AEMO WEMDE
Integration.
A multi-layered Solar Curtailing mechanism designed to optimize the financial performance of Solar Farms. Orchestrating Python services, Radix SCADA, and Bachmann M1 logic for high-availability market response.
PLC LAYER
Bachmann M1
DNP3 Modbus OPC UASCADA LAYER
Radix Automation
ECMA JS Event ManagerMIDDLEWARE
Linux Engine
Python 3 SystemD DebianMarket Design & Background
The WEMDE System Constrained Economic Dispatch (SCED) API replaces the legacy AEMO WEM Balancing Market, introducing critical shifts in price calculation and interval management. The engine ensures the lowest overall cost of dispatch while maintaining power system security through co-optimized Energy and Essential System Services (ESS).
WEMDE (The Engine)
Performs mathematical optimization every five minutes based on participant offers, network constraints, and system requirements like load forecasts and inertia limits.
WEMS (Wholesale Electricity Market Systems)
The overarching IT framework housing the Market Participant Interface (MPI), serving as the primary gateway for all bid and offer submissions.
RTMS (Real-Time Market Submissions)
A modernized interface allowing for "Standing" and "Variation" submissions for energy and ESS (Regulation, Contingency, and RoCoF) via Web UI or API.
View AEMO Documentation →5-Minute Dispatch
As of Oct 2023, intervals are 5 minutes, while trading remains at 30. We track the average of six Market Clearing Prices to determine the final energy price.
Security Infrastructure
Participants manage private SSL Keys and generate CSRs signed by DigiCert (CA) for authenticated WEMDE engine communication.
API & Script Resilience
The Python gateway uses a Linux systemd watchdog to ensure the service never halts. It parses real-time WEMDE data and passes heartbeats to the SCADA and PLC layers to verify system integrity.
PLC State Machine
The Bachmann M1 runs a robust state machine that coordinates plant operating modes and safety systems. During aemo curtailing mode if the price signal is stale or the heartbeat stops incrementing, the machine transitions the plant to a default safe state. The PLC also manages connections to all plant sub systems including the SMA Power Plant Controller (PPC) to control MVPS inverter output Power.
Fail-Safe Logic: In the event of communication loss, the system prioritizes plant safety over market participation until manual or automated recovery occurs.
SCADA Logic & Curtailment
The Radix SCADA system acts as the central intelligence hub. It logs prices to a high-resolution database and executes meta-scripts to analyze price thresholds. If the current price drops below the configurable Curtail Price, the system issues a Modbus command to the PLC to ramp down output.
Traceability & Audit
Critical alarms notify O&M personnel via email for API timeouts or setpoint deviations. Every curtailment action is logged for auditable performance analysis.
Initialize Discussion.
Ready to integrate your industrial assets with the Australian energy market?
info@while0x1.com