Timing window arc detection
AssigneeEaton Corporation
InventorsCharles J. Tennies, Bruce C. Beihoff, James E. Hansen
Life of this patent
Estimating the term…
Abstract
An arc detection method and apparatus is provided for an electric circuit having an electrified conductor (46) connecting a voltage source (26) to a load (30). The arc detector includes a field sensor (62) sensing an electromagnetic field established about the conductor by the occurrence of an electrical arc in the circuit, and generating a field responsive signal in response thereto. Arc discrimination circuitry responds to the field sensor and generates a tentative arc signal in response to a given characteristic of the field responsive signal. Arc timing window circuitry responds to the arc discrimination circuitry and generates a confirmed arc signal in response to a given timing characteristic of the tentative arc signal.
Claims30
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detector comprising a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto, an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal, an arc timing window circuit responsive to said arc discrimination circuit and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, wherein said field sensor comprises an E field sensor sensing the E field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating an E field responsive signal.
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detector comprising a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto, an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal, an arc timing window circuit responsive to said arc discrimination circuit and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, wherein said given characteristic of said field responsive signal is a random chaotic pattern of said field responsive signal, and wherein said field sensor comprises an E field sensor sensing the E field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating an E field responsive signal, and a B field sensor sensing the B field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating a B field responsive signal, and wherein said arc discrimination circuit comprises a first dual differentiator circuit differentiating said E field responsive signal twice with respect to time to provide the second derivative of said E field responsive signal, a second dual differentiator circuit differentiating said B field responsive signal twice with respect to time to provide the second derivative of said B field responsive signal, and an AND circuit having a first input from said first dual differentiator circuit, and a second input form said second dual differentiator circuit, and having an output providing said tentative arc signal to said arc timing window circuit when both said E field responsive signal and said B field responsive signal have a random chaotic pattern.
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detector comprising a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto, an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal, an arc timing window circuit responsive to said arc discrimination circuit and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, wherein said conductor has a line side extending from said arc detector to said voltage source, and a load side extending from said arc detector to said load, and wherein said arc discrimination circuit comprises a direction sensing circuit detecting whether said arc is from said load side or said line side and generating a direction indicative signal, and wherein said arc discrimination circuit generates said tentative arc signal in response to a given characteristic of said field responsive signal and a given characteristic of said direction indicative signal, and wherein said arc discrimination circuit comprises an AND circuit having a first input from said field sensor, and a second input from said direction sensing circuit, and having an output supplied to said arc timing window circuit.
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detector comprising a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto, an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal, an arc timing window circuit responsive to said arc discrimination circuit and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, wherein said conductor has a line side extending from said arc detector to said voltage source, and a load side extending from said arc detector to said load, and wherein said arc discrimination circuit comprises a direction sensing circuit detecting whether said arc is from said load side or said line side and generating a direction indicative signal, and wherein said arc discrimination circuit generates said tentative arc signal in response to a given characteristic of said field responsive signal and a given characteristic of said direction indicative signal, and wherein said field sensor comprises an E field sensor sensing the E field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating an E field responsive signal, and a B field sensor sensing the B field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating a B field responsive signal, and wherein said arc discrimination circuit comprises an AND circuit having a first input from said E field sensor, a second input form said B field sensor, and a third input form said direction sensing circuit, and having an output providing said tentative arc signal to said arc timing window circuit.
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load said arc detector comprising a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto, an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal, a dual window timing circuit responsive to said arc discrimination circuit and providing a first timing window during which the cumulative duration of said tentative arc signal is timed, and a second conditional timing window during which the cumulative duration of said tentative arc signal is timed, said second window being conditional upon the cumulative duration of said tentative arc signal reaching a first threshold during said first window, said timing circuit generating a confirmed arc signal if the cumulative duration of said tentative arc signal during said second window reaches a second threshold.
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detector comprising:
- a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto;
- an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal;
- an oscillator circuit of known frequency outputting clock pulses;
- a first counter circuit initiated by said tentative arc signal and counting clock pulses up to a first given count;
- a second counter circuit enabled by said tentative arc signal and counting clock pulses when said tentative arc signal is present up to a second given count;
- a third counter circuit initiated by said second counter circuit reaching said second count, and counting clock pulses up to a third given count;
- a fourth counter circuit enabled by said tentative arc signal when said second counter circuit reaches said second count, and counting clock pulses when said tentative arc signal is present up to a fourth given count, said fourth counter circuit providing a confirmed arc signal when said fourth count is reached.
