Patent Application
20160264077
The present application relates generally to electrified vehicles and, more particularly, to optimized heating, ventilating, and air conditioning (HVAC) system control for electrified vehicles.
An electrified vehicle is typically configured to utilize an electric motor to at least optimally generate drive torque to propel the electrified vehicle. In some implementations, the electrified vehicle includes a regenerative braking system configured to convert the vehicle's kinetic energy into electrical energy instead of having the kinetic energy converted into wasted heat by the vehicle's brakes. This electrical energy could be used, for example, to recharge a battery system of the electrified vehicle. The battery system, however, has restrictions as to how much energy/charge it is capable of storing and thus some of the electrical energy generated by the regenerative braking system could be lost. Thus, while such electrified vehicle systems work for their intended purpose, there remains a need for improvement in the relevant art.
In accordance with one aspect of the invention, a system for maximizing energy efficiency in an electrified vehicle is provided. In one exemplary implementation, the system includes a heating, ventilating, and air conditioning (HVAC) system configured to provide heating, ventilation, and air conditioning for at least one of (i) a cabin of the electrified vehicle and (ii) a battery system of the electrified vehicle; a regenerative braking system configured to convert kinetic energy of the electrified vehicle to electrical energy; and a controller configured to, based on a vehicle torque request, control a distribution of the electrical energy generated by the regenerative braking system between (i) recharging the battery system and (ii) powering the HVAC system.
In accordance with one aspect of the invention, a method for controlling an HVAC system of an electrified vehicle is provided. In one exemplary implementation, the method includes determining, at a controller of the electrified vehicle, a vehicle torque request and, based on the vehicle torque request, controlling, by the controller, a distribution of electrical energy generated by a regenerative braking system of the electrified vehicle between (i) recharging a battery system of the electrified vehicle and (ii) powering the HVAC system.
In one exemplary implementation, the controller is configured to control the distribution of the electrical energy generated by the regenerative braking system such that the HVAC system is supplied with an average actual power over a period equal to an average desired power of the HVAC system over the period. In one exemplary implementation, the controller is configured to control the distribution of the electrical energy generated by the regenerative braking system such that during the period the HVAC system is provided at least one of (i) an actual power less than its desired power and (ii) an actual power greater than its desired power.
In one exemplary implementation, the controller is configured to decrease the electrical energy provided from the regenerative braking system to the HVAC system in response to an increase in the vehicle torque request. In one exemplary implementation, the controller is configured to increase the electrical energy provided from the regenerate braking system to the HVAC system in response to a decrease in the vehicle torque request.
In one exemplary implementation, the controller is configured to control the distribution of the electrical energy generated by the regenerative braking system between (i) recharging a battery system of the electrified vehicle and (ii) powering the HVAC system during only non-highway driving by the electrified vehicle.
In one exemplary implementation, the battery system is configured to at least partially power both (i) an electric motor configured to generate drive torque to propel the electrified vehicle and (ii) the HVAC system.
Further areas of applicability of the teachings of the present disclosure will become apparent from the detailed description, claims and the drawings provided hereinafter, wherein like reference numerals refer to like features throughout the several views of the drawings. It should be understood that the detailed description, including disclosed embodiments and drawings referenced therein, are merely exemplary in nature intended for purposes of illustration only and are not intended to limit the scope of the present disclosure, its application or uses. Thus, variations that do not depart from the gist of the present disclosure are intended to be within the scope of the present disclosure.
As previously discussed, at least some of the electrical energy generated by a regenerative braking system of an electrified vehicle could be lost due to restrictions on the battery system. Moreover, the battery system is configured to provide electrical energy to other components of the electrified vehicle, such as a heating, ventilating, and air conditioning (HVAC) system. Thus, in certain high demand scenarios, the battery system could be unable to output enough electrical energy (e.g., current) to the electric motor to meet a torque request. Accordingly, techniques are presented for optimized HVAC system control for electrified vehicles. The techniques include, based on a vehicle torque request, controlling a distribution of the electrical energy generated by the regenerative braking system between (i) recharging the battery system and (ii) powering the HVAC system. The techniques provide for increased energy efficiency (e.g., less or zero wasted electrical energy) and/or improved electrified vehicle responsiveness due to the lesser load on the battery system.
Referring now to
The electrified vehicle 100 includes a regenerative braking system 128 configured to convert kinetic energy of the electrified vehicle 100 into electrical energy (e.g., a current or power), such as when the electrified vehicle 100 is coasting or would otherwise be decelerating due to use of the brakes 132 of the electrified vehicle 100. As is known to those skilled in the art, a regenerative braking system converts the kinetic energy of the electrified vehicle into electrical energy by using the electric motor 116 as a generator instead of wasting such kinetic energy through conventional use of the brakes 132, which converts the excess kinetic energy into heat.
The electrified vehicle 100 also includes an HVAC system 136 configured to provide heating, ventilating, and air conditioning (climate control) to at least one of (i) cabin 140 of the electrified vehicle 100 and (ii) the battery system 112. For example only, the HVAC system 136 could be used to heat, cool, or otherwise ventilate the battery system 112 during extreme operating temperatures. In one exemplary implementation, the HVAC system 136 is controlled based on feedback from one or more temperature sensors 144 in the cabin 140. While temperature sensors 144 are shown and discussed herein, it will be appreciated that other suitable sensors could be additionally or alternatively utilized (e.g., humidity sensors). A controller 148 is configured to control operation of the electrified vehicle 100, such as controlling the electrified powertrain 104 and the HVAC system 136. Specifically, the controller 148 is configured to control the electrified powertrain 104 to output a desired torque corresponding to a vehicle torque request.
In one exemplary implementation, the vehicle torque request is provided via a driver interface 152 (e.g., an accelerator pedal). While the term vehicle torque request is used herein, it will be appreciated that the optimized HVAC control could also be performed based on an actual torque command (e.g., based on the vehicle torque request) by the controller 148 to the electrified powertrain 104. The driver interface 152 could also include controls enabling the driver to control the HVAC system 136 (a general on/off switch, cabin temperature set point controls, ventilation/fan controls, etc.)
In one exemplary implementation, the controller 148 is also configured to perform at least a portion of the techniques of the present disclosure. More particularly, the controller 148 is configured to, based on the vehicle torque request, control a distribution of the electrical energy generated by the regenerative braking system 128 between (i) recharging the battery system 112 and (ii) powering the HVAC system 136. In one exemplary implementation, the controller 148 is configured to control the HVAC system 136 such that an average power provided to the HVAC system 136 over a period equals a desired power for the HVAC system 136. This desired power for the HVAC system 136 represents a power for the HVAC system 136 to achieve requested parameters (airflow, cabin temperature, etc.). Thus, while the actual power provided to the HVAC system 136 may be lesser than and/or greater than its desired power over the period, the average actual power provided to the HVAC system 136 over the period should equal or approximately equal the average desired power over the period.
Referring now to
Referring now to
It should be understood that the mixing and matching of features, elements, methodologies and/or functions between various examples may be expressly contemplated herein so that one skilled in the art would appreciate from the present teachings that features, elements and/or functions of one example may be incorporated into another example as appropriate, unless described otherwise above.
