zxc ® 30-Dec-2012 19:35

Hyundai Synchronous Brushless A.C Generators / Instruction Manual

Language: english
Author: Hyundai
Genre: Instruction Manual
Format: PDF
Quality: Scanned pages
Number of pages: 48
Description: (1) Type definition
The scope of suppiy of the machine designs available is determined entirely by the data given in the catalogs or offers.
The machines of basic design are open-circuit cooled brushiess low-voltage synchronous machines with top-mounted excitation control unit. The machines have a shaft-mounted exciter on the inboard side of the non-drive endshield. The three-phase AC they generate is rectified and feds to the rotor winding of the main machine.
The excitation current required for the shaft-mounted exciter is provided by the main machine via an excitation control unit accommodated in the top mounted housing and via a thyristor voltage regulator. For further information, see the supplementary instructions entitled THYRIPART excitation system, on page 11-17.
Depending on the application, the machines may also be designed in accordance with the type variant
defined beiow trie iaoie.
(2) Specification & Regulation
The machines comply with the applicable DIN standards and with the requirements of VDE0530.
They may have been adapted to different classification requirements and foreign standards and regulations. Unless otherwise stated, the rated output for continuous operation applies to a frequency of 50Hz, a cooling-air temperature of 40‘C and a site altitude of up to 1000m above sea level.
(3) Degree of protection
The DIN 40050 or IEC 34-5 degree of protection of basic design machines is IP 23. Such machines are suitabie for operation indoors and may be provided with a built-on fitter box or with pipe connections. Closed'circuit cooled machines comply with degree of protection IP 54. The degree of protection of the machine supplied is shown in the dimension drawing.
(4) Type of construction
The machines are normally provided with two bearings (DIN42950 types of construction B3 or B20) or with one bearing (DIN42950 types of construction B2 or B16). The type of construction of the machine supplied is shown in the dimension drawing.
(5) Cooiing and ventilation
The basic design machines use self-ventilation by a shaft-mounted internal fan at the AS-end. Cooling air enters the top housing (at the BS-end) and cools the excitation control unit and subsequently the windings and core packs of the exciter and of the main machine before leaving the top housing at the BS-end.
On machines provided with air filters at the air inlet the loading condition of the filter should be monitored.
In machines having closed-circuit cooling, the air-to-water cooler is accommodated in the top-mounted box in transverse arrangement, in front of the excitation control unit. The primary cooling air circulated by the internal fan is re-cooled in the cooler and passed through the excitation control unit, the exciter and the main machine.


2. EXCITATION SYSTEM (operation)
3.2 FLANGE TYPE SLEEVE BEARING (ring tub. sys)
3.3 FLANGE TYPE SLEEVE BEARING (forced iub. sys)
3.4 ROLUNG CONTACT BEARINGS (series 02 and 03)
3.5 COUPLING (single bearing generator)
3.6 COUPUNG (ckxfcte bearing generator)
4.4 BEARING PART (roller and sleeve bearing).

Full Description

(6) Connecting up
Check The system voltage against the data given on the rating plate. Select the size o? the supply cables so as —<4^11! raring. Connect the machines in accordance with the diagram in working drawing.
Before closing the terminal box. check to see that
- its interior is clean and free from any cable chippings
- ail terminal screws or bolts are tight
- the minimum clearances in air are maintained {>10mm for 500V, >14mm for IkV and >60mm for 6kV; check for any projecting wire ends)
• entry openings not in use are closed off by firmly screwed-in plugs
- for maintaining the particular degree of protection all sealing sur faces of the terminal box are in order. The surfaces of metal-to-metal sealing joints must be cleaned and thinly regreased.
3efore starting a machine and during operation make sure that all relevant safety regulations are complied with.
(7) Insulation testing
Before commissioning and after long periods of storage or standstill the insulation resistance of the windings to (he frame must be measured with DC voltage. Do not c scontinue measurement before the finai resistance value is indicated(with high-voltage machines, this process may take up to 1 minute.)
The limit values for minimum insulation resistance and critical insulation resistance(for measurement at a v/inding temperature of 25*C) and for measuring voltage can be derived from the following table depending on the rated voltage for machine.
Limit values at rated voltage
Rated voltace Rated voltage
<2kV > 2kV
Measuring voltage 500V OC 500V OC
(min.lOOV DC) (max. 1000V DC)
Minimum insulation tOffi 10022
resistanco with now.
cleaned of repaired windings
Critical specific insulation 0.5K/W 5 BMW
resistance after long
period of operation
Dry new windings have insulation resistance values between 1005JQ and 2000!JQ or higher. If the insulation resistance valueis in the region of the minimum value, damp and or dirt can be the cause. If the insulation resistance value falls below this minimum figure, the cause must be established and the v/inding dried.
terfi}>£t«uUfd ii ia<i3 Jy fi&», i.e. wan a temperature fistf of 50K(e.g. from 25‘C to 75'C) it falls to about 1/30 of the initial value.
During operation the insulation resistance of the windings may decrease as result of environmental and operating conditions.
