Automotive Electronics

Specially with the use of power electronics there are many Automotive Electronics applications. Some of the general and common applications are listed below;

Alternator

Best use of power electronics based automotive electronics is for automotive power generation i.e. use of Alternator. Alternators are used in automotive application to charge the battery and to power the electrical system when automotive engine is running. Let’s discuss in detail how alternator works in application related to automotive electronics;

The main modules of alternators are stator, rotor, diode and a voltage regulator

The rotor inside the alternator rotates fast, when the alternator belt or V-belt rotates the pulley on the alternator. The rotor is mainly a group of magnets that rotates with high speed, inside a stator which is a wounded form of copper wires.

This high speed rotation of rotor along with stator copper wires generates electricity by the principle of electromagnetism. This generated electricity lead through the copper wires to the diode by the means of wire harness. The diode changes the electricity from AC to DC current and used for charging of car battery.

Last module is voltage regulator which will off the flow of power to the battery if the voltage rises above a certain or pre-defined level, this will helps the battery from getting overcharged and heated. When the car battery is drained, current is allowed to flow again into it from the alternator and this process repeats again and again.

Figure 1 at below shows Alternator in detail.

Alternator in detail

DC to DC Converters

Another best use of power electronics based automotive electronics is for power conversion in automobiles i.e. use of DC to DC Converters.

A DC - DC converter is a circuit which converts direct current (DC) from one voltage level to another voltage level.

DC-DC converter are used in automobiles for converting the high voltage of the battery pack used for the power train to a lower voltage for charging the secondary battery and operating secondary electric applications in electric vehicles.

A DC-DC converter uses switching method to change DC voltage level to another voltage level. The converted voltage may be high or low. This converted voltage is stored temporarily in transformer or capacitor for a short duration so that it is easily and continuously available for the external load at a different voltage. Apart from switching conversion method linear power conversion method are also used but it have disadvantage of power loss. Switching conversion provides high efficiency as fast switching components like MOSFET’s are used in the converters.

DC to DC converter topologies can be made bidirectional and able to flow power in both direction by changing all diodes with individually controlled active power rectification. A bidirectional converter is useful in automotive applications which need regenerative braking of vehicles, where power is supplied to the wheels while driving, but in return supplied by the wheels when braking.

Figure 2 at below shows a DC-DC Linear Regulated Power Supply.

DC-DC Linear Regulated Power Supply

DC to AC Inverter

One more best use of power electronics based automotive electronics is for power inverters in automobiles i.e. use of DC to AC Inverters.

AC motors are used because of their efficiency for converting electrical energy into mechanical energy. Thus, for proper working of AC motors, DC to AC inverter is required which converts DC power stored in batteries to the AC power.

According to the quality of output inverters can be classified as;

     Square Wave Inverter
     Modified Sine Wave Inverter
     Pure Sine Wave Inverter

For the application H-bridge type of inverter can be used, the IGBT act as a switch (when a signal is applied to the gate, they turn on and then turn off when the signal is removed).

By closing first side upper and second side lower IGBT a positive DC supply is applied to the load. By closing second side upper and first side lower IGBT gives negative DC supply across the load. Switching control circuits are used to produce the required gate signals to produce the required PWM waveform.

Figure 3 at below shows a 12V DC to 240V AC Automotive Inverter.

12V DC to 240V AC Automotive Inverter

Conclusion

Definitely there are many applications of power electronics based automotive electronics and here we discussed some of the common applications. Power electronics creates its special place in automobiles by providing the advantages of high efficiency, fast operation, high reliability, easiness, cost effectiveness, safety and by ease of placement.