DC motor & DC generator

DC Motor

Simple DC motor consists of a permanent magnet stator and rotor coil with a commutator near one end to properly provide current to the coil. It is the lowest cost motor solution. It can also be made very small easily. For low power design, its power density is often very high.

DC Generator

Components of a generator:

Rotor: In its simplest form, the rotor consists of a single loop of wire made to rotate within a magnetic field. In practice, the rotor usually consists of several coils of wire wound on an armature.

Armature: The armature is a cylinder of laminated iron mounted on an axle. The axle is carried in bearings mounted in the external structure of the generator. Torque is applied to the axle to make the rotor spin.

Coil: Each coil usually consists of many turns of copper wire wound on the armature. The two ends of each coil are connected either to two slip rings (AC) or two opposite bars of split-ring commutator (DC).

Stator: The stator is the fixed part of the generator that supplies the magnetic field in which the coils rotate. It may consist of two permanent magnets which opposite poles facing and shaped to fit around the rotor. Alternatively, the magnetic field may be provided by two electromagnets.

Field electromagnets: Each electromagnets consists of a coil of many turns of copper wire wound on a soft iron core. The electromagnets are wound, mounted and shaped in such a way that opposite poles face each other and wrap around the rotor.

Brushes: The brushes are carbon blocks that maintain contact with the ends of the coils via the slip rings (AC) or the split-ring commutator (DC), and conduct electric current from the coils to the external circuit

Concepts

There are some concepts that needed to be understood while doing this project. First and foremost is the wind turbine concept. A wind turbine is a device that converts kinetic energy from the wind into mechanical energy. If the mechanical energy is used to produce electricity, the device may be called a wind generator or wind charger.

An electrical generator is a device that converts mechanical energy to electrical energy, generally using electromagnetic induction. The source of mechanical energy may be a reciprocating or turbine steam engine, water falling through a turbine or waterwheel, an internal combustion engine, a wind turbine, a hard crank, or any other source of mechanical energy. 

         

KLIA Ekspres details

KLIA EKSPRES

KLIA Ekspres has been chosen as the place for my research. Data needs to be collected in order to able to proceed to the next stage. An interview has been made with Mr. Mohd Rizal, the engineer of KLIA Ekspres. Below shows the data obtained during the interview:-

•      Destination : KLIA to KL SENTRAL

•      3 Stops ( Bandar Tasik Selatan, Putrajaya/Cyberjaya, Salak Tinggi)

•      Distance : 57 kilometers

•      Journey : 28 mins

•      Top speed : 176 km/h

•      Commercial top speed : 160km/h

•      15 mins interval (peak hours)

•      20 mins interval (off peak)

KLIA Ekspres Specification

Model	Desiro ET 425 M Electric Multiple Unit
Manufacturer	Siemens AG
No. of trains	8
No. of carriages	2 propulsion carriages 2 passenger carriages
Dimensions	Length - 68700 mm Width - 2840 mm Height - 4160 mm
Weight	120 Metric Tonnes
Electrical System Voltage	25 kV/50 Hz
Acceleration	1.0 m/s²
Top Speed	176 km/h
Commercial Top Speed	160 km/h
No. of passengers	156 seated
Tracks	Length - 57 km Width - 1435 mm

KL SENTRAL to KLIA

KLIA to KL SENTRAL

Flow chart of the project

This is the flow chart of the project. The system starts when wind generator voltage is being detected. Then, the voltage will be displayed on LCD. Next the battery voltage is being detected. If the battery voltage is over 12V, green LED is turn on and red LED is off while if the battery voltage is less than 12V the red LED is on and green LED is off. The battery keeps charging if the battery voltage is less than 12V If the battery voltage is over 12V then the battery will stop charging.

Block diagram of the project

After confirmation with supervisor, this is the new block diagram for Wind Turbine Generator in Train System.

Project Description

• Wind charger is operating using 12V battery. This system is using LCD to show wind generator and battery voltage. When the battery voltage is low, motor will charge the battery.
• When system is operating, voltage sensor detect wind generator voltage and show on LCD. Voltage sensor detects battery voltage. If battery voltage more than 9V, green LED will turn on. Else, red LED will turn on. Battery voltage will show on LCD.
• Voltage sensor detects battery voltage. If battery voltage less than 12V, system will start charge the battery. Else, system will stop charging.

Block Diagram Explaination

In every project, there must be inputs and outputs. For this Wind Turbine Generator in Train System, the DC motor acts as the input while LCD display and LEDs act as the output. Both input and outputs are connected to the charging circuit. The charging circuit is operating using 12V DC battery. The input from the DC motor will charge the 12V DC battery. In this case the voltage produced by rotating wind turbine DC motor. The LCD will display the current battery voltage and wind voltage. Two LEDs are being used which are red LED and green LED. The red LED indicates battery is less than 12 V while the green LED indicates the battery is over 12V. PIC microcontroller 16F877A is being used as the main controller for the whole system. The input and output are being connected at microcontroller pins. In other words, it acts as the brain for the whole system. The charging operation will be controlled by the PIC. Whenever the battery is less than 12V the battery will charge, else not charging. Voltage regulator is being connected to PIC16877A. This is to prevent over 5V supply because PIC16F877A only support voltage of 5V.