Guide To Synchronising and Load Sharing Part 1
Guide To Synchronising and Load Sharing Part 1
Guide To Synchronising and Load Sharing Part 1
Deep Sea Electronics Plc Highfield House Hunmanby North Yorkshire YO14 0PH ENGLAND Sales Tel: +44 (0) 1723 890099 Sales Fax: +44 (0) 1723 893303 E-mail: sales@deepseaplc.com Website: www.deepseaplc.com
Deep Sea Electronics Guide to Synchronising and Load Sharing Deep Sea Electronics Plc All rights reserved. No part of this publication may be reproduced in any material form (including photocopying or storing in any medium by electronic means or other) without the written permission of the copyright holder except in accordance with the provisions of the Copyright, Designs and Patents Act 1988. Applications for the copyright holders written permission to reproduce any part of this publication should be addressed to Deep Sea Electronics Plc at the address above. Any reference to trademarked product names used within this publication is owned by their respective companies. Deep Sea Electronics Plc reserves the right to change the contents of this document without prior notice.
1 BIBLIOGRAPHY
1. Diesel generator handbook. L.L.J.Mahon. ISBN 0-7506-1147-2 2. On-Site Power Generation. EGSA Education Committee. ISBN 0-9625949-3-8
Page
7 8
THE NEED FOR SYNCHRONISING .............................................................. 19 METHODS OF ADJUSTING VOLTAGE & FREQUENCY ............................. 20
8.1 8.2 8.3 8.4 REMOTE SPEED / VOLTAGE POTENTIOMETERS ........................................................20 DC VOLTAGE INPUT ........................................................................................................20 RAISE / LOWER PUSH BUTTONS ...................................................................................20 CAN / ELECTRONIC ENGINE SPEED CONTROL ..........................................................21 GOVERNOR WITH REMOTE SPEED CONTROL CAPABILITY .....................................22 AVR WITH REMOTE VOLTAGE ADJUST CAPABILITY .................................................22 FUNCTION COMPARISON CHART..................................................................................23 SYNC / LOAD SHARE PROTECTION COMPARISON CHART .....................................24
10
10.1 CHOOSING A LOAD SWITCHING DEVICE .................................................................25 10.1.1 CONTACTORS ...........................................................................................................25 10.1.2 CHARGED SPRING BREAKERS ...............................................................................25 10.1.3 AIR CIRCUIT BREAKERS (ACBS) .............................................................................25 10.1.4 MOTOR OPERATED BREAKERS .............................................................................26 10.1.5 MANUALLY OPERATED BREAKERS .......................................................................26 10.2 NEUTRAL EARTHING ...................................................................................................26 3
11
11.1 SYNCHRONISING ......................................................................................................... 27 11.2 LOAD SHARING ............................................................................................................ 27 11.3 START/STOP ON LOAD DEMAND .............................................................................. 27 11.4 COMPATIBILITY............................................................................................................ 27 11.5 CONNECTIONS ............................................................................................................. 28 11.6 SPECIFICATIONS ......................................................................................................... 29 11.7 MSC ALARMS ............................................................................................................... 30 11.7.1 MSC ID ALARM .......................................................................................................... 30 11.7.2 MSC DATA ERROR ................................................................................................... 30 11.7.3 MSC FAILURE ............................................................................................................ 30 11.7.4 MSC TOO FEW SETS ................................................................................................ 30
12
12.1
13
2 INTRODUCTION
A general overview of generator uses is given including synchronising. This is only to be treated as a guide to newcomers to this particular subject, and should not be treated as a total learning package. Part 2 of this manual details the interfacing the DSE controllers with many of the most common AVRs and Governors in use on generating sets.
Further detailed information on this subject is contained in the DSE Load Share Design and Commissioning Guide (DSE PART 057-047).
