Condition monitoring by cross-correlation of switching-mode power supplies
AssigneeAker Subsea AS
InventorPhilip Michael Bagley
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Abstract
A method of monitoring an output signal of a switching-mode power supply for the presence and magnitude of the switching frequency comprises sampling the output signal at a sampling frequency above the minimum Nyquist limit to provide a succession of samples; cross-correlating a reference signal and the samples to provide cross-correlation values; and monitoring the cross-correlation values to ascertain the magnitude of a component of the output signal at or near the frequency of the reference signal.
Claims8
A method of monitoring an output of a switching-mode power supply operating at a known switching frequency, comprising:
- sampling the output of the power supply at a sampling frequency above the minimum Nyquist limit to provide a succession of samples;
- cross-correlating a reference signal at the switching frequency and the said samples to provide cross-correlation values;
- and
- monitoring the cross-correlation values to ascertain the magnitude of a component of the output signal at or near the switching frequency.
A switching-mode power supply operating at a known switching frequency, comprising:
- a series switches;
- a source of a switching signal operating the switch at the switching frequency;
- an inductor in series with the switch;
- a shunt diode forming a loop with the inductor and a load;
- an output filter;
- means for sampling the output of the power supply at a sampling frequency above the minimum Nyquist limit to provide a succession of samples;
- means for cross-correlating a reference signal at the switching frequency and the said samples to provide cross-correlation values;
- and
- means for monitoring the cross-correlation values to ascertain the magnitude of a component of the output signal at or near the switching frequency.
A method of monitoring the condition of a capacitor of an output filter of a switching-mode power supply operating at a known switching frequency, comprising:
- sampling the output signal of said power supply at a sampling frequency above the minimum Nyquist limit to provide a succession of samples;
- cross-correlating a reference signal at said switching frequency and said samples to provide cross-correlation values;
- and
- monitoring said cross-correlation values to ascertain the magnitude of a component of said output signal at or near the switching frequency, said magnitude representing the condition of said capacitor.
Dependencies are inferred from the claim text.