I01�High-voltage�Components
4.�Electrical�Machine�Electronics
52
4.1.�Electrical�machine�electronics�(EME)
4.1.1.�Introduction
The�electrical�machine�electronics�EME�serves�mainly�as�control�electronics�for�the�electrical�machine,
which�drives�the�I01.�It�assumes�the�task�of�converting�the�DC�voltage�(up�to�about�400 V�DC)�from
the�high-voltage�battery�into�a�three-phase�AC�voltage�(up�to�about�360 V�AC)�for�activating�the
electrical�machine�as�a�motor.�Vice�versa,�when�the�electrical�machine�works�as�an�alternator,�the
electrical�machine�electronics�converts�the�three-phase�AC�voltage�of�the�electrical�machine�to�a
direct�current�voltage�and�can�thus�charge�the�high-voltage�battery.�This�takes�place�during�brake
energy�regeneration.�For�these�two�operating�modes�a�bidirectional�DC/AC�converter�is�necessary
which�can�work�as�both�an�inverter�and�a�rectifier.
The�DC/DC�converter�which�is�also�integrated�in�the�electrical�machine�electronics�ensures�the�voltage
supply�to�the�12 V�vehicle�electrical�system.�The�electrical�machine�electronics�has�another�control
unit�which�bears�the�same�name,�"EME"�for�short.
The�entire�electrical�machine�electronics�of�the�I01�is�located�in�an�aluminium�housing.�The�control
unit�of�the�bidirectional�AC/DC�converter�for�the�conversion�of�the�AC�voltage�to�direct�current�voltage
for�charging�the�high-voltage�battery,�as�well�as�conversion�of�the�direct�current�voltage�from�the�high-
voltage�battery�to�3-phase�AC�voltage�and�the�DC/DC�converter�for�the�voltage�supply�of�the�12 V
vehicle�electrical�system�are�located�in�this�housing.
The�housing�of�the�electrical�machine�electronics�cannot�be�opened�in�Service.
The�electrical�machine�electronics�of�the�I01�is�developed�and�supplied�by�the�relevant�departments�of
BMW�AG.�The�production�is�carried�out�in�a�division�of�the�plant�in�Dingolfing.
Only�Service�employees�who�satisfy�all�the�prerequisites�are�permitted�to�work�on�the�designated
high-voltage�components:�suitable�qualifications,�compliance�with�the�safety�rules,�procedure
following�the�exact�repair�instructions.
The�diagnosis�and�repair�of�the�high-voltage�components�is�only�allowed�in�a�retail�service
center�that�has�qualified�and�certified�service�technicians.�These�technicians�must�have
completed�the�ST1403b�I01�High�Voltage�Battery�and�Maintenance�instructor�led�course�and
successfully�passed�the�hands�on�certification.
4.1.2.�Installation�location
The�electrical�machine�electronics�is�installed�in�the�rear�of�the�I01,�in�an�area�separated�from�the
luggage�compartment.
