GPS Compliance That Protects Your Dispatch Rights. From connection application through to commercial operations, we ensure your generator continues to meet registered performance requirements at every stage of its lifecycle. Our GPS compliance support helps align actual plant behaviour with approved parameters, manage ongoing obligations, and maintain reliable grid performance across operational changes and system updates.
GPS Advisory Across the NEM
Generator Performance Standards Framework
Australian Grid Markets
Asset Types Supported
GPS Categories Covered
The solar farm achieved commercial operations on schedule, but fourteen days later AEMO issued a market notice because the generator was not performing within its registered parameters. The Plant Wide Management System was operating reactive power control in a mode that differed from the registered plant model submitted during the connection process. This technical discrepancy had been present since commissioning because nobody had verified the as-built control configuration against the registered parameters in the connection agreement’s technical schedules before commercial operations were declared. The consequence was that the project was dispatched below its registered capacity for nineteen days, not because the physical plant could not generate at full capacity, but because AEMO’s registered record of what the plant could do did not match what it was actually doing. This Generator Performance Standards compliance gap remained invisible during development and construction and was discovered only when AEMO’s monitoring system identified the discrepancy in real-time dispatch data.
Generator Performance Standards compliance is not a connection application requirement that is satisfied once and forgotten. It is a continuous operating obligation that runs from the connection application, where GPS conditions are established, through commissioning, commercial operations, and every modification, firmware update, or control system change that affects the plant’s electrical behaviour. Since 2009, our team has managed GPS obligations for solar, wind, BESS, and hybrid projects across Australia’s National Electricity Market, supporting projects from feasibility stage through formal GPS condition acceptance by AEMO. Our grid connection consulting that establishes GPS conditions before the connection offer is signed helps projects define compliance requirements early and manage GPS obligations throughout the plant lifecycle.
GPS compliance failures are not always dramatic. They rarely cause blackouts or equipment damage. They consistently cause dispatch limitations, compliance investigations, and in some cases, financial penalties under AEMO’s compliance and enforcement framework. These are the failure modes we see in practice. GPS compliance failures are always identifiable before they become AEMO compliance events. The question is whether anyone is looking at the right time. Learn more about our owner’s engineer and independent verification services for GPS compliance.
A 200MW solar farm in South Australia changed inverter models after the initial GPS assessment. The replacement inverter met mandatory fault ride-through requirements but failed the negotiated reactive current injection standard agreed in the connection agreement.
A 100MW / 200MWh BESS in Queensland providing FCAS services failed to meet its registered active power response time at lower states of charge. Operational data showed slower response due to BMS ramp rate settings introduced to protect battery cells.
The BMS adjustment was treated as an operational change without assessing its impact on GPS registered parameters. The link between operational settings and GPS obligations was not documented.
A GPS modification application was submitted to AEMO, and revised BMS procedures were implemented to maintain compliance. The approval process took 3 months, during which FCAS availability was restricted.
A 150MW wind farm in Victoria experienced turbine disconnections during a frequency disturbance because protection relay settings exceeded the GPS mandatory underfrequency operating limit.
The EPC contractor applied relay settings from a standard template without completing a GPS compliance review against NER Schedule 5.2.5 requirements.
Relay settings were corrected across affected turbines, followed by testing and AEMO notification under NER Rule 4.15.10. The compliance matter was resolved through corrective action without penalty due to prompt remediation.
GPS compliance engineering is not a single engagement. It is a set of advisory and technical workstreams that run from before the connection application is filed through to the management of registered parameter obligations throughout the plant’s operating life. The scope below covers every workstream we provide — when each is needed, what it produces, and what it protects.
Before the connection application is filed, we assess the proposed plant against GPS mandatory standards in NER Schedule 5.2 to identify compliance risks, negotiation requirements, and required engineering solutions. This includes evaluating plant capability, potential mitigation measures, and technical pathways such as reactive compensation, controller design, or PSCAD modelling before submission.
We prepare GPS performance standard information required for AEMO connection applications, covering mandatory, negotiated, and minimum technical requirements. We verify proposed performance claims against the plant’s actual technical capability to ensure the standards can be demonstrated during commissioning and supported throughout operation.
