Back to results
US 10,374,409 B2Granted
Method of detecting arc events in a power system, and a power system including an arc detector
AssigneeAnalog Devices Global
InventorMartin Murnane
Life of this patent
Estimating the term…
Abstract
Power systems having a DC content, such as photovoltaic (solar) panels present a problem if an arc fault appears because of a small break in a cable. The present disclosure describes an arc fault detection system that captures data in segments, examines the frequency spectrum to remove ‘false arc’ signatures and interference from a power converter of the power system, and then examines the cleaned frequency spectrum for arc events.
Claims29
A method of using a data processor for detecting arc events in a photovoltaic system having a switched mode converter therein, the method comprising:
- analysing a current flow in the system to form a frequency domain representation based upon the current flow;
- identifying one or more relatively narrow spurs in the frequency domain representation, wherein the one or more relatively narrow spurs include one or more inverter switching spurs respectively having a frequency width of less than 400 Hz;
- modifying the frequency domain representation including applying one or more notch filters respectively centered over the respective one or more inverter switching spurs so as to remove influence of the one or more inverter switching spurs;
- processing resulting sample values over a window within the frequency domain representation in which the influence of the one or more inverter switching spurs has been removed, and determining existence of an arc if the result of the processing falls in a range of values indicative of the existence of the arc, the range of values indicative of the existence of the arc being determined using the frequency range representation excluding the one or more relatively narrow spurs or after the removing of the influence of the one or more inverter switching spurs;
- and
- generating an adjustment to at least one of one or more switches in the photovoltaic system or one or more devices coupled to the photovoltaic system to inhibit the current flow based on determining the existence of the arc.
3 more elements
A method of using a data processor for detecting arc events in a power system, the method comprising:
- performing a frequency domain analysis to identify system operation components in a frequency range under investigation;
- analysing a frequency distribution across the frequency range under investigation where the frequency distribution is modified so as to remove influence of one or more relatively narrow spurs including one or more inverter switching spurs having a frequency width of less than 400 Hz by applying one or more notch filters respectively centered over the respective one or more inverter switching spurs;
- comparing an attribute of the frequency distribution with a threshold value to indicate presence or absence of an arc event;
- and
- generating an adjustment to at least one of one or more switches in the power system or one or more devices coupled to the power system to inhibit current flow based on the indication of the presence or absence of the arc event.
2 more elements
An arc detector for a power distribution system, the arc detector including a data processor arranged to perform arc detection by:
- analysing a current flow in the power distribution system to form frequency domain representation based upon the current flow;
- identifying one or more system operation components iii the frequency domain representation;
- modifying the frequency domain representation so as to remove influence of the system operation components including one or more inverter switching spurs respectively having a frequency width of less than 400 Hz;
- processing resulting sample values over a window within the frequency domain representation in which the influence of the system operation components including the one or more inverter switching spurs has been removed by applying one or more notch filters respectively centered over the respective one or more inverter switching spurs, and determining existence of an arc if the result of the processing falls in a range of values indicative of the existence of the arc, the range of values indicative of the existence of the arc being determined using the frequency range representation in which the influence of the system operation components including the one or more inverter switching spurs has been removed;
- and
- generating an adjustment to at least one of one or more switches in the power distribution system or one or more devices coupled to the power distribution system to inhibit the current flow based on determining the existence of the arc.
3 more elements
A system comprising:
- an arc detector including a data processor configured to:
- perform a frequency domain analysis to identify system operation components in a frequency range under investigation;
- analyze a frequency distribution across the frequency range under investigation where the frequency distribution is modified so as to remove influence of one or more relatively narrow spurs including one or more inverter switching spurs having a frequency width of less than 400 Hz by applying one or more notch filters respectively centered over the respective one or more inverter switching spurs;
- compare an attribute of the frequency distribution with a threshold value to indicate presence or absence of an arc event;
- and
- generate an adjustment to at least one of one or more switches in a power system or one or more devices coupled to the power system to inhibit current flow based on the indication of the presence or absence of the arc event.
3 more elements
Dependencies are inferred from the claim text.