IE85282B1 - A controller - Google Patents

Abstract

ABSTRACT A controller for synchronising different types of generator sets with a grid network is disclosed. The controller is operatively connected to a generator set by a communications link for the transmission of engine control input signals for controlling the operation of the generator set engine and generator control input signals for controlling the power generated by the generator. The controller is able to be installed for use with different generator sets, irrespective of the make, model or brand of generator set.

Description

A Controller Introduction The present invention relates to a controller for synchronising different types of generator sets with a grid network, each type of generator set having different control inputs and each generator set connectable to a grid network and an operational unit and comprising a generator driven by an engine for producing electrical power for supply to the grid network and/or the operational unit, the controller being operatively connected to a generator set by a communications link for the transmission of engine control input signals for controlling the operation of the engine and generator control input signals for controlling the power generated by the generator.

Engine generators are commonly used in industrial type installations to provide a back-up power supply in the event of a mains or grid network failure. Such engine generators typically require a controller to monitor the mains supply and then bring the engine generator on-line when necessary so that an operative unit, such as an industrial plant, may be powered as required.

Increasing demand is being placed on the public grid network, and this demand has necessitated the use of private electricity systems for use in conjunction with the grid network. The use of engine generator systems, hereinafter ‘generator sets‘, as a means to provide such private electricity systems is also increasing. Such combined systems enable a variety of power sharing and saving schemes to be implemented, such as peak shaving, which effectively involves switching supply from the grid network to a private electricity system during periods of peak usage at which times the electricity supplied from the grid is most expensive.

However, in order for such combined systems to be implemented the voltage and phase angle of the generator set must be synchronised or matched with that of the grid network so that the generator can be seamlessly brought on-line as a load is transferred from the grid network. In this way, when the peak usage period is approached, the generator set may be started and run as required with the power generated being transferred to the operative unit, thereby providing considerable - 2 _ savings to operators during these periods.

However, large volumes of previously installed generator sets are not equipped for synchronisation with the grid network, with the result that such power saving schemes are unable to be implemented. Furthermore, obtaining the equipment required for synchronising a specific generator set with the grid network is problematic as quite often there is no such suitable equipment available. In other cases, the equipment that is available for that particular brand or make of generator set is prohibitively expensive to purchase and install.

It is a therefore one object of the present invention to provide a controller for synchronising different types of generator sets with a grid network which goes someway toward overcoming at least the above problems, and/or which will provide the public and/or industry with a useful choice.

It is acknowledged that the term ‘comprise’ may, under varying jurisdictions be provided with either an exclusive or inclusive meaning. For the purpose of this specification, and unless otherwise noted explicitly, the term comprise shall have an inclusive meaning — i.e. that it may be taken to mean an inclusion of not only the listed components it directly references, but also other non-specified components.

Accordingly, the term ‘comprise’ is to be attributed with as broader interpretation as possible within any given jurisdiction and this rationale should also be used when the terms ‘comprised’ and/or ‘comprising’ are used.

Further aspects of the present invention will become apparent form the ensuing description which is given by way of example only.

Statements of Invention According to the invention, there is provided a controller for synchronising different types of generator sets with a grid network, each type of generator set having different control inputs and each generator set connectable to a grid network and an operational unit and comprising a generator driven by an engine for producing electrical power for supply to the grid network and/or the operational unit, the controller being operatively connected to a generator set by a communications link for the transmission of engine control input signals for controlling the operation of the engine and generator control input signals for controlling the power generated by the generator characterised in that the controller comprises a master control unit having a plurality of interfaces, each of which interfaces are one of an engine controller interface and a generator controller interface, the engine controller interface for converting generic engine control signals output by the master control unit into engine control input signals, and the generator controller interface for converting generic generator control signals output by the master control unit into generator control input signals, the controller further comprising an operator control panel having means for selecting an engine controller interface and a generator controller interface corresponding to the control inputs required by the generator set connected to the grid network.

The provision of such a controller provides numerous advantages over the present situation in industry. In particular, the controller will be able to be installed for use with different generator sets, irrespective of the make, model or brand of generator set.

