Dîwarên Elektrîk Traction

Pêşnûmara

Drive ku elektrîk tenzayên bikarhêner ji bo serandina parêz e. Yek ji têkiliyên sereke yên drive ku elektrîk ye da ku werger û hencên di du cihan de destnuskirin. Drive ku elektrîk serandina bi rêzikên divê yek ji du cihaneke tên bêrîne: AC traction drive ên yek fasî û DC traction drive.

Xizmetên Serandina Elektrîk

Xizmetên serandina elektrîk bi rastîn dikarin wek hev çend dasteyên bêrîne:

• Trenên elektrîk

• Trenên Main - Line

• Trenên Suburban

• Otobüsên elektrîk, tram û trolleys

• Veyikên ku hêsan bi battery û solar - powered

Di navbera vê xizmetên serandina elektrîk de pêşnûmara herêmî hatî ye.

Trenên Elektrîk

Trenên elektrîk, ku li rayên nîshtînên tekerîn re hatine, bi rastîn di du cihan de ve têkildar in: trenên main - line û trenên suburban.

Trenên Main - Line
Li wan trenan de, guhertina zorê ya motorê ji du rêzikên din dike: jî ber lîneyên serdemîn û ji lokomotiva elektrîk an ji generator set diesel û ji lokomotiva diesel.

Li lokomotivaya elektrîk, motorê serandina divê li nav lokomotiva be. Lîneyek serdemîn li vir û li vir reyên demîn hatine saz kirin. Karwanê ku bi şeritê reyîn hatine saz kirin li lokomotivaya hatine saz kirin. Vê şerit reyî ser şeritê reyî ya guhertinê lihetiye, wêra lihetina elektrîk bi lokomotiva. Şeritê reyî ya guhertinê herêmî şeritê contact wire derbasdar e. Ji bo lihetina piştguhêr u tevaniyê nîşan kiriya, kablên catenary û dropper wires bikar anîn.

Li trenên high - speed, karwanê pantograph collector bikar anîn. Formê wê wek pentagon e, vê formê ya taybet hatine navkirin. Collector dikare şerit reyî ya ku bi springên bi guherandî ser şeritê contact wire lihetiye. Herêmî şerit reyî ji çelîk hatine şandin, vê şerit reyî rolê taybet dikare li ser lihetina piştguhêr u tevaniyê nav nehatiye. Li ser şeritê contact wire li hetiye. Li ser şeritê contact wire li hetiye. Li ser şeritê contact wire li hetiye. Li ser şeritê contact wire li hetiye. Li ser şeritê contact wire li hetiye. Li ser şeritê contact wire li hetiye. Li ser şeritê contact wire li hetiye.

Guhertina single - phase power supply li vir reyên demîn hatine saz kirin. Dîmokar bi karwanê enter lokomotiva dike. Di navbera vê li primary coil ya step - down transformer dike û bi wheels ya lokomotiva ser ground ya guhertina dayîn derket. Secondary coil ya power transformer guhertina power modulator dayîn û li ser vê guhertina traction motor dirav bike. Anîna secondary output ya transformer guhertina auxiliary devices wek fans û air - conditioning systems dayîn.

Trenên Suburban
Trenên suburban, ku herêmî local trains derbasdar ne, ji bo serandina kêmtirin rengîn hatine dizayn kirin. Wan trenan serandina zaf û serandina zaf bikar anîn. Ji bo li serandina zaf û serandina zaf, trenên suburban coaches motorized bikar anîn. Vê pêşka rêzikên weight û driving wheels li ser total train weight zêdetir bike.

Her coach motorized bi electric drive system û pantograph collector hatine saz kirin. Herêmî motorized û non - motorized coaches bi rêzikê 1:2 bikar anîn. Ji bo trenên suburban ku hêsan bi guhertina zêde, vê rêzikê dikare li 1:1 zêdetir bike. Trenên ku ji motorized û trailer coaches îrovan hatine Electrical Multiple Unit (EMU) trains derbasdar ne. Guhertina power supply mechanism ji bo trenên suburban bi guhertina trenên main - line tevahî ye, bi yek ji wan cihan: trenên underground suburban.

Trenên underground direct - current (DC) power supply system bikar anîn. Vê hilbijartisê bi rastîn li ser faktora ku DC supply systems li ser clearance between the power conductor û body ya tren ên hêsan e. Anîna DC systems design ya power modulator sipser bike, li vir cost û complexity ên hêsan e. Trenên above - ground overhead transmission lines bikar anîn. Anîna power li ser running rails û conductors installed on one side of the tunnel dayîn.

