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Control electricity distribution network
Level
6
Credits
15
Purpose
People credited with this unit standard are able to: demonstrate knowledge of
power system operation; identify and communicate current distribution
network status; plan scheduled and unscheduled equipment outages and
switching; operate distribution network equipment; manage distribution
network loading; respond to and manage distribution network events; and
report control of the electricity distribution network.
Subfield
Electricity Supply
Domain
Electricity Supply - Power System Management
Status
Registered
Status date
11 December 2009
Date version published
11 December 2009
Planned review date
31 December 2014
Entry information
Recommended: Unit 15568, Coordinate power system
outages, or demonstrate equivalent knowledge and
skills.
Accreditation
Evaluation of documentation and visit by NZQA and
industry.
Standard setting body (SSB)
Electricity Supply Industry Training Organisation
Accreditation and Moderation Action Plan (AMAP) reference
0120
This AMAP can be accessed at http://www.nzqa.govt.nz/framework/search/index.do.
Special 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 industry
specific equipment, procedures, and processes.
2
Safety of personnel and plant must be a priority throughout the assessment. If the
safety requirements are not met the assessment must stop.
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3
Performance and work practices in relation to the elements and performance criteria
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) (2004) Wellington: Electricity
Engineers’ Association. A full list of current legislation and industry codes is
available from the Electricity Supply Industry Training Organisation, PO Box 1245,
Waikato Mail Centre, Hamilton 3240.
4
The phrase in accordance with industry requirements is implicit in all elements and
performance criteria in this unit standard.
5
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.
6
Practical workplace exercises or simulations should be used for training and
assessment where possible.
Elements and performance criteria
Element 1
Demonstrate knowledge of power system operation.
Range
may include but is not limited to – active and reactive power, characteristics of
end use loads and distribution plant, generation of active and reactive energy,
power flows, distribution theory, static and dynamic behaviour of total system,
types of faults and protection schemes.
Performance criteria
1.1
Theory of electrical energy as applied to various loads is described.
Range
1.2
may include but is not limited to – resistive, inductive reactive and
capacitive reactive loads; motors, inductors, capacitors.
The capabilities and characteristics of power system equipment are described.
Range
may include but is not limited to – generators, transformers,
overhead lines and cables, capacitors, inductors, circuit breakers
and switchgear, normal and short term current and capacity
ratings, fault ratings, electrical characteristics.
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1.3
The principles of electrical power system operation are described.
Range
1.4
The principles of electrical network protection are described.
Range
1.5
may include but is not limited to – efficiency and voltages; losses,
load sharing; load control systems, system reliability and security;
construction methods, fault work, commissioning new equipment,
planning; communications and System Control and Data
Acquisition (SCADA) systems, computerised monitoring and
control systems.
may include but is not limited to – fault levels, fault types, set
points, system earthing, busbar, equipment and circuit protection,
over current, earth fault, differential, distance, unit and non-unit
protection.
The responsibilities of electricity distribution network controllers are defined.
Range
may include but is not limited to – safety, reliability and security of
network and supply, maintenance of system voltages at zone
substations, effects of switching reactive loads on voltage and
current, optimum utilisation of equipment within ratings, switching
for loading relief, use of load control, manual load shedding in
event of prolonged system voltage, frequency excursions, network
switching for work requirements, fault analysis and restoration
switching, management of work control systems, transfer of
control and assurance protocols.
Element 2
Identify and communicate current distribution network status.
Range
may include but is not limited to – unavailable plant, network open point
configuration, equipment loadings, import/export loadings, network and
substation voltages, temporary constraints, indications and alarms.
Performance criteria
2.1
Equipment status is determined.
Range
2.2
Planned events which impact on equipment status are identified and their
impact determined and recorded.
Range
2.3
may include but is not limited to – SCADA and panel
instrumentation, field communication and reports.
may include but is not limited to – permits, assurances, prepared
outage and switching plans.
Controller handover procedures are completed ensuring that all relevant
information is transferred to the new controller.
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Element 3
Plan scheduled and unscheduled equipment outages and switching.
Range
may include but is not limited to – permits, assurances, earth fault inhibit,
reclose block, equipment overload relief, embedded generation; operational
requests, issues and cancellations, opportunity outage requests, equipment
commissioning plans, non-emergency faults, customer notification.
Performance criteria
3.1
Prepared outage and switching plans include all necessary procedures and
resources to achieve the required outcome and allocate resources to optimise
safety and efficient use.
Range
may include but is not limited to – distribution network and
substation single line diagrams and displays, network modelling
tools, disruption minimisation, customer impact, reliability and
security of supply.
3.2
Plans include identified risks with hazards being identified and eliminated,
isolated, or minimised.
3.3
Plans are in a standard format with defining locations and types of systems for
repair and overhaul.
