Trimark’s T1-S SCADA now includes the option to accept, schedule and execute California ISO (CAISO) Automated Dispatch System (ADS) commands.
This functionality allows utility-scale PV resources to participate in the real-time energy market by responding to 5-minute dispatch commands.
“Integrating ADS handling into the plant SCADA improves efficiency and eliminates the requirement for separate integration processes,” said Bob Wood, Trimark’s Chief Technology/Operations Officer.
Trimark’s T1-S SCADA integrates with the CAISO ADS application to automate acceptance and execution of secure CAISO instructions including startup, shut down, transition, curtail and ancillary service requests. These functions support CAISO’s mission of managing California’s electric grid in real time.
“The frequency, complexity and decision criteria required to accept and execute these commands would be overwhelming for an individual,” said Wood. “Trimark’s T1-S SCADA manages the security, assessment and execution of ADS instructions automatically in a matter of seconds.”
CAISO’s ADS system facilitates secure, real-time dispatch instructions to power generation resources that participate in the real-time energy market. ADS sends unambiguous dispatch instructions to generation resources, tracks the real-time operational profile, records the transaction, and documents whether the instruction was approved or rejected.
Under normal conditions, CAISO dispatches an ADS instruction (e.g. startup, shut down, transition) every five minutes. CAISO can also dispatch energy instructions (e.g. Max) on a 10 minute, 15 minute, or hourly interval. ADS commands are also used to communicate ancillary service awards.
When the T1-S SCADA ADS module receives a command, CAISO allows 90 seconds for the resource to start the action. During this time, T1-S SCADA authenticates the command, reviews the instruction against pre-defined acceptance criteria, and documents the transaction. If the command meets the acceptance criteria, and the resource can deliver the power characteristic required, T1-S SCADA will automatically coordinate adjustments across all plant devices (e.g. inverters, energy storage, capacitor banks) to meet the instruction. Upon acceptance, CAISO expects the resource to smoothly ramp changes over two minutes to reach the new target. T1-S SCADA ensures that the changes in power characteristics at the point of interconnection occur in a controlled, manner, thereby avoiding grid disturbances.
All dispatches and resulting control actions are recorded with time stamps and retained for reporting and auditing.
News item from Trimark