DESC:FORM 2

THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003

COMPLETE SPECIFICATION
(See Section 10 and Rule 13)

Title of invention:
POWER MANAGEMENT SYSTEM

Applicant:
Mazagon Dock Shipbuilders Limited
A company Incorporated in India under the Companies Act, 1956
Under Ministry of Defence,
(A Govt. of India Undertaking)
Having address:
Dockyard Road, Mazagon,
Mumbai - 400010, Maharashtra, India

The following specification particularly describes the invention and the manner in which it is to be performed.

CROSS-REFERENCE TO RELATED APPLICATIONS AND PRIORITY
[001] The present application claims priority from Indian Provisional Application 201821042946 filed on November 15, 2018.
TECHNICAL FIELD
[002] The present disclosure, in general, relates to the field of shipbuilding. More particularly, the present subject matter relates to power management system on a ship.
BACKGROUND
[003] The subject matter discussed in the background section should not be assumed to be prior art merely as a result of its mention in the background section. Similarly, a problem mentioned in the background section or associated with the subject matter of the background section should not be assumed to have been previously recognized in the prior art. The subject matter in the background section merely represents different approaches, which in and of themselves may also correspond to implementations of the claimed technology.
[004] The role of the electrical plant is very essential for powering any land based systems or marine vessels. The requirements of electrical power and its management in a warship is extremely critical, making the electrical plant the backbone of entire system, providing electrical power for all the systems including propulsion and weapons. The increasing levels of power, automation, and control in a warship require significant additional technological developments to keep pace with the requirements. The complexity of the control problem continuously demands new hardware structures and new tools for control development and testing of the power management systems.
[005] Referring to Figure 1, a typical power distribution system of a marine vessel is explained. The electrical power requirements in marine vessels such as ships are typically around 3.6 MW, which is generated by four Gas Turbine Generators (GTGs) (102). In addition to this, a 1 MW Diesel Alternator (DA) is located in Auxiliary Machinery Room (AMR) to cater to the blackout or dead bus or Hi-Load conditions. There is also an emergency generator located above the main deck to ensure that electric supply is available to emergency and safety systems, in case of a crisis. The power is consumed by numerous equipment spread across hull, engineering and electrical systems fitted on board. The electrical power generated needs to be distributed across the 165m long, 17.5m wide floating platform to meet the requirements of various electrical equipment functioning on-board. The intelligent and efficient use of the limited electrical power available is very crucial in a combat platform where numerous systems including weapons function with power redundancy requirements.
[006] The distribution of Electrical power inside a marine vessel, such as a Destroyer class ship, is effected through a complex network of power generators, power receivers and controllers. Two Main Switchboards (MSB's) (FWD & AFT) (104) located respectively at forward and aft side of the ship receives full power generated by the four GTGs (102) and the DA. The MSBs (104) acts as a hub where the power generated by the GTGs (102) is received and is further distributed to various Energy Distribution Centers (EDCs) (106) spread widely across the ship. Critical electrical loads like GT/GTG Auxiliaries, Weapons and major loads like AC plants, Air Compressor are fed directly from the MSBs (104). The EDCs (106) act as the source for the power supply to all the consumers either directly or through transformers to cater to the system loads. Most of the electrical loads are fed from normal and alternate supplies through Changeover Switches where if normal supply is from FWD Switchboard then alternate supply will be from Aft Switchboard and vice versa. The emergency generator and associated switchboard shall be completely isolated from the main machinery spaces.
[007] High level of redundancy is built into a warship's electrical systems. There are some machineries and equipment in the warships which needs to be always in running condition and requires frequent monitoring and controlling. Also, there is a need to constantly monitor the status of all loads and initiate some action (if necessary) based on the status. For this, all the data has to be made available on a single display in an Automatic Power Management System (APMS) (108) console. The data has to be transmitted to the APMS (108) along with every condition which makes it necessary to have robust network for communication. Hence, the redundancy in the communication network is extremely desired for smooth operation of warship.
[008] A dedicated system which shall encompass the distribution, control and management of the power generated is a pre-requisite for the efficient use of the limited electrical power generated within the ship and to ensure running of all critical loads at a given time. This demands an intelligent Power Management System (PMS). Power management entails the integration of the ship's electric plant and electrical load management with ship operations and machinery systems control as an automated control.