We support GPS condition negotiations through engineering assessments, PSCAD simulations, and technical justification for alternative performance standards. Our approach ensures connection agreement conditions reflect actual plant capability while avoiding obligations that cannot be technically or commercially achieved.
We develop and validate PSCAD EMT models to demonstrate compliance with GPS requirements, including system strength, fault ride-through capability, and reactive current injection performance. The modelling evidence supports connection agreements and AEMO acceptance of GPS technical requirements.
We monitor construction changes including inverter replacements, controller updates, and equipment variations that may affect GPS compliance. We assess GPS impacts, manage change requirements, and ensure modifications are reviewed before energisation to prevent commissioning issues.
We prepare GPS commissioning evidence packages including test results, PSCAD outputs, protection settings, and controller records required for AEMO acceptance. We coordinate with commissioning teams to ensure testing and documentation meet GPS condition requirements.
We manage AEMO registered parameters by tracking plant capabilities, GPS standards, protection characteristics, and controller configurations. We identify modification impacts, manage amendment requirements, and ensure registered records accurately represent the operating plant.
We provide ongoing GPS compliance monitoring by reviewing operational data against registered parameters, identifying emerging risks, and recommending corrective actions before issues become compliance events. We also support required reporting obligations throughout plant operation.
We manage GPS modification applications for inverter replacements, firmware updates, controller upgrades, and other plant changes. Our services include technical assessments, updated modelling, revised parameters, and AEMO submissions to ensure approved implementation.
Generator Performance Standards are the technical performance requirements that every generating system connecting to the National Electricity Market must meet under Chapter 5 of the National Electricity Rules. They are established through the connection application process, confirmed in the connection agreement, and enforced through AEMO’s compliance and monitoring framework throughout the plant’s operating life.
The GPS framework is divided into three categories of standard. Understanding which category applies to each performance attribute — and what the implications of each category are — is the foundation of GPS compliance engineering. National Electricity Rules Schedule 5.2 Generator Performance Standards
The minimum technical requirements every generating system connecting to the NEM must meet under the NER. These standards are non-negotiable and must be satisfied as a condition of connection. If a plant cannot meet mandatory requirements, engineering modifications are required before connection approval.
No — mandatory standards cannot be negotiated below the minimum threshold defined in the NER. Generators can negotiate higher performance levels but cannot operate below the required minimum standard.
Failure to meet mandatory standards results in a breach of the connection agreement. AEMO may issue compliance notices, restrict dispatch, or refer the matter for enforcement action under the National Electricity Law.
No — mandatory standards cannot be negotiated below the minimum threshold defined in the NER. Generators can negotiate higher performance levels but cannot operate below the required minimum standard.
Failure to meet mandatory standards results in a breach of the connection agreement. AEMO may issue compliance notices, restrict dispatch, or refer the matter for enforcement action under the National Electricity Law.
Minimum technical requirements apply to all generating systems regardless of GPS category. These requirements cover essential connection elements including protection systems, metering, and communication systems required before a plant can connect to the NEM.
No — minimum technical requirements are fixed regulatory requirements and must be satisfied as part of the connection process.
Failure to meet these requirements can prevent connection approval. The connection application cannot proceed until all minimum technical obligations are fulfilled.
NER Schedule 5.2 defines GPS across eight performance attribute areas. Each attribute has a mandatory standard floor, a default negotiated standard above the floor, and often a maximum standard ceiling. The specific requirements differ by generating system technology — what is required of a synchronous machine differs from what is required of an inverter-based resource in several important respects. AEMO Generator Performance Standards Technical Guidance.
NER Reference: S5.2.5.1
Generating units must remain connected within the required voltage range and withstand defined voltage disturbances, including fault ride-through conditions.
IBRs require PSCAD modelling or testing to prove voltage ride-through capability and ensure protection settings do not cause unwanted tripping.
NER Reference: S5.2.5.2
Generating units must remain connected during normal and abnormal frequency conditions, including defined underfrequency and overfrequency events.
IBR protection settings, including underfrequency, overfrequency, and ROCOF functions, must be coordinated to maintain GPS compliance.
NER Reference: S5.2.5.3
Generating units must provide active power control within required ramp limits and respond to AEMO dispatch instructions within registered response times.
