GUYANA POWER AND LIGHT INC

Transcription

1 GUYANA POWER AND LIGHT INC The Terms of Reference REQUEST FOR PROPOSALS: CONSULTANCY SERVICES COORDINATING GENERATOR PROTECTION WITH TRANSMISSION PROTECTION AND GENERATOR CONTROLS (GPL-PI ) November 2016 Closing Date: January 24, 14:00 hours or 2:00pm Opening Date: January 24, 14:30 hours or 2:30pm Page 1

2 STANDARD REQUEST FOR PROPOSAL SELECTION OF CONSULTANTS/FIRM CONSULTANCY SERVICES COORDINATING GENERATOR PROTECTION WITH TRANSMISSION PROTECTION AND GENERATOR CONTROLS Page 2

3 3 Contents Scope of Consultancy Services Evaluation and Qualification Criteria...11 Commercial Terms....12

4 GUYANA POWER AND LIGHT INC REQUEST FOR PROPOSALS: CONSULTANCY SERVICES GPL-PI The Guyana Power and Light Inc. hereby invite eligible Consultancy Firms to submit bids to provide Consultancy Services for Coordinating Generator Protection with Transmission Protection and Generator Controls. The services to be provided include: a) Inception Meeting & Data Preparation b) Short-Circuit Analysis c) Coordinating Generator Protections with Transmission Protection and Generator Controls d) Preparation of Reports Prospective Consultants are required at this stage to submit technical and financial proposals for providing all of these services. The Terms of Reference can be obtained from Secretary - Procurement and Inventory Accounting Manager, Guyana Power & Light Inc, 40 Main Street Georgetown for a non refundable fee of Three Thousand Guyana Dollars (GY$3,000). A copy can also be downloaded from our web site Interested Consultants may obtain further information from the System Planning and Design Manager, Guyana Power & Light 257/259 Middle Street, Cummingsburg, Georgetown, Tel or at hwoolford@gplinc.com Qualification requirements include valid Income Tax, NIS Compliance Certificates and Business Registration Sealed proposals must be delivered on or before January 24, 2017 at 14:00 hours to The Secretary to the Tender Board and labeled as follow: Consultancy Services for Coordinating Generator Protection with Transmission Protection and Generator Controls, The Secretary to the Tender Board, Guyana Power & Light, 91 Duke Street, Kingston GPL - PI Opening of proposals is schedule for 14:30hrs (2.30 pm) on January 24, 2017 in GPL s Board Room, 91 Duke Street, Kingston in the presence of consultants or their representatives who choose to attend in person. Interested Consultants downloading the Terms of Reference are advised to forward a registration to procurementofficer@gplinc.com or supv_procurement@gplinc.com stating the following: Name of bidder, Address, Contact No. and address. The Guyana Power & Light is not obligated to accept the lowest or any proposal Page 4

5 Coordinating Generator Protection with Transmission Protection and Generator Controls Scope of Consultancy Service Brief Summary of GPL System Development and Expansion In 2013, the Guyana Power & Light Inc. (GPL Inc.) invested in a US $42M Infrastructural Development Program (IDP) that realized the construction of seven (7) new 69/13.8 kv substations and installation of a new 69/13.8 kv substation transformer. This program included a total installation of MVA of transformer capacity, km of 69 kv transmission lines and km of ADSS fiber optic cable for the SCADA supported system. Central Georgetown and a few villages on its outskirts were once operating at 50Hz. Subsequently a Frequency Conversion Project-Phase 2 was initiated with the injection of US$9M to convert from 50Hz to 60Hz. This project was completed in As part of the Frequency Conversion Project- Phase 2, a 22 MW Wärtsilä Power Plant was converted to 60Hz. In addition, a 26 MW, HFO fired Power Plant was commissioned at Vreed-en-Hoop at a cost of US$ 29M in With the combined system and significant other changes in transmission and distribution network topology, the need to perform a protection coordination study became vital as it relates to further improvements in system reliability and security for the Demerara Berbice Interconnected System (DBIS). In addition with an updated load forecast, changes in system line loading and voltage profiles were observed. Such changes can likely affect the timing of the future system reinforcements that were presented in an initial interconnection study report of In order to provide guidance for future reinforcements, an update to the system planning (interconnection) study was proposed. This update focused on the steady state analysis, line loading and voltage levels to establish when action would need to be taken to maintain the overall system integrity. The short-circuit analysis was also updated to ensure that the breaker duties were not exceeded due to the significant changes made to the system by the said IDP. For the interconnection study update, stability analysis was not performed since in the said initial interconnection study, no stability issues were found under a range of load and generation patterns, and contingency conditions. GPL Inc. subsequently entered into a contractual agreement on January 26, This agreement resulted in obtaining improved protection settings for the 69kV system, that is, to protect the transmission lines and substation transformers. The updated interconnection study was focused on addressing the following points to ensure that GPL s system improvements over the past three years will meet GPL s overall objective of providing electric service to the citizens of Guyana in a reliable manner: Page 5