[009] Monitoring insulation of the electrical systems along with the other functional parameters is also an important activity which is performed as a health check in any electric system. The condition of the electrical insulation indirectly points to the reliability, availability, and integrity of complete electrical & instrumentation system in the ship.
[0010] In a nut shell, there are hundreds of equipment transmitting vast amount of data of several categories which needs to be supervised and controlled for precise performance of each equipment to achieve the collective functions of a floating weapon platform. The development and use of interfaces between different supervisory control elements on the ship is limited by their number and complexity. By making power management integral to the operation of any ship machinery control system, much greater gains can be made. The overall performance of a ship equipped with the power management capabilities in comparison with the one operating with redundant generator capacity and traditional load shedding in the event of a casualty, is much higher.
[0011] The Power Management System (PMS) is a group function which monitor and control the Electrical Power on board the vessel from Generators to the last consumer in each system based on a manner of integration of such systems. The PMS can be a separate system or can be integrated into a Ship Automation system. The PMS should have self-contained design using the state of art technology requiring minimum changes to the existing power equipment on-board and must also cater most adverse environmental and electrical conditions. The APMS (108) is typically employed for remote control and monitoring of generation and distribution of electrical energy right up to the EDC (106) level and to ensure continuous power supply to the ship’s systems, in accordance with the various operational conditions.
[0012] In most of the ships, the APMS consists of three Operating Consoles located in FWD, aft, and mid region of the vessel and five Remote Terminal Units (RTUs) located in various places on board. Data from the respective MSB and EDC is collected through data acquisition units, which is the RTU. The operating consoles have necessary control and monitoring facility whereas the RTUs act as the data acquisition units, collecting data from MSBs, EDCs, and DA. In Destroyer class ships, space is an important aspect, and hence availability of more open space in the passageways and lobbies for the men and material movement is most important. An RTU panel is a bulky structure, typically of size 812(W) x 1800(H) x 602(D), that makes it difficult to get the RTU mounted in a limited space available in TCR compartments and lobbies and consist of approximately 500 terminals. There are around 800-1000 in-out connections involved in each of the RTU. Massive efforts and lot of time is spent in executing these connections during the fit out of the vessel. Since lot of control connections are involved in the RTU, the possibility of mismatch in connection is very high and the fault finding exercise at STW stage is cumbersome, involving one to one tracking of connections with MSBs and EDCs. This delays the test and trial activity.
[0013] During the initial stage of design of the EDCs (106), when most of the loads are not finalized (such as in a warship), Over Load (OL) setting range has to be defined appropriately so that it can absorb the variation in the load at the final stages of the project when the system loads are finalized. At this point of time, the type of release used in the EDC’s (106) outgoing breakers plays an important role. In P15A, EDC Outgoing breakers with Thermal magnetic release are conventionally used which has limited setting range. This makes it difficult to accommodate any major change in the load during advanced stages of construction.
[0014] In most of the ships, the APMS (108) Consoles and RTUs are connected through Dual Redundant Ethernet network. Two Ethernet switches are mounted in the MCR console which provides a Switch level redundancy. Also, two separate Ethernet cables, one from Port Side and other from Starboard side, form two rings of the ethernet network. If one ring fails in operation, the data is transmitted through other ring, so the redundancy of the network is provided. Manual operating mechanism is used in the ships, for switching ON/OFF the breaker. It is observed that sometimes the need arises to switch off the supply of any particular load remotely through the APMS (108) due to occurrence of fault or during generator overload conditions. Also, the insulation fault monitoring is up to Switchboard level, in which it is possible only to know about the insulation fault occurrence. Exact EDC and specific outgoing feeder of the EDC can only be known with the help of a handheld device. Troubleshooting can be carried out only on dead Switchboard. The APMS console in most of the ships is larger in size as compared equipment mounted in it. Hence, there remains a need for motorized operating mechanism for easier operation along with more redundancy and extended insulation monitoring, wherein everything is optimized for occupying lesser space. Since all the control and monitoring functions materialize through the APMS consoles, it boils down to improved design of the consoles through developments in technology involved which is strongly required.