IBR plants providing FCAS services require faster active power response and accurate control performance to maintain market availability.
NER Reference: S5.2.5.4
Generating units must provide reactive power capability within the required power factor range at the high-voltage connection point.
IBR reactive power capability depends on transformer losses and must be verified at the point of connection during GPS assessment.
NER Reference: S5.2.5.5
IBR current limits require specific controller configuration to prioritise reactive current injection during fault conditions.
NER Reference: S5.2.5.6
Protection systems must meet required response, reliability, and selectivity standards while aligning with GPS voltage and frequency requirements.
Protection relay changes require GPS impact assessment to prevent settings drifting from approved compliance values.
NER Reference: S5.2.5.7
IBR plant controllers require tuning and PSCAD validation to manage oscillation risks, including SSCI concerns.
NER Reference: S5.2.5.8
Generating units must provide fault current levels consistent with registered parameters for protection and system strength assessments.
IBR fault current limitations affect protection coordination and require accurate assessment at the collector network and point of connection.
PSCAD/EMTDC is a high-detail electrical simulation tool used to understand how inverter-based resources (IBR), such as solar, wind, and BESS plants, behave under real grid conditions. AEMO requires PSCAD modelling when traditional RMS simulation tools cannot capture fast electrical responses or complex interactions within the plant and the wider power system.
Through PSCAD studies, engineers can evaluate important GPS compliance areas such as how the plant responds during faults, whether it can maintain stable operation in weak grid conditions, how reactive current is injected during voltage disturbances, and whether multiple inverter controls could create system interaction issues.
An AEMO GPS PSCAD study is different from a general PSCAD analysis because it must follow specific AEMO compliance requirements. This includes using approved plant models, applying required disturbance events, measuring defined performance outputs, and preparing technical evidence that demonstrates compliance for the connection approval process.
For system strength shortfall conditions and complex IBR GPS assessments
Model types: manufacturer-provided EMT model or validated generic model
Weeks: typical timeline from data collection to AEMO-accepted PSCAD output
PSCAD model must match installed inverter firmware — not manufacturer class
Evaluates the impact of new IBR connections on grid strength using PSCAD modelling to verify system security under weak grid conditions.
AEMO GPS S5.2.5a — System Strength / NER Rule 5.3.4a
Feasibility / Connection Application Stage
Uses PSCAD simulations to verify IBR voltage and frequency ride-through performance against AEMO GPS requirements.
AEMO GPS S5.2.5.1 (Voltage). AEMO GPS S5.2.5.2 (Frequency)
Connection Application / Connection Condition Acceptance
Validates inverter reactive current response during faults to ensure compliance with GPS reactive power control requirements.
AEMO GPS S5.2.5.5 — Reactive Power Control
Connection Application / Condition Acceptance
Verifies plant controller settings provide positive damping and meet AEMO oscillation performance requirements.
AEMO GPS S5.2.5.7 — Oscillation Damping
Connection Condition Acceptance / Post-Commissioning
GPS compliance requirements apply to all generating systems, but each asset type has different technical risks and compliance challenges. Solar PV, wind, BESS, and hybrid plants require specific assessments to identify potential GPS issues and maintain reliable operation throughout the plant lifecycle.
Solar PV GPS compliance focuses on reactive power capability, voltage ride-through, fault response, protection coordination, and plant controller performance to ensure the plant operates within AEMO requirements.
Protection relay changes after commissioning or inverter firmware updates can alter plant behaviour without GPS impact assessment or registered parameter updates.
Reactive power capability assessment, protection review, PSCAD modelling where required, and ongoing registered parameter management.
Wind farm GPS compliance focuses on frequency performance, reactive power capability, oscillation damping, and potential control interactions between multiple wind generation assets.
Incorrect frequency protection settings or SSCI risks between connected wind farms can create GPS compliance issues.
Frequency compliance checks, SSCI screening, controller tuning validation, and protection parameter management.
BESS GPS compliance requires validation across different states of charge, including active power response, reactive power capability, and alignment with FCAS performance requirements.
Changes to BMS operational settings or unverified reactive power capability at different SOC levels can create compliance gaps.
