Traction Motors: Difference between revisions

Revision as of 00:45, 15 March 2025

Motorized rail vehicles with electric drivetrains are propelled by traction motors. Traction motors (TM, for short) are electric motors that are typically positioned around vehicles' axles, and rely on electricity to run.

When throttle is operated on electric vehicles, electrical power is delivered from the power source to the motors, through a series of different components. On diesel-electric vehicles the response may be a bit delayed, because the engine needs to spool up in order to generate the required power.

At very low vehicle speeds traction motors produce high torque with high electric current. As the speed increases, however, traction motors produce increasingly more counter-electromotive force. This force opposes the supply voltage, causing both current and torque to drop. The faster the vehicle goes, the more power it needs to maintain the same acceleration.

For this reason, it is crucial to operate the throttle notch by notch, and always keep the current at a nominal level, by carefully observing the ammeter and traction motor temperature gauges and not letting any go into red.

When an electric vehicle accelerates under heavy load, it can be exposed to a high current for a prolonged period. Over time, this will warm up the traction motors . Depending on the session difficulty settings , traction motors may trip the respective breaker when they overheat, or much worse - short-circuit and set the vehicle on fire . A very high current surge can trip the breaker even before it comes to overheating, although still at a risk of damage.

Damage to electrical powertrain can result in individual traction motors seizing to work. Since electric vehicles usually have more than one motor, power will then be automatically distributed to the remaining operational ones. With fewer driving axles on a vehicle, wheelslip is more likely to occur, however.

An electric vehicle's traction can be improved by adding a slug .

On some electric vehicles, traction motors can dynamically reconfigure their circuits to better optimize load on the generator. This is called “transition”, and results in brief disengagements of traction motors at certain speeds. This is normal behavior.

Traction motors can only withstand speed up to a certain amount, usually indicated red on the speedometer. Going above that speed can result in catastrophic failure , even if traction motors are in no way engaged.

For the traction motors to be operational, respective breakers need to be enabled.

Installing an amp limiter , or overheat protection gadgets, makes it easier to manage traction motors load and temperature.

One of the advantages of traction motors is their rheostatic and regenerative braking ability.

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 <!--T:1-->
-Traction motors (TM, for short) are electric motors that {{pll|Rail Vehicle Types|vehicles}} with {{pll|Powertrains Overview|electric transmissions}} come equipped with. Traction motors are typically positioned around individual wheel axles, and rely on {{pll|Electricity|electricity}} to be spun and to propel vehicles.
+{{pll|Rail Vehicle Types|Motorized rail vehicles}} with {{pll|Powertrains Overview|electric drivetrains}} are propelled by traction motors. Traction motors (TM, for short) are electric motors that are typically positioned around vehicles' axles, and rely on {{pll|Electricity|electricity}} to run.
 <!--T:2-->
-When {{pll|Throttle|throttle}} is operated on electric vehicles, desired electrical power is sent from the {{pll|Electric Powersource|power source}} to the traction motors. On {{pll|Powertrains Overview|diesel-electric}} vehicles, this indirectly adjusts fuel injection and engine spin rate in order to output the required electrical power from the generators.
+When {{pll|Throttle|throttle}} is operated on electric vehicles, electrical power is delivered from the {{pll|Electric Powersource|power source}} to the motors, through a series of different components. On {{pll|Powertrains Overview|diesel-electric}} vehicles the response may be a bit delayed, because the engine needs to spool up in order to generate the required power.
 <!--T:3-->
-At very low speeds traction motors receive high electric current, producing high torque. As speed increases, however, traction motors produce increasingly more counter-electromotive force. This force opposes the supply voltage, causing both current and torque to drop. The faster the vehicle goes, the more power needs to be supplied to maintain the same acceleration.
+At very low vehicle speeds traction motors produce high torque with high electric current. As the speed increases, however, traction motors produce increasingly more counter-electromotive force. This force opposes the supply voltage, causing both current and torque to drop. The faster the vehicle goes, the more power it needs to maintain the same acceleration.
+<!--T:5-->
+For this reason, it is crucial to operate the throttle notch by notch, and always keep the current at a nominal level, by carefully observing the ammeter and traction motor temperature gauges and not letting any go into red.
 <!--T:4-->
-When a loaded electric vehicle accelerates, it can be exposed to high current for a prolonged period. Over time, this will {{pll|Powertrain Overheating|warm up the traction motors}}. Depending on the session {{pll|Difficulty|difficulty settings}}, traction motors may trip the {{pll|Breakers|respective breaker}} when they overheat, or much worse - {{pll|Electrical Powertrain Damage|short-circuit and set the vehicle on fire}}. A very high current surge can trip the breaker even before it comes to overheating, although still at a risk of {{pll|Damage Overview|damage}}.
+When an electric vehicle accelerates under heavy load, it can be exposed to a high current for a prolonged period. Over time, this will {{pll|Powertrain Overheating|warm up the traction motors}}. Depending on the session {{pll|Difficulty|difficulty settings}}, traction motors may trip the {{pll|Breakers|respective breaker}} when they overheat, or much worse - {{pll|Electrical Powertrain Damage|short-circuit and set the vehicle on fire}}. A very high current surge can trip the breaker even before it comes to overheating, although still at a risk of damage.
-<!--T:5-->
-At low speeds, especially when climbing positive {{pll|Grade Signs|grades}} under load, it is crucial to operate the throttle gently, notch by notch and keep the current at a nominal level, by carefully observing the ammeter and traction motor temperature gauges and not letting any go into red.
 <!--T:7-->
-{{pll|Electrical Powertrain Damage|Electrical powertrain damage}} can result in individual traction motors seizing to work. Since electric vehicles usually have more than one motor, power will then be distributed to the remaining operational ones. With fewer driving axles on a vehicle, {{pll|Wheelslip|wheelslip}} is easier to occur, however.
+{{pll|Electrical Powertrain Damage|Damage to electrical powertrain}} can result in individual traction motors seizing to work. Since electric vehicles usually have more than one motor, power will then be automatically distributed to the remaining operational ones. With fewer driving axles on a vehicle, {{pll|Wheelslip|wheelslip}} is more likely to occur, however.
 <!--T:12-->
-Number of traction motors on a electric vehicle can be supplemented by adding a {{pll|Slug|slug}}, in order to improve {{pll|Traction Overview|traction}}.
+An electric vehicle's {{pll|Traction Overview|traction}} can be improved by adding a {{pll|Slug|slug}}.
 <!--T:8-->
@@ Line 26: / Line 26: @@
 <!--T:9-->
-Traction motors can only withstand speed up to a certain amount, usually indicated red on the speedometer. Going above that speed can result in {{pll|Electrical Powertrain Damage|catastrophic failure}}, regardless of whether the traction motors, or the {{pll|Reverser|reverser}}, are engaged or not.
+Traction motors can only withstand speed up to a certain amount, usually indicated red on the speedometer. Going above that speed can result in {{pll|Electrical Powertrain Damage|catastrophic failure}}, even if traction motors are in no way engaged.
 <!--T:10-->
-For the traction motors to be operational, {{pll|Breakers|respective breakers}} must be enabled.
+For the traction motors to be operational, {{pll|Breakers|respective breakers}} need to be enabled.
 <!--T:11-->
-Installing an {{pll|Amp Limiter|amp limiter}} or {{pll|Overheating Protection|overheat protection gadgets}} makes it easier to manage traction motors load and temperature.
+Installing an {{pll|Amp Limiter|amp limiter}}, or {{pll|Overheating Protection|overheat protection}} gadgets, makes it easier to manage traction motors load and temperature.
 <!--T:13-->