The controller will therefore be able to be retrofitted to facilities in which a generator set is already installed so that the generator set may be synchronised with the grid, thereby enabling peak shaving and other schemes to be implemented. Such a provision is specifically enabled by the present inventions use of an engine controller interface and a generator controller interface, each for respectively receiving and converting the generic engine control input signals and the generic generator control input signals from a master control unit into input control signals specific to the particular generator set installed.

In one embodiment of the invention, each engine controller interface further converts engine status feedback signals transmitted from the engine into generic engine feedback signals and each generator controller interface further converts generator status feedback signals transmitted back from the generator into generic generator feedback signals for processing by the master control unit.

Conversely, the ability for each interface to respectively convert engine status feedback signals as well as generator status feedback signals into generic feedback signals is advantageous as operators will be then able to monitor feedback from the generator set irrespective of the make, model and brand of the generator set.

In one embodiment of the invention, a plurality of engine controller interfaces and generator controller interfaces for a plurality of different generator sets are stored in and selectable from an interfaces database connected to the master control unit.

Preferably, the database comprises a look-up table of entries corresponding to available interfaces from which an operator selects the required engine controller interface and generator controller interface.

Storing the engine controller interfaces and generator controller interfaces for a plurality of different generator sets in a database having a look-up table function will provide operators with an efficient means for selecting the interfaces required for a particular generator set, thereby enabling synchronisation of the generator set with the grid. in one embodiment of the invention, the values of various operating parameters of the generator set are settable by the operator using the operator control panel.

Preferably, the operator control panel further comprises a digital display screen for displaying icons representing system status information including the magnitudes of the electrical power generated by the generator, the speed of the engine and the generic generator and/or the engine feedback signals.

Detailed Description of the Invention The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which: Fig. 1 is a stylised view showing a controller according to the invention.

With reference to Fig. 1, there is shown a controller, indicated generally by the reference numeral 1, for synchronising different types of generator set, one of which generator set is indicated generally by the reference numeral 2, with a grid network 3. it should be appreciated that the term ‘type’, in the context of generator sets, is being used in the specification to refer to the alternative brands, makes and models of generator set which are available.

Each generator set 2 is connectable to the grid 3 and an operational unit 4. The operational unit 4 shown represents a variety of entities, such as a building, or a sub- system within a building, for example, a lighting or ventilation system, which may be connected to the grid 3. Each type of generator set 2 has a plurality of different control inputs. For example, different brands, makes and models of generator set 2 are each configured to receive and process different inputs to implement the functions of the generator set 2.

Each generator set 2 comprises a generator 5 driven by an engine 6 for producing electrical power for supply to the grid network 3 and/or the operational unit 4. The controller 1 is operatively connected to the generator set 2 by a communications link 7 for the transmission of engine control input signals for controlling the operation of the engine 6 and generator control input signals for controlling the power generated by the generator 5. The engine control input signals should generally provide the input signals required for starting and stopping the engine, but may also include the input signals required by the engine for pre~glow control, air-start solenoid control, fuel solenoid control, crank time, crank delay time, crank repeats, crank fail alarms, idle/rated control, cool down control and/or emergency shutdown. Similarly, the generator control input signals should provide the input signals required by the generator for monitoring and regulating voltage, current and power factor, as well as real, reactive and apparent power. Further control input signals transmitted should protect the generator from over/under voltage and frequency, as well as frequency mismatch, loss of excitation, over/reverse power and over-current. In addition to the above, the controller 1 also monitors the grid network 3 to detect loss of supply.

Accordingly, the controller 1 will operate in conjunction with an engine speed controller on the engine 6 to control speed and load, and in conjunction with a voltage regulator associated with the generator to control voltage, power factor and current.

The controller 1 comprises a master control unit 8 having a plurality of interfaces, each of which interfaces are one of an engine controller interface 9 and a generator controller interface 10. Each engine controller interface 9 converts generic engine control signals output by the master control unit 8 into the engine control input signals which are required for processing by the specific engine 6 of the generator set 2 to implement the functions of the engine 6. Similarly, each generator controller interface converts generic generator control signals output by the master control unit 8 into the generator control input signals which are required for processing by the specific generator 5 of the generator set 2 to implement the functions of the generator 5. it should be appreciate therefore that the master control unit 8 generates generic input signals which are able to be used by any type of generator set, irrespective of brand, make and model, and the interfaces effectively convert these generic input signals into generator specific signals which can be processed by the specific generator set, that is, the generator and the engine, being used.

