High voltage bus and auxiliary heater control system for an electric or hybrid vehicle

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:872925

Murty, Balarama Vempaty ^[1]

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1. West Bloomfield, MI

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.

• Research Organization: Midwest Research Institute, Kansas City, MO (United States)
• DOE Contract Number: AC36-83CH10093
• Assignee: General Motors Corporation (Detroit, MI)
• Patent Number(s): US 6040561
• OSTI ID: 872925
• Country of Publication: United States
• Language: English

Related Subjects

voltage
bus
auxiliary
heater
control
electric
hybrid
vehicle
controller
circuit
immersion
electrically
connected
thermally
coupled
coolant
loop
containing
core
climate
responds
cabin
heat
requests
generating
pulse
width
modulated
signal
operate
duty
cycle
appropriate
amount
heating
requested
dissipate
excess
energy
produced
power
unit
provide
braking
regenerative
desirable
manual
utilizes
safe
discharge
bank
storage
capacitors
following
disconnection
battery
connectors
transmit
operating
various
systems
clamping
monitors
operates
clamp
exceeds
pre-selected
maximum
phase
operation
threshold
charging
charged
threshold voltage
climate control
operating power
clamping circuit
regenerative braking
storage capacitor
hybrid vehicle
modulated signal
control circuit
electric vehicle
pulse width
energy storage
electrically connected
duty cycle
hybrid electric
energy produced
auxiliary heat
bus voltage
thermally coupled
voltage clamping
coolant loop
auxiliary power
loop containing
voltage bus
width modulated
provide electric
voltage clamp
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