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产品： GENERATOR SET 型号： 3512B GENERATOR SET PTM 配置： 3512B Generator Set Oil Field Land Rig PTM00001-UP
系统运行 — 基本原理
Electrical System for All Caterpillar Products
AC charging circuits include an alternator and a regulator. The alternator is really an AC generator. The alternator produces AC current, like the generator, but rectifies the current by using diodes. Alternators are generally more compact than generators of equal output. Alternators supply a higher current at low engine speeds.
Illustration 4
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• During normal operation, the generator (or alternator) supplies all current and recharges the battery
In both charging circuits, the battery starts the circuit when the battery supplies current to the starting motor in order to start the engine (Illustration 2, top diagram). The engine then drives the generator (or alternator). This produces current to take over the operation of the ignition, lights, and accessory loads in the whole system.
媒体编号 -SEGV3008-01
发布日期 -01/06/2004
关闭 SIS
更新日期 -28/06/2004
i02104634
Charging System
SMCS - 1400
Introduction to the Charging System
The charging system converts mechanical energy from the engine into electrical energy in order to charge the battery. The charging system supplies current in order to operate the electrical systems of the machine.
• The regulator opens the charging circuit. The regulator closes the charging circuit.
• The regulator prevents the battery from overcharging.
• The regulator limits the generators output to safe rates.
Generators
Illustration 3
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Generators in DC charging circuits will be covered briefly. The generator is still found on some older machines. To service this equipment, you should have a working knowledge of how the charging system functions. The majority of this lesson will focus on AC charging circuits, which have replaced DC charging circuits in the late model machines.
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• During starting, the battery supplies all the load current
• During peak operation, the battery helps the generator (or alternator) supply current
The regulator in AC charging circuits limits the alternator voltage to a safe preset level. Transistorized models are used in many of the modern charging circuits.
The generator supplies the electrical power. The generator rectifies the current mechanically by using commutators and brushes.
The regulator has three functionation
Illustration 2
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Charging circuits operate in three stages:
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As the armature rotates through the magnetic field of the poles, voltage is generated. The ends of the armature loop are connected to a split ring that is called a commutator. Brushes contact the commutator and wires connect the brushes to a load. Current will flow since the circuit is complete. To ensure a strong current and proper flow, wires are wound around the magnetic poles and the wires are attached to the brushes. The wiring is called the field circuit of the generator.
• DC charging circuits that use generators.
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Once the engine is started, the generator (or alternator) provides the current to the machine electrical systems (Illustration 2, bottom diagram). The generator supplies current as long as the engine is running above the idle speed. When the engine is at idle or stops, the battery takes over part or all of the load. However, an alternator will continue to supply current during engine idling.
The basic generator has two components:
Armature - a rotating wire loop (conductor)
Magnetic poles - stationary magnetic field
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The generator produces electrical energy by using electromagnetic induction. Electromagnetic induction is used to generate electricity in the charging system. Electromagnetic induction occurs when there is relative movement between a conductor and a magnetic field. As the conductor cuts through the field a voltage is induced in the conductor. This voltage causes current flow when the conductor is connected to a circuit. The amount of output depends on the strength of the magnetic field, the speed at which the magnetic field is cut, and the number of conductors cutting the field.