AVR Self-Excited for Hydro Power Generator Power Plant Hpp Alternator 100kw Scada System

• Customization: Available
• After-sales Service: Installation Guide Service
• Function: Brushless
• Model NO.: CS-2438
• Demoulding: Automatic
• Condition: New
• Certification: ISO
• Warranty: 12 Months
• Automatic Grade: Automatic
• Installation: Vertical
• Driven Type: Electric
• Mould Life: >1,000,000 Shots
• Generator Type: Synchronous Generator
• Rated Frequency: 50/60Hz
• Voltage: 0.4/6.3kv
• Excitation: Brushless
• Input: 110/220V
• AVR: AVR
• Excitation Method: Self-Exicted
• Transport Package: Export
• Specification: 600X500X500CM
• Trademark: Wawushan
• Origin: China

Product Description

Product Description

Generator Excitation System

The system which is used for providing the necessary field current to the rotor winding of the synchronous machine, such type of system is called an excitation system. In other words, excitation system is defined as the system which is used for the production of the flux by passing current in the field winding. The main requirement of an excitation system is reliability under all conditions of service, a simplicity of control, ease of maintenance, stability and fast transient response.

The amount of excitation required depends on the load current, load power factor and speed of the machine. The more excitation is needed in the system when the load current is large, the speed is less, and the power factor of the system becomes lagging.

Brushless Excitation System

This system is shown in the figure below. The rotating portion being enclosed by a dashed line rectangle. The brushless excitation system consists an alternator, rectifier, main exciter and a permanent magnet generator alternator. The main and the pilot exciter are driven by the main shaft. The main exciter has a stationary field and a rotating armature directly connected, through the silicon rectifiers to the field of the main alternators.

The excitation system is the single unit in which the each alternator has its exciter in the form of generator. The centralised excitation system has two or more exciter which feeds the bus-bar. The centralised system is very cheap, but the fault in the system adversely affects the alternators in the power plant.
 

The pilot exciter is the shaft driven permanent magnet generator having rotating permanent magnets attached to the shaft and a three phase stationary armature, which feeds the main exciter field through silicon rectifiers, in the field of the main alternator. The pilot exciter is a shaft driven permanent magnetic generator having rotating permanent magnets attached to the shaft and a 3-phase stationary armature, which feeds the main's exciter through 3-phase full wave phase controlled thyristor bridges.

The system eliminates the use of a commutator, collector and brushes have a short time constant and a response time of fewer than 0.1 seconds. The short time constant has the advantage in improved small signal dynamic performance and facilitates the application of supplementary power system stabilising signals.

The generator have a brushless excitation system to facilitate maintenanceand inspection. The excitation system consists of a revolving armature typesynchronous generator (main AC Exciter) directly connected to the generatorshaft and a revolving silicon rectifier installed to the same revolving shaft as theexciter.The 3-phase AC current generated by the AC exciter is converted intoDC current by the revolving rectifier and directly supply the generator fieldwinding without the slip ring.Excitation transformer connected to the generator terminals are provided tosupply the excitation power. Thyristors controller fed from the generator terminalsvia the excitation transformer are provided to excite the main exciterthrough the voltage regulator.The rated excitation current must make possible the operation of the generatingunit with rated output (PF=0.90), rated frequency and generator rated voltage.The excitation system is able to deliver continuously 110% of theabove rated excitation current and for 10 sec. a current needed to reach therequired ceiling voltage.

The 3-phase AC exciter is fed by an excitation transformer tapped fromthe main generator leads and through the control element of the voltageregulator. The generated voltage by three-phase rotor winding (AC exciter)is rectified by a silicon diode bridge circuit and supply the DC current tothe main generator rotor. The voltage stabilization on the generator during loadvariation is achieved by altering the exciter current via the voltageregulator's thyristors control element. 

generator have a separate excitation system capable of providingthe excitation requirements of the generator for its rated output at the powerfactor and voltage and of allowing the generator to operate with a safe margin ofstability under steady and transient load conditions. The excitation system inconjunction with the automatic voltage regulator have a rapid response totransient conditions of the system.The voltage of the generator, with the windings at the maximum operatingtemperature, is capable of manual adjustment in smoothly graduatedstops between 50% and 110% of rated voltage.Means is provided to limit the excitation of prolonged operation at theceiling level, so to not endanger the excitation system.The excitation system is self-exciting and is able to operatewithout an external AC supply. If the excitation system requires auxiliary DCsupplies for starting these will be supplied from the main station battery.Demands on DC supplies for this purpose is kept to minimum. Rotating DCmachines will not be accepted. The performance of the excitation system not be adversely affected by generator terminal voltage disturbances underfault conditions.The rotating AC exciters are direct driven and where applicable the excitershall comply with the requirements specified for the main generator.The shaft-mounted rectifier assemblies employ silicon diodes of approvedmanufacture. The diodes are capable of withstanding the maximumcentrifugal forces in service and vibrations associated with the machine shaft,without fatigue or failure. The diodes  feed into the generator field withoutthe need for slip ring current collector. Means are provided for thedetection of diode failure.Surge suppression circuits are provided on the diodes to eliminate thevoltage peaks. Rectifiers are protected against over-voltages under faultconditions. Over current protection are provided for protecting each rectifieragainst internal short circuits. Provision are made for the initiation of thenecessary alarms when a fault occurs.Rectifier assemblies  have an adequate number of parallel connectedrectifiers to ensure that no individual rectifier operates at greater than two-thirdsof the manufacturer's recommended current rating and maximum permissibletemperature at any condition of normal load, and to ensure that the maximumexpected transient peak inverse voltage across the rectifier,  not exceedpermissible values.When rectifiers are connected in parallel, the rectifier assembly shall becapable of continuing operation at rated load on the loss of one third of therectifying capacity of the complete rectifier assembly without exceeding themanufacturer's recommended current and temperature ratings on the remainindividual rectifiers.31Rectifiers  preferably be naturally cooled.Excitation transformer are three phase, two windings, naturally cooled, drytype rated for required excitation power.The excitation transformer operate under the voltage and frequencyconditions specified for the generator. The transformer is directlyconnected to the generator feeder at 6.3 KV cubicles. 
 