Should you have any queries arising from this manual please contact our Technical Department:
INTERNATIONAL TEL: +44 (0) 1723 890099 INTERNATIONAL FAX: +44 (0) 1723 893303 E-mail: support@deepseaplc.com Web: http://www.deepseaplc.com
3.1
A.V.R. Governor
Automatic Voltage Regulator. Fitted to the alternator to regulate the output of the generator. Engine Speed Governor. Fitted to the engine to electronically control the speed of the engine. When load is applied to a generator fitted with a droop governor / AVR, the speed/voltage will drop. This is called droop. It is common for a droop set to drop between 3% and 10% in speed / voltage from no load applied to full load applied. A governor with no speed droop, or where speed droop is disabled is known as an isochronous governor. The engine speed remains constant so long as the load levels are within the sets capability. To get the supplies identically matched, ready for paralleling. Connect two or more supplies together. These supplies must be in synchronism before this can occur. centre point of an electronic pot, digital resistance or AVR/Governor. The nominal voltage or frequency of the system i.e. 230V 50Hz. This is not necessarily the same as the Datum. (i.e. when droop governors/AVRs are used, the datum will be higher than the nominal ) The AC distributed power supply of a power generation company. Often also called the grid, or utility supply.
Droop
Nominal
Mains supply
Generator uses
4 GENERATOR USES
AC Power Generators are widely used to supply power to a load at mains voltage levels. Most people first encounter a generating set when used as the primary power source. An example of this is the small trailer mounted generators often seen in use supplying power to highway maintenance equipment. Other terms used to describe a generator as the sole supply are Primary power or Prime power. Knowledge of prime power generation in this way is assumed and is not covered within this manual.
4.1
STANDBY GENERATORS
Generators are commonly used as a backup to the mains supply. Due to their nature, backup supply generators are rarely seen by the public! Should the mains supply fail, the generator will be started and used to provide power until it returns. Applications include factories, offices, schools, emergency services (including hospitals), airports, telecommunications providers etc. Backup generators fall into two main categories:
Illustration
4.1.1 TRANSFER SWITCH
Description
The most common form of backup generator to the mains supply is a single generator in standby mode. When the mains supply fails, the load is left without power until the generator is started. Once the set is available, the transfer switch changes over so that the load is supplied by the generator. Typically, the down time will be around 15 seconds, but may be longer depending upon the time taken to run the engine to nominal speed and other application dependent factors. When the mains supply returns, the load-switching device (contactors/breakers) will momentarily remove power from the load (typically 1 second) before transferring the load back to mains supply power. The break in supply when transferring back to the mains can be eradicated by synchronising the generator supply to the returned mains supply, and closing the supplies in parallel with each other for a short period of time. Then, the generator load switch is opened, returning the mains to supply power to the load. There has been no break in supply to the load during this return transfer process. Terms often used for this procedure are bumpless transfer, no break return and no break transfer. Additionally, the same procedure can be used to transfer from mains supply to generator supply enabling, for instance, on load testing of the genset with no break in supply to the load. This can also be performed if the supply authority informs customers of a scheduled break in supply.
4.1.2
NO BREAK TRANSFER
Generator uses
4.2
Electricity supply boards have many tariffs based upon the customers load demand. In some cases, the tariffs can treble or more during certain times of the day if a specific load level is exceeded. In this example, the customer is charged more for his electricity in the hours around midday, as his load level places his power usage into the next charging tariff. In some cases, it can be more cost effective for the customer to provide an alternative power supply during this time of high tariff. There are a number of possibilities open to him:
Illustration
GENSET SUPPLY.
Description
During the time of high load level a single (or multiple) generator(s) could be started, and then used to power the load using a no break transfer. This genset supply must be capable of supplying the entire load during this time of high usage.
4.3
In this example, a DSE 20 controller is being used in a base load peak lopping system. The controller has been configured to start the generating set at 10am, synchronise with the mains and parallel the supplies. It will then export a fixed amount of power (kW) to the load and maintain a specified power factor (both configurable). If the set is large enough to supply the entire load, mains failure duty is also available.
Generator uses
Illustration
4.3.1 TRUE PEAK LOPPING AND IMPORT/EXPORT CONTROL
Description
A more advanced variation of the peak lopping system described above is to use a 7520 (for single set) or DSE8610 with DSE8660 (up to 32 sets). In this situation variable Peak Lopping or true import/export can be achieved. The DSE8660 or DSE7520 will monitor the site load levels and vary the generator(s) power production. This can be used to ensure the set is used at its economic load level, and prevents the system exporting power. It can also be used to hold the mains usage to a certain level (DSE Mains Mode), helping to avoid higher electricity board tariffs or supplementing the mains supply on a site with limited supply available.
