Generator Performance Guideline Public Forum 8 April 2019 Safety - - PowerPoint PPT Presentation

Generator Performance Guideline Public Forum

8 April 2019

Safety briefing

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Contents

• Overview
• Generator Performance Guideline
• The Performance Criteria
• Next steps

Overview

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• New technologies underpinning the changing electricity supply are providing customer choice, reducing carbon emissions and

providing low cost supply of energy. However, they are also creating operational challenges for a system and market designed for a traditional one-way flow of energy.

• Synchronous generation that has historically provided most of the services required to keep the system secure and reliable

(either as required by standards, a paid service, or inherently as a by-product of energy production) is making way for low cost, zero emission, renewable generation.

• Distributed, non-synchronous resources are technically able to provide most (and potentially in the future all) of the essential

services.

• However the standards and market arrangements need to incentivise this capability, and also provide new revenue streams to

existing generators.

Traditional Electricity System Evolved Electricity System

The system is evolving rapidly

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Market inefficiencies System security at risk

500 1000 1500 2000 2500 00:00:00 03:00:00 06:00:00 09:00:00 12:00:00 15:00:00 18:00:00 21:00:00 00:00:00

System load (MW) Time of day

28/10/2018 2020 2022 2024 2026 2028

• Increasing penetration of DER

and large-scale renewables is resulting in reduced inertia, voltage control capability and system strength from remaining synchronous generators; and increasing variability.

• It will be necessary to intervene

in the market to ensure required levels of system security are maintained.

• Critical that all power system

resources are able to support the system.

And presenting new challenges

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• Energy landscape in Western Australia is transforming rapidly
• Current Technical Rules no longer fit for purpose
• Collaborative approach is required
• Visibility for generators currently in the connections pipeline

The need for an interim guideline

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The journey so far

• WP and AEMO did an initial review of what was required to be changed.
• There was an initial engagement with generators who were actively

progressing their projects and feedback requested from them.

• Based on the initial review as well as the finalisation of the NER

requirements, WP engaged a consultant to develop more details around the requirements, together with AEMO.

• The guideline was shared with the generators likely to be connecting in

the near future and feedback again requested from them and their EPC contractors.

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Generator Performance Guideline

The following areas of performance are included:

• Reactive power capability and control
• Active power control
• System strength
• Frequency control
• Disturbance ride-through
• Generator protection
• Models

What is included?

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• Aim is to facilitate a move away from TR

derogations

• Generators advised to target ideal standard to

ensure future compliance

• Ideal compliance provides automatic access
• Compliance between ideal and minimum

standard requires justification from the generator

• Tripartite negotiation with WP/AEMO and Generator
• Capability below the minimum standard will

prevent network access

Levels of compliance

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• Guideline was developed to target future generation connections.
• Existing generators must continue to perform to the standards agreed at the

time of their connection

• Existing generators may be required to comply when facilities undergo an

upgrade or modification

Grandfathering?

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• Review stakeholder feedback and update the Guideline
• Approach to rule changes will be determined in consultation with

the wider Electricity Sector Reform Initiatives

• We will provide advice to industry on timing and approach as soon

as possible

Will the Technical Rules be updated?

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The Performance Criteria

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The approach

• Facilitate the introduction of compliance levels
• Common requirements for all technologies (where possible)
• Alignment with the NER and International best practice
• Standards tuned to the needs of the SWIS

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Technical Rules Current Requirements -

Reactive power capability

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• Varying requirements based on technology
• No flexibility when considering network requirements
• Based on historic generation portfolio and consumer behaviour
• Derogations have previously been required
• Not aligned with the NER and international best practice

Technical Rules Current Requirements -

Reactive power capability

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Induction Generation Synchronous Generation Inverter Generation

Please note: Figures are from the Technical Rules

Proposed Generator Performance -

Reactive power capability

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Ideal Standard Minimum Standard

Reactive power capability

Current technical rules comparison NER comparison Ideal standard developed considering the performance requirements specified in clause 3.3.3.1 of the Technical Rules with some adjustments made to adopt a performance requirement which is appropriate for all generation technologies. The minimum allows non-scheduled generating systems to achieve the reactive power capability by reducing the active power output when the ambient temperature exceeds 25oC. Minimum standard is greater than NER minimum. The size and isolated nature of the SWIS means we have a greater requirement for generation of reactive power.

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What are the main changes?

• Consistent requirements for all generation types
• Minimum standard based on current derogations

Reactive power control

Current technical rules comparison NER comparison The ideal will provide a similar level of performance to the current TR, but offers the ability for a wider set of control modes The ideal standard requires generators to have the ability to regulate voltage, reactive power and power factor and switch between modes as required. Control modes nominated by Western Power and AEMO. We have adopted NER automatic as the ideal standard We have adopted NER minimum as the minimum standard

What are the main changes?

• Introduction of a wider set of control modes
• NER standards adopted but they are aligned with TR clause 3.3.4.5

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Active power control

Current technical rules comparison NER comparison The ideal standard retains the ramp rate provisions specified in clause 3.3.3.5 of the Technical Rules. Embeds requirement for capability of control through AGC. Requirements apply to all new large generators subject to energy source availability. NER aligned.

What are the main changes?