Generator Excitation System is a crucial component in the power generation industry. It is responsible for providing stable and reliable power supply to various applications. Our excitation system is designed to meet the high demands of power generation and is suitable for a wide range of generators.

Product Overview

Our Generator Excitation System is a state-of-the-art product that guarantees efficient and reliable power generation. It is designed with the latest technology and high-quality materials to ensure superior performance and durability. The system is suitable for different types of generators, including horizontal synchronous generators.

Key Features

• Runner Blade: Fixed
• Rated Frequency: 50HZ
• Product Type: Excitation System
• Generator Type: Horizontal Synchronous Generator
• Output Capacity: 50KW To 20MW

Efficient Excitation System

Our Excitation System is designed to provide efficient and stable power supply to meet the high demands of power generation. With its advanced control system, it can adjust the excitation current and voltage to maintain the desired output and optimize the generator's performance.

Reliable Power Generation

The Generator Excitation System ensures reliable power generation even in challenging conditions. It has a robust design and is equipped with protection features to prevent damage from voltage fluctuations or overloading. This guarantees uninterrupted power supply and protects your generator from potential damage.

Flexible Output Capacity

Our Excitation System offers a wide range of output capacity options to suit different power generation needs. It can handle a capacity of 100KW to 20MW, making it suitable for small to large-scale power generation applications.

Quality Assurance

We are committed to delivering high-quality products to our customers. Our Generator Excitation System undergoes rigorous testing and inspection before leaving the factory to ensure excellent performance and reliability. We also offer after-sales support and maintenance services to ensure your system operates smoothly.

Conclusion

In conclusion, our Generator Excitation System is a reliable and efficient solution for your power generation needs. With its advanced technology, flexible output capacity, and superior performance, it is the perfect choice for any generator. Choose our excitation system and experience a stable and uninterrupted power supply.

 

Features:

1. Product Name: Generator Excitation System
2. Capacity: 1370 KW
3. Dimension: 3Mx3Mx2.5M
4. Rated Frequency: 50HZ
5. Efficiency: 89%-95%
6. Input AC Voltage: 100V

 

Technical Parameters:

Product Name	Generator Excitation System
Capacity	1370 KW
Rated Frequency	50HZ
Efficiency	89%-95%
Dimension	3Mx3Mx2.5M
Product Type	Excitation System
Runner Blade	Fixed
Rated Current	100A
Output Capacity	100KW To 20MW
Generator Type	Horizontal Synchronous Generator
Voltage	0.4KV/6.3KV

 

Automatic Voltage Regulator (AVR)

The construction of the AVR vary with the excitation used. All receive input from the stator of the generator when it rotates. AVRs with the capability of receiving a second input to reduce or eliminate internal harmonics caused by load feedback signals are used for non-linear load applications. The two types commonly used are:

• Silicone Controlled Rectifier (SCR) - Senses power level from the stator and determines its firing for the exciter voltage. Can cause troubles when used with non-linear loads.
• Field Effect Transistor (FET) - Senses power level from the stator and translates in to a Pulse Width Modulated (PWM) signal to the exciter. This style of AVR can be used for excitation methods. Non-linear loads do not cause feedback resulting excitation breakdowns.

Shunt or Self-excited 

The shunt method is features a simple and cost effective design to provide input power to the AVR. This method requires no additional components or wiring. When problems arise troubleshooting is simplified with less components and wiring to validate.

As the generator is rotated, the stator supplies input voltage to the AVR. In addition the AVR has sensors that monitor the output of the stator. 

The AVR supplies power the exciter and is rectified to DC current. The current is induced onto the stator for load output.

The biggest drawback to this system is the AVR is impacted by the load the generator is powering. When the load increases the voltage begins to decrease and the AVR must provide more current to the exciter to support the demand. This pushes the AVR to its limits. If the AVR is pushed beyond it's limits the excitation field collapses. The output voltage is reduced to a small amount.

If a short circuit occurs in the supply to the AVR, the generator will not have an excitation source. This causes a loss of generator power output.

Generators with shunt or self-excited methods can be used on linear loads (constant load). Applications that have non-linear loads (varying load) are not recommend for generators with this excitation method. Harmonics associated with non-linear loads can cause excitation field breakdowns.