NOTE: - It is recommended that the mains decoupling is enabled in the DSE module when paralleling a generating set with the mains. Additional equipment of this type is normally specified by the local electricity Supply Company to protect against the generator feeding the mains grid in the case of a mains failure. If in doubt, you should refer to your local Electricity Supply Company for advice. NOTE:- Mains decoupling functionality is included within the DSE8600 and DSE8700 series controllers. DSE 7500 and DSE 5500 include this function in versions 8 or above. When using other controllers, this functionality should be provided externally. Additional equipment of this type is normally specified by the local electricity Supply Company to protect against the generator feeding the mains grid in the case of a mains failure. If in doubt, you should refer to your local Electricity Supply Company for advice.
Generator uses
4.4
MULTIPLE GENERATORS
There are many reasons for requiring more than one generator on the same site. The most commons reasons are described below:
Illustration
4.4.1 MUTIPLE SET PRIME POWER
Description
In this example, the site has four generating sets, used as the primary power source. One genset will be running all the time, to provide power to the site. If the load demand of the site increases, one or more generators will be automatically called to start. They will then synchronise onto the bus, and provide power in parallel with the other set(s). At this point, the sets connected to the bus will share the load, normally utilising load sharing equipment. Using multiple generating sets rather than one large set allows for maintenance to be performed on one of the sets while the other set(s) are still available for duty. Additionally, if load demands are low, individual generators can be started as required, rather than one large generator being used at (for instance) only 25% of its full load rating. If the overall size of the load increases, for instance due to factory expansion another set can be added to increase capacity with minimal disruption to the rest of the system. Using this system, redundancy can be built in by utilising a larger number of gensets than is required to supply the load. This way, the load can still be supplied if one or more sets are unavailable due to engine failure or maintenance. The DSE controllers have no master ensuring a seamless transition when one or more sets are removed from the system.
10
Generator uses
4.4.2
Illustration
Description
If multiple gensets in parallel are used to backup the mains supply, care should be taken when designing the system. In the example above for instance, should the mains supply fail, two possibilities exist. Firstly, if only two generating sets are providing power to the bus, they must be capable of supplying the currently active load. Secondly, if none of the sets are available, they will all start up simultaneously. The first set will close onto the dead bus, and supply power to the load. Again, the set must be capable of supplying this power to the currently active load. Two solutions exist : a) Ensure each generating set is capable of supplying the entire load so that the above situations will not occur. b) Ensure before closing the load switch and powering the load with the generating sets, that all of the generating sets are available and synchronised onto the generator bus. While running in this manner, not in parallel with the mains supply, this is called island mode.
4.4.3
The DSE333 automatic transfer switch can be used to monitor the mains supply to ensure it is within limits. Should the mains supply fail, the 333 can be used to remote start on load demand the DSE8610 controllers used in the example shown. All sets in the system will start together. The first available set will close onto the dead bus. The other generating sets will synchronise onto the generator bus, and then close in parallel with it. Configure and output of the DSE8610s to all available sets on load and connect them all to the auxiliary generator ready input DSE333 automatic transfer switch. The DSE333 module will sense the generator bus voltage and frequency, and once within limits will wait for the presence of the auxiliary generator ready input. This signifies the correct closure of all sets in the system onto the generator bus. The mains generator load transfer is then performed by the DSE333 automatic transfer switch controller. Note that this functionality can be provided by any of the DSEAts range of controllers.