6 1. Update the transmission planning studies for the immediate (2014) and medium term (2020), reflecting investments in the system and the latest load forecast. 2. Based on the above, protection coordination analysis was conducted on the 69kV transmission system and Substation and Generator Step-Up (GSU) transformers. Summary of Generator Protections, Control Status and Needs Mal-operation of generator protections during major system disturbances; with the new protection settings for the transmission system implemented, have brought to light the need for better coordination of generator protection with generator s capability, Automatic Voltage Regulator (AVR) control and the transmission system protections. Generator protections should be secured during frequency fluctuations and low voltage system conditions, while still providing the required degree of protection to the generators, during disturbances in the power system. The generator AVR needs to properly control VAr support to rapidly stabilize system voltage, while at the same time, the engine Governor and Power System Stabilizer (PSS) should be able to maintain frequency stability during major system disturbances and prevent unnecessary operation of generators protection devices. The following task outline summarizes the processes which the Consultant should follow to address the scope of work which GPL has outlined: 1. Inception Meeting & Data Preparation 2. Short-circuit Analysis 3. Coordinating Generator Protections with Transmission Protection and Generator Controls 4. Draft and Final Report Task 1: Inception Meeting and Data Preparation Inception Meeting With enough time in advance to the Inception Meeting, the Consultant shall prepare an information request document. The objective of this request is to allow GPL to prepare and organize the requested information with some time in advance to the inception meeting. Upon project startup, the Consultant shall attend the Inception meeting with GPL team to: Page 6 1. Establish communication channels; key contacts, reporting frequency and procedures. 2. Clarify the study methodology, process, assumptions, and reporting needs. 3. Refine the scope of work and schedule, if necessary. 4. Discuss the data needs. Subsequent to this meeting, GPL will provide substantially all the data necessary for project initiation. This data includes but not limited to the following:

7 1. Current transmission system data in form of PSS Sincal compatible files and/or Microsoft Excel format, with existing protection settings. This data will include the following: a. Identification of all existing 69 kv substations in the system as well as those 13.8 kv substations that create parallel paths with the 69 kv system. b. Transmission line impedances and charging (positive and zero sequence), ratings (normal and emergency) for all lines in the system at 69 kv and those at 13.8 kv (if any) that create a parallel path with the 69 kv system. c. Transformer data including impedances, number and range of taps, control mode (load or off load), vector group, connection to ground and ratings. d. Protection Settings for Transmission lines, Substations and GSU Transformers. e. Equivalent loads to be modeled at the 13.8 kv side of the substations and generator bus bars. f. Location of reactive compensation in the system. g. Interrupting capability of 69 kv breakers in the system. 2. Current Power Generation System in Microsoft Excel format, with existing protection settings. This data will include the following: a. Single Line Diagram of Power Plants with layout of existing Protection Scheme. b. Protection Settings for all Generators. c. Technical Specifications for Generator and Alternators. 3. Information on proposed system changes/expansion schedules and in particular dates and details for the integration into the DBIS. Note, for cost efficiency this meeting would have to be conducted via conference call and WebEx facilities to make presentations, in the case of an overseas Consultant. After five (5) business days of the said meeting an inception report shall be prepared and delivered to GPL Inc. This report shall summarize the agreements reached in the inception meeting and shall include any update to the propose work schedule and approach to the initial information request. Task 2: Short Circuit Analysis The Consultant shall conduct short circuit analysis using the sequence data obtained in the data gathering and model. The Consultant shall determine the three phase and single phase currents (symmetric, asymmetric and DC component) as necessary on the GPL system. The short circuit current will be determined in the most conservative configuration characterized by most generation online. The short circuit levels shall be calculated using PSS Sincal and will be based on ANSI standard C The Consultant shall compare the results of this study with the short-circuit withstand ratings of existing equipment in the each power plant for each generator. In addition, in the event of underrated Page 7

