Definite Minimum Time Lag (IDMTL), directional overcurrents, basic concept of
earth fault protection and restricted earth fault protection, basic concept
differential, basic distance protection, flash detection, circuit breaker fail, digital
fibre, earth testing substation sites, Neutral Earthing Resistor (NER) and
Peterson coils, batteries and charges, trip circuit supervision.
Evidence requirements
3.1
Methods and procedures required to test multiple input protection schemes
using protection relays are described.
Range
3.2
Testing methods and procedures used are described.
Range
3.3
may include but is not limited to – generators, transformers, sub
stations, transmission lines, energising signals, role of
microcontroller, the different types of microcontroller memory, selfsupervision, universal overcurrent relay, Current Transformer (CT)
burden compared to IDMTL relays, reset times and starting
characteristics, dual setting banks, digital displays, recovery of
fault information from memory, auxiliary power requirements,
testing of static relays;
evidence of at least two examples of each item is required.
Test procedures for test plans for multiple input protection schemes for the use
of relays are described in detail with the aid of diagrams.
Range
3.4
relays deployed in the protection of any of the following –
generators, transformers, sub stations, transmission lines, or their
combination.
includes but is not limited to – earth fault (restricted and
unrestricted instantaneous, inverse, and definite time), overcurrent
(instantaneous, inverse, and definite time), differential, overall
differential, differential earth fault (delta primary), under voltage,
over voltage, performance characteristics, primary and secondary
injection, pick up, timing, drop off, polar plots, time discrimination,
functional checks for one of digital, electro-mechanical or solid
state relay types, setup Power System Management (PSM)
settings and curves, burden, setting and testing of device, factors
effecting the choice of plug setting.
The special note in IEC regulation 68150 is discussed.
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011
NZQA registered unit standard
26020 version 4
Page 5 of 7
Outcome 4
Demonstrate knowledge of High Voltage (HV) protection.
Evidence requirements
4.1
The transition from electro-mechanical relays to electronic and digital
microprocessor-based relays is discussed.
Outcome 5
Describe the principles of circuit and busbar protection in the electricity supply industry.
Range
low impedance, high impedance, schematic design.
Evidence requirements
5.1
The principles of distance-time and definite distance protection are identified
and described in terms of circuit impedance, distance, phase faults, earth faults,
and distance relays.
5.2
The principles of busbar protection are identified and described in terms of
circulating current and current balance.
5.3
The principles of circuit breaker failure protection in terms of back-up protection
and relay flags are identified and described.
Outcome 6
Demonstrate knowledge of System Control and Data Acquisition (SCADA) systems.
Evidence requirements
6.1
The functionality of SCADA systems is described.
6.2
The requirements of setting up a SCADA system are described.
Outcome 7
Demonstrate knowledge of communications.
Range
fibre, ethernet, radio.
Evidence requirements
7.1
The different methods of communication in protective systems are described.
7.2
The requirements of setting up protective systems using the different
communication methodology are described.
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011
NZQA registered unit standard
26020 version 4
Page 6 of 7
Outcome 8
Demonstrate knowledge of ‘as built’ diagrams and system documentation procedures.
Evidence requirements
8.1
An understanding of ‘as built’ diagrams, and procedures for revising the
appropriate documentation, is demonstrated.
8.2
A simple system protective system is designed, analysed, and expressed on an
‘as built’ diagram.
Outcome 9
Demonstrate knowledge of safety and safe working practices when operating in a HV
environment.
Range
up to either 220 kV AC or 350 kV DC.
Evidence requirements
9.1
Precautions and safe working practices when engaged in electrical testing of
equipment and protection schemes are identified and described.
Range
9.2
Managing potential hazards in the workplace is discussed.
Range
9.3
use of appropriate personal protective equipment (PPE) for the
work environment, maintaining PPE in a safe reliable condition,
inspection of PPE prior to use, procedures for inspection following
any incident, basic instrument and hand tool maintenance and
care.
Work authorisations are described.
Range
9.4
the effect on humans of electric shock and the dangers of
electrical power arcs (relevant recent electrical industry accidents
with analysis of their cause may be included), maintenance and
repair work procedures, troubleshooting, testing on energised
electrical circuits, components, or systems.
levels of authorisations, how to request work authorisations,
responsibilities, examples of documents in current use, typical
commissioning programs.
Electrical work hazards in the workplace are identified.
Range
defined work areas, lock and tag procedures, HV structure
diagrams including exposure to higher fault levels, step and touch
voltages, electrostatic charges, emergency response systems and
procedures to follow to ensure safety in the event of an incident.
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011
NZQA registered unit standard
26020 version 4
Page 7 of 7
Replacement information
This unit standard replaced unit standard 21230.
Planned review date
31 December 2013
Status information and last date for assessment for superseded versions
Process
Version Date
Last Date for Assessment
Registration
1
20 November 2009
31 December 2012
Revision
2
15 January 2010
31 December 2012
Revision
3
22 October 2010
31 December 2012
Revision
4
21 July 2011
N/A
0120
Consent and Moderation Requirements (CMR) reference
This CMR can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Please note
Providers must be granted consent to assess against standards (accredited) by NZQA,
before they can report credits from assessment against unit standards or deliver courses
of study leading to that assessment.
Industry Training Organisations must be granted consent to assess against standards by
NZQA before they can register credits from assessment against unit standards.
Providers and Industry Training Organisations, which have been granted consent and
which are assessing against unit standards must engage with the moderation system that
applies to those standards.
Requirements for consent to assess and an outline of the moderation system that applies
to this standard are outlined in the Consent and Moderation Requirements (CMRs). The
CMR also includes useful information about special requirements for organisations wishing
to develop education and training programmes, such as minimum qualifications for tutors
and assessors, and special resource requirements.
Comments on this unit standard
Please contact the Electricity Supply Industry Training Organisation info@esito.org.nz if
you wish to suggest changes to the content of this unit standard.
Electricity Supply Industry Training Organisation
SSB Code 101813
© New Zealand Qualifications Authority 2011