The critical value of the insulation resistance at a v/inding temperature of 25*C can be calculated depending on the rated voltage by multiplying the latter(kV) by the specific critical resistance value in the table(«5/kV). e.g.: critical resistance for rated voltage 660V: O.ookV x 0.5,iG/kV=0.331K If the measured insulation resistance value is above the calculated critical figure during operation, the machine can still operate further.
When the measured value reaches or fall below this critical insulation resistance figure, however, the windings must either be dried, or the rotor must be removed and the windings thoroughly cleaned and dried. If the measured value approaches the critical value, the resistance should subsequently be checked at appropriate short intervals.
Insulation resistance measurements on low-voltage machines with a measuring voltage of 1000V are only permissible if the insulation resistance has previously been measured with a measuring voltage of a maximum of 500V and has not fallen below the permitted values.
(3) Noise emission
The noise level of the generator will not exceed that specified in Part 9. VDE 0530(1981).
{9) Vibration stability
Reciprocating engines used as prime mover impress vibrations on the alternator because of the pulsating torque output.
Permissible vibration stress measured at the bearing is:
(10) Transport
The rotor of machines with cylindrical roller bearings, angular-contact ball bearings or double sleeve bearing are locked in positionfor transport by a shaft block to protect the bearings.
Do not remove this block until the transmission element is fitted.
Should the machine have to be transported after the transmission element is fitted, other suitable measures have to be taken.
If the machine is not put into service immediately after
racker ru
(11) Storage
The location for storage shoula be dry and little dusty. There shall be r-c fear to.' winding.; being attacked by
The machined surfaces of coupling "art, foots pari, etc. are coated
with rust resisting grease. If coating is broken, immediately remo'/erust or moisture and recoat with grease for rust prevention.
If machine is to be stored for some time, apply all opening with waterproof paper, wooden or metallic covers.
However, it is necessary to protect from wind and rain during trans-portation and storage and to select less humid place for storage.
For storage for a long time or in the rainy season, it is best to Insert heaters to remove moisture or prevent its condensation.
To keep the coil dry, it is desirable to maintain the coil temperature several degrees above room temperature and for this purpose, arrange heaters appropriately under the machine part to warm the coils.
For this purpose(for long time storage), the space heater is prepared inside of the generator and its specification is described in generator final specification and on the nameplate attached at the generator.
(12) Installation
The lubrication measures for normal bearings to be carried out before or during erection of the machines are specified in the instructions Rolling Contact Bearings and Sleeve Bearings on page from 20 to 26. Install the machines so that the cooling air has free access and can escape unobstructed.
Warm exhaust air must not be drav/n in again.
Louver openings must face downwards to maintain the particular degree protection.
Remove the shaft block(where applicable).
Adhere to the instructions attached to the shaft extension or shown in the terminal box.
The rotors are normally balanced dynamically by means of a half feather key placed in the shaft extension.
Align the machines carefully and accurately balance the elements to be fitted on the shaft to ensure smooth and vibration-free running.
Place shims under the feet of the machines if necessary to prevent these from being stressed mechanically.
Transmission elements may be fitted and removed only by means of a suitable tool.
The feather keys in the shaft extensions are only secured to prevent them from tailing out during
transmission element having been fitted.
On machines with the shaft extension pointing upwards, care m .ist be taken to see that water ccnno: enter ?he supper oearna
(13' Operation
Covers fitted to prevant access to rotating and current carrying parts or io correct the air flow for better cooling must not be open in operation.
(14) Maintenance
Before starting any work on a machine, make sura that it has been disconnected from the power supply and that unintentional starting is safely prevented.
Clean the cooling air passages at regular intervals matched to the degree of pollution, using oil-free compressed air, for example.
The inside of totally-enclosed fan-cooled machines need only be cleaned during normal overhauls.
If dust or moisture has penetrated into the terminal compartment, this should be carefully cleaned and dried, in particular the surfaces of the insulating parts. Check the seals and eliminate the leak.
Before forcing off a part, replace two upper fixing screws with longer screws or threaded bolts to support the part after forcing it out of its central facility.
(15) Inspection
The first inspection should be carried out after approximately 500hours.
The rate of fouling should be assessed and appropriate periods for cleaning the cooling air ducts decided upon.
The following checks should also be carried out:
- running smoothness of machine satisfactory.
- rotor alignment within tolerances.
- no subsidence or cracks in the foundation.
- all fixing bolts of mechanical and electrical joints tight.
- insulation resistance of windings satisfactory (compare with previous reading and record).
- no bridging of any bearing insulation.
Any excessive deviations or changes ascertained during the checks must be corrected immediately. Damaged or used locked elements from released bolted jointsmust be renewed.
The basic intervals between inspections are approximately 4000hours, 1000 switching operations or 1year for intermittent operation and approximately 16000hours or 2years for continuous operation; in each case, whichever occurs first.
The cleaning of all parts becoming fouled by the flow of cooling air depends on the intervals decided after the
Cleaning shootd be carried out with dry compressed air. 1
Information on oil changes, regreasing, etc. is given on the lubrication instruction plate on the machine or in the supplementary instructions for bearings.