8 equipment, the Consultant shall provide recommended ratings for breakers, bus bars etc. for each power plant in the report. Task 3: Coordinating Generator Protection with Transmission Protection and Generator Control The Consultant shall analyze the electrical system with given data and verify that coordination exists among generator and transmission line protections; and generator control, inclusive of generator bus bar protection. The Consultant shall, in addition, propose modified settings as required to achieve coordinated operation of the protection schemes and generator control (Automatic Voltage Regulator (AVR), Power System Stabilizer (PSS), etc). Coordination as defined by IEEE Standard C37.113, is The process of choosing settings or time delay characteristics of protective devices such that operation of the device will occur in a specified order to minimize customer service interruption and power system isolation due to a power disturbance. In terms of Generator-Transmission Protection Coordination, the generator protection should not trip for faults on the transmission system unless the transmission system primary and back-up protection fails to eliminate system element(s) associated with the fault to reduce contributing fault currents. Additionally, the generator protection and control should not trip for stable transient voltage reductions and power swings. All calculations and coordination procedures shall be done in accordance with IEEE Standard C For each generator, the voltage regulator controls and limits functions such as over and under excitation and volt/hertz limiters. The Consultant shall ensure that these relays are coordinated with the generator s short duration capabilities and all other associated protective relays. The protective relays for both generation and transmission systems shall be coordinated and AVR control shall be coordinated with generator protective relays. The results shall be documented in tables and diagrams showing the coordination all relays and generator control. Task 3a-Coordiantion of Generator and Transmission System Protections In the generation system, protection functions offered by digital relays are provided by Vamp 210, Spad 330 and Spam 150C (together) and GPU 2000R. In the case of protection functions offered by electromechanical relays these are provided by Canadian General Electric, Westinghouse and Toshiba relays. The Consultant shall perform all necessary calculations to determine the correct settings for the aforementioned generator protection relays such that coordination can exist with the transmission system protection relays. Page 8

9 The Consultant shall also note the presence of the under impedance relay (21B) and voltage restrained/controlled phase overcurrent (51V) in some of the relays. These are commonly known as system back-up protection. In the case of relay 21B, it is also important to note that the protection of the transmission system is based on distance protection. The settings for these relays (21B and 51V) shall be calculated to respond to faults on the transmission system and their tripping shall be delayed to allow the transmission system protection to first clear the fault. As it relates to undervoltage protection relay (27), the settings for this relay shall be determined as per IEEE Standard C to ensure correction operation during system disturbances. The Consultant shall ensure that the loss of field protection relay (40) is coordinated with the generator capability curve, AVR under excitation limiter (UEL) and steady state stability limit. Task 3b-Coordination of Generator Protection with Generator Control During system disturbances which can result in stress conditions for the generator control system, the AVR limits (under and over excitation) can be frequently challenged when system conditions such as voltage collapse or steady state stability limits are approached. The Consultant shall ensure: 1. AVR limiters (UEL and OEL) are coordinated with the generator capability, steady state stability limits and loss of field relays. 2. Power System Stabilizers settings can respond in conjunction with the AVR to provide positive damping in the event of power oscillations. The Wärtsilä generators have the following control mode for Engine and Generator: 1. Engine Control Modes a. Speed Droop b. True kw Control c. Isochronous Load Sharing 2. Generator Control Modes a. Voltage Droop Compensation b. Power Factor Control The Consultant shall advice on the selection criteria for the most suitable/appropriate control mode of operation to be assigned for engine and generator to ensure stable operation of the generators during system disturbances and to avoid mal-operation of generator and transmission protection relays. Task 4: Draft and Final Reports The Consultant shall prepare interim memo/reports at the end of each of the above task, a comprehensive draft report, and a final report to document the results and recommendations, power system models, methodology, calculations and results of the work. In addition, the Consultant shall Page 9

10 prepare presentations to show progress of work, results and findings to GPL for review and feedback. Software model(s) should be provided along with reports during the review process. The final report shall include but not limited to the following sections: 1. Introduction, executive summary and recommendations, assumptions, impedance one line drawing, and copies of the project one line drawings. 2. Descriptions of short circuit studies illustrated with diagrams, tables, exhibits, graphs and charts. 3. Tabulations of equipment ratings versus calculated short circuit values and X/R ratios, and commentary regarding same. 4. Protection coordination curves, generator capability curve coordinated with R-X impedance diagrams, