Korrektur eines Referattextes

Horst · Gast

Meine Frage:
Hallo,

ich muss bald ein Referat über die Funktion einer Drehstromlok halten. Bin allerdings bisher in der Grammatik nicht so stark gewesen. Könnt Ihr mir vielleicht den folgenden Text korrigieren?

Wäre sehr nett.
Danke!
Gruß
Horst

Meine Ideen:
I want to talk about the electricity of a three-phase locomotive I chose for my presentation the ES64U4with four axles, which Siemens build since 2006. It is 19,58m long and has a weight of 87t. The continuous demand is 6-6,4 MW. This locomotive set the world record for the fastest electro locomotive with a velocity of 357 km/h
The locomotive can be supplied with three different types of voltages and frequencies. The voltages are alternating voltage 15kV/16,7Hz for example in Germany or Austria or 25kV/50Hz in Poland and the direct voltage of 3kV for instance in Italy.
I will start do describe the electronics of the locomotive on the roof. There are four pantographs. The two in the middle are for the direct current, the other are for the alternating current. Under the metal strips on the top of the pantograph, which is used to get the current from the catenary into the electric network of the locomotive, there is a small air duct with a high pressure of air. When the pantograph is damaged or worn, the pressure will be lower. Now the electronic of the train recognizes the mistake and the pantograph will be sunk. Therefore the catenary remains intact.
Then there are the main switches, they are on the roof, too. They can switch off or on the current. One is for the direct and the other for the alternating current. The main switches are operated via compressed air.
The next component is the transformer. The transformer is attached between the bogies of the locomotive, because it is voluminous and in the locomotive there is no space for it. It has an weight of nearly 18t. On the primary side of the transformer there is a coil like in normal transformer, but on the secondary side there is a special coil, because it has an extra connection. Because of that there are two different transmissions of the current. This is the trick to use two different alternating currents. Therefore behind the secondary side of the transformer there is always the same voltage.
Then there are two power converters. One supplies two motors of the locomotive. First a power converter converts the alternating current in direct current. It happens in the rectifier. When the catenary has a direct current, this current is connected at this point with the power converter.
Secondly motor power converters, one for a motor, produce three phase current with adjustable frequencies and voltages for different velocities and numbers of cars or weight. The board computer of the locomotive can address every motor power converter separately to get the best attraction.
But there are also two inverters, one in every power converter. They convert the direct current in a three phase voltage of 440V. One of the two inverters produces a constant frequency. This voltage is used for instance for the board computer or the air presser. The other inverter produces a frequency between 2 and 60 Hz. The cooling tower and the fans of the motors require this voltage. In the cooling tower there are fans. The fans refrigerate pipes, which transport coolant to the transformer and the power converters. When they are too hot, the coolant has to be cooler and therefore the fans have to be faster. Because of that they need for a higher motor speed a high frequency. When they are cool, the fans can be slower and they need a lower frequency.
Let´s come to the motors. The locomotive has four asynchronous traction motors. A motor has a continuous power of 1640kW. Every motor has an axle gear and is mounted in the bogie. One motor is for one axle. When a motor is damaged or has a short circuit, the board computer recognized the problem and power off this motor automatically. Now the locomotive can use three motors and the ride can go on without a stop. Actually the locomotive has a lower power now.
The motor can be used as an alternator, when the locomotive brakes. Then electrical energy is returned in the catenary. But it is only possible, when the catenary has alternating current. When there is direct current, the produced energy is converted into heat in the resistors.