The checks stated for the first inspection after 500hours should be performed during these inspections also.
When a machine is dismantled the following checks should be made:
- slot wedges in stator and rotor cores tight.
- windings.connection leads and insulating parts in satisfactory condition and no discolouration.
After reassembly, again follow the instructions given for installation.
(1) Stator frarn^ and :• ig
The stator frcr™ is of wv. '.od .-'osign. Th« tfato' cor-? fe centred in the frame and Icckes against rotation and shifting.
Ths stator winding is of two-layer coil design with insulation class F.
This insulation is made in a special way and comprises integrated-mica & enamel coated insulating material impregnated with cast resin.
It is characterized by high dielectric strength, resistance to moisture, aggressive gases and vapours, as well as rigidity and long life.
(2) Rotor and windings
The shaft for machines of type of construction B3 and B20 is designed with a normal cylindrical shaft extension for two bearings; in the case of types of B2 and B16 the shaft is fitted with a flange.
The rotor core of the main machine is mounted on the shaft, tensioned axially and supports the field and damper windings.
The damper winding bars lie in the slots of the rotor core and are welded to the rings. The rotor core of the exciter is mounted on the shaft and supports the three-phase field winding.
The rectifier supporting wheel is mounted on the shaft between the two laminated cores.
The rotor is balanced dynamically.
(3) A.C Exciter
The AC exciter is composed for revolving-armature type three phase synchronous generators.
In revolving-armature type generators, unlike the ordinary ones, the stator and rotor are in reverse relation.
The armature is installed at the shaft end on the non-connection side where AC power is generated, and the output of static excitation device for control is connected to the field winding installed on the fixed side as shown in Fig. 2.
- of the mounting screws between 4.5Mm and 5.5Nm.
- of the contact screws oelv/een 2.5<\'m and 3.5Nm.
(5) Excitation system
The combination of an excitation unit with a thyrist or voltage regulator is called a THYRIPART-excitation system.
The excitation unit supplies a load-dependent field current slightly higher than would be required for producing the rated voltage.
The regulator variably reduces the field current as necessary to obtain constant alternator voltage.
This method of load-dependent excitation (compounding) results in excellent dynamic response to load switching applications and short-circuits.
A block diagram is shown in Fig. 14, 15, 19 & 20.
(6) Shaft
Concerning the generator shaft, the ship's classification certified forged steel shall be applied and designed with ample strength for coupling of prime mover.
(7) Bearing
Depending on the design and the operating conditions specified in the order, the machines are fitted with grease-lubricated rolling-contact bearings or with sleeve bearings with or without forced-oil lubrication.
For a full description and special instructions, reference should be made to the supplementary instructions.
{8) Cooling fan
To let the required amount of cooling air pass through, a fan of either cast iron or of welded construction of steel plate is provided.
Concerning the site of its installation, in either case, it is to be arranged on the prime mover's side of the
It Is of one-way ventilating system which takes into the air from the opposite side of the prime mover and exhausts the air to the prime mover's side.
We have taken into consideration that the engine's oil vapor should not be sucked into the machine.
(9) End shield AS/BS
Both the end shields are designed as flat plates and can take either a bearing or a shaft extension in accordance with the particular type of machine construction. .
The exciter yoke ring, in which the exciter poles are bolted in regular distribution, is welded to the BS-end shield.
(10) Rotor locking device
The following instructions supplementing and modifying the basic operating instructions apply to single bearing generators of type of construction B2 or B16 which are coupled with diesel engines or turbines: See the instruction manual on page 27.
(11) Insulation for the prevention of shaft current (high voltage and large machines)
To prevent the shaft current caused by the unbalance of magnetic resistance of magnetic circuits the insulator is provided to end shield BS side as shown in Fig. 5. The shaft voltage is high-frequency voltage of usually 1 volt or less and rarely several volt.
When a Shaft current by this voltage flows, the shaft and journal part are tan^sned and in the worst case, sparking results in minuts black spots.
There is a possibility that the oil film is broken locally, developing a bum-out trouble.
When disassembling or assembling, be sure to measure the insulation resistance.
The value of 1 to 3 IQ will be satisfactory.
It is generally said that shaft voltage for bearings has the limits as follows.
(12) Thermometer
For the checking of the bearing temperature, the bearing is provided with a mercury thermometer.
(13) Space heater
In order to prevent the accumulation of moisture and condensation
while the generator is in idle, space heaters are provided in side with in the stator frame.
The space heaters are so equipped as to be easily removed from outside of enclosure.
The heater elements are stainless-sheathed nichrome heater, filled with insulators in the sheath and is U-shaped as shown in
The type designation for the alternators is changed from HFC to HFJ.
Due to the closed-circuit cooling system the degree of protection has been upgraded from IP 23 to IP 44 and IP 54.
The electrical version of the alternator remains unchanged.
The alternators HFJ can easily be converted for emergency operation as an open-circuit aircooled machine if the coolant system or the cooling element fails.