Full SOC range GPS assessment, BMS impact review, FCAS alignment assessment, and commissioning evidence validation.
Hybrid GPS compliance evaluates the combined plant performance, including coordination between renewable generation controllers and BESS systems across all operating conditions.
Assessing only the generation component without validating the integrated hybrid plant can lead to GPS compliance risks.
Hybrid plant GPS assessment, PSCAD modelling, operating mode validation, and combined registered parameter management.
Registered parameter management is one of the most critical GPS compliance obligations for generator owners. These parameters define the plant’s operating capabilities, limits, and constraints within AEMO systems. Any modification affecting registered parameters requires assessment and, where applicable, an amendment before implementation. Integrating GPS parameter reviews into the plant change management process helps prevent compliance gaps by keeping engineering changes, operational settings, and compliance requirements aligned. Proper renewable energy due diligence that includes GPS registered parameter review helps identify potential risks before major project decisions are made.
Yes — If registered parameters are affected
Yes — If GPS-related control parameters change
Yes — If reactive power capability at POC is affected
Yes — Whole-of-plant GPS reassessment required
Not typically — If settings remain unchanged
GPS compliance is not a single milestone. It runs from the feasibility assessment — before a connection application has been filed — through to the management of registered parameters and modification applications throughout the plant’s operating life. The six phases below describe our engagement at each stage of the project lifecycle.
Assess plant characteristics against GPS requirements before connection application, including reactive power capability, fault ride-through risks, and PSCAD modelling requirements. We identify potential GPS conditions and advise on design choices affecting compliance.
Prepare GPS performance standard information for AEMO connection application. Verify proposed standards against plant capability and complete required PSCAD modelling where needed.
3–6 weeks
Performance Standard Information Schedule
Review AEMO proposed GPS conditions, assess technical requirements, and support negotiation where conditions require clarification or adjustment based on engineering evidence.
4–12 weeks
GPS Condition Negotiation Record
Monitor plant configuration changes during construction and assess their impact on GPS requirements. Maintain change records and prepare amendments where required.
Construction Phase
GPS Change Register
Prepare commissioning evidence including test results, PSCAD outputs, protection settings, and controller records required for AEMO GPS condition acceptance.
Commissioning Phase
GPS Condition Acceptance Letters
Provide ongoing GPS compliance support through parameter management, modification reviews, amendment applications, compliance monitoring, and reporting.
Ongoing Retainer
GPS Compliance Records
Generator Performance Standards compliance is a technical discipline that improves with experience — not because the standards change frequently (they do not), but because the failure modes become predictable, the AEMO engagement patterns become familiar, and the GPS implications of construction-phase decisions become second nature. Since 2009, our team has managed GPS conditions for solar, wind, BESS, and hybrid projects across the NEM and SWIS.
AEMO has defined positions for GPS mandatory and negotiated standards, and experience plays a critical role in understanding which conditions can be challenged and what technical evidence is required. Our team helps reduce negotiation delays, avoid commercially restrictive conditions, and establish GPS requirements that align with the plant’s actual technical capability.
GPS compliance evidence must meet AEMO’s technical expectations for PSCAD outputs, performance testing records, and registered parameter documentation. We prepare structured evidence packages that align with AEMO requirements, reducing the risk of delays during technical assessment and condition acceptance.
GPS compliance is an ongoing obligation that continues beyond the connection application. We support the complete lifecycle, including connection submissions, construction monitoring, commissioning evidence, and ongoing registered parameter management, providing a consistent compliance partner throughout plant operations.
Our GPS assessments are independent of EPC contractors, equipment suppliers, and commercial interests. We provide objective advice on GPS impacts of design choices, equipment changes, and plant modifications, helping owners make technically informed decisions based on compliance requirements.
