Self-calibrating voltage sensor
AssigneeSchweitzer Engineering Laboratories, Inc.
InventorsLaurence V. Feight, Ryan W. Swartzendruber, Kurt J. Fenske
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Abstract
A voltage sensor consists of a number of capacitive voltage sensors coupled to test points in an electrical power system. The outputs of the voltage sensors are digitized and processed by a digital processor, which determines a normal value for the monitored AC voltages, and then determines if the monitored AC voltages are acceptable based on variations from the normal value.
Claims17
A method for detecting when a monitored AC voltage falls outside of an acceptable range comprising:
- i) calculating an average peak voltage value based on measured peak voltage values of the monitored AC voltage, wherein the average peak voltage value is calculated by accumulating a sum of a predetermined number of measured peak voltage values, subtracting a previously calculated average peak voltage value from the sum, adding a present measured peak voltage value to the sum, and dividing the sum by the predetermined number;
- ii) calculating the acceptable range based on the average peak voltage value;
- and
- iii) generating a voltage-out-of-range signal if the monitored AC voltage exceeds the acceptable range.
A system for detecting when a monitored AC voltage falls outside of an acceptable range comprising:
- i) at least one voltage acquisition circuit, the voltage acquisition circuit generating a digital signal representative of the monitored AC voltage;
- ii) a processor coupled to the voltage acquisition circuit for executing a voltage monitoring algorithm and for generating a voltage out-of-range signal when the monitored AC voltage falls outside of the acceptable range, wherein
- the processor
- (a) calculates an average peak voltage value based on measured peak voltage values of the monitored AC voltage wherein the average peak voltage value is calculated by accumulating a sum of a predetermined number of measured peak voltage values, subtracting a previously calculated average peak voltage value from the sum, adding a present measured peak voltage value to the sum, and dividing the sum by the predetermined number;
- (b) calculates the acceptable range based on the average peak voltage value, and
- (c) generates a voltage-out-of-range signal if the monitored AC voltage exceeds the acceptable range.
Dependencies are inferred from the claim text.