Range
may include but is not limited to – operating orders, transfer of
control and work authority forms, system and substation plant,
equipment records.
3.4
Plans and specifications are complete, concise, and legible.
3.5
Plans are prepared and made available for all personnel involved in
implementing the plans within the scheduled timeframe.
3.6
Notice is initiated to customers and other parties affected by the outage.
Element 4
Operate distribution network equipment.
Range
may include but is not limited to – system integrity, quality control, connection
and disconnection process, remote or local or manual operation, switchgear,
tap changers, embedded generation, other ancillary plant equipment.
Performance criteria
4.1
Authority for equipment operation is obtained.
Range
includes but is not limited to – transfer of control, delegated
authority.
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4.2
The plant and equipment to be operated are identified and the procedures for
the operation of such equipment are complied with.
Range
4.3
Operating decisions are determined.
Range
4.4
may include but is not limited to – equipment availability and
service condition, resource consent and loading limits, impact,
options, alternatives, maximum efficiency.
Equipment is operated within defined equipment capabilities.
Range
4.5
includes but is not limited to – circuit and equipment switching,
application and removal of safety measures, tap changing; circuit
breakers, reclosers, sectionalisers, disconnectors, fuses, links,
earth switches, SCADA systems.
may include but is not limited to – knowledge of operating
standards and processes, operating orders, circuit ratings,
equipment ratings, emergency ratings.
Equipment is monitored.
Range
may include but is not limited to – SCADA indications, alarms,
status, defects, checkback confirmation, field communications.
Element 5
Manage distribution network loading.
Range
network component ratings and emergency ratings, predetermined and
estimated maximum demands, load control equipment, point of supply
constraints, import, export.
Performance criteria
5.1
Circuit and equipment load is monitored.
Range
5.2
may include but is not limited to – load rating and emergency
rating schedules, operating instructions, predictions of peak loads,
permissible short time overloading, temperature and weather
environment.
Load control equipment is operated.
Range
may include but is not limited to – pilot control, ripple control,
power line control, time of use control, automatic under frequency
load shedding, automatic load control.
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5.3
Distribution system power flows are optimised.
Range
may include but is not limited to – electrical constraints, resource
consents, optimised losses, reliability and security, circuit and
equipment rating constraints, open and closed rings, optimum
open points.
Element 6
Respond to and manage distribution network events.
Range
may include but is not limited to – emergencies, unscheduled events, abnormal
conditions, alarms, circuit and equipment faults, operation of protection, under
voltage.
Performance criteria
6.1
System is stabilised.
Range
6.2
The event, and cause of event, is identified using all available resources.
Range
6.3
may include but is not limited to – SCADA alarms and protection
flaggings acknowledged, logging, reports, time sequence.
The impact of the event on the distribution network, its circuits and equipment,
public safety, customer service, and the environment is determined and
responded to.
Range
6.5
may include but is not limited to – plant and equipment status
indications, protection flaggings and event reports; SCADA,
reports, line fault indicators, local knowledge, defect notification.
The event is acknowledged.
Range
6.4
may include but is not limited to – isolation of non-compliant safety
and supply conditions, frequency, voltage, islanded generation,
single phasing, load limits.
may include but is not limited to – equipment serviceability,
security of supply, local control, resource consent and remaining
circuit and equipment loading limits, local control instead of
SCADA, hazardous condition, contamination, Civil Defence.
The event is analysed to identify options to remedy or mitigate undesired
conditions and identify future actions.
Range
may include but is not limited to – restoration planning,
contingency analysis tools, contingency plans, notification of
defect to initiate repair.
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6.6
The event reporting is conducted.
Range
may include but is not limited to – logging systems, protection
event recordings, database systems, maintenance logging
systems, statistical details.
Element 7
Report control of the electricity distribution network.
Range
includes but is not limited to – log book, database systems, statistics, test
reports and results, equipment status changes, equipment history, permits,
work authorities, protection relay event recordings.
Performance criteria
7.1
Recorded information is accurate, complete, concise, and legible.
7.2
Network information is recorded in the required format and filed in the correct
location.
Range
7.3
may include but is not limited to – loadings, voltages, events,
instructions, results of investigation.
Recorded information is forwarded to other parties as required.
Please note
Providers must be accredited by NZQA, or an inter-institutional body with delegated
authority for quality assurance, before they can report credits from assessment against
unit standards or deliver courses of study leading to that assessment.
Industry Training Organisations must be accredited by NZQA before they can register
credits from assessment against unit standards.
Accredited providers and Industry Training Organisations assessing against unit standards
must engage with the moderation system that applies to those standards.
Accreditation requirements and an outline of the moderation system that applies to this
standard are outlined in the Accreditation and Moderation Action Plan (AMAP). The
AMAP 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.
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