In this case the degree of protection is IP 23 with the rated output
unaltered as shown on page 31, 32 & 33.
Please provide the following information with any enquiry:
Alternate rated output Classification society Coolant temperature (air)
Cooling water inlet temperature Fresh water or sea water
(15) TefiffSne! 'oox
Cable GtiUy to the 3 main oonr.r .: ^.VAr*., arid cc
• 2 fiett terminals +F1, -F2 a.:- ‘fior as required.
Tho cabf-a entry plates ara suppBsd und.iHad or drilled with cab -; /Jand as required, ratar to sea in Fig. 7.
{ HF. 5 TYPE )
(1) Stator and Stator Windings Assembly 4-11 : Varistor module 4-13: Connector rings
(2) Rotor and Windings Assembly 4-12 : Hub 4-14: Rectifier module
(3) A.C Exciter Assembly
(4) Rectifier Assembly (Fig. 8-1)
(5) Excitation Equipment
(6) Shaft
(7) Bearing
(8) Cooling Fan
(9) End Shield AS/BS
(10) Rotor Lock*g device
(11) Insulation for prevention of shaft current (Fig. 5)
(12) Thermometer
(13) Space heater
(W) Coder (15) Terminal box
HFC5 (Air to air cooling)
Fig. 9 Sectional drawing for HF. 5 type generator (Double sleeve bearing).
(1) Stator and Stator Windings Assembly
(2) Rotor and Windings Assembly
(3) A.C Exciter Assembly
(4) Rectifier Assembly (Fig. 9-1)
(5) Excitation Equipment
(6) Shaft
(7) Bearing
(8) Cooling Fan
(9) End Shield AS/BS
(10) Terminal box
(11) Insulation for prevention cf shgfi current (Fir;. 5) Thcfwcmciar
(13) Space heater ('4) Cooler
4-11 : Varistor module 4-13 : Connector rings
4-12: Hub 4-14: Rectifier module
Fig. 9-1 Rectifier Assembly.
Fig. 10 Sectional drawing for HF. 6 type generator (Single sleeve bearing).
(1) Stator frame and Stator Windings Assembly
(2) Rotor and Windings Assembly
(3) A.C Exciter Assembly
(4) Rectifier Assembly (Fig. 10-1)
(5) Excitation Equipment
(6) Shaft
(7) Bearing
(8) Cooling Fan
(S) End Shield AS/BS
(10) Rotor Lock'g device
(11) Insulation for prevention of shaft current (Fig. 5)
(12) Thermometer
(13) Space heater
(14) Cooler
(15) Terminal box
4-11 : Varistor module 4-12: Hub
4-13: Connector nngs 4-14: Rectifier module
Fig. 10-1 Rectifier Assembly.
Rg. 11 Sectional drawing tor HF. 6 type generator (Double sleeve bearing).
(1) Stator frame and Stator Windings Assembly
(2) Rotor and Windings Assembly
(3) AC Exdter Assembly
(4) Rectifier Assembly (Fig.11-1)
(5) Excitation Equipment
(6) Shaft
(7) Bearing
(8) Cooling Fan
(9) End Shield AS/BS HO) Tormina! box
(1) Description
Brushless synchronous generators consist of th<» main machine and of the exciter.
The main machine field winding is powered froiv* the exciter rotor winding via a rotating, three-phase bridge- connected rectifier set.
The exciter is THYRIPART-excited.
Excitation equipment and thyristor voltage contry>uer are combined in the THYRIPART excitation sya^m The excitation current required is supplied by th^ majn machine proper via the excitation equipment wf>^ js adjusted to deliver a field current resulting in a generator output voltage above the maximum r^rencQ value over the entire load range when the voltacs^ controller is inactive.
The actual function of the voltage controller is.to* provide a by pass for a variable portion of the cu.iren( supplied by the excitation equipment for controlling ^ generator voltage.
The thyristor regulator modulo consists of two assemblies: the requlator module and the firing Module with thyristor in buck circuit.
The three-phase generator voltage, having been, reduced to 24V by the measuring-circuit transfor>^verSi is applied to teminals 17,18 and 19. A direct vott$£ge Qf approx. 30V(teminal 20 to terminal 13 or 14) is produced at the output from the rectifier bridge ^ rated voltage of the generator.
This rectified voltage provides the actual value p^e and the supply to the control amplifier.
The regulator module supplies output temlnal 1 & A^th a control voltage of approx..
1 to 10V, which is proportional to the control deviation. Depending on the reference potential of terminal 16, terminal 12 of the comparator point of the control amplifier can be given an additional d.c pulse, e.g for reactive power control in parallel operation.
For tuning to the signal level, a rheostat must be soldered onto the available soldering pins.
The power supply for the gate control module (s) is available from terminal 11.
Fig. 12 Regulator; spresy 15.
In the control circuit of the firing module, a time adjustable firing Impulse for the thyristor is formed from the control voltage of terminal 15 in comparison with a saw tooth voltage.
