BMW I01, Информация о продукте

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I01�High-voltage�Components
7.�EKK
133
• Housing
• EKK�control�unit
• Three-phase�current�synchronous�motor
• AC�inverter
• Air�conditioning�compressor.
These�individual�components�are�never�replaced�separately��The�entire�EKK�is�always�replaced.�At�this
stage�the�tasks�of�some�components�are�explained�in�order�to�better�explain�the�function�of�the�EKK.
7.2.1.�EKK�control�unit
The�EKK�control�unit�controls�the�engine�speed�of�the�three-phase�motor�in�the�EKK�based�on�the
requests�of�the�IHKA�and�reports�the�operating�status�back�to�the�IHKA�control�unit.�The�EKK�control
unit�communicates�with�the�IHKA�via�the�LIN�bus.�The�IHKA�is�the�master�control�unit�for�the�EKK.
7.2.2.�Three-phase�current�synchronous�motor
A�three-phase�synchronous�motor�is�used�as�the�drive�for�the�EKK.�The�energy�is�taken�from�the
high-voltage�battery.�The�necessary�three-phase�current�is�converted�in�the�EKK�using�an�AC�inverter
(DC/AC�converter).�The�three-phase�synchronous�motor�is�operated�in�the�engine�speed�range
between�860�and�8600 rpm�and�is�infinitely�variable.�It�uses�an�electrical�power�of�up�to�4.5 kW.�The
maximum�power�is�required,�for�example,�at�high�ambient�temperatures,�high�interior�temperatures,
high�temperatures�of�the�high-voltage�battery�and�low�air�flow�of�the�cooling�module.
7.2.3.�AC�inverter
The�DC/AC�converter�converts�the�direct�current�voltage�into�the�three-phase�alternating�current
that�is�required�to�operate�the�three-phase�synchronous�motor.�The�EKK�control�unit�and�the�DC/
AC�converter�are�integrated�in�the�aluminium�housing�of�the�EKK�and�are�cooled�by�the�gaseous
refrigerant�flowing�past.�If�the�temperature�of�the�DC/AC�converter�exceeds�125 °C,�the�high-voltage
supply�is�shut�off�by�the�EKK�control�unit.�The�attempt�is�made�through�different�measures�such�as
speed�increase�for�cooling�initially�not�to�allow�the�temperature�to�rise�so�high.�The�temperature�is
monitored�by�the�electric�A/C�compressor�control�unit.�If�the�temperature�drops�below�112 °C,�the
EKK�continues�to�run.
The�supply�voltage�for�EKK�has�a�voltage�range�of�about�200 V�to�410 V.�The�power�is�reduced�above
and�below�this�voltage�range�or�the�EKK�is�switched�off.
7.2.4.�Air�conditioning�compressor
To�compress�the�refrigerant,�the�spiral�compressor�(also�known�as�the�scroll�compressor)�is�used.
R134a�refrigerant�is�used�for�the�US�market.