Patents by Inventor Hidenari Amo
Hidenari Amo has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 7233470Abstract: A distance relay apparatus includes a directional relay element which performs computation to detect a fault, which occurs in the forward direction from an installing point of the relay apparatus, based on a voltage and a current which are received from an object to be protected, a zone-1 distance relay element which performs computation to detect a fault within a predetermined zone, a fault detecting relay element which performs computation to detect a fault within a zone that is narrower than that of the zone-1 distance relay element in terms of data time length which is shorter than that used for the computation of the zone-1 distance relay element, and a logic element which outputs a relay signal in accordance with a detecting operation of the zone-1 distance relay element, the fault detecting relay element, and the directional relay element.Type: GrantFiled: July 9, 2003Date of Patent: June 19, 2007Assignee: Kabushiki Kaisha ToshibaInventors: Takahiro Kase, Hidenari Amo, Tetsuo Matsushima
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Patent number: 7106565Abstract: A directional ground relay (50) for receiving electric values relating to voltage and current from a power transmission line (1) to be protected. The directional ground relay may decide a direction of a fault in the power transmission line based upon the electric values. The directional ground relay comprises a zero-phase sequential current calculation unit (10-2) for calculating a zero-phase sequential current based upon the current detected from the power transmission line. The directional ground relay further comprises a phase-comparison unit (10-3) configured to compare a phase of the zero-phase sequential current to a phase of voltage corresponding to the voltage in the power transmission line, to decide whether the zero-phase sequential current is within a pre-determined range, and to output the phase of the voltage as a faulty phase of voltage, when the zero-phase sequential current is within the pre-determined range.Type: GrantFiled: July 21, 2003Date of Patent: September 12, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Takahiro Kase, Yasutaka Sonobe, Hidenari Amo
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Patent number: 6989977Abstract: A digital directional relay converts a voltage value and a current value of a power system into digital voltage data and digital current data by periodic sampling and determines a direction of a fault using the digital voltage data and the digital current data. In the digital directional relay, a variation in unbalanced component voltage and a variation in unbalanced component current are computed using both voltage data at a reference point in time and voltage data at a point in time elapsed from the reference point in time by a given sampling interval and using both current data at reference time and current data at time elapsed from the reference time by a given sampling interval, respectively. A relationship in phase between these variations is obtained to determine whether a forward fault or a reverse fault occurs.Type: GrantFiled: January 27, 2003Date of Patent: January 24, 2006Assignee: Kabushiki Kaisha ToshibaInventors: Takahiro Kase, Hidenari Amo, Yasutaka Sonobe
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Patent number: 6937453Abstract: A directional comparison distance relay system for protecting a power transmission line. The relay system comprises a fault detection unit which includes a directional distance relay element for deciding whether a fault is in forward or reverse directions; a short-circuit distance relay element for deciding whether a fault is within a protection zone by distance calculation; and an evolving fault detecting unit for deciding an evolving fault when a forward earth fault directional relay in a single phase and a reverse directional relay in a phase are in operation. The relay system further comprises a block unit for blocking trip of a circuit breaker at a near end due to the short-circuit distance relay, and for blocking permissive trip signal to a circuit breaker at the far end, based on an operation of the evolving fault detecting unit.Type: GrantFiled: January 21, 2003Date of Patent: August 30, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Takahiro Kase, Hidenari Amo, Yasutaka Sonobe
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Patent number: 6906903Abstract: A protection relay for determining whether or not a fault point of a power system exists in a predetermined range including a filter section for inputting sampling data of a voltage and a current in the power system to a digital filter having a predetermined transfer function and outputting a first voltage data and a first current data, and a second voltage data and a second current data normal to the first voltage data and the first current data, respectively, a calculator for calculating a predetermined measurement value based on the first and second voltage data, and the first and second current data at a first time and the first and second voltage data, and the first and second current data at a second time different from the first time, and an operation decision section for performing an operation decision based on the predetermined measurement value obtained by the calculator.Type: GrantFiled: March 1, 2002Date of Patent: June 14, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Kurosawa, Hidenari Amo, Hideyuki Takani
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Patent number: 6873508Abstract: In a protective relay system according to an aspect of the present invention, a direction of a fault is correctly determined during system oscillation using one of a negative-phase-sequence relay and a zero-phase-sequence relay. A circuit breaker is tripped only when an internal fault is determined at both terminals to be protected using a carrier signal. Thus, even though a fault occurs during system oscillation, the circuit breaker can be tripped against the internal fault.Type: GrantFiled: August 26, 2002Date of Patent: March 29, 2005Assignee: Kabushiki Kaisha ToshibaInventors: Takahiro Kase, Hidenari Amo, Yasutaka Sonobe
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Publication number: 20040057178Abstract: A directional ground relay (50) for receiving electric values relating to voltage and current from a power transmission line (1) to be protected. The directional ground relay may decide a direction of a fault in the power transmission line based upon the electric values. The directional ground relay comprises a zero-phase sequential current calculation unit (10-2) for calculating a zero-phase sequential current based upon the current detected from the power transmission line. The directional ground relay further comprises a phase-comparison unit (10-3) configured to compare a phase of the zero-phase sequential current to a phase of voltage corresponding to the voltage in the power transmission line, to decide whether the zero-phase sequential current is within a pre-determined range, and to output the phase of the voltage as a faulty phase of voltage, when the zero-phase sequential current is within the pre-determined range.Type: ApplicationFiled: July 21, 2003Publication date: March 25, 2004Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Takahiro Kase, Yasutaka Sonobe, Hidenari Amo
