Gm Global Technolgoy Operations, Inc.

S M Nayeem Hasan

David P Tasky

Mohammad N Anwar

Timothy P Philippart

Bryan M Ludwig

Steven E Schulz

Wei D Wang

Sean E Gleason

John William Meyer, Iii

A circuit for compensating for low battery voltage available to power a load includes a power source, an inductor electrically coupled to the power source, a first switch configured to control current flow from the power source to the inductor, and a first diode connecting a first supply rail to the inductor. The circuit also includes a second switch configured to electrically connect the anode of a second diode to the inductor, with the cathode of the second diode connected to a second supply rail. A controller is configured to cycle the first and second switches to achieve a desired voltage values at the first and second supply rails. The second supply rail is electrically connected to the load. The controller is configured to enable the second switch to switch to a closed state only when the voltage at the power source is below a first predetermined threshold voltage.

Stabilizing power supply voltage to a load during auto start

A number of variations may include a method which may include determining a temperature rise in an IGBT junction without the use of a temperature estimation or measurement device because determination may be made by first determining the power loss due to the conduction losses of the IGBT and power loss associated with switching the IGBT where these losses may be determined by utilizing the saturation voltage of the IGBT, IGBT PWM duty cycle, IGBT switching frequency, fundamental frequency along with a lookup table for the switching energies and the phase current going through the IGBT. The determined power loss may be multiplied by a measured, sensed or obtained thermal impedance from the IGBT junction. Finally, the determined temperature rise of the IGBT junction may be added to a measured, sensed or obtained temperature of the coolant in order to determine the absolute temperature of the IGBT junction.

Online IGBT junction temperature estimation without the use of a dedicated temperature estimation or measurement device

A pre-charge circuit is disclosed for a vehicle including a battery and a load. The pre-charge circuit includes a time delay circuit configured to, in response to receiving power from the battery, generate a first voltage. The first voltage increases from a first value toward a second value. The pre-charge circuit includes a switch control circuit configured to, in response to the first voltage, provide a second voltage that follows the first voltage. The pre-charge circuit includes a switching circuit configured to selectively connect the battery to the load based on the second voltage and disconnect the load from the battery in response to the second voltage reaching a predetermined threshold value. The pre-charge circuit includes an output circuit configured to restrict an amount of power and inrush current that is provided from the battery to the load through the switching circuit.

Self turn-on and turn-off pre-charge circuit to limit bulk capacitor inrush current

A vehicle includes a rechargeable energy storage system (RESS), an electric traction motor, a traction power inverter module (TPIM), a high-voltage direct current (HVDC) bus that electrically connects the RESS to the TPIM, a passive discharge circuit connected across the positive and negative rails of the bus, and a microprocessor. The circuit includes a semiconductor switch. The microprocessor provides an output signal at a first voltage level that opens the switch and prevents discharge of the HVDC bus when the microprocessor is operating normally, and at a default second voltage level that closes the switch in the presence of a predetermined vehicle condition to thereby discharge the HVDC bus. An optocoupler may receive the output signal, and a zener diode may be in electrical parallel with an output side of the optocoupler. The switch may be an insulated gate bipolar transistor or a thyristor in different embodiments.

Passive high-voltage DC bus discharge circuit for a vehicle

Methods and apparatus are provided for detecting a phase current sensor fault in a multi-phase electrical motor. The method comprises, receiving an input torque command T* and measuring a set of feedback signals of the motor including a phase current Ix for each of the phases of the motor, generating direct and quadrature command phase currents Id*, Iq* for the motor corresponding to a value of the input torque command T*, determining a total command current Is=[(Iq*)2+(Id*)2]&#xbd;, generating a negative sequence current Ineg, where for three phases Ineg=(&#x2153;)[Ia+(&#x3b1;2)Ib+(&#x3b1;)Ic], where &#x3b1;=ej2&#x3c0;/3, combining Ineg and Is to provide a normalized negative sequence current Inn=Ineg/Is, comparing the normalized negative sequence current Inn to a predetermined threshold value INN* to determine the presence of a phase current sensor fault, and executing a control action when Inn&#x3e;INN*.

Protection of motor drive systems from current sensor faults

A method for monitoring electric isolation of a high voltage DC bus to detect ground isolation faults includes monitoring voltage differentials between a positive DC electric power bus and a negative DC electric power bus and a chassis ground. Electrical isolation between each of the positive and negative DC electric power buses and the chassis ground is monitored using a ratio of the voltage differentials.

Method and apparatus to monitor loss of ground isolation of an electric motor drive circuit

A vehicle includes an energy storage system (ESS) rechargeable using electrical power from an off-board AC power supply, a traction power inverter module (TPIM), one or two motors, and a controller. The TPIM has two inverters. The controller energizes designated semiconductor switches of the TPIM and designated induction coils of the motor to boost electrical power from the AC power supply for charging the ESS when the vehicle is not running. With two motors, a contactor allows induction coils of a first motor to be connected to the switches of the first inverter as an input filter, and an additional semiconductor switch is positioned between the ESS and an output side of the switches of the second inverter. A controller charges the ESS by energizing designated semiconductor switches of the TPIM and induction coils of the motor to charge the ESS without using an onboard battery charger module.

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Novi, MI, United States of America

S M Nayeem Hasan