OBJECTIVES OF THE INVENTION
[0015] It is an objective of the invention to provide a power management system having a compact design.
[0016] It is another objective of the invention to provide a power management system that reduces Setting to work (STW) efforts.
[0017] It is yet another objective of the invention to provide a power management system that is cost effective, provides operational ease, and ease in troubleshooting.
[0018] It is still another objective of the invention to provide a power management system that provides a single point control and monitoring of entire system.
SUMMARY
[0019] Before the present power management system is described, it is to be understood that this application is not limited to the particular system, and methodologies described, as there can be multiple possible embodiments, which are not expressly illustrated in the present disclosures. It is also to be understood that the terminology used in the description is for the purpose of describing the particular implementations, versions, or embodiments only, and is not intended to limit the scope of the present application.
[0020] In one implementation, a power management system for marine vessels is disclosed. The power management system comprises Remote Terminal Units (RTUs) used as data acquisition units. The RTUs are built in respective Main Switchboards (MSBs), MSB-Distribution Panel, Energy Distribution Centres (EDCs), and Diesel Alternator (DA) Local Control Panel (LCP) to eliminate RTU Panels. All digital and analog input/output control signals are pre-wired to the RTU of respective MSB's and EDC's. Data communication from the MSB, EDCs and APMS is based on dual redundant Ethernet switches and dual Ethernet ports in the data acquisition unit (RTU). The EDCs Outgoing Breakers have motorized operating mechanism.
[0021] The EDCs comprise a plurality of Outgoing Breakers (MCCB) with microprocessor release for supplying power to all electrical components. The plurality of Outgoing Breakers (MCCB) is draw out type or plug out type. A module may be present for allowing mounting of the MCCB and connected to bus bar arrangement of the EDCs. The EDCs have a dimension of 1800mm(W)*1700mm(H)*600mm(D). The EDCs have a uniform structure to provide interchange ability to the plurality of MCCB for connection with the EDCs.
[0022] The power management system further comprises an Automated Power Management system (APMS) for remote monitoring and controlling input-output data of the MSBs, EDCs, and DAs. Two APMS consoles may be present in a Master-Slave configuration for processing data received from the EDCs and the MSBs. The power management system may further comprise an insulation monitoring system extended up to the EDCs level for providing On-line diagnostic insulation fault detection without requiring shutting down the EDCs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawing. For the purpose of illustrating the disclosure, there is shown in the present document example constructions of the disclosure; however, the disclosure is not limited to the specific methods and apparatus disclosed in the document and the drawing.
[0024] Figure 1 illustrates a power distribution system, in accordance with prior art.
[0025] Figure 2 illustrates an Automated Power Management system (APMS) architecture, in accordance with an embodiment of the current disclosure.
[0026] The figure depicts an embodiment of the present disclosure for purposes of illustration only. One skilled in the art will readily recognize from the following discussion that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles of the disclosure described herein.
DETAILED DESCRIPTION
[0027] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although a power management system, similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, power management system is now described.
[0028] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments for outside machining of web of submarine. However, one of ordinary skill in the art will readily recognize that the present disclosure of power management system is not intended to be limited to the embodiments described, but is to be accorded the widest scope consistent with the principles and features described herein.
[0029] In one embodiment, the power management system described by current invention provides several technological developments including data communication, operational ease, compact design, advanced operational features, insulation monitoring system, and aesthetics and ergonomics. All such technological developments are herein below described with reference to the current power management system (alternatively referred as P15B).
[0030] Data communication: In P15B, all the data acquisition units (RTU) are built in the respective MSB, MSB-Distribution Panel, EDC and DA LCP, thereby eliminating the RTU Panels. All the digital and analog input& output control signals are prewired to the RTU of respective MSB's and EDC's. This has resulted in the reduction of occupied space in FWD and AFT TCR's and lobbies.
[0031] The data communication from MSB, EDC and APMS is based on dual redundant Ethernet switches and dual Ethernet ports in the data acquisition unit (RTU). All the data in MSB's and EDC's need to be shared via dual redundant Ethernet based networks to the APMS system. Due to above change in the design, there is elimination of Control cable requirement by around 6-7 km making it an economical proposition. Consequently, freeing up of main run cable space. As all the MSB's and EDC's gets tested during FAT's in the OEM premises, the STW time requirement onboard has enormously reduced. Hence, service engineer requirements and other yard efforts in terms of laying cables on-board ship and connectorisation work are reduced by almost 80%.It is a true dual redundant ethernet network based on ethernet switches and dual ethernet ports in the RTU. No loss of APMS control due to single point communication failure. Trouble shooting has become much faster than earlier.
[0032] Operational Ease: Up gradation of the EDC Outgoing Breakers (MCCB) is done as follows:
[0033] Release Function in MCCB: Breakers with microprocessor release are used In P15B, which has some unique advantages and a comparison with existing power management systems (P15A) is listed below in the table:
P15A P15B
Feature Thermal Magnetic Release Microprocessor Release
Overload Current Range 0.8 - 1.0In 0.4 - 1.0In
Short Circuit Current Range 8In 2 - 8In
Range of Motors which can be connected to MCCB 42KW – 53KW 21KW – 53KW

