Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a rotating brushless exciter generator coupled to a power system through a breaker. One or more of the turbine-generator plants are operated by a hybrid digital computer control system during sequenced startup, synchronizing, load, and shutdown operations. The program system for the computer and external analog circuitry operate in a multiple gas turbine control loop arrangement. Automatic synchronization is achieved with a hybrid subsystem which includes the programmed computer and external phase detection circuitry. An automatic synchronization program for the computer is divided into rough speed and voltage matching, fine speed matching and breaker closure subprograms.

Abstract: Two gas turbine power plants are started and accelerated by fuel controls on selection of dead load mode. The startup is coordinated so that one turbine-generator is controlled as the lead unit and it is driven to a speed higher than normal, short of overspeed condition at which time its breaker is closed on an auxiliary bus. Shortly thereafter the second turbine-generator is synchronized to the first and its generator breaker is closed to the auxiliary bus. The two units are then ready for a simultaneous 200% load pickup from the dead load bus. After the load is applied, the lead unit is placed under isochronous control and the follow unit is tracked to the lead unit. Turbine lead/follow roles can be reversed during startup under certain conditions, and predetermined data is exchanged between the controls to enable coordinated dead load pickup operation.

Abstract: A gas turbine power plant is provided with an industrial gas turbine which drives a rotating brushless exciter generator coupled to a power system through a breaker. One or more of the turbine-generator plants are operated by a hybrid digital computer control system during sequenced startup, synchronizing, load, and shutdown operations. The program system for the computer and external analog circuitry operate in a multiple gas turbine control loop arrangement. Logic macro instructions are employed in programming the computer for logic operations of the control system.

Abstract: An optimized high load blocking limit is independently computer calculated for each gas turbine-generator unit as a dynamic function of combustor shell pressure and exhaust temperature every second. A low load blocking limit can be calculated as a function of the high blocking limit. The high and low dynamic limits then define a band of megawatts instantaneously available to the system. At the dispatch computer, load-frequency control is executed and the calculated load demands are dispatched to the various gas turbine-generator units which respond without exceeding the respective high and low load blocking limits. A turbine control unit load reference is modified by the dispatched load change and each unit load control operates its turbine fuel control valves to satisfy the load demand.

Abstract: A black start generating system for a steam plant comprises a gas turbine-generator and a control system which operates the turbine in a modified dead load mode to accept successive load steps in accordance with a black plant startup sequence. In the dead load mode, certain limits are placed on control operations to protect the turbine while permitting load stepping during plant startup.

Abstract: Improved turbine speed controlling valve operation is provided through the accumulation for direct entry into a digital computer of a count of displacement pulses generated by incremental rotation of the turbine output shaft. The digital computer is operative to position the control valves in response to the speed of rotation of the output shaft calculated either as a function of the number of pulses accumulated in a predetermined interval or the time required to accumulate a preselected count, depending upon the operating point of the turbine. The accumulation of displacement pulses can be inhibited while the time measurement is being read to avoid errors in measurement.Resumption of the accumulation of displacement pulses and the measurement of time is synchronized to preserve accuracy.

Abstract: A local maintenance controller permits continued power generation during maintenance or failure of a primary gas turbine control system by manually for maintenance purposes or automatically for failure purposes assuming turbine control to thereby insure continued operation. The local maintenance controller set forth is particularly suitable for use in conjunction with a computer implemented gas turbine control system.Transfer between the local maintenance controller and the primary control system is effected in a bumpless manner so that load swings are absent. However, if the turbine was operating at system reserve at the time of transfer, the local maintenance controller reduces the load to peak value until primary control is resumed. Operation at any other load at the time of transfer is maintained by the controller. Transfer back to primary control is also effected in a bumpless manner.