Patents by Inventor Tiefu Zhao
Tiefu Zhao 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: 11747841Abstract: An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.Type: GrantFiled: December 9, 2020Date of Patent: September 5, 2023Assignee: Eaton Intelligent Power LimitedInventors: Jonathan Michael Schaar, Tiefu Zhao
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Publication number: 20210287858Abstract: A voltage regulation device includes: a plurality of taps; a first electrical contact configured to connect to one of the plurality of taps; a second electrical contact configured to connect to one of the plurality of taps; and a network electrically connected to the first electrical contact and to the second electrical contact. The network is configured to control a voltage differential between the first electrical contact and the second electrical contact or an amount of current that flows in the first electrical contact and the second electrical contact.Type: ApplicationFiled: February 19, 2021Publication date: September 16, 2021Inventors: Jonathan Michael Schaar, Tiefu Zhao, Yafeng Wang
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Publication number: 20210165433Abstract: An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.Type: ApplicationFiled: December 9, 2020Publication date: June 3, 2021Inventors: Jonathan Michael Schaar, Tiefu Zhao
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Patent number: 10890932Abstract: An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.Type: GrantFiled: August 5, 2019Date of Patent: January 12, 2021Assignee: Eaton Intelligent Power LimitedInventors: Jonathan Michael Schaar, Tiefu Zhao
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Publication number: 20200057461Abstract: An apparatus for a load tap changer includes a first primary winding electrically connected to a first contact, the first contact configured to connect to one of a plurality of taps in a load tap changer; a second contact, the second contact configured to connect to one of the plurality of taps in the load tap changer; a magnetic core; and a control circuit including: a secondary winding configured to magnetically couple to the first primary winding and the magnetic core; and an electrical network electrically connected to the secondary winding, the electrical network being configured to prevent magnetic saturation of the magnetic core during switching of the first or second contact.Type: ApplicationFiled: August 5, 2019Publication date: February 20, 2020Inventors: Jonathan Michael Schaar, Tiefu Zhao
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Patent number: 10141787Abstract: The present invention provides a receiving circuit for magnetic coupling resonant wireless power transmission comprising: a resonant circuit, which comprises a resonant coil and a resonant capacitor; a rectifying circuit, the input of which is electrically connected to the two terminals of the resonant capacitor; a storage capacitor, the two terminals of which are electrically connected to the output of rectifying circuit; and a DC-DC converter, the input of which is electrically connected to the two terminals of the storage capacitor and the output of which is electrically connected to a rechargeable battery. The receiving circuit for magnetic coupling resonant wireless power transmission of the present invention can save energy and has high charge efficiency.Type: GrantFiled: March 3, 2015Date of Patent: November 27, 2018Assignee: Eaton Capital Unlimited CompanyInventors: Gerald Zheng, Jack Gu, Bruce Wu, Tiefu Zhao, Jun Xu, Birger Pahl, Yahan Hua
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Patent number: 10116230Abstract: A method of operating an AC to DC converter circuit can be provided by changing a configuration of a DC output filter circuit to reshape a current waveform in a rectifier circuit, included in the AC to DC converter circuit, based on an operating efficiency of the AC to DC converter circuit. Related circuits and articles of manufacture are also disclosed.Type: GrantFiled: December 30, 2013Date of Patent: October 30, 2018Assignee: Eaton Capital Unlimited CompanyInventors: Tangshun Wu, Jr., Jun Xu, Tiefu Zhao, Birger Pahl
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Patent number: 10038324Abstract: A wireless power transfer circuit can include an input port that can be configured to couple to a power source, an ac excitation circuit having a port coupled to the input port, a resonant circuit coupled to the ac excitation circuit, and a controller circuit that can be configured to operate the ac excitation circuit. The wireless power transfer circuit can operate to inductively transfer power from the resonant circuit and the controller circuit can be configured to change an operating frequency of the ac excitation circuit and change a configuration of the resonant circuit responsive a change in indicated efficiency of the wireless power transfer.Type: GrantFiled: January 6, 2015Date of Patent: July 31, 2018Assignee: Eaton Intelligent Power LimitedInventors: Prasanna Nirantare, Tiefu Zhao, Birger Pahl, Milind Kothekar, Yahan Hua
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Patent number: 10020802Abstract: An integrated circuit is provided with an MCU, which is configured to generate a PWM control signal that is free of switching pattern information therein. A current-estimating gate driver is provided, which is responsive to the PWM signal. This gate driver is configured to drive first and second gate terminals of first and second parallel switching devices (within a hybrid switch) with gate signals that establish a second switching pattern within the hybrid switch. These gate driving operations are performed in response to measuring a first voltage associated with a terminal of the hybrid switch when being driven by gate signals that establish a first switching pattern within the hybrid switch that is different from the second switching pattern. The duty cycles of the gate signals associated with the second switching pattern are unequal and the duty cycles of the gate signals associated with the first switching pattern are unequal.Type: GrantFiled: June 27, 2017Date of Patent: July 10, 2018Assignee: Eaton Intelligent Power LimitedInventors: Tiefu Zhao, Jiangbiao He, Yakov Lvovich Familiant, Mengbin Ben Yang
