|DENNY, NATHAN - MAC, U OF AZ, TUCSON
Submitted to: United States Committee on Irrigation and Drainage Conference
Publication Type: Proceedings
Publication Acceptance Date: 9/30/2005
Publication Date: 10/20/2005
Citation: Strand, R.J., Clemmens, A.J., Denny, N.T. 2005. Training scada operators with real-time simulation. United States Committee on Irrigation and Drainage Conference. p. 319-328
Interpretive Summary: Irrigation districts have used supervisory control and data acquisition (SCADA) computer systems for many years. Operators usually receive training while operating the actual canal system. Training an operator in this manner is sometimes difficult as the training can be interrupted. Additionally, it is difficult to teach a new operator how to handle alarm and emergency situations while running the real canal unless those conditions happen to occur. This paper describes a prototype system that replaces the canal with a computer simulation. This replacement allows trainees to focus on canal operation and allows the trainer to easily repeat emergency situations.
Technical Abstract: Many irrigation districts use SCADA software to manage their canal systems. Whether homegrown or commercial, these programs require a significant amount of training for new operators. While some SCADA operators are hired with extensive field experience, others are hired with no field experience at all and require extended training to gain an understanding of the behavior of open-channel systems. Additionally, many new operators have little or no experience with general computer use. Regardless of experience, these operators usually receive SCADA training while managing the actual canal system and their training is driven by the day-to-day operation of the system. Similar to the training needs of human operators, canal automation systems need to be tested for situations, such as hardware vandalism, a large storm event, or a canal breach, that cannot be created easily in an actual canal without wasting water, causing significant fluctuations in adjoining pools, or potentially causing severe damage. Additionally, the SCADA software itself needs to be tested for proper response to various alarm conditions. Currently, there are no practical methods to simulate emergency conditions for SCADA systems. The U.S. Water Conservation Laboratory (USWCL) has created a method for replacing the real canal with a simulation model without making any changes to the SCADA software. The connection from the SCADA computer to the radio is replaced with a connection to another computer that performs the canal simulation. If the simulation model were a good representation of the canal, gates, etc., the SCADA operators would not be able to tell the difference. This additional computer also runs software modeling the telemetry system, including communications, sensors and remote terminal units (RTU’s) or programmable logic controllers (PLC’s), as well as the physical components of the canal sites such as gate positions and battery voltages. Through the simulation system, situations such as a noisy transducer, a stuck gate, an electrical failure, or an unexpected supply or demand change can be simulated. If needed, these situations can be easily repeated. This paper describes this prototype system and potential uses for training and for validation of SCADA and automatic control functions.