11
Generator uses
4.4.4
Illustration
Description
In the example above, it was not possible to perform no break transfers to/from the mains supply. If a DSE8660 mains controller is fitted, to monitor the mains supply and power supplied by the mains to the load, additional possibilities exist, the most important of which are : 1) Should the mains supply fail, DSE8660 can call for the generating sets, which will synchronise and close onto the generator bus. When the sets are available on the generator bus DSE8660 can close the generator bus interconnecting load switch. When the mains supply returns, the generator bus can be synchronised and closed in parallel with it, to allow a no break return to the mains supply. 2) As the power being supplied by the mains is also being monitored, the DSE8660 can pass this information to the generator controllers, allowing load sharing between the generator bus and the mains supply. 3) No-break on load testing is possible, by calling for generators to start. The first to become available will close onto the dead generator bus, the remaining generators synchronising with the now live generator bus and closing in parallel with it. The DSE8660 will then communicate with the generating set controllers to effect synchronism of the generator bus with the mains supply. When synchronism has been achieved, the DSE8660 can close the supplies in parallel.
4.4.5
Due to local electrical supply conditions or historical growth of the load, it is possible for the load to be fed by more than one incoming AC mains supply. Normally each mains supply will feed a separate part of the load. The DSE8660 module allows the standby generators to parallel with any one of the mains supplies at a time and will transfer the loads accordingly. Peak lopping is also possible on any one DSE8660 module in the system, in the event of a mains failure condition peak lopping can be automatically terminated to ensure the gen-sets are available for standby operation. NOTE: - It is recommended that the mains decoupling is enabled in the module when paralleling a generating set with the mains. Additional equipment of this type is normally specified by the local electricity Supply Company to protect against the generator feeding the mains grid in the case of a mains failure. If in doubt, you should refer to your local Electricity Supply Company for advice. NOTE:- Mains decoupling functionality is included within the DSE8600 and DSE8700 series controllers. DSE 7500 and DSE 5500 include this function in versions 8 or above. When using other controllers, this functionality should be provided externally. Additional equipment of this type is normally specified by the local electricity Supply Company to protect against the generator feeding the mains grid in the case of a mains failure. If in doubt, you should refer to your local Electricity Supply Company for advice.
12
5.1
5.1.1
SINGLE SETS
SINGLE SET NO BREAK RETURN WITH MAINS
A single set primarily used to provide backup to the mains supply should it fail. When the mains supply returns, the generator is synchronised to the mains supply and momentarily closed in parallel with it before opening the generator load switching device. 8620 7520 5520 Generator Mode (Fixed export or Base load) Mains Mode (Import / Export control or peak lopping)
Controller :
NOTE: - It is recommended that the mains decoupling is enabled in the DSE module when paralleling a generating set with the mains. Additional equipment of this type is normally specified by the local electricity Supply Company to protect against the generator feeding the mains grid in the case of a mains failure. If in doubt, you should refer to your local Electricity Supply Company for advice.
5.1.2
A single set used solely to parallel with the mains. No control of the mains breaker is provided. If the mains breaker opens, the decision must be made if the set can be used to power the load (if the set is large enough. Upon mains return, the set breaker must be opened before the mains breaker can be closed. 8610 8710 7510 5510 Fixed export through Mains parallel mode operation of the DSE 10 controller.
Controller :
NOTE: - It is recommended that the mains decoupling is enabled in the DSE module when paralleling a generating set with the mains. Additional equipment of this type is normally specified by the local electricity Supply Company to protect against the generator feeding the mains grid in the case of a mains failure. If in doubt, you should refer to your local Electricity Supply Company for advice.
13
5.2
5.2.1
MULTIPLE SETS
MULTIPLE SET PRIME POWER
Two or more sets are used to provide power to the load, sharing power equally as a percentage of the sets full load rating. Sets are automatically started and stopped depending upon load levels allowing economic use of the available generators. 8610 (max 32 set system) 8710 (max 32 set system) Controller : 7510 (max 16 set system) 5510 (max 16 set system) Full control of the kW/KVAr load share is possible, the sets equally sharing the kW load between them pro rata (i.e. same percentage of their rating).
NOTE: - DSE8610 and DSE8710 are compatible in the same system. Load Share options : DSE5510 and DSE7510 are compatible in the same system. HOWEVER DSE8610 and DSE8710 cannot be used in the same system as DSE5510 or DSE7510. A DSE125 MSC is used to interface these two devices together. Contact DSE for further advice.