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Publication number: 20170344039Abstract: A voltage regulator includes a tap changer coupled to a voltage source terminal and a voltage load terminal, The voltage regulator also includes a first switch and a first current transformer coupled in series between the voltage load terminal and a first movable contact of the tap changer. The voltage regulator further includes a second switch and a second transformer coupled in series between the voltage load terminal and a second movable contact of the tap changer, A first silicon controlled rectifier and a second silicon controlled rectifier are controlled by a first control circuit and a second control circuit, respectively. The first control circuit and the second control circuit each include a rectifier, a gating switch, and a positive voltage detector.Type: ApplicationFiled: May 27, 2016Publication date: November 30, 2017Applicant: COOPER TECHNOLOGIES COMPANYInventors: Frederick Alan Stich, Tiefu Zhao
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Publication number: 20170294911Abstract: An integrated circuit is provided with an MCU, which is configured to generate a PWM control signal that is free of switching pattern information therein. A current-estimating gate driver is provided, which is responsive to the PWM signal. This gate driver is configured to drive first and second gate terminals of first and second parallel switching devices (within a hybrid switch) with gate signals that establish a second switching pattern within the hybrid switch. These gate driving operations are performed in response to measuring a first voltage associated with a terminal of the hybrid switch when being driven by gate signals that establish a first switching pattern within the hybrid switch that is different from the second switching pattern. The duty cycles of the gate signals associated with the second switching pattern are unequal and the duty cycles of the gate signals associated with the first switching pattern are unequal.Type: ApplicationFiled: June 27, 2017Publication date: October 12, 2017Inventors: Tiefu Zhao, Jiangbiao He, Yakov Lvovich Familiant, Mengbin Ben Yang
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Patent number: 9722581Abstract: An integrated circuit is provided with an MCU, which is configured to generate a PWM control signal that is free of switching pattern information therein. A current-estimating gate driver is provided, which is responsive to the PWM signal. This gate driver is configured to drive first and second gate terminals of first and second parallel switching devices (within a hybrid switch) with gate signals that establish a second switching pattern within the hybrid switch. These gate driving operations are performed in response to measuring a first voltage associated with a terminal of the hybrid switch when being driven by gate signals that establish a first switching pattern within the hybrid switch that is different from the second switching pattern. The duty cycles of the gate signals associated with the second switching pattern are unequal and the duty cycles of the gate signals associated with the first switching pattern are unequal.Type: GrantFiled: December 19, 2014Date of Patent: August 1, 2017Assignee: Eaton CorporationInventors: Tiefu Zhao, Jiangbiao He, Yakov Lvovich Familiant, Mengbin Ben Yang
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Publication number: 20170070082Abstract: The present invention provides a receiving circuit for magnetic coupling resonant wireless power transmission comprising: a resonant circuit, which comprises a resonant coil and a resonant capacitor; a rectifying circuit, the input of which is electrically connected to the two terminals of the resonant capacitor; a storage capacitor, the two terminals of which are electrically connected to the output of rectifying circuit; and a DC-DC converter, the input of which is electrically connected to the two terminals of the storage capacitor and the output of which is electrically connected to a rechargeable battery. The receiving circuit for magnetic coupling resonant wireless power transmission of the present invention can save energy and has high charge efficiency.Type: ApplicationFiled: March 3, 2015Publication date: March 9, 2017Applicant: COOPER INDUSTRIES HOLDINGSInventors: GERALD ZHENG, JACK GU, BRUCE WU, TIEFU ZHAO, JUN XU, BIRGER PAHL, YAHAN HUA
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Patent number: 9397657Abstract: An integrated circuit includes a hybrid switch having first and second switching devices of different type therein. A control circuit is provided, which is configured to drive the first and second devices with respective first and second control signals having first and second unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a first current range. The control circuit is further configured to drive the first and second devices with respective third and fourth control signals having third and fourth unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a second current range outside the first current range. The first duty cycle may be greater than the second duty cycle and the third duty cycle may be less than the fourth duty cycle.Type: GrantFiled: December 19, 2014Date of Patent: July 19, 2016Assignee: Eaton CorporationInventors: Tiefu Zhao, Jiangbiao He, Vijay Bhavaraju, Mengbin Ben Yang
