GridServe performed a high-level steady-state network assessment for two proposed 4.99MW Battery Energy Storage Systems (totalling 9.98MW) in Leongatha. The project involved complex modelling to integrate dual high-capacity inverters into the AusNet 22kV distribution network, ensuring grid stability across multiple switching configurations.
Key Project Scope & Deliverables
- Dual-Site Impact Assessment: Analysed the simultaneous operation of two independent BESS units connected to the Leongatha Zone Substation, evaluating their cumulative impact on feeder thermal limits and voltage stability.
- Network Reconfiguration Modelling: Evaluated two distinct switching scenarios to optimize the connection path. Identified that transitioning a portion of the feeder through strategic switch automation significantly reduced required conductor replacement lengths and improved the overall voltage profile.
- Thermal & Voltage Remediation: Developed a comprehensive reconductoring strategy to address initial “Fail” results in thermal loading and steady-state voltage variations.
- Advanced Trip & Variation Analysis: Validated that a simultaneous 100% generation trip of both BESS units would maintain voltage variations within the strict limits required by the Network Service Provider (NSP).
- Long-Term Sensitivity Studies: Conducted 10-year forecasted modelling to ensure the dual-BESS configuration remains compliant with future load growth and network evolution through 2031.
- Control Strategy Optimization: Verified the effectiveness of Power Factor Control mode in mitigating voltage profile deviations during both high-demand import and low-demand export cycles.
Key Challenges
- Pre-existing Non-compliance: Navigating a project where the existing network already exhibited voltage profile deviations, requiring detailed analysis to prove the BESS would not materially exacerbate these conditions.
- Complex Switching Logic: Balancing the benefits of feeder reconfiguration against traditional infrastructure upgrades to achieve the most cost-effective path to compliance.
- Simultaneous Operation Hazards: Modelling “worst-case” scenarios where both 4.99MW systems operate at peak capacity, ensuring no localized overloading or excessive voltage rise at the Points of Connection (PoC).
Technical Standards Followed
- NER (National Electricity Rules): Generator Performance Standards (GPS).
- AusNet Services Technical Standards: 22kV Distribution network guidelines.
- AS/NZS 3000: Electrical installations.