High voltage bus and auxiliary heater control system for an electric or hybrid vehicle
First Claim
1. An auxiliary heater control system for a vehicle having a climate control system and one or more wheels powered by an electric motor that is energized from a power source via a voltage supply bus, said heater control system comprising:
- a heater control circuit having an electric heating element that is electrically coupled to the voltage supply bus and thermally coupled to the climate control system to provide heat for use by the climate control system using energy from the power source, said heater control circuit further including an input and being responsive to a control signal on said input to provide operating power from the voltage supply bus to said heating element; and
a vehicle system controller having an input for receiving a cabin heat request from the climate control system and having an output coupled to said input of said heater control circuit, said system controller being responsive to a cabin heat request to provide said heater control circuit with said control signal, whereby said electric heating element provides heat to the climate control system in response to a cabin heat request;
wherein said vehicle system controller is operable to monitor the voltage on the voltage supply bus and to provide said control signal to said heater control circuit when the monitored voltage exceeds a lower threshold voltage, whereby said electric heating element dissipates energy supplied to said voltage supply bus when the monitored voltage exceeds the lower threshold voltage.
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Accused Products
Abstract
A control system for an electric or hybrid electric vehicle includes a vehicle system controller and a control circuit having an electric immersion heater. The heater is electrically connected to the vehicle'"'"'s high voltage bus and is thermally coupled to a coolant loop containing a heater core for the vehicle'"'"'s climate control system. The system controller responds to cabin heat requests from the climate control system by generating a pulse width modulated signal that is used by the control circuit to operate the heater at a duty cycle appropriate for the amount of cabin heating requested. The control system also uses the heater to dissipate excess energy produced by an auxiliary power unit and to provide electric braking when regenerative braking is not desirable and manual braking is not necessary. The control system further utilizes the heater to provide a safe discharge of a bank of energy storage capacitors following disconnection of the battery or one of the high voltage connectors used to transmit high voltage operating power to the various vehicle systems. The control circuit includes a high voltage clamping circuit that monitors the voltage on the bus and operates the heater to clamp down the bus voltage when it exceeds a pre-selected maximum voltage. The control system can also be used to phase in operation of the heater when the bus voltage exceeds a lower threshold voltage and can be used to phase out the auxiliary power unit charging and regenerative braking when the battery becomes fully charged.
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Citations
15 Claims
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1. An auxiliary heater control system for a vehicle having a climate control system and one or more wheels powered by an electric motor that is energized from a power source via a voltage supply bus, said heater control system comprising:
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a heater control circuit having an electric heating element that is electrically coupled to the voltage supply bus and thermally coupled to the climate control system to provide heat for use by the climate control system using energy from the power source, said heater control circuit further including an input and being responsive to a control signal on said input to provide operating power from the voltage supply bus to said heating element; and a vehicle system controller having an input for receiving a cabin heat request from the climate control system and having an output coupled to said input of said heater control circuit, said system controller being responsive to a cabin heat request to provide said heater control circuit with said control signal, whereby said electric heating element provides heat to the climate control system in response to a cabin heat request; wherein said vehicle system controller is operable to monitor the voltage on the voltage supply bus and to provide said control signal to said heater control circuit when the monitored voltage exceeds a lower threshold voltage, whereby said electric heating element dissipates energy supplied to said voltage supply bus when the monitored voltage exceeds the lower threshold voltage. - View Dependent Claims (2, 3, 4, 5, 6)
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7. An auxiliary heater control system for a vehicle having a climate control system and one or more wheels powered by an electric motor that is energized from a power source via a voltage supply bus having an energy storage device, said heater control system comprising:
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a heater control circuit having an electric heating element that is electrically coupled to the voltage supply bus and thermally coupled to the climate control system to provide heat for use by the climate control system using energy from the power source and energy storage device, said heater control circuit further including an input and being responsive to a control signal on said input to provide operating power from the voltage supply bus to said heating element; a vehicle system controller having an input for receiving a cabin heat request from the climate control system and having an output coupled to said input of said heater control circuit, said system controller being responsive to a cabin heat request to provide said heater control circuit with said control signal, whereby said electric heating element provides heat to the climate control system in response to a cabin heat request; said vehicle system controller being operable upon disconnection of the power source from the voltage supply bus to provide said control signal to said heater control circuit, whereby said heater control circuit is operable to discharge the energy storage device via the voltage supply bus following disconnection of the power source from the voltage supply bus. - View Dependent Claims (8, 9)
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10. A control system for a hybrid electric vehicle having an auxiliary power unit and one or more wheels powered by an electric motor that is energized using the auxiliary power unit and a power source via a voltage supply bus, said control system comprising:
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a control circuit having an energy dissipation device that is electrically coupled to the voltage supply bus to dissipate energy supplied to the voltage supply bus, said control circuit further including an input and being responsive to a control signal on said input to provide operating power from the voltage supply bus to said energy dissipation device; and a vehicle system controller having an output coupled to said input of said control circuit, said system controller being operable to generate said control signal to thereby cause said control circuit to dissipate energy supplied to the voltage supply bus by the auxiliary power unit. - View Dependent Claims (11, 12, 13, 14, 15)
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Specification