Control system for servo valve and control method therefor, and combined-cycle electric-power generating plant and gas turbine plant
AssigneeHitachi, Ltd.
InventorsKazuyasu Asakura, Shouei Takahashi
Life of this patent
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Abstract
An object of the present invention is to provide a control system and a control method for servo valve which can stably continue to control a servo valve when a break occurs in servo coils of a servo valve having a plurality of servo coils. In the present invention, voltages of a plurality of servo coils 3A, 3B, 3C are detected by wire break detecting means individually provided to servo amplifiers 2A, 2B. 2C. The servo amplifiers 2A, 2B. 2C performs wire break detection and wire break compensation.
Claims11
A method for controlling a servo valve with a control system, the servo valve having a plurality of servo coils, the servo valve being excited by said servo coils, the method comprising:
- outputting a servo control voltage command based on an opening degree difference between a target opening degree and a real opening degree of said servo valve;
- converting said servo control voltage command to current to excite said plurality of servo coils to a predetermined current value and to perform compensation of servo coil breaks;
- detecting a break in one of said servo coils by detecting a change of voltage of each of said plurality of servo coils;
- and
- increasing the servo control voltage command to compensate for the detected break in one of said servo coils.
A method for controlling a servo valve with a control system, the servo valve having three servo coils, the servo valve being excited by said servo coils, the method comprising:
- outputting a servo control voltage command for each of said servo coils based on an opening degree difference between a target opening degree and a real opening degree of said servo valve;
- converting said servo control voltage command to current to individually excite each of said three servo coils to a predetermined current value and to perform compensation of servo coil breaks;
- detecting a break in one of said servo coils by detecting a change of voltage of each of said three servo coils;
- and
- increasing the servo control voltage command to compensate for the detected break in one of said servo coils.
Dependencies are inferred from the claim text.