[0034] In the above provided table, ‘In’ stands for Rated current.
[0035] Due to extensive coverage of OL and SC Current range, one Microprocessor can replace 3 types of Thermal Magnetic MCCB's. Hence there is less OBS and inventory of MCCB's. During initial stage when most of the loads are not finalized, allocation of loads to MCCB's became a difficult task since the Overload Current Setting range is so extensive that it can accommodate loads even if they vary by around 30-35% after finalization.
[0036] MCCB Operating Mechanism: The Outgoing breakers of EDCs are frequently needed to switch ON/OFF. In P15B, all the outgoing breakers of all the EDCs have motorized operating mechanism. This has resulted in increase of the APMS range of operation.
[0037] Compact Design: Energy Distribution Centre (EDC) consists of 1 incoming breaker and around 20-25 outgoing breakers. Each of the outgoing breakers can be either draw out type or Plug out type. A module is prepared by mounting MCCB on it and this module gets connected to the bus bar arrangement of the EDCs. In P1 5A, EDCs consisted of this kind of modules arranged in Left Hand side (LHS) and Right Hand side (RHS) structure. These EDCs are generally located in Passageways and lobbies for uniform distribution of power. Since the EDC are bulky and occupy a chunk of space, a lot of consideration was given in reducing the dimensions of EDC Panel since the reduction in size was going to effect at 14 locations inside ship. Also, access space for maintenance activity of EDC is reviewed. Consequently, the width is reduced drastically by 900mm without compromising the functionality of EDC. This made the interchange ability of MCCB's within the EDC or with other EDC, very easy.
[0038] Referring to Figure 2, an Automated Power Management system (APMS) architecture is now explained. The APMS is a graphical Operator Work Station (OWS) based remote control and monitoring system which monitors the input-output data of MSBs (202a, 202b) and EDCs (204). Inputs to PLC are the I/O signals from the MSBs (202a, 202b), EDCs (204), and DA (206) which get processed and displayed on APMS Console via 1 GB Ethernet network including Switches, Fibre Optic Cables, and CAT6 cable. The advanced features introduced in P15B are as follows:
[0039] Distributed Dual Redundant Architecture: In P15B, 10-port Ethernet switches are mounted in some of the EDCs, MSB Dist. Sections, and Consoles which are interconnected with each other through Cat6 cables to form two Rings of Ethernet Network (208a, 208b). Each equipment (EDC, MSB, and Console) is connected to these two rings (208a, 208b). If one ring fails in operation, data is transmitted through other ring, providing Ring level redundancy.
[0040] Two controllers provided in Master-Slave Configuration: The data from the EDCs and MSBs are processed and managed through a master PLC. In P15B, PLC's located in individual EDC's MSB's and DA's process the data which get processed and displayed on Console via Ethernet network. Apart from this, PLC's are also located in Control Station-1 (Fwd) and in Control Station-2 (Aft) which act in a Master-Slave Configuration which is configurable. This two PLC's are connected through Hot Stand by Link. In case the Master PLC fails, the Slave PLC comes in to operation preventing the System failure.
[0041] Increased range of APMS: In P15B, the reach of APMS has been increased and now APMS is able to monitor and control each outgoing feeder of EDC. In Pl5B, the reach of APMS has been increased and now APMS is able to monitor and control each outgoing feeder of EDC.
[0042] Insulation Monitoring System: In P15B, the Insulation monitoring system has been extended up to the EDC level with On-line diagnostic insulation fault without shutting down the EDC. Insulation fault of specific Outgoing feeder can be known with Hand Held Device. Interface to APMS for immediate attention in case of faults. This reduces the time for trouble shooting.
[0043] Aesthetics & ergonomics aspects of APMS console: Size of the console has been reduced by approximately 25% and more aesthetic & ergonomics aspects are taken in to consideration. The level of comfort in operating the console equipment has increased.
[0044] Exemplary embodiments for power management systems discussed above may provide certain advantages. Though not required to practice aspects of the disclosure, the following features may provide the multiple advantages:
[0045] In P15B, all the data acquisition units (RTU) are built in the respective MSB, MSB Distribution, Panel, EDC and DA LCP, thereby eliminating the RTU Panels. All the digital and analog input & output control signals are prewired to the RTU of respective MSB's and EDC's. This has resulted in the reduction of occupied space in FWD and AFT TCR's and lobbies.
[0046] In P15B, the reach of APMS has been increased and now APMS is able to monitor and control each outgoing feeder of EDC.
[0047] Currently described power management system provides a compact design. The data acquisition units i.e. the Remote terminal Units (RTUs) which get incorporated in the EDCs and MSBs itself in Pl5B provides savings in space, resulting in more open spaces in TCR's and lobbies.
[0048] Currently described power management system also provides reduction in Setting to work (STW) efforts. The requirement of control cables is reduced by around 6km. The efforts in laying the cables and connectorisation work have also reduced. Ultimately, the STW time is reduced by 80% which makes the system ready for trial much earlier. No manpower is required in the installation of the RTU Panel since it is completely eliminated from the system.
[0049] Currently described power management system also provides adaptability. Due to the use of microprocessor based MCCBs, virtually NIL modifications are now required which is otherwise essential at the later stages of the project which results in time and cost saving.
[0050] Currently described power management system is cost effective. Even though there is marginal increase in the cost of breakers, overall savings are enormous since the expenses for modification of EDC during advanced stages of the project are almost zero.
[0051] Currently described power management system provides operational ease. Due to usage of motorized breakers, it becomes possible to operate the EDC outgoing breakers through APMS.
[0052] Currently described power management system provides ease in troubleshooting. Detection and monitoring of insulation fault is extended from MSB level to the EDC level.
[0053] Currently described power management system provides decongestion. Due to distributed type of dual redundancy network, the availability of the APMS system for operation has increased making it more reliable and sustainable.
[0054] Currently described power management system provides reliability and sustainability. More reliable and sustainable APMS system is provided due to distributed type of redundancy network, thereby increasing the availability of the power distribution system.
[0055] Currently described power management system provides a single point control and monitoring of entire system, reducing operational efforts of a responsible electrical engineer.
[0056] Although implementations for power management system have been described in language specific to structural features and/or methods, it is to be understood that the appended claims are not necessarily limited to the specific features of power management system as described. Rather, the specific features are disclosed as examples of implementations of power management system.
,CLAIMS:
1. A power management system for marine vessels, comprising:
Remote Terminal Units (RTUs) used as data acquisition units, wherein the RTUs are built in respective Main Switchboards (MSBs), MSB-Distribution Panel, Energy Distribution Centres (EDCs), and Diesel Alternator (DA) Local Control Panel (LCP) to eliminate RTU Panels;
the EDCs comprising a plurality of Outgoing Breakers (MCCB) with microprocessor release for supplying power to all electrical components; and
an Automated Power Management system (APMS) for remote monitoring and controlling input-output data of the MSBs, EDCs, and DAs.

