Patents Assigned to Ballard Power Systems Corporation
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Patent number: 7012810Abstract: A DC bus for use in a power module has a positive DC conductor bus plate parallel with a negative DC conductor bus plate. One or more positive leads are connected to the positive bus and are connectable to a positive terminal of a power source. One or more negative leads are connected to the negative bus and are connectable to a negative terminal of a power source. The DC bus has one or more positive connections fastenable from the positive bus to the high side of a power module. The DC bus also has one or more negative connections fastenable from the negative bus to the low side of the power module. The positive bus and negative bus permit counter-flow of currents, thereby canceling magnetic fields and their associated inductances, and the positive and negative bus are connectable to the center portion of a power module.Type: GrantFiled: March 27, 2002Date of Patent: March 14, 2006Assignee: Ballard Power Systems CorporationInventors: Scott Parkhill, Sayeed Ahmed, Fred Flett
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Patent number: 6987670Abstract: A dual power module architecture employing a high degree of modularity, that allows a base power module to be quickly, easily, and cost effectively configured to address a large variety of applications.Type: GrantFiled: August 14, 2003Date of Patent: January 17, 2006Assignee: Ballard Power Systems CorporationInventors: Sayeed Ahmed, Fred Flett, Ajay V. Patwardhan, Douglas K. Maly
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Publication number: 20050281067Abstract: Independent phase output voltage control for a 3-phase 4-wire DC/AC inverter, for example, is provided. With the independent phase output voltage control, all three phase output voltages from the DC/AC inverter can be separately and effectively controlled to provide balanced 3-phase voltages from the DC/AC inverter to an unbalanced load, and/or to provide unbalanced 3-phase voltages from the DC/AC inverter to a balanced or unbalanced load. The independent phase output voltage control method can be applied to an inverter power system, with outputs of N-phase (N+1) wire configurations. Here, N can be any integer number greater than zero.Type: ApplicationFiled: June 21, 2004Publication date: December 22, 2005Applicant: Ballard Power Systems CorporationInventors: Duo Deng, Kon-King Wang
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Publication number: 20050270806Abstract: A power converter architecture interleaves full bridge converters to alleviate thermal management problems in high current applications, and may, for example, double the output power capability while reducing parts count and costs. For example, one phase of a three phase inverter is shared between two transformers, which provide power to a rectifier such as a current doubler rectifier to provide two full bridge DC/DC converters with three rather than four high voltage inverter legs.Type: ApplicationFiled: June 4, 2004Publication date: December 8, 2005Applicant: Ballard Power Systems CorporationInventor: Lizhi Zhu
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Patent number: 6940735Abstract: A power converter system advantageously employs a modular, bi-directionally symmetrical power converter assembly in a readily customizable configuration to interconnect a direct current power source to a three-phase alternating power grid. Connections external to the power converter assembly are selected to optimize the power converter system for a specific application, such as interconnecting a photovoltaic array to the three-phase electrical power grid. The electrical interconnections of various elements including isolation transformers, voltage sensors, and control switches are optimized to improve efficiency and reliability.Type: GrantFiled: November 14, 2003Date of Patent: September 6, 2005Assignee: Ballard Power Systems CorporationInventors: Duo Deng, Vijay Bhavaraju
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Patent number: 6937483Abstract: A device and method of commutation control for an isolated boost converter provides a unique commutation logic to limit voltage spikes by utilizing switches on the secondary side to minimize a mismatch between current in the inductor and current in the leakage inductance of the transformer when commutation takes places. To minimize this mismatch, the current in the leakage inductance is preset at a certain level that approaches the current in the inductor prior to the commutation, thus significantly reducing the power rating for a clamp circuit and enabling use of a simple passive clamp circuit. In addition, through unique timing of the turn-on of the secondary switches, soft switching conditions are created that eliminate turn-on losses and the reverse recovery problems of free-wheeling diodes.Type: GrantFiled: January 15, 2003Date of Patent: August 30, 2005Assignee: Ballard Power Systems CorporationInventors: Lizhi Zhu, Xingyi Xu