14
5.2.2
Two or more sets are used to provide backup to the mains supply. When the mains supply fails, the sets are started, synchronised and paralleled together. The generators bus is then closed to feed the load, the sets sharing power equally as a percentage of their full load rating. Sets are automatically started and stopped depending upon load levels allowing economic use of the available generators. When the mains supply returns, there will be a break in supply to the load while the transfer takes place. 8610 (max 32 set system) 8710 (max 32 set system) Controller : 7510 (max 16 set system) 5510 (max 16 set system) DSE333 ATS controller DSE333 handles BREAK change between mains / generator bus. NO PARALLEL operation with mains is possible. Full control of the kW/KVAr load share is possible, the sets equally sharing the kW load between them pro rata (i.e. same percentage of their rating).
NOTE: - DSE8610 and DSE8710 are compatible in the same system. DSE5510 and DSE7510 are compatible in the same system. HOWEVER DSE8610 and DSE8710 cannot be used in the same system as DSE5510 or DSE7510. A DSE125 MSC is used to interface these two devices together. Contact DSE for further advice.
15
5.2.3
Two or more sets are used to provide backup to the mains supply. When the mains supply fails, the sets are started, synchronised and paralleled together. The generators bus is then closed to feed the load, the sets sharing power equally as a percentage of their full load rating. Sets are automatically started and stopped depending upon load levels allowing economic use of the available generators. When the mains supply returns, there will be NO break in supply to the load while a ramped transfer takes place. A DSExx60 controller is connected to the load share controllers via the Multi Set Communications link and monitors the mains supply, signalling all available sets to start should the supply fail. Additionally the controller will start the sets if the mains load reaches a configurable level to provide peak lopping and import/export control. All available sets will start and after the minimum number of sets have successfully paralleled with each other, the controller will transfer the load to the generator bus. The generators will then share the load using their load sharing communications link, sets being stopped / started depending upon load demands (if enabled) Upon mains restoration, the controller will synchronise the generator bus to the mains and ramp the load back to the mains. The sets are then instructed to cool down and stop. DSE8610 (max 32 set system) DSE8710 (max 32 set system) DSE8660 or DSE8760 mains controller Controller : 7510 (max 16 set system) 5510 (max 16 set system) DSE7560 or DSE5560 mains controller DSExx60 handles mains monitoring and soft transfer between mains / generator bus. Full control of the kW/KVAr load share is possible, the sets equally sharing the kW load between them pro rata (i.e. same percentage of their rating). Generator Mode (Fixed export or Base load) Mains Mode (Import / Export control or peak lopping) Load Share options :
NOTE: - DSE86xx and DSE87xx are compatible in the same system. DSE55xx and DSE75xx are compatible in the same system. HOWEVER DSE86xx and DSE87xx cannot be used in the same system as DSE55xx or DSE75xx. A DSE125 MSC is used to interface these two devices together. Contact DSE for further advice.
16
5.2.4 5.2.5
MULTIPLE MAINS SUPPLIES SINGLE SET STANDBY TO MULTIPLE MAINS SUPPLY (NO BREAK RETURN)
Set(s) are used to provide backup to multiple mains supplies. Should one of the mains supplies fails, the set is started, and the appropriate load is transferred to the generator set. Should further mains supplies fail, the appropriate loads will also be transferred to the generator. Should one of the mains supplies return, there will be NO break in supply to the load while a ramped transfer takes place. This will be repeated for each returning mains supply until the generator set is transferred off load and finally stopped. The order of the mains restoration depends upon module priority and operating state. This priority is covered in the DSExx60 operator manual.
DSE8610 (max 32 set system) DSE8710 (max 32 set system) DSE8660 or DSE8760 mains controller Controller : 7510 (max 16 set system) 5510 (max 16 set system) DSE7560 or DSE5560 mains controller
17
Load Sharing
6 LOAD SHARING
6.1 ACTIVE POWER SHARING
We have discussed the synchronising of one or more supplies to the mains or bus supply. Once these supplies are closed in parallel with each other, the power will be shared between the supplies depending upon the generating set characteristics. Control over the sets active power is achieved by controlling the amount of fuel into the engine. Instructing the governor to increase fuel to the engine will also have little or no effect on engine speed because the generator is tied to the other supply. Instead, the generator will supply more power to the load. This in turn decreases the amount of power provided by the other supplies. This is known as Kilowatt (kW) control. This can be taken a step further, by paralleling multiple generating sets, all operating isochronously (zero droop). Utilising an active load-sharing controller such as the DSE8610, precise changes can be made to the amount of power supplied to the load by each generating set. This is achieved by altering the amount of fuel supplied to the engine, and monitoring the amount of power supplied by the set. Each controller can communicate with the others, passing information regarding load levels. This can also be used to bring in or drop off other generating sets as load demands change.