An arc detector for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detector comprising:
- a field sensor sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, and generating a field responsive signal in response thereto;
- an arc discrimination circuit responsive to said field sensor and generating a tentative arc signal in response to a given characteristic of said field responsive signal;
- an oscillator circuit of known frequency outputting clock pulses;
- a first flip flop circuit set by said tentative arc signal;
- a first counter circuit enabled by said first flip flop circuit when set and counting clock pulses up to a first given count;
- a second counter circuit enabled by said tentative arc signal and counting clock pulses when said tentative arc signal is present;
- a second flip flop circuit set by said second counter circuit if the latter reaches a second given count;
- a third flip flop circuit set by said first counter circuit when the latter reaches said first count;
- a fourth flip flop circuit set by said tentative arc signal if said second flip flop circuit is set;
- a third counter circuit enabled by said fourth flip flop circuit when set and counting clock pulses up to a third given count;
- a fourth counter circuit enabled by said tentative arc signal if said second flip flop circuit is set, and counting clock pulses up to a fourth given count;
- a fifth flip flop circuit set by said fourth counter circuit when the latter reaches said fourth count, said fifth flip flop circuit when set providing a confirmed a signal.
An arc detection method for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detection method comprising sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, an generating a field responsive signal in response thereto, discriminatingly responding to said field responsive signal and generating a tentative arc signal in response to a given characteristic of said field responsive signal, timing said tentative arc signal and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, comprising timing the cumulative duration of said tentative arc signal during a first timing window, timing the cumulative duration of said tentative arc signal during a second conditional timing window, said second window being conditional upon the cumulative duration of said tentative arc signal reaching a first threshold during said first window, and comprising generating said confirmed arc signal if the cumulative duration of said tentative arc signal during said second window reaches a second threshold.
An arc detection method for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detection method comprising sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, an generating a field responsive signal in response thereto, discriminatingly responding to said field responsive signal and generating a tentative arc signal in response to a given characteristic of said field responsive signal, timing said tentative arc signal and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, comprising sensing the E field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating an E field responsive signal.
An arc detection method for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detection method comprising sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, an generating a field responsive signal in response thereto, discriminatingly responding to said field responsive signal and generating a tentative arc signal in response to a given characteristic of said field responsive signal, timing said tentative arc signal and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, comprising sensing the E field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating an E field responsive signal, sensing the B field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating a B field responsive signal, differentiating said E field responsive signal twice with respect to time to provide the second derivative of said E field responsive signal, differentiating said B field responsive signal twice with respect to time to provide the second derivative of said B field responsive signal, ANDing said second derivative of said E field responsive signal and said second derivative of said B field responsive signal such that a random chaotic pattern of both said E field responsive signal and said B field responsive signal is necessary to provide said tentative arc signal.
An arc detection method for an electric circuit including an electrified conductor connecting a voltage source to a load, said arc detection method comprising sensing an electromagnetic field established about said conductor by the occurrence of an electrical arc in said electric circuit, an generating a field responsive signal in response thereto, discriminatingly responding to said field responsive signal and generating a tentative arc signal in response to a given characteristic of said field responsive signal, timing said tentative arc signal and generating a confirmed arc signal in response to a given timing characteristic of said tentative arc signal, wherein said conductor has a line side extending from said arc detector to said voltage source, and a load side extending from said arc detector to said load, and comprising detecting whether said arc is from said load side or said line side and generating a direction indicative signal, and generating said tentative arc signal in response to a given characteristic of said field responsive signal in combination with a given characteristic of said direction indicative signal, comprising sensing the E field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating an E field responsive signal, sensing the B field established about said conductor by the occurrence of an electrical arc in said electric circuit and generating a B field responsive signal, ANDing said E field responsive signal and said B field responsive signal and said direction indicative signal and providing the result as said tentative arc signal.
Dependencies are inferred from the claim text.