The overvoltage protector, which operates at voltages over 600V between terminals 1 and 5, then switches the thyristor through.
The excitation current is normally bucked with a single pulse.
If higher excitation is required two firing modules for two-pulse ’buck" operation will be provided.
(1) Thyristor voltage controller
When the generator Is operating by itself, the thyristor voltage controller controls the generator voltage to the preset reference value. Frequency changes due to the droop characteristics of theprime mover do not influence the accuracy of the generator output voltage. Design and adjustment of the main machine, exciter, excitation equipment, thyristor voltage controller and reference-value selector permit gradual changes in the generator output voltage form 95% to 105% rated voltage via potentiometer Usoll under steady-state conditions and at loads varying between no load to rated load and power factors between 0.8 and unity, unless otherwise specified on the rating plate.
If the generators are operated at less than 95% or more than 105% rated voltage, their output must be reduced.
Unrestricted operation with no k>ad(opened generator breaker) and partial speeds is permissible.
During running the excitation circuit must not be interrupted since this would give rise to voltage surges. If the generator must be de-excited this can be accomplished by short-circuiting the field winding of the exciter (terminals +F1 and -F2) (Fig.13).
In this case, a dangerously high voltage may develop at the generator terminals as a result of residual magnetism.
(2) Transformer adjustment
The tappings used on the transfomers are marked at test report.
It is strongly recommended that the original adjustments be left unchanged.
No responsibility can be assumed by the supplier for any damage or incorrect operation resulting from a change in the .original adjustments, tn the case of identical plants, the THYRIPART excitation system or single parts may be interchanged if need arises; those transformer tapping must always bo
used which confirm to the original transformer.
(3) Direction of rotation of the generator
The generators are generally suitable for clockwise and anti-clock-wise operation.
Generators which must run only in a definite direction of rotation, have the rating plate marked with a corresponding direction arrow and with the addition “only".
. If only one direction of rotation is permissible for
electrical reasons, the excitation system is connected in the works for the direction of rotation given in the order. To change the direction of rotation it is necesssry to change the connections according to the connection diagram and to check whether only one definite direction of rotation is permissible for mechanical reasons(e.g. fan with curved fan blades).
(4) Controller gain setpoint of voltage integral action
The controller module includes the three potentiometers Usoll, Vr and Tn. The generator rated voltage was adjusted In the works on potentiometer Usoll and the transient response characteristic of the controller on potentiometers Vr and Tn.
The controller gain adjusted on potentiometer Vr where-as the integral action time and the optimum transient response characteristic is adjusted on potentiometer Tn.
Turning the knob of Vr in direction of descending numerals and that of Tn in direction of ascending numerals normally stabilizes the control circuit and reduces the control rate.
The setpoint of the generator voltage can be shifted via potentiometer Usoll and via a supplementary external reference-value selector (R=1.5KB, P>1W) to be connected to auxiliary terminals 20 and 21 (Fig. 13) with the above potentiometer set to the mid-position (subsequent extention of the setting range specified in the order-particularly for full output-is only possible following consultation.)
The new adjustment of the potentiometer must be fixed with the aid of the set screw.
(5) Parallel operation, droop compensating equipment
When provide with droop compensation, a brushless synchronous generator is suitable for operating in parallel with other generators or with a supply system. The kW output is adjusted through the governor of the prime mover. The speed characteristic of the prime mover should be linear and rise by min. 3% and max. 5% between rated load and no load.
The droop compensating equipment ensures uniform distribution of the reactive power and reduces the generator output voltage in linear with the increase in reactive current.
The droop compensating circuitly is adjusted to provide ; a generator voltage droop of 6% at zero p.f. and no voltage droop at unity p.f. between no load and rated load as a function of the generator current.
With this setting, a voltage droop of 3.6% is obtained at
0.8 p.f. When operated by it self or in parallel with generators having the same voltage characteristic, a voltage accuracy of ± 1.8% is thus obtained if the rated voltage is adjusted by means of the setpoint potentiometer at 50% generator load.
With the generator operating by itself, no droop
compensating equipment is required. It can be deactivated by short-cirorftinc Ihe secondary side of the intermediate transformers, if the nautrals of alternators in a system are interconnected and/or connected directly to those of transformers and loads, balancing currents of three times system frequency can occur.
Their magnitude must be measured in the alternator neutral conductors under all possible load conditions to be met in service.
To prevent the alternators overheating, these currents of three times system frequency must not exceed approximately 50% of the respective alternator current. Excessive currents should be limited, e.g. by means of neutral reactors or similar fitted on the plant side; a specific enquiry Is necessary for these items.
No periodic maintenance inspections of the THYRIPART excitation equipment are required. Excessive dust deposits should, however, be removed using dry, compressed air.
In the case of faults it is advisable to check voltage controller, excitation equipment and main machine with exciter separately.
For troubleshooting in the thyristor voltage controller all the leads connecting excitation equipment and thyristor voltage controller must be disconnected and if fitted, the intermediate transformers of the droop-compensating equipment secondaries short-circuited.