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Publication number: 20040008458Abstract: A distance relay apparatus includes a directional relay element which performs computation to detect a fault, which occurs in the forward direction from an installing point of the relay apparatus, based on a voltage and a current which are received from an object to be protected, a zone-1 distance relay element which performs computation to detect a fault within a predetermined zone, a fault detecting relay element which performs computation to detect a fault within a zone that is narrower than that of the zone-1 distance relay element in terms of data time length which is shorter than that used for the computation of the zone-1 distance relay element, and a logic element which outputs a relay signal in accordance with a detecting operation of the zone-1 distance relay element, the fault detecting relay element, and the directional relay element.Type: ApplicationFiled: July 9, 2003Publication date: January 15, 2004Inventors: Takahiro Kase, Hidenari Amo, Tetsuo Matsushima
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Publication number: 20030151867Abstract: A directional comparison distance relay system for protecting a power transmission line. The relay system comprises a fault detection unit which includes a directional distance relay element for deciding whether a fault is in forward or reverse directions; a short-circuit distance relay element for deciding whether a fault is within a protection zone by distance calculation; and an evolving fault detecting unit for deciding an evolving fault when a forward earth fault directional relay in a single phase and a reverse directional relay in a phase are in operation. The relay system further comprises a block unit for blocking trip of a circuit breaker at a near end due to the short-circuit distance relay, and for blocking permissive trip signal to a circuit breaker at the far end, based on an operation of the evolving fault detecting unit.Type: ApplicationFiled: January 21, 2003Publication date: August 14, 2003Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Takahiro Kase, Hidenari Amo, Yasutaka Sonobe
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Publication number: 20030142451Abstract: A digital directional relay converts a voltage value and a current value of a power system into digital voltage data and digital current data by periodic sampling and determines a direction of a fault using the digital voltage data and the digital current data. In the digital directional relay, a variation in unbalanced component voltage and a variation in unbalanced component current are computed using both voltage data at a reference point in time and voltage data at a point in time elapsed from the reference point in time by a given sampling interval and using both current data at reference time and current data at time elapsed from the reference time by a given sampling interval, respectively. A relationship in phase between these variations is obtained to determine whether a forward fault or a reverse fault occurs.Type: ApplicationFiled: January 27, 2003Publication date: July 31, 2003Inventors: Takahiro Kase, Hidenari Amo, Yasutaka Sanobe
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Publication number: 20030039086Abstract: In a protective relay system according to an aspect of the present invention, a direction of a fault is correctly determined during system oscillation using one of a negative-phase-sequence relay and a zero-phase-sequence relay. A circuit breaker is tripped only when an internal fault is determined at both terminals to be protected using a carrier signal. Thus, even though a fault occurs during system oscillation, the circuit breaker can be tripped against the internal fault.Type: ApplicationFiled: August 26, 2002Publication date: February 27, 2003Inventors: Takahiro Kase, Hidenari Amo, Yasutaka Sonobe
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Patent number: 6498709Abstract: A digital distance relay for deciding whether a fault point is within a stipulated operation region by obtaining an impedance to the fault point. The relay comprises: means for deciding whether the impedance is within a specified region by applying a value proportional to the relative phase; and means for deciding the fault point is within the stipulated operation region if: (a) when the load current indicates a sending direction, the positive-phase resistance and reactance are within a stipulated region based on stipulated positive-phase resistance and reactance, and the impedance is decided within the specified region; or (b) when the load current indicates a receiving direction, the positive-phase resistance and reactance are within a stipulated region based on stipulated positive-phase resistance and reactance, or the impedance is decided within the specified region.Type: GrantFiled: June 27, 2001Date of Patent: December 24, 2002Assignee: Kabushiki Kaisha ToshibaInventors: Yasuhiro Kurosawa, Tetsuo Matsushima, Hidenari Amo, Hiroshi Saito
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Publication number: 20020149893Abstract: A protection relay for determining whether or not a faultal point of a power system exists in a predetermined range, comprises filter section for inputting sampling data of a voltage and a current in the power system to a digital filter having a predetermined transfer function and outputting a first voltage data and a first current data, and a second voltage data and a second current data normal to the first voltage data and the first current data, respectively, calculator for calculating a predetermined measurement value based on the first and second voltage data, and the first and second current data at a first time and the first and second voltage data, and the first and second current data at a second time different from the first time, and operation decision section for performing an operation decision based on the predetermined measurement value obtained by the calculator.Type: ApplicationFiled: March 1, 2002Publication date: October 17, 2002Inventors: Yasuhiro Kurosawa, Hidenari Amo, Hideyuki Takani
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Publication number: 20020012213Abstract: A digital distance relay for deciding whether a fault point is within a stipulated operation region by obtaining an impedance to the fault point. The relay comprises: means for deciding whether the impedance is within a specified region by applying a value proportional to the relative phase; and means for deciding the fault point is within the stipulated operation region if: (a) when the load current indicates a sending direction, the positive-phase resistance and reactance are within a stipulated region based on stipulated positive-phase resistance and reactance, and the impedance is decided within the specified region; or (b) when the load current indicates a receiving direction, the positive-phase resistance and reactance are within a stipulated region based on stipulated positive-phase resistance and reactance, or the impedance is decided within the specified region.Type: ApplicationFiled: June 27, 2001Publication date: January 31, 2002Applicant: KABUSHIKI KAISHA TOSHIBAInventors: Yasuhiro Kurosawa, Tetsuo Matsushima, Hidenari Amo, Hiroshi Saito