6.2
Again, consider two identical generating sets closed together in parallel. Adjusting the amount of field excitation in one of the generators has the effect of that generator supplying more or less of the reactive power to the load, matched by an equal drop in the reactive power supplied by the other generator. Reactive power is the power used to supply inductive or capacitive load. Uses of reactive power control include: 1) Where multiple generators are used in parallel with each other, the reactive power is equalised between the sets, removing circulating currents caused by imbalance in the reactive power (VAr) supplied by the paralleled generating sets. This circulating current can generate heat in the alternator windings. If left unchecked, excess circulating current can also damage the alternator windings. 2) Power factor control or VAr control. This feature maintains a specific power factor where one generating set is used in parallel with the mains supply. This is normally used so that the generator maintains its VAr to keep its output at the site loads average power factor level, to minimise demands on the mains supply.
18
WARNING! Attempting to close the supplies in parallel when they are not in synchronism can result in damage to the generating set system. For example: If synchronising (using two gensets) is effected 120 out of phase, the coupling torque can be as high as 12 times full load torque, depending on the ratio of engine and generator inertias (Source: Diesel Generator Handbook L.L.J. Mahon). The actual synchronising process can be achieved through various methods. Put simply, each method involves manipulating the engine governor to increase/decrease engine speed (which has a direct relationship with generator frequency) and the Automatic Voltage Regulator (which controls the alternator excitation field to produce voltage). The engine governor determines engine speed, by sensing the speed of rotation of the flywheel (normally using a magnetic pickup probe). The governor can then control the actuator to adjust the amount of fuel into the engine, which changes engine speed (similar to the accelerator in a car). Most governors are also fitted with a remote speed adjust input to allow an external device to increase or decrease the set speed of the engine. The Automatic Voltage Regulator effects change in the generator output voltage by controlling the alternators exciter field. The AVR adjusts the voltage output to the required set voltage. Most AVRs are also fitted with a remote volts adjust input to allow an external device to increase or decrease the set voltage of the alternator. Automatic synchronisers act upon the remote speed adjust and remote volts adjust inputs of the governor and AVR to affect synchronism and voltage matching. The method of interface between the automatic synchroniser and the governor/AVR depends upon the type of governor and AVR being used, and are described in the section entitled Methods of Adjusting Voltage and Frequency.
19
Illustration
Variable resistance
Description
This diagram shows a two terminal connection to the governor/AVR. The value of the variable resistor (rheostat) depends upon the requirements of the governor/AVR being used. This type of interface is suitable for connection direct to the analogue governor output of the DSE8610 or DSE8710 controllers. This diagram shows a three terminal arrangement, for connection to a potentiometer. The value of the potentiometer depends upon the requirements of the governor/AVR being used. This type of interface is usually suitable for connection direct to the analogue governor output of the DSE8610 or DSE8710 controllers.
Potentiometer
8.2
DC VOLTAGE INPUT
Another analogue interface often used by governor manufacturers utilises a DC voltage, the level of which is proportional to the engine speed required. An example of this is the G.A.C.ESD5500E that accepts a DC signal from 2V to 8V to represent adjustment away from the set speed point. When the DC level is at 5V, the engine speed is the governors set speed. This type of interface is suitable for connection direct to the analogue governor output of the DSE8610 or DSE8710 controllers.
8.3
Push buttons to raise/lower the engine speed / alternator output voltage can also be used. The push buttons are fitted to the control panel and allow step changes in voltage / frequency with a single press of the button.