In this case the generator voltage must rise above the maximum reference value as given under “Description”. In this case the thyristor voltage controller is defective. Trouble shooting should be continued according to' table 1. : on page 34.
2.4 wiODH OF QPE&AJlOn (HR 6)
Brushiess synch ronus generators consist of th-s main machine and of the exciter.
The main machine fio’cS windincj is powered from the-exciter rotor winding via a rotating, three-phase bridge-connected rectifier set.
The exciter is THYRIPART-excited.
The excitation equipment and the thyristor voltage controller are combined in the THYRIPART exci' ..n system.
The field current required is supplied by the main machine via the excitation unit '
This is adjusted in such a manner that the generator voltage which is above the maximum setpoint value develops over the entire load range when the voltage controller is inactive (open plug connection X1).
The thyristor voltage controller provides a by pass for part of the current supplied by the excitation unit for controling the generator voltage.
The voltage controller 6GA2492 comprises the voltage regulator 6GA2491 and the power module (rectifier, thyristor in '‘buck’’ circuit and resistor in “buck" circuit).
(2) Mode of operation of controller
The generator voltage is fed to the controller via plug : connector X1 in a single-phase, two-circuit arrangement.
Transformer T1 steps down the generator voltage which is then rectified by the load-side rectifier brirfrje
This rectified voltage provides the actual pulse signal Uist the setpoint voltage Usoll and the supply voltage
0 for the controller.
If Ihe system uses a reactive current compensator, current trans-former T15 or interposing transformer T4 of the excitation unit is connected to load resistor R1 via plug-in contacts X2/5 and X2/9.
In this operating mode the actual voltage is composed of the secondary voltage of transformer T1 and the voltage of load resistor R1.
The magnitude of the resulting reduction in generator voltage can be set with potentiometer S.
If an external set point selector is used, this is connected by contacts X2/1(A1) and X2/3(A3).
In this case microswitch S1/3 of the controller must be opened.
A DC voltage of 0 to 10V can be fed in via plug-in contacts X2/6 and X2/2. This voltage acts on the comparator point of the control amplifier. The setpoint can thus, for instance, be preset by higher-level equipment
Control amplifier <£> (proportional again adjustable by potentiometer K and reset time by potentiometer T) out puts a DC voltage which is converted into a time-adjustable firing pulse for thyristor V18 or V28 via the loadside pulse unit <D.
The generator excitation circuit is fed from rectifier bridge V29.
Resistor R48 and thyristor V28 form a parallel by pass circuit to the field winding through which part of the current supplied by the excitation unit flows. This method provides for generator voltage control. In order to optimize the correcting action, a disturbance variable is injected into the control amplifier via resistor R47.
Overvoltages above DC 600V in the excitation circuit cause the overvoltage protector ® to operate and continuously fire the thyristor. Protection is thus provided for the stationary excitation circuit of the generator.
(3) installation
Excitation equipment, thyristor voltage controller, main machine and exciter are supplied factory-wired.
The main leads and the reference-value selector, if necessary.
must be connected to the terminals in the terminal box according to the connecting diagram supplied with the machine.
2.5 OPERATION (HF. 6) •'
. (1) Thyristor voltage controller The voltage controller regulates the voltage so that it complies with the setpoint
The design and adjustment of the generator and of the excitation equipment permit continuous changes of the terminal voltage in the range of ±5% rated voltage via the setpoint selector under steady-state conditions and at loads varying form no load to rated load and power factors from 0.8 to unity unless specified otherwise on the rating plate. If several rated voltages and frequencies are indicated on the rating plate, the above data apply to each of the rated voltages stated. If the generators are operated at voltages exceeding Un ±5% the generator output must be reduced. Unrestricted operation at no load is permitted if the speed is reduced.
During operation the excitation circuit must not be interrupted since this would give rise to voltage surges. If the generator must be deexcited, this can be accomplished by short-circuiting the field winding of the exciter terminals +F1, -F2.
NOTE: in this case a remnant voltage of approx.
5% to 10% rated voltage may develop at the generator terminals.
(2)Transformer adjustment
The tappings used on the transformers are shown in the test report.—
It is strongly advised not to change the original . adjustments, v No responsibility can be assumed by the supplier for any damage or incorrect operation resulting from a change in the original adjustments.
In the case of identical plants, the THYRIPART excitation system or the individual components can be interchanged if the need arises.
However the transformer tapings must be used which are shown in the circuit diagram of the generator and which correspond to those of the original transformer.
(3) Controller gain, setpoint voltage integral action The control module comprises potentiometers U.K.T, R47 and S.
The rated generator voltage has been adjusted in the works on potentiometer U, and the dynamic behaviour of the controller on potentiometers K, T and R47.
The settings are shown in the test certificate.
Potentiometer K Is used to adjust the controller gain and potentiomter T to adjust the integral action time, whereas poten'Jomter R47 is used to inject a disturbance variable into the comparator point of the control amplifier in ordsr to adjust the dynamic behaviour.
Turning of the knob of K and R47 in the direction of descending numerals and that of T in the direction of ascending numerals normaily stabilizes the control circuit and reduces the control rate.
