Deere mpany : Patent Issued for Method and Inverter with Thermal Management for Controlling an Electric Machine (USPTO 9698722)
The patent's inventors are Loken, David M. (
This patent was filed on
From the background information supplied by the inventors, news correspondents obtained the following quote: "An electric motor may feature a rotor with permanent magnets and a stator, such as an interior permanent magnet (IPM) motor or an IPM synchronous motor. An inverter may control the electric motor or other electric machine, such as an alternating current, variable frequency motor. In certain prior art, the maximum current that can be provided by the inverter to the electric motor is limited by the junction temperatures of the switching devices of the inverter. At stall and low fundamental frequency operation, the current output capability of an inverter is limited to lower output capability than can be achieved at higher fundamental frequency operation. Thus, there is a need for an improved method and inverter with thermal management for controlling an electric machine."
Supplementing the background information on this patent, VerticalNews reporters also obtained the inventors' summary information for this patent: "In accordance with one embodiment, a method or inverter with thermal management is presented for control of an electric machine. An electronic data processing system determines a fundamental frequency of one or more inverter phases based on a torque command to control the torque, speed or direction of the electric machine (e.g., motor). The electronic data processing system establishes an initial reference output current based on the torque command or other input data. A temperature estimation module estimates each junction temperature of a corresponding semiconductor device, among a plurality of semiconductor devices, for each phase of an inverter. The temperature estimation module or the data processing system determines a hottest device with a highest junction temperature among the semiconductor devices. A thermal adjustment module or data processing system determines if the highest junction temperature parameter (e.g., an absolute junction temperature, or rise or difference in the junction temperature) is less than maximum junction temperature parameter (e.g., an absolute maximum junction temperature, or maximum rise or maximum difference in in junction temperature) for the respective semiconductor device or deciding whether or not to adjust a duty cycle of the semiconductor devices."
For the URL and additional information on this patent, see: Loken, David M.; Wu, Long; Fu, Tianjun; Shaw, Robert B.;
Keywords for this news article include: Electronics, Semiconductor,
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