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Patent number: 6936991Abstract: A closed-loop permanent magnet motor control method and system optimally partitions torque and flux-weakening currents to produce a desired torque without exceeding the capability of the DC source. A maximum limit for allowable torque current and a minimum threshold for the maximum torque current are determined, and the flux current is varied based at least in part on whether the maximum torque current limit is above or below the minimum threshold while operating in a flux-weakening region to compensate for the variability of the DC source voltage.Type: GrantFiled: May 30, 2003Date of Patent: August 30, 2005Assignee: Ballard Power Systems CorporationInventors: Li Chen, Roy I. Davis, Stephen Stella, Tod R. Tesch
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Patent number: 6927988Abstract: A method for diagnosing faults using a load. In the method IGBTs are controlled such that certain currents are expected. If the currents are not as expected, a fault may be diagnosed.Type: GrantFiled: May 28, 2003Date of Patent: August 9, 2005Assignee: Ballard Power Systems CorporationInventors: Bing Cheng, Kent M. Harmon
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Patent number: 6919650Abstract: A hybrid use of a phase-locked-loop controller and a microprocessor-based controller to synchronize the phase angles of a three-phase AC power source, such as a static power converter, with those of a three-phase power grid. The phase-angle synchronization may enable the AC power source to be safely connected to the power grid to provide additional power capacity.Type: GrantFiled: May 31, 2002Date of Patent: July 19, 2005Assignee: Ballard Power Systems CorporationInventor: Doug D. Deng
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Patent number: 6914354Abstract: Methods and related systems providing removal of heat from electric motors via fluid baths.Type: GrantFiled: December 30, 2002Date of Patent: July 5, 2005Assignee: Ballard Power Systems CorporationInventors: David Seniawski, Jason M. Cardinal, Sayeed Ahmed
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Publication number: 20050128706Abstract: A power module comprises first and second substrates carrying semiconductor devices and coupled to respective pluralities of heat exchange members without intervening thermally insulative structures. One or more heat exchange loops circulate a heat exchange medium thermally coupled to the heat exchange members. Substrates may function as integral bus bars.Type: ApplicationFiled: December 16, 2003Publication date: June 16, 2005Applicant: Ballard Power Systems CorporationInventors: Douglas Maly, Kanghua Chen, Ajay Patwardhan, Sayeed Ahmed, Pablo Rodriguez, Gerardo Jimenez
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Patent number: 6906404Abstract: A power module employs at least one capacitor electrically coupled across the input terminals to reduce voltage overshoot. The capacitor may be surface mounted to a high side collector plating area and a low side emitter plating area. The power module may employ a lead frame and terminals accessible from an exterior of a module housing, for making electrical couplings to externally located power sources and/or loads.Type: GrantFiled: August 14, 2003Date of Patent: June 14, 2005Assignee: Ballard Power Systems CorporationInventors: Douglas K. Maly, Sayeed Ahmed, Ajay V. Patwardhan, Fred Flett
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Patent number: 6900643Abstract: A system including a current sensor to sense a current provided by an electronic power converter, the current sensor includes an output; an overcurrent detection circuit with an input coupled to an output of the current sensor; and a logic control circuit configurable to maintain the current provided by the electronic power converter in response to the sensed current having a short circuit magnitude, the logic control circuit including an input coupled to an output of the overcurrent detection circuit and at least one output coupled to at least one switch of the electronic power converter.Type: GrantFiled: August 6, 2003Date of Patent: May 31, 2005Assignee: Ballard Power Systems CorporationInventors: Duo Deng, Kerry E. Grand, Steven J. Kowalec
