Emerson’s Laurence O’Toole and Felipe Londono were joined by Mitsubishi Hitachi Power Systems (MHPS)’s Michael Glover to present on gas turbine control enhancements at the 2019 Ovation Users’ Group conference.
MHPS and Emerson formed an alliance in 2008 to provide state of the art turbine and controls solutions. The solutions include balance of plant (BOP) controls, generator excitation, process control devices and instrumentation, and MHPS Engineering supports control settings and logic development.
The needs of the power industry are changing, and these changes affect gas turbine controls. Fast start options are required to meet dispatch times in areas with high intermittent renewable energy supplies. Flexibility is critical to meet the dynamic conditions in starting and stopping these turbines.
Michael shared some examples of projects that have been executed. In these projects, MHPS and Emerson jointly presented proposals instead of independently submitting proposals. Total scope integration includes fuel skid integration, control software, auxiliaries, control system, documentation and commissioning.
MHPS partners with OSIsoft, IBM’s Watson, Emerson, sparkcognition, Exele and more for advanced analytics. 3 key steps to developing valuable analytics include determining the use case – What are historical or future problems? Second, identifying necessary data sources and determine what’s available and what’s missing. And third, find the right software partner to collaborate with to develop the platform & applications customized for the requirements of the projects.
Laurence described fast start using fast premix recovery. It includes fast start to base load in lean-lean and fast premix transfer to transfer on load to achieve total time to base load in 10 minutes with a load time of 4 minutes and 14MW per minute. This compares with a normal 22 minutes total time to base load for a normal startup.
Automatic tuning or autotune technology can be used to improve flexibility in dry low NOx turbines. Autotune makes small changes in control system parameters based on self-learning, incremental tuning logic. It optimizes gas turbine performance from emissions and combustion dynamics standpoint and it learns over time the best combination of fuel split bias settings to better accommodate varying ambient conditions and fuel energy compositions.
Felipe discussed the Ovation Machinery Health Module (MHM) to provided embedded condition monitoring of turbines with orbit plots, spectrum and waveform analytics. These help spot mechanical problems early before they lead to unplanned outages or expensive repairs.
Laurence describe the Ovation Local Advanced Pattern Recognition (APR) prognostics in the turbine control system. This local APR can use high-speed, higher resolution data including high-speed history. These APR prognostics identify vibration changes, oil system anomalies, exhaust changes, abnormal disc temperatures, efficiency degradation and time to cost to stop—indicating health of lube system and/or bearings.
One way to address NERC MOD-027 on frequency response requirements is automated frequency test response testing. A droop response test injects a bias into the speed signal, simulating a step change in grid frequency. A response to an increase and decrease in grid frequency is tested.
Visit the Gas Turbine Controls section on Emerson.com for more one these and other technologies to provide greater flexibility, reliability and availability for your gas turbine generators.