초록 ▼

To detect any abnormal loss of a feedback signal in an electric power system wherein a plurality of feedback signals are respectively derived from various system quantities, such as voltage and current, and are used as inputs to a controller that regulates the output of a controllable source of powe

To detect any abnormal loss of a feedback signal in an electric power system wherein a plurality of feedback signals are respectively derived from various system quantities, such as voltage and current, and are used as inputs to a controller that regulates the output of a controllable source of power, the controller is arranged to estimate the desired value of the system quantity from which a first feedback signal is derived, to compare the estimated desired value with the actual value of the same quantity (as indicated by the first feedback signal), and to signal a malfunction if this comparison reveals that the first feedback signal is faulty.

대표청구항 ▼

In a controller for a system which includes means for supplying a controllable amount of electric power to an electric load circuit, means for deriving at least first, second and third feedback signals that are representative, respectively, of certain system quantities, and means associated with the

In a controller for a system which includes means for supplying a controllable amount of electric power to an electric load circuit, means for deriving at least first, second and third feedback signals that are representative, respectively, of certain system quantities, and means associated with the power supplying means for varying the amount of power supplied to the load circuit as a function of the value of a variable control signal produced by the controller in selective response to the feedback signals and to a given command signal, improved means for detecting the loss of a feedback signal, comprising: a. first means for periodically estimating the desired value of a predetermined system quantity that is represented by the first feedback signal; b. second means associated with said first means and responsive to said first feedback signal for finding the difference between the estimated desired value of said predetermined quantity and the actual value thereof as indicated by said first feedback signal; c. third means for providing a biased error value equal to said difference value plus or minus a predetermined bias value; d. integrating means associated with said third means for providing a resultant value that is representative of the time integral of said biased error value; e. polarity detecting means associated with both said third means and said integrating means for periodically causing said bias value to be added to said difference value if the polarity of said resultant value is negative and for periodically causing said bais value to be subtracted from said difference value if the polarity of said resultant value is positive; and f. level detecting means responsive to said resultant value for signaling the loss of said first feedback signal if the magnitude of said resultant value exceeds a predetermined threshold.