The engine controller interface 9 is further configured to convert engine status feedback signals transmitted back from the engine via feedback loop 12 into generic engine feedback signals which can be processed by the master control unit 8. For example, feedback signals relating to oil pressure and/or water temperature which are specific to the engine 6 will be transmitted to the engine controller interface 9, and converted into generic engine feedback signals for processing by the master control unit 8. Similarly, the generator controller interface 10 is also configured to convert generator status feedback signals transmitted back from the generator via loop 13 into generic generator feedback signals which can be processed by the master control unit 8. Such generator status feedback signals will generally comprise information relating to the voltage, current and power factor of the generator 5.

Also shown is an interfaces database 14 which is connected to the master control unit 8 in which a plurality of engine controller interfaces and generator controller interfaces fora plurality of different generator sets are stored in and selectable from.

The database 14 comprises a look—up table of available interfaces from which an operator selects the engine controller interface and generator controller interface required by the generator set 2 for converting the generic engine control signals into the engine control input signals for the engine 6 and the generic generator control signals into the generator control input signals for the generator 5.

The controller 1 further comprises an operator control panel 11 having means by which an operator may select an engine controller interface 9 and a generator controller interface 10 which correspond to the control inputs required by the generator set 2 connected to the grid network 4. Such a selection may alternatively be made automatically by the master control unit 8 sensing various properties of the control input signals required by the engine and generator. The operator control panel 11 may also be interacted with directly by an operator to be field programmable, or by a laptop, PDA or other computing device 15.

The operator control panel 11 also comprises a digital display screen for displaying icons representing system status information including the magnitudes of the electrical power generated by the generator 5, the speed of the engine 6 and the generic generator and engine feedback signals. The values of various operating parameters of the generator set 2 are also settable by the operator via the operator control panel 11 or the computing device 15, where such parameters are transmitted as the input control signals to the engine 6 and generator 5 as required. in use, the present invention will eliminate significant problems in the industry. The controller of the present invention is able to be retrofitted to previously installed generator sets so that synchronisation with a grid network can be achieved. Use of the controller will alleviate the requirement to re-install a new generator set in the event that the original manufacturer of the generator set is unable to provide the necessary equipment to facilitate synchronisation as the controller of the present invention is able to be used with any generator set, irrespective of make, model or brand.

Aspects of the present invention have been described by way of example only and it should be appreciated that additions and/or modifications may be made thereto without departing from the scope thereof as defined in the appended claims.

Claims (1)

1. CLAIMS A controller for synchronising different types of generator sets with a grid network, each type of generator set having different control inputs and each generator set connectable to a grid network and an operational unit and comprising a generator driven by an engine for producing electrical power for supply to the grid network and/or the operational unit, the controller being operatively connected to a generator set by a communications link for the transmission of engine control input signals for controlling the operation of the engine and generator control input signals for controlling the power generated by the generator characterised in that the controller comprises a master control unit having a plurality of interfaces, each of which interfaces are one of an engine controller interface and a generator controller interface, the engine controller interface for converting generic engine control signals output by the master control unit into engine control input signals, and the generator controller interface for converting generic generator control signals output by the master control unit into generator control input signals, the controller further comprising an operator control panel having means for selecting an engine controller interface and a generator controller interface corresponding to the control inputs required by the generator set connected to the grid network. A controller as claimed in claim 1, in which each engine controller interface further converts engine status feedback signals transmitted from the engine into generic engine feedback signals and each generator controller interface further converts generator status feedback signals transmitted back from the generator into generic generator feedback signals for processing by the master control unit. A controller as claimed in any preceding claim, further comprising an interfaces database having a |ook—up table of entries corresponding to available interfaces from which an operator selects the required engine controller interface and generator controller interface. A controller as claimed in any preceding claim, in which the values of various operating parameters of the generator set are settable by the operator using the operator control panel. A controller as claimed in any preceding claim, in which the operator control panel further comprises a digital display screen for displaying icons representing system status information including the magnitudes of the electrical power generated by the generator, the speed of the engine and the generic generator and/or the engine feedback signals. A controller substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.