Generator Performance Standards are the technical performance requirements that every generating system connecting to Australia’s National Electricity Market must meet under Chapter 5 of the National Electricity Rules. They are established through the connection application process — the connecting party proposes performance standards for each attribute area, AEMO and the Network Service Provider assess the proposal, and the agreed performance standards are documented as conditions in the connection agreement. GPS applies to every generating system connecting to the NEM regardless of technology type or capacity — solar PV, wind, BESS, gas, and hydro generators all have GPS obligations. The specific standards that apply depend on the technology type: some GPS attributes are designed for synchronous generators and have equivalent provisions for inverter-based resources (IBRs); others are specifically calibrated for IBR characteristics. GPS conditions become binding on the generator owner when the connection agreement is executed. They remain binding throughout the operating life of the plant — not just during the connection and commissioning phase. A generator that meets GPS conditions at commissioning and then allows its registered parameters to drift from the connection agreement values is in GPS non-compliance even if its physical capability has not changed. For BESS projects, GPS obligations interact with the Market Ancillary Service Provider (MASP) registration obligations — ensuring the two sets of obligations are aligned is part of the GPS compliance engineering scope.
A mandatory performance standard under NER Schedule 5.2.5 is the minimum technical requirement that every generating system must meet as a condition of connection to the NEM. Mandatory standards are set by the NER — they are not negotiable below the minimum threshold defined in the rules. Every generator connecting to the NEM must meet the mandatory standards regardless of its technology type, size, or commercial arrangements. A negotiated performance standard under NER Schedule 5.2.5a is a standard above the mandatory minimum that the connecting party and AEMO/NSP agree is technically and commercially justified for the specific plant. Negotiated standards are plant-specific — they are established through a negotiation process during the connection assessment and documented in the connection agreement as conditions. The practical difference from a compliance perspective is significant: both mandatory and negotiated standards are equally binding once documented in the connection agreement. A generator that meets the mandatory standard but fails its negotiated standard is in GPS non-compliance. The negotiated standard is not a ‘better than required’ voluntary commitment — it is an enforceable condition that the generator owner has agreed to meet as a condition of receiving the connection. The negotiation opportunity — where the connecting party and AEMO agree on a standard that differs from the default — is most valuable for GPS attributes where the default negotiated standard would impose compliance obligations that the plant configuration cannot meet, or where the plant can offer a higher standard in exchange for a relaxation elsewhere. Managing this negotiation is one of the core GPS engineering services we provide.
PSCAD electromagnetic transient (EMT) modelling is required for GPS compliance in several specific scenarios under AEMO’s assessment methodology. The most common triggers are: System Strength Impact Assessment (SSIA): Where a new IBR connection would reduce system strength below the minimum level maintained by the relevant TNSP, AEMO requires an SSIA conducted in PSCAD to assess whether the shortfall creates power system security concerns. Complex plant fault ride-through compliance: For plants with complex inverter configurations, co-located BESS, or grid-forming inverter technology, AEMO may require PSCAD modelling to demonstrate voltage and frequency ride-through compliance rather than accepting the inverter manufacturer’s type-tested results. Reactive current injection response: Where the GPS negotiated standard for reactive current injection during fault conditions is specific — and where the plant controller coordinates injection across multiple inverter units — PSCAD modelling is typically required to demonstrate the injection profile. Sub-synchronous control interaction (SSCI) screening: For IBR connections in high-penetration areas of the NEM (particularly South Australia), AEMO may require SSCI screening in PSCAD to assess whether the new plant’s controller interacts adversely with neighbouring IBR controllers. PSCAD modelling for GPS compliance requires a validated plant model — either the inverter manufacturer’s provided EMT model or a validated generic model from an AEMO-approved library — parameterised to the specific firmware version and control configuration installed in the project. A PSCAD model parameterised to the wrong firmware version produces GPS compliance evidence that does not accurately represent the plant’s actual behaviour.
GPS non-compliance in an operating generator carries a defined regulatory consequence under the National Electricity Rules. The sequence of consequences depends on the nature of the non-compliance and how it is discovered. Where the generator self-identifies a GPS non-compliance, the National Electricity Rules require the generator to notify AEMO as soon as practicable under NER Rule 4.15.10. Self-reporting is treated more favourably than non-compliance identified through AEMO’s monitoring systems — the AER’s compliance and enforcement framework provides for mitigating factors including prompt self-disclosure and cooperative remediation. Where AEMO’s monitoring systems identify GPS non-compliance from the plant’s real-time telemetry data, AEMO will issue a notice to the generator requiring an explanation and a remediation plan. AEMO may also impose interim operating restrictions — restricting the plant’s dispatch below its registered capacity — until the non-compliance is resolved. For serious or persistent GPS non-compliance, the AER (Australian Energy Regulator) can investigate under the National Electricity Law and impose civil penalty proceedings. Civil penalties for GPS non-compliance can be substantial — the National Electricity Law provides for penalties up to $100,000 per non-compliance day for serious contraventions. The practical implication: the most cost-effective GPS compliance strategy is to prevent non-compliance from occurring. For operating plants, this requires maintaining the registered parameter management process — ensuring every modification that affects GPS performance is assessed and, where required, registered with AEMO before implementation.