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Publication number: 20050105306Abstract: A power converter system advantageously employs a modular, bi-directionally symmetrical power converter assembly in a readily customizable configuration to interconnect a direct current power source to a three-phase alternating power grid. Connections external to the power converter assembly are selected to optimize the power converter system for a specific application, such as interconnecting a photovoltaic array to the three-phase electrical power grid. The electrical interconnections of various elements including isolation transformers, voltage sensors, and control switches are optimized to improve efficiency and reliability.Type: ApplicationFiled: November 14, 2003Publication date: May 19, 2005Applicant: Ballard Power Systems CorporationInventors: Duo Deng, Vijay Bhavaraju
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Patent number: 6894450Abstract: Circuits and methods for use with an integrated circuit chip having internal back EMF estimation to control a permanent magnet synchronous motor includes an AC current feedback circuit, a scaling circuit, and a current regulator. Additionally, a speed regulator may be employed. In one embodiment, during operation at very low speed, the speed regulator is in an open loop control mode due to a back EMF detection limitation of the IC chip, and only the current regulator is active. A feedback current signal, together with a user-defined command current signal, serves the input of the current regulator, which controls the AC motor current and drives the motor speed from standstill. Once the motor speed reaches a certain level, the measured back EMF from the IC chip is sufficient to estimate the motor speed, which is compared with a user-defined command speed, and an error of the these two signals provides the input of a speed regulator.Type: GrantFiled: January 16, 2003Date of Patent: May 17, 2005Assignee: Ballard Power Systems CorporationInventors: Bing Cheng, Duo Deng, Fengtai Huang
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Patent number: 6890218Abstract: A three-phase connector carries all three phases in one connector and keeps the phases properly isolated from each other and the motor case. The three-phase connector has metal connector components that are spaced from one another and supported in a nylon over molding covering each of the connector components, except for upper and lower exposed ends of the connector components, which are each drilled and tapped to receive bolts. First and second connector components extend above and below a flange of the three-phase connector with their respective exposed upper and lower ends offset in different planes than the exposed upper and lower ends of the third connector component.Type: GrantFiled: May 21, 2003Date of Patent: May 10, 2005Assignee: Ballard Power Systems CorporationInventors: Ajay V Patwardhan, John Franklin
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Publication number: 20050083714Abstract: A power converter may employ a planar transformer to minimize winding conduction loss, and the switching devices of the power converter may be aligned in lines parallel to an edge of the planar transformer to minimize the termination leakage inductance. The windings of the planar transformer may be thermally conductively coupled to one or more heat sinks carried by a circuit board which are with respective ones of the switching devices, to provide a cooling path for the planar transformer.Type: ApplicationFiled: October 16, 2003Publication date: April 21, 2005Applicant: Ballard Power Systems CorporationInventors: Lizhi Zhu, John Van Dyke, Richard Hampo
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Publication number: 20050057106Abstract: Apparatus and method for cooling and preventing the deterioration of the windings of an electric machine. The apparatus includes an electrically insulative spacer wedgingly disposed between adjacent windings.Type: ApplicationFiled: December 4, 2003Publication date: March 17, 2005Applicant: Ballard Power Systems CorporationInventors: Timothy Allen, David Seniawski, Ziaur Rahman
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Patent number: 6867987Abstract: A multilevel inverter control system having logic configured to substantially minimize and area between a target waveform and a step signal of a multilevel inverter.Type: GrantFiled: June 13, 2003Date of Patent: March 15, 2005Assignee: Ballard Power Systems CorporationInventors: Bing Cheng, Fengtai Huang
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Publication number: 20050055496Abstract: An efficient emulation of EEPROM employing flash memory employs a fixed location for an address pointer in flash memory and such that an erase operation is required only once every nth update where n is the number of bits at the fixed location, thus avoiding the need to erase the sector on every update and avoiding delays associated with linked lists for determining the address of the most up-to-date information. Use of bit shifting provides fast determination of the desired address.Type: ApplicationFiled: September 9, 2003Publication date: March 10, 2005Applicant: Ballard Power Systems CorporationInventor: Venkatapathi Nallapa