Otobüsên Elektrîk, Tram û Trolleys
Vê tiplên otobüsên elektrîk herêmî bi single - motor - driven coach design hatine saz kirin. Guhertina power li ser low - voltage DC overhead lines installed alongside the road dayîn. Ji bo faktora ku hêsan bi current requirements ên kêmtir, current collection mechanism herêmî rod with a grooved wheel at its end, or two rods connected by a contact bow hatine saz kirin. System collector herêmî flexible û additional conductor ên hêsan e, li vir return of the electrical current û li ser stable û continuous power supply for the vehicle's operation.

Trams ji tiplên otobüsên elektrîk ne ku li ser rail hatine saz kirin û herêmî bi single - motor coach hatine saz kirin. Ji bo faktora ku hêsan bi passenger capacity ên zêde, herêmî bi unpowered trailer coaches attached dayîn. System collector wê herêmî bi system collector ya otobüsên elektrîk tevahî ye. Notably, return path for the electrical current bi one of the rails dayîn. As trams operate on fixed rails, their routes along the road are predetermined, providing a reliable and consistent transportation service.

Electric trolleys herêmî bi transportation of materials within mines û factories bikar anîn. Vê vehicles herêmî bi rail hatine saz kirin û herêmî bi trams tevahî ye, bi main difference lying in their physical shape.

Sernasîlên Mîhengî yên Drive ku Elektrîk Serandina

Sernasîlên key yên drive ku elektrîk serandina di navbera vê tevahî ne:

• High Torque Requirement: Traction drives need to generate substantial torque during the starting and acceleration phases to propel the heavy mass of the vehicle. This high - torque demand ensures that the train or other traction vehicle can overcome inertia and achieve the desired speed efficiently.

• Single - Phase AC Supply in AC Traction: For economic considerations, a single - phase power supply is commonly utilized in alternating - current (AC) traction systems. This choice helps in reducing costs related to infrastructure, power generation, and distribution, making the overall operation more financially viable.

• Voltage Fluctuations: The power supply in electric traction systems experiences significant voltage fluctuations. These fluctuations are particularly pronounced when the locomotive moves from one supply section to another, often resulting in momentary discontinuities. Such voltage variations can pose challenges to the stable operation of the traction equipment and require careful design and control strategies to mitigate their effects.

• Harmonic Interference: Both AC and DC traction systems inject harmonics into the power source. These harmonics can interfere with nearby telephone lines and signal systems, potentially causing disruptions to communication and signaling infrastructure. Adequate filtering and mitigation measures are essential to minimize this interference and ensure the proper functioning of these critical services.

• Braking Systems: Traction drives mainly rely on dynamic braking, which converts the kinetic energy of the moving vehicle into electrical energy, either dissipating it as heat or feeding it back into the power grid. Additionally, mechanical brakes are used when the vehicle is stationary to provide reliable stopping and holding capabilities, ensuring safety in all operating conditions.

Duty Cycle of Electric Traction Drives

Duty cycle of an electric traction drive can be effectively understood through the analysis of speed - time curves and power - torque - time diagrams. Consider a traction drive operating between two consecutive stations on a level track. At the start, the train accelerates using the maximum achievable torque. During this acceleration phase, the power consumption of the drive increases linearly with the rising speed, reflecting the energy required to overcome inertia and propel the vehicle forward.

At time t1, the traction drive reaches its base speed, and simultaneously, the maximum allowable power is attained. Following this, further acceleration proceeds under a constant - power condition. As the speed continues to increase during this phase, both the torque and the acceleration gradually decrease.

By time t2, the drive torque becomes equal to the load torque, at which point a steady speed is achieved. The acceleration process from 0 to t2 can be divided into two distinct stages. From 0 to t1, the acceleration is characterized by a constant torque, where the drive applies a consistent rotational force to rapidly build up speed. Then, from t1 to t2, the acceleration occurs under a constant - power regime. Here, as the speed rises, the drive sacrifices torque to maintain the fixed power output, resulting in a diminishing acceleration rate until the equilibrium with the load torque is established at t2.

Between time t2 and t3, the train maintains a constant speed while operating at a steady drive power. This period is referred to as the free - running phase. During this stage, the train glides smoothly along the track, with the driving force precisely balancing the resistive forces, ensuring a consistent and efficient motion.

When the appropriate moment arrives at time t4, the braking system is engaged. This action initiates a controlled deceleration process, gradually reducing the train's speed until it eventually comes to a halt at the next station, ready to serve the next batch of passengers or transport its cargo to the intended destination.