US 4,071,897 A · Power plant speed channel selection system

Abstract

A turbine control system incorporating a speed monitoring system for generating an actual turbine speed measurement for control of turbine speed and load is disclosed. The speed monitoring system employs two identical speed channels each of both analog and digital form and a third channel of only analog form. The two identical speed channels of digital form and the third channel of analog form are coupled to a programmed digital computer based process controller for use in controlling turbine speed and load. The two identical speed channels of analog form and the third channel are coupled to an overspeed protection controller for use in preventing turbine overspeed. Within each controller, an identical channel is selected without preference to be used as the actual turbine speed measurement. A transfer between identical speed channels will only be performed if a malfunction is detected in that identical channel utilized as the actual turbine speed measurement. This transfer will be performed without affecting the operation of the turbine as controlled by either of the two controllers. The malfunction of any two of the input channel forms to a respective controller disables only the speed control function of that controller.

Claims17

Dependent claims

A system for controlling the operation of a turbine power plant in accordance with monitored speed, said system comprising:

speed detection means;
a first conversion means governed by said detection means to generate both a first digital speed signal and a first analog speed signal;
a second conversion means similar to said first conversion means governed by said speed detection means to generate both a second digital speed signal and a second analog speed signal;
a third conversion means governed by said speed detection means to generate a third analog speed signal;
a first turbine controller governed by said first and second digital speed signals and said third analog speed signal to control the operation of the turbine below a predetermined speed level in accordance with a selected one of said first and second digital speed signals;
and
a second turbine controller governed by said first, second and third analog speed signals to control the operation of the turbine above a predetermined speed level in accordance with a selected one of said first and second analog speed signals.

4 more elements

A system for generating signals representative of turbine speed for use in control of turbine operation comprising:

speed detection means;
a first conversion means governed by said detection means to generate both a first digital speed signal and a first analog speed signal;
a second conversion means similar to said first conversion means governed by said speed detection means to generate both a second digital speed signal and a second analog speed signal;
a third conversion means governed by said speed detection means to generate a third analog speed signal;
a first means governed by said first and second digital speed signals and said third analog speed signal to select one of the first and second digital speed signals as being representative of turbine speed for use in control of turbine operation below a predetermined speed level;
a second means governed by said first, second and third analog speed signals to select one of said first and second analog speed signals as being representative of turbine speed for use in control of turbine operation above a predetermined speed level.

3 more elements

A system for controlling the operation of a turbine power plant above a predetermined speed level, said system comprising:

speed detector means;
conversion means governed by said detection means to generate first, second and third analog speed signals;
a turbine controller;
means governed by said first, second and third analog speed signals to control the operation of the turbine controller above a predetermined speed level in accordance with a selected one of said first and second analog speed signals;
means governed by said first, second and third analog speed signals to control the operation of the turbine controller in accordance with the other of either said first and second analog speed signals in response to the detection of a malfunction as indicated by said selected analog speed signal only, whereby said first and second analog speed signals govern the turbine controller without preference.

2 more elements

Dependencies are inferred from the claim text.

Power plant speed channel selection system

Life of this patent

Power plant speed channel selection system

Life of this patent

Abstract

Claims17