Hybrid Automobiles Hybrid Automobiles It switches easily between - PDF document

Hybrid Automobiles 1 Hybrid Automobiles 2 Observations about Hybrid Observations about Hybrid Automobiles Automobiles � A hybrid car propels itself on fuel or batteries A hybrid car propels itself on fuel or batteries � It combines electrical and mechanical power It combines electrical and mechanical power Hybrid Automobiles Hybrid Automobiles � It switches easily between fuel, batteries, or both It switches easily between fuel, batteries, or both � It can recharge its batteries during braking It can recharge its batteries during braking � It can turn its engine off when not needed It can turn its engine off when not needed � It can restart its engine quickly and easily It can restart its engine quickly and easily Hybrid Automobiles 3 Hybrid Automobiles 4 5 Questions about Hybrid 5 Questions about Hybrid Question 1 Question 1 Automobiles Automobiles � How does a hybrid car power its wheels? How does a hybrid car power its wheels? � How does a hybrid car power its wheels? How does a hybrid car power its wheels? � How does a hybrid car generate electric power? How does a hybrid car generate electric power? � How does it combine engine and battery power? How does it combine engine and battery power? � How does a hybrid car use that electric power? How does a hybrid car use that electric power? � How does a hybrid car manage that power? How does a hybrid car manage that power? � If magnets don’t move, can they affect charge? If magnets don’t move, can they affect charge? Hybrid Automobiles 5 Hybrid Automobiles 6 Combining Mechanical Power Combining Mechanical Power The Transaxle The Transaxle � A hybrid automobile uses a machine that blends A hybrid automobile uses a machine that blends � A hybrid car’s transaxle is a gear assembly that A hybrid car’s transaxle is a gear assembly that � � rotary mechanical power from its fuel rotary mechanical power from its fuel- -burning engine burning engine � couples together its engine, motors, and wheels couples together its engine, motors, and wheels � rotary mechanical power from its electric motors rotary mechanical power from its electric motors � conveys mechanical power between those devices conveys mechanical power between those devices � rotary mechanical power from its wheels � r t r m rotary mechanical power from its wheels r t r m h ni h ni l p l p r fr m it r fr m it h h l l � r pl � replaces the transmission of a normal car r pl replaces the transmission of a normal car th tr n mi i n f th tr n mi i n f n rm l n rm l r r � That “transaxle” can transfer mechanical power That “transaxle” can transfer mechanical power between any of those devices in either direction! between any of those devices in either direction! 1

Hybrid Automobiles 7 Hybrid Automobiles 8 Rotary Power Rotary Power Question 2 Question 2 � Recall that to provide rotary power to a machine Recall that to provide rotary power to a machine � How does a hybrid car generate electric power? How does a hybrid car generate electric power? � you must exert a torque on that machine you must exert a torque on that machine � in the direction of its angular velocity. in the direction of its angular velocity. � The transaxle allows engine, motors, and wheels Th The transaxle allows engine, motors, and wheels Th l l ll ll i i d d h h l l � to exert torques on one another to exert torques on one another � as they turn in various directions at various speeds as they turn in various directions at various speeds � and thereby transfer rotary power to one another. and thereby transfer rotary power to one another. � Power can flow in any direction via the transaxle! Power can flow in any direction via the transaxle! � Hybrid Automobiles 9 Hybrid Automobiles 10 Clicker Question Clicker Question Generating Electricity Generating Electricity � A coil of wire forms a closed circuit with a A coil of wire forms a closed circuit with a � Recall that changing magnetic fields Recall that changing magnetic fields lightbulb. If you sweep the north pole of a bar lightbulb . If you sweep the north pole of a bar � produce electric fields, produce electric fields, magnet past the coil of wire, the lightbulb magnet past the coil of wire, the lightbulb will will � which propel currents through conductors, which propel currents through conductors, � which produce magnetic fields. which produce magnetic fields. hi h pr d hi h pr d m m n ti fi ld n ti fi ld � � Changing Changing magnetic effects magnetic effects induce induce currents currents A. blink once. blink once. A. � Moving magnets have changing magnetic fields Moving magnets have changing magnetic fields B. blink twice. blink twice. B. � and can induce currents in coils of wire and can induce currents in coils of wire C. not blink at all. not blink at all. C. � with magnetic fields that oppose the moving magnets. with magnetic fields that oppose the moving magnets. � Mechanical power becomes electrical power! Mechanical power becomes electrical power! Hybrid Automobiles 11 Hybrid Automobiles 12 An AC Generator An AC Generator Question 3 Question 3 � An AC Generator resembles a transformer An AC Generator resembles a transformer � How does a hybrid car use that electric power? How does a hybrid car use that electric power? � except that it has no primary coil except that it has no primary coil � Does it need both generators and motors? Does it need both generators and motors? � and instead uses a spinning magnet and instead uses a spinning magnet � How different are generators and motors? How different are generators and motors? � to induce AC current to induce AC current in its secondary coil. in its secondary coil. � Magnet rotation speed Magnet rotation speed sets the AC frequency. sets the AC frequency. � Magnet strength, turns Magnet strength, turns in the coil, and rotation in the coil, and rotation speed set voltage rise. speed set voltage rise. 2