The stability of the control circuit can also be improved by increasing the bucking resistance, the voltage setting range of the controller then, however, being reduced at the lower end.
The setpoint of the generator voltage can be shifted via potetiometer U or an additional external setpoint seIector(R=4.7K2, P greater than 1W) to be connected to terminals A1 and A3. Potentiometer U should be set to the centre position, and microswitch S1/3 on the printed-clrcuit board should be opened.
(4) Parallel operation droop compensation equipment
When provided with droop compensation equipment, brushiess synchronous generators are suitable for operating in parallel with each other or with a supply system.
The KW output is adjusted by the governor of the prime mover.
The speed characteristic of the prime mover should be linear and rise by at least 3% and not more than 5% between rated load and no load.
Parallel connection on the exciter side or droop compensation equipment ensures uniform distribution of the reactive power and reduces the generator output voltage in linear proportion to the increasing reactive current.
Regarding generators with current transform .> croop compensaton, potentiometer S in the oor.v ^ or is adjusted so that there is no reduction in the tjener? or voliago at unity p.f. but a 6% reduction at zero p.f.
The corresponding voltage reduction at 0.3 p.f. is 3.6%. In isolated operation and at any loading condition or the generator, the droop compensation provided for the generator voltage can be checked with the following relationship:
If the generator is to operate by it self, droop compensation equipment is not required. It can be deactivated by short-circuiting the associated current transformer on the secondary side or setting potentiometer S on the contoriler to the left-hand stop. If the neutral points of several generators are interconnected or connected direct with the neutral points of transformers and loads, currents at 300% frequency may occur.
Their magnitude should be checked by measurementsin the neutral conductors of the generators under all load conditions occurring.
To avoid overheating of the genrerators, these currents must not exceed a value equal to about 50% of the rated generator current. Higher currents should be limited by instaling neutral reactors or similar means.
The THYRIPART excitation system requires no maintenance.
For maintenance or the other parts of the generater
r.'or :o the trouble-shooting table 2. as shewn on pa~-35.
When ordering spare parts, please state the type and serial number of the generator as specified on the rating plate.
The purpose of this checklist is to ensure that a!! installation and inspection work is fully carried out.
It is therefore essential for the list to be filled in carefully. The number of relevant questions will depend on the scope of the work to be carried out, .•
In the "Answer’ column, "yes" or "no" or "n/a*
(for "not applicable") should therefore be checked off in each case.
In some lines, additional data or information must be entered or irrelevant items deleted.
If any further explanations are necessary the; sr ' id be placed in the report or final spec of generator
Condition of machines before installation
Packing of all machine components undamaged?
Paintwork undamaged?
Winding guards properly fixed and locked?
All parts of the enclosure properly assembled?
Stator foot bolts tightened properly?
Stator dowel-pinned?
Earthing or protective conductor connected?
HV machines must be connected to the earth bus by a conductor of equal cross-section.
LV machines are to be included in the protection
arrangements by the connection of the green-yellow protective conductor or the concentric conductor of the cable to the protective conductor connecting terminal.
Condiuon or oeanngs aitd shait
Have any shipping bearing shells and'or shaft blocks been removed"1
Anti-rust coating removed? shaft journals satisfactory?
Oil rings fitted in the bearings? Circularity of oil rings satistactory?
Oiking skits of bearings shells deburred and rounded off?
Joint locked?
Bearing sealing rings property fitted?
Bearing thermometers fitted? All bearing bolts property tightened and locked?
Bearing filled with oil to centre marks of oil-level sight glasses?
Running of oil rings checked?
Oil circulation system
Oil pipework cleaned and pickled?
Pressure reducer fitted?
Oil flow rates Reference Drive-end
journal bearing ! / /min
journal bearing / /min
The specified oil flow rates are indicated on the bearing instruction plate. With the specified flow rates, about half the clear cross-sections of the oil drain pipes are filled with oil.
Rolling bearings
Grease lubrication
Type of grease
Alignment Answer Install -
yes no rVa • ation
Axial alignment of the stator ,
and rotor to each other with .
the aid of:
the factory(for synchronous machines)?
A pointer fitted by the factory and aligned to a shaft recess(for induction machines)?
3.1.1 Inspection schedule
Check bearing.
LO. condition.
Oil ring.
Check eletric circuit.
Earth fault by earth lamp.
Check loading condition.
Voltage, output kW, current.
Check insulation resistance.
Caution : Before checking insulation resistance,
disconnect and earthed the leads from A.V.R. Bolts and nuts.
Tighten all bolts and nuts.
Check ventilation openings.
Check air intake opening and its air filter, clean or replace the filter if necessary.
Every 6 monthly
Change lubrication oil and clean bearing.
At the same time, check fitting or seating of bearing.
Clean generator. ' . ’
Inspect generator winding and air filters for dirt, dust oil and salt vapor accumulation.
Blow off contamination by dry and oil free compressed air. Wipe off accumulated vapor by a lint free colth and adequate solvent.