Illustration
RAISE / LOWER PUSH BUTTONS
Description
This diagram shows switched inputs to the governor/AVR to raise/lower speed/voltage. This type of interface is suitable for direct connection to outputs configured to raise/lower DSE8610 or DSE8710 controllers, though it is usual to fit interposing slave relays between the controller and the governor/AVR to provide isolation between the devices.
NOTE:- Governor and AVR connections are covered in detail (including typical connection for commonly used governors and AVRs) in the DSE Guide to Synchronising and Load Sharing Part 2.
20
8.4
Some electronic engine ECUs support speed control via the CAN data interface negating the requirement to connect additional speed control signals to the speed controller. This feature is supported by the DSE8700, DSE8600, DSE7500 and DSE5500 series controllers.
NOTE:- Connections to electronic engine ECUs are detailed in the DSE publication Electronic Engines and DSE wiring and the Guide to Synchronising and Load Sharing Part 2.
21
This can be an electronic governor with either analogue (preferred) or digital (raise/lower inputs) to control engine speed. Alternatively it could be an electronic engine ECU (CANbus for instance) that supports speed control over the engine data link (CAN) or via analogue / digital control signals. You should check with the engine supplier about these possibilities. If you use digital raise/lower inputs you must have droop configured in the governor. If you use analogue or CAN for speed control, it is usual to disable governor droop.
9.2
This can be an Automatic Voltage Regulator with either analogue (preferred) or digital (raise/lower inputs) to control generator output. You should check with the alternator supplier about these possibilities. The alternator manufacturer will usually demand that a Droop Kit is fitted to the alternator to maintain warranty if you are paralleling with another set. While this is recommended, it is not always necessary. Again, you should consult with the alternator manufacturer if in any doubt. If an AVR with remote voltage adjust capability does not exist, you may still be able to load share. You will need to fit a Droop Kit to the AVR. In this instance, no voltage matching will take place and rudimentary VAr (reactive power) sharing will take place using the droop kit. The DSE module will not control the AVR.
22
9.3
Link5000Plus
Link5000Plus
Link5000Plus
Link5000Plus
Link5000Plus
Link5000Plus
23
9.4
Phase rotation protection Dead bus relay Frequency check Voltage check Phase angle check Fail to synchronise alarm Generator reverse power Mains reverse power Loss of excitation protection Earth fault protection Negative phase sequence protection Vector shift R.O.C.O.F.
NOTE:- With DSE5500 series controllers, Mains decoupling, Vector shift and R.O.C.O.F. is fitted internally to versions 8.0 and above only. NOTE:- Model 5560 must be used in conjunction with one or more 5510 controllers. It is not a stand alone module.
24
NOTE: - The closing time of any load switching device slave relays should also be taken into account. For instance, plug in relays typically used in generating set control panels have an operation time of 10ms-20ms. NOTE: - If fitting a mains (utility) Breaker with a trip position, it is recommended to fit one equipped with auxiliary contacts to indicate the tripped position. This can be fed into an input configured to auxiliary mains failure so that the module is informed of mains (utility) supply breaker tripping should this occur. This is particularly important when the module is operating in parallel with the mains (utility) supply. WARNING!: Manually operated breakers CANNOT be used as they cannot be operated within the required closing time.
10.1.1 CONTACTORS
Contactors normally operate fast enough for paralleling applications but care should be taken to choose a contactor that the manufacturer specifies be fast enough for use in paralleling applications. (See above).
25
This diagram shows a typical situation where the generator neutral conductor is earthed. The mains neutral conductor is earthed by the supply company. If the generator is placed in parallel with the mains supply, the neutral will be earthed at two points, creating an earth loop, which in turn generates current flow in the loop. To prevent this situation, the generator neutral earth link can be broken when the supplies are in parallel using a neutral earthing contactor in the neutral to earth link. Similarly, when two or more sets are in parallel with each other, it is important to ensure that only one neutral to earth link exist in the system at any one time. Control over the neutral earthing is not made by the DSE controller. Provision for this function must be made by external switching, often utilising auxiliary contacts of the load switching devices.