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Publication number: 20160197485Abstract: A wireless power transfer circuit can include an input port that can be configured to couple to a power source, an ac excitation circuit having a port coupled to the input port, a resonant circuit coupled to the ac excitation circuit, and a controller circuit that can be configured to operate the ac excitation circuit. The wireless power transfer circuit can operate to inductively transfer power from the resonant circuit and the controller circuit can be configured to change an operating frequency of the ac excitation circuit and change a configuration of the resonant circuit responsive a change in indicated efficiency of the wireless power transfer.Type: ApplicationFiled: January 6, 2015Publication date: July 7, 2016Inventors: Prasanna Nirantare, Tiefu Zhao, Birger Pahl, Milind Kothekar, Yahan Hua
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Publication number: 20160191021Abstract: An integrated circuit is provided with an MCU, which is configured to generate a PWM control signal that is free of switching pattern information therein. A current-estimating gate driver is provided, which is responsive to the PWM signal. This gate driver is configured to drive first and second gate terminals of first and second parallel switching devices (within a hybrid switch) with gate signals that establish a second switching pattern within the hybrid switch. These gate driving operations are performed in response to measuring a first voltage associated with a terminal of the hybrid switch when being driven by gate signals that establish a first switching pattern within the hybrid switch that is different from the second switching pattern. The duty cycles of the gate signals associated with the second switching pattern are unequal and the duty cycles of the gate signals associated with the first switching pattern are unequal.Type: ApplicationFiled: December 19, 2014Publication date: June 30, 2016Inventors: Tiefu Zhao, Jiangbiao He, Yakov Lvovich Familiant, Mengbin Ben Yang
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Publication number: 20160191046Abstract: An integrated circuit includes a hybrid switch having first and second switching devices of different type therein. A control circuit is provided, which is configured to drive the first and second devices with respective first and second control signals having first and second unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a first current range. The control circuit is further configured to drive the first and second devices with respective third and fourth control signals having third and fourth unequal duty cycles, respectively, when the first and second devices are supporting a forward current in a second current range outside the first current range. The first duty cycle may be greater than the second duty cycle and the third duty cycle may be less than the fourth duty cycle.Type: ApplicationFiled: December 19, 2014Publication date: June 30, 2016Inventors: Tiefu Zhao, Jiangbiao He, Vijay Bhavaraju, Mengbin Ben Yang
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Patent number: 9287418Abstract: A system and method for selectively connecting photovoltaic (PV) arrays of a PV power system in series and parallel arrangements is disclosed. A DC-to-AC power inverter in the PV power system is electrically coupled to a plurality of PV arrays to receive a DC output therefrom and invert the DC output to an AC output, with the DC-to-AC power inverter including a DC link that receives the DC output from the plurality of PV arrays. A contactor arrangement is positioned between the plurality of PV arrays and the DC-to-AC power inverter, with the contactor arrangement including a plurality of contactors that are switchable between an on state and an off state to selectively connect the plurality of PV arrays to the DC-to-AC power inverter in a specified arrangement, so as to control a level of DC voltage received by the DC-to-AC power inverter from the plurality of PV arrays.Type: GrantFiled: June 29, 2012Date of Patent: March 15, 2016Assignee: Eaton CorporationInventors: Prasanna S. Nirantare, Vijay Bhavaraju, Tiefu Zhao, Jun Xu, Christopher Scott Thompson
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Patent number: 9123466Abstract: Wireless power transfer systems include at least one foil-type transmitter/receiver coil with a plurality of turns, which is configured to reduce eddy current losses therein when energized to conduct an alternating current that supports inductive power transfer including coil-to-coil power electrical transfer, inductive heating, etc. The plurality of turns includes at least an outermost turn with a first arcuate-shaped corner having a concave inner surface, which faces an immediately adjacent one of the plurality of turns. The immediately adjacent one of the plurality of turns may also have a second arcuate-shaped corner with a concave inner surface facing an innermost one of the plurality of turns. The first arcuate-shaped corner may have a non-uniform radius of curvature and/or an innermost one of the plurality of turns may have an arcuate-shaped corner, which is a mirror image of the first arcuate-shaped corner when the coil is view in transverse cross-section.Type: GrantFiled: November 11, 2013Date of Patent: September 1, 2015Assignee: Eaton CorporationInventors: Qingjie Zheng, Yilei Gu, Tangshun Wu, Tiefu Zhao, Jun Xu, Birger Pahl, Yahan Hua
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Publication number: 20150188446Abstract: A method of operating an AC to DC converter circuit can be provided by changing a configuration of a DC output filter circuit to reshape a current waveform in a rectifier circuit, included in the AC to DC converter circuit, based on an operating efficiency of the AC to DC converter circuit. Related circuits and articles of manufacture are also disclosed.Type: ApplicationFiled: December 30, 2013Publication date: July 2, 2015Inventors: Tangshun Wu, Jun Xu, Tiefu Zhao, Birger Pahl