Yes — plant modifications that affect the generating system’s electrical characteristics or control behaviour can trigger GPS registered parameter amendment obligations. This is one of the most common sources of GPS compliance gaps in operating plants. A registered parameter amendment is required when a modification changes any parameter that is documented in the plant’s registered parameters with AEMO. The most common modifications that trigger amendment obligations are: inverter replacement (including replacement with the same model from the same manufacturer where a firmware change is involved), plant controller software upgrades that change reactive power control parameters, transformer replacement where the new transformer has different impedance, addition of co-located BESS to an existing solar or wind plant, and any modification that changes the plant’s active power or reactive power capability at the high-voltage bus. The amendment process requires the generator owner to prepare and submit a technical assessment of the modification’s impact on GPS performance to AEMO before the modification is implemented — not after. A modification that is implemented without an approved amendment application creates a GPS compliance gap: the plant is operating with characteristics that differ from its AEMO-registered parameters. The challenge in operating plants is that modifications are often managed by the O&M contractor or the EPC contractor without reference to the GPS registered parameters — because the GPS records are held separately from the operational team. Our registered parameter management service exists to bridge this gap: we maintain the GPS compliance records for operating plants and review every modification request for GPS impact before approval.
The South West Interconnected System (SWIS) in Western Australia operates under a different regulatory framework from Australia’s National Electricity Market. The SWIS is regulated by the Economic Regulation Authority (ERA) and operates under the Electricity Industry Act 2004 (WA) and the Wholesale Electricity Market (WEM) Rules — a separate set of market rules from the National Electricity Rules that govern the NEM. For generating systems connecting to the SWIS, the equivalent of GPS is the Technical Rules administered by Western Power (the transmission network operator in the SWIS). Western Power’s Technical Rules Chapter 3 specifies the performance requirements for connecting generating facilities — the equivalent function to NER Schedule 5.2 in the NEM, but with different specific requirements. Key differences between SWIS Technical Rules and NEM GPS: The SWIS has lower system inertia than the NEM and different frequency management challenges, which affect the frequency ride-through requirements applied to new connections. The system strength framework is different — the SWIS does not use the same System Strength Framework as the NEM, though system strength concerns exist and are addressed through Western Power’s connection assessment process. The compliance and enforcement framework is different — regulated by the ERA rather than the AER. For developers with projects in both the NEM and the SWIS, understanding these differences is important — GPS compliance knowledge from NEM projects does not transfer directly to SWIS connections. Our team has experience with Western Power’s Technical Rules and can provide GPS-equivalent compliance support for SWIS connections.
Generator Performance Standards compliance risks become more expensive the later they are identified. Risks found during feasibility can be resolved before major design decisions, while issues discovered after connection approval may require modification applications, PSCAD studies, and AEMO negotiations. The connection agreement is not the end of GPS compliance; it begins the ongoing registered parameter management obligation. Every modification, firmware update, and O&M activity affecting plant electrical behaviour must be assessed for GPS impact before implementation.
Since 2009, our team has managed GPS conditions for solar, wind, BESS, and hybrid projects across Australia’s National Electricity Market, helping establish compliant GPS conditions, manage modifications, and identify compliance risks before they become operational issues. GPS compliance is not a project milestone. It is a plant obligation. The difference between managing it as one and managing it as the other is measured in compliance events.
Tell us your project type, NEM region, and where you are in the project lifecycle — connection application, construction, commissioning, or operating. We will identify the GPS compliance work your project needs and propose a scoping approach.
info@americanpowerengineers.com · Melbourne, Australia · Same-business-day response
