EV.4.2 Motor Controller

When you connect the motor to the battery, current flows through the motor windings and causes the motor shaft to start rotating. A higher voltage will generally result in a faster motor speed. When the motor is running, it will draw current from the battery. If the motor is overloaded or prevented from rotating (stalled), it will draw a very high current from the battery, which can lead to overheating and damage to the motor or the battery. 

An inductor is a component, usually a coil of wire, that resists change of current over its terminals. This is because the magnetic flux through the coil due to the current decreases as the current decreases, and as a result, an electromotive force (emf) acts to oppose this change in frequency.

When shorted, an inductor acts as a wire with no resistance. This occurs in the component's steady state (DCSS).

As we define our motor controller as having properties of an inductor, we are able to replace the component symbol of Motor to the component symbol of Inductor.

As shown in the video above, it will resist the change of current over its terminals. This will be the case outside of its steady state.

In steady state, though, the inductor will short (as shown in the video), and act as a wire.

As soon as this happens, the battery is solely wired to itself and shorts. 

At high voltage, this results in an astronomical current. This would cause our motor to burn up, and for our accumulator to be sent into thermal runaway. Everything would heat within milliseconds!