2. The power management system as claimed in claim 1, further comprising pre-wiring all digital and analog input/output control signals to the RTU of respective MSB's and EDC's.

3. The power management system as claimed in claim 2, wherein data communication from the MSB, EDC and APMS is based on dual redundant Ethernet switches and dual Ethernet ports in the data acquisition unit (RTU).

4. The power management system as claimed in claim 1, wherein the EDCs Outgoing Breakers have motorized operating mechanism.

5. The power management system as claimed in claim 1, wherein the plurality of Outgoing Breakers (MCCB) are draw out type or plug out type.

6. The power management system as claimed in claim 1, further comprising a module allowing mounting of the MCCB and connected to bus bar arrangement of the EDCs.

7. The power management system as claimed in claim 1, wherein the EDCs have a dimension of 1800mm(W)*1700mm(H)*600mm(D).

8. The power management system as claimed in claim 1, wherein the EDCs have a uniform structure to provide interchange ability to the plurality of MCCB for connection with the EDCs.

9. The power management system as claimed in claim 1, further comprising a Master-Slave configuration of two APMS consoles for processing data received from the EDCs and the MSBs.

10. The power management system as claimed in claim 1, further comprising an insulation monitoring system extended up to the EDCs level providing On-line diagnostic insulation fault detection without requiring shutting down the EDCs.