• Adoption of the NER approach (supports move to security constrained economic dispatch)
• TR 3.3.3.5 ramp rates retained for ideal standard to reflect requirements of isolated system
• Better definition of the performance requirements

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System strength

Current technical rules comparison NER comparison System strength is not currently covered by TR. Generators undertake a preliminary assessment of system strength using the Minimum Short Circuit Ratio (MSCR) method described in the AEMO

• guideline. If this indicates there is insufficient

Available Fault Level (AFL) to accommodate the new generator connection then this would trigger the need for Western Power to carry out a detailed assessment using an Electro-Magnetic Transient (EMT) model of the generator. We will adopt the assessment method set out in the AEMO System Strength Impact Assessment guideline providing alignment with Eastern States. https://www.aemo.com.au/Electricity/National- Electricity-Market-NEM/Security-and- reliability/System-Strength-Impact-Assessment- Guidelines

What are the main changes?

• Generators need to consider system strength when making an application
• System strength <3 an Electro-Magnetic Transient (EMT) model will be required by Western Power to assess

compliance

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Frequency control

Current technical rules comparison NER comparison The ideal standard reflects the current TR for scheduled generation and applies that level of performance for all generating units. Minimum requirement for non-scheduled generation is subject to energy source availability. NER has a market to provide ancillary services and does not align with the WEM approach.

What are the main changes?

• None – TR requirements maintained.

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Disturbance ride-through (frequency)

Current technical rules comparison NER comparison Frequency threshold aligned to the frequency

• perating standards for the SWIS specified in the

Technical Rules. The withstand times for over and under-frequency events specified in the minimum standard reflect those specified in clause 3.3.3.3(b) of the Technical Rules. The RoCoF requirements are more relaxed than those specified in clause 3.3.3.3(d) of the Technical Rules, but better reflect expected capabilities of thermal generators as identified through the AEMC review. The over and under frequency ride through in the ideal standard reflects the approach adopted in the NER The RoCoF requirements reflect those in the NER which have been developed by the AEMC considering international practice.

What are the main changes?

• NER requirements adopted (TR and NER requirements are aligned)
• Adopting automatic NER as ideal TR provides relaxed requirements for ROCOF
• Adopting minimum NER as minimum TR is also not a large change.

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Disturbance ride-through (voltage)

What are the main changes?

• More detailed specification of requirements than is currently in TR
• Reflects NER S5.2.5.4

Current technical rules comparison NER comparison The proposed performance standard expands on the requirements of the Technical Rules which focus more on the requirement to ride through low voltages immediately following faults. Collectively the performance standard for voltage ride through and that proposed for riding through multiple contingency events provides a more detailed specification of required performance than is contained in the Technical Rules. Aligned with NER requirements.

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Disturbance ride-through (multiple contingencies)

What are the main changes?

• Fill gaps in the TR and align our requirements with those used in the NEM.
• Reflects NER S5.2.5.5

Current technical rules comparison NER comparison The Technical Rules do not specify a requirement to ride through multiple contingency events. NER clauses to be utilised to ensure generation can ride through multiple disturbances and provide consistency The proposed standards reflect those recently introduced into the NER.

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Disturbance ride-through (partial load rejection)

What are the main changes

• Current TR requirement used as ideal standard
• NER minimum standard adopted to provide negotiation range

Current technical rules comparison NER comparison The ideal standard reflects the current Technical Rules requirements. Performance level now specified as % of generator rating rather than system load. Minimum standard is based on the minimum requirement specified in the NER.

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Disturbance ride-through (quality of supply)

What are the main changes

• Reflects NER S5.2.5.6, no equivalent requirement in TR
• Provides requirement to ride through power quality outcomes consistent with the NER

Current technical rules comparison NER comparison The Technical Rules do not specify a requirement to ride through power quality events. Adopting the proposed NER standards addresses this gap in the Technical Rules. Aligned with the NER

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Generator protection

What are the main changes?

• Western Power is seeking to clarify current requirements.
• WP factsheet, “Anti Islanding Protection for transmission generators.doc” provides further

elaboration.

• WP factsheet will merge into final rule changes.

Current technical rules comparison NER comparison No changes to TR requirements. Further clarification on the TR requirements for anti islanding is provided. Aligned with NER requirements

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Model provision including EMT

What are the main changes?

• EMT models are required, the timing of model submission is based on system strength impact

assessment

• Models will allow Western Power to ensure new connections “do no harm” to exiting connections.

Current technical rules comparison NER comparison The modelling requirement builds on that in the Technical Rules. No change for RMS PowerFactory model, consistent with Western Power Generator and Load Model Guidelines. EMT models are now required. Aligned with the recently revised NEM system model guideline to specify the requirement for EMT models.

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Q&A

Wrap Up/Next Steps

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• Provide feedback by Friday 10 May 2019 to

RegulatoryReforms@westernpower.com.au

• Review stakeholder feedback and publish the updated Guideline
• Determine approach to formalising the Guideline in consultation with

Electricity Sector Reform Initiatives before implementing the proposed standards

• Provide advice to industry on timing and approach to implementation as

soon as possible

Head office 363 Wellington Street Perth, WA 6000 westernpower.com.au Perth Head office 152 St Georges Terrace, Perth, WA 6000 aemo.com.au