Check electrical connection.
- Inspect for loose electrical connection.
- Inspect cracked, frayed or oil soaked insulation Tighten or replace if neccessary.
3.2 FLANGE-TYPE SLEEVE BEARING (for ring lubrication system)
3.2.1 Mounting
The flange-type sleeve bearings of electrical machines
They are ring-lubricated(Fig. 24) and are subject to the following instructions supple-menting and modifying the operating instrucrtions of the machine:
Corresponding to the operating conditions the sleeve bearings of new machines have a favorable bearing clearance which should not be changed.
Also scaping(spot-grinding) is not allowed to do not make worse the antifrictional qualities.
It is recommended that the contour of the transmission element remains within the hatched range(see Fig. 24 and the table. 4 on page 37) to remove the upper part of the bearing housing for maintenance without removing the transmission element.
Before the machines are aligned and commissioned, the bearings should be filled with lubricating oil, because the machines are delivered without oil in the bearings(oil type is indicated on the name plate for bearing).
3.2.2 Oil change
Check the bearing temperature regularly.
The governing factor is not the temperature rise itself, but the temperature variations over a period of time.
If abrupt variations without apparent cause are noticed., shut down the machine and renew the oil.
The lubrication oil indicated on the data plate is used for starting up the machines at an ambient temperature of above +5*C.
At lower temperatures(to about -20*C) it is sufficient to preheat the oil. If the ambient temperature are below -20*C another type of oil according to the special conditions is used.
Do not mix oils of different grades.
Recommended oil changing intervals are about 3000
and 6000 operating hours in the case of intermittent
^ . • • , - 1.1*.
.. . «, •
When cleaning, first flush the bearings with kerosene and then with oil.
Pour in the kerosene and oil through the top sight-glass hole.
Leave the drain open until all the kerosene has been removed and clean oil runs out.
Now, plug the drain and fill the bearing with oil up to the centre of the lateral inspection glass.
When the machine has run up to speed, check the oil ring through the top inspection glass to see that it rotates correctly, and check the bearing temperature, should the bearing temperature not drop to the normal value after the oil change, it recommended that the surfaces of the bearing shells be inspected.
If the bearings are fitted with thermometers for checking the bearing temperature, fill the thermometer well in the upper bearing shell for thermofeeler with oil to improve heat transfer and top up with oil every time the lubricating oil is changed.
3.2.3 Dismantling, assembling When dismantling the machine the lower part of the bearing housing need not be unscrewed from the end shield, when opening the bearing housing, locate before, if on which side of the machine the adjusting shims(upper and lower parts) are installed.
These shims must be installed at the same place when assembling-the machine.
Exceptions are possible if the stator core was changed. Drain the oil, take off the upper part of the bearing housing and the upper bearing shell, lift the shaft very slightly and trun out the lower bearing shell "and the sealing rings in peripheral direction.
The oil ring can be withdrawn by holding it at an inclined position to the shaft.
Fig. 23 Oil pockets and oil grooves.
If only slight damage has occurred to the bearing surface, it may be re-conditioned by scraping, as long as the cylindrical shape of the bore is maintain, so that a good oil film can form.
The lining must be renewed if n>ore serious damage is found.
The oil pockets and grooves of the new lining or scraped shell should be cleaned and finished with particular care(Fig. 23).
The replacement bearing shells az& delivered by the works with a finished inner diameter.
Only if the bearing shells wei; delivered unfink := i, the inner diameter is 1 rnrn smalter than the finished diameter.
Oil rings which have become bent through careless handling will not turn evenly.
Straighten or replace such rings.
Replace any damaged sealing rings.
<11 ("ml 80 100 120 ISO 180 715
(mm| 140 ICO 170 1BO 210 248
a l*wn* 6 8 10 15 18 22
1. Screw plug
(thermometer mounting and oil filling point)
2. Inspection glass
3. Sealing ring for 2
4. Sealing ring for 1
5. Bearing housing, upper part, drive end
6. Cylindrical pin
7. Sealing ring, upper half, drive end
8. Guide pin to prevent twisting ..
9. Upper bearing shell, drive end-----------
10. Oil ring, drive end
11. Lower bearing shell, drive end
12. Bearing ring, lower half, drive end •
13. Sealing ring, lower half, drive end
14. Taper pin
15. Guide pin to fix botted parts
16. Sealing ring for 17 . :■.
17. Drain plug
18. Bearing housing, upper part, non-drive end
19. Sealing ring, upper half, non-drive end
20. Upper bearing shell, non-drive end
21. Oil ring, non -drive end
22. Lower bearing shell, non-drive end
23. Bearing housing, lower part, non-drive end
24. Sealing ring, lower half, non-drive end . 25. Upper adjusting shim,, drive end
26. Sealing cover, drive end
27. Lower adjusting 6him, drive end
28. Upper adjusting shim, non-drive end
29. Scaling cover, non-drive end
30. Lower adjusting shim, non-drive end
31. Protective cap
32. Pressure compensation opening
Rating: 4.7 / 5 (Votes: 18)
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