26
11.1 SYNCHRONISING
o o First Set on the Bus determination (Virtual Key) Security against bus sensing failure (Broken fuse)
11.4 COMPATIBILITY
o o o o The load demand scheme uses the DSE controllers MSC link. DSE7500 series are compatible with DSE5500 and DSE550 series controllers. For instance a DSE7510 controller can be used in a load demand scheme with a DSE5510 controller. DSE8600 series controllers are NOT compatible with DSE7510, DSE5510 or DSE550 series controllers without the use of DSE125 MSC interface. Contact DSE for further advice. Priority based upon engine hours is available on all DSE8610 and DSE7510 controllers. It is not available on DSE5510 controllers prior to Version 6 and is not available on DSE550 controllers.
For details of Run priority and balance engine hours, see DSE Part Number 056-013 Load Demand Scheme
27
11.5 CONNECTIONS
o o o o o o o o o o o A maxmium of 32 generator controllers (DSE8610) can be connected to the MSC link. A maxmium of 32 mains controllers (DSE8660) can be connected to the MSC link. A combined maximum of 40 DSE8600 series controllers can be connected to the MSC link. A maxmium of 16 generator controllers (DSE7510 / DSE5510) can be connected to the MSC link. A maxmium of 16 mains controllers (DSE7560 / DSE5560) can be connected to the MSC link. A combined maximum of 20 DSE7500 / DSE5500 series controllers can be connected to the MSC link. DSE8620, DSE7520 and DSE5520 DO NOT connect to the MSC link and cannot be used in multiset systems or systems including DSE8660, DSE7560 or DSE5560 MSC is a high speed data transmission line. As such it must be wired in cable rated for such operation. DSE Stock and Supply Belden 9841 cable which is suitable for MSC link operation (DSE part number 016-030) Ensure spurs off the MSC link are not used. The connections MUST be in daisy chain fashion, with the cable entering, and leaving the middle controllers as shown below. Ensure termination resistors are fitted to the beginning and end of the MSC data link as shown below. A termination resistor is supplied in the box with every DSE controller that has an MSC link connection. The maximum combined length of the MSC link must not exceed 240m (320yds). If further range is required, use DSE124 MSC Link Extender.
28
11.6 SPECIFICATIONS
Parameter Connection type Value Twin conductors with screen. Ensure screen is connected to SCR terminal of every controller on the bus. 120 0.050/m 75pF/m 110pF/m 120 4W (supplied loose with controller) 32(only 3 shown above for clarity) 32 40 16 (only 3 shown above for clarity) 16 20 16 1 250m 1m * BELDEN 9841 120 cable.
Cable impedance Maximum cable resistance Maximum cable capacitance (between conductors) Maximum cable capacitance (conductor to shield) Termination resistors (one at each end of cable run) Max number of 8610/8710 controllers per bus Max number of 8660/8760 controllers per bus Max number of 86xx + 87xx controllers per bus Max number of 7510/5510 controllers per bus Max number of 7560/5560 controllers per bus Max number of 55xx + 75xx controllers per bus Max number of 550 controllers per bus Max number of 556 controllers per bus Max cable length Max Spur length (see note 2 below) Recommended cable
NOTE :- * Deep Sea Electronics part number of BELDEN 9841 cable: 016-030
WARNING! 120 impedance cable must be used for the MultiSet Communications Link. Use of any other impedance cable may cause intermittent failures in communications, indicated by MSC alarms although the system may function normally during engine / panel testing.
NOTE 1: - The 120 terminator must be enabled on the first and last devices on the communications bus. See section header MSC Settings for further details.
NOTE 2: - It is important that the MultiSet Communications Link cable is run from one module to the next in a bus fashion. Spurs off this bus should be avoided where possible, but where a spur is unavoidable; its length should be kept less than 1m from the bus cable.
29
CAUTION! - Care should be taken to ensure that correct wiring is used between the modules, the MSC terminator is correctly enabled on only end units on the link and that maximum cable run distances are not exceeded. Should data error alarms be apparent, operation of the MultiSet system may not be possible.
NOTE:- For details on the MSC failure alarm settings, you are referred to the appropriate PC configuration manual.
30
31
Typical connections
13 TYPICAL CONNECTIONS
13.1.1 TYPICAL SINGLE LINE DIAGRAM OF MULTI SET MAINS FAIL
32
Typical connections
33
34