19478 version 3

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Demonstrate knowledge of HVDC in the role of a power system controller

Level / 5
Credits / 10

PurposePeople credited with this unit standard are able to demonstrate knowledge of: normal HVDC operation, the effects of outages on HVDC operation, and disturbances and trippings affecting the HVDC link.

Subfield / Electricity Supply
Domain / Electricity Supply - Power System Management
Status / Registered
Status date / 16 April 2010
Date version published / 16 April 2010
Planned review date / 31 December 2014
Entry information / Open.
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

Special notes

1This unit standard is intended for, but not restricted to, workplace assessment. The range statements across the unit standard can be applied according to enterprise specific equipment, procedures and processes.

2Safety of personnel and plant must be a priority throughout the assessment. If the safety requirements are not met the assessment must stop.

3Performance 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)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.

4The phrase in accordance with industry requirements is implicit in all elements and performance criteria in this unit standard.

5Industry requirementsinclude all asset owner requirements; manufacturers’ specifications; and enterprise requirements which cover the documented workplace policies, procedures, specifications, business, and quality management requirements relevant to the workplace in which assessment is carried out.

6Asset ownerrefers to the owner of an electricity supply network that takes its point of supply from Transpower NZ and delivers electricity to industrial, commercial, and residential customers.

7The range of this unit standard is limited to demonstrating a basic knowledge of the fundamental circuits, arrangement, and operation of the HVDC transmission system equipment as applied on the New ZealandHVDCInter-Island power transmission.

8Terms and abbreviations related to this unit standard:

HVDC– High voltage direct current

DC–Direct current

AC–Alternating current

Elements and performance criteria

Element 1

Demonstrate knowledge of normal HVDC operation.

Performance criteria

1.1Configuration of main circuit equipment and related systems in the New Zealand HVDC system is described.

Rangemay include but is not limited to – HVDC single line diagram, interconnecting transformer, communication circuits, runback controller, fast reaction emergency dump (FRED) scheme, over frequency trip, neutral earthing resistors.

1.2Description identifies the control modes for pole operation.

Rangemay include but is not limited to – separate current control mode, joint current control mode, joint power control mode.

1.3Description identifies the power and current modulation functions.

Rangemay include but is not limited to – ramp up, voltage stabiliser, frequency stabiliser, spinning reserve sharing, emergency over frequency control, Haywards islanded constant frequency control.

1.4Description identifies the preferred pole loading.

Rangemay include but is not limited to – minimising mercury arc valve disturbances, submarine cable loading limits, Benmore interconnecting transformer loading limits.

1.5Description identifies the preferred voltage and reactive power control functions and equipment.

Rangemay include but is not limited to – direct voltage control (DVC) function, reactive power control (RPC) function, AC filters, DC harmonic filters.

1.6Description identifies the preferred configuration of AC busbars.

Rangemay include but is not limited to – Haywards 220kV bus, Haywards 110kV bus, Benmore 220kV bus.

1.7Description identifies the terms associated with HVDC trips.

Rangemay include but is not limited to – bipole tripping, Pole 1 tripping, Pole 2 tripping, half pole 1A or 1B tripping.

Element 2

Demonstrate knowledge of the effects of outages on HVDC operation.

Performance criteria

2.1Description identifies the effect of an outage of equipment associated with the HVDC.

Rangemay include but is not limited to – AC/DC converters, busbars, circuit breakers and switches, communications, control and protection cubicles, deluge systems, disturbance recorders, electrode lines and stations, generators, half poles, harmonic filters, poles, runbacks, SCADA, stabilisers, submarine cables, synchronous condensers, transformers, transmission lines.

Element 3

Demonstrate knowledge of disturbances and trippings affecting the HVDC link.

Performance criteria

3.1Description identifies the disturbance recorder systems associated with the HVDC.

Rangemay include but is not limited to – data acquisition system (DAQ), transient fault recorders (TFR), transient line fault locator (TLFL).

3.2Description identifies the energisation of large transformers.

3.3Description identifies the effect of AC system faults.

3.4Description identifies the effect of DC line faults.

3.5Description identifies the effect of signal oscillation problems.

3.6Description identifies the effect of mercury arc valve faults.

Rangemay include but is not limited to – consequential arc back (CAB).

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 if you wish to suggest changes to the content of this unit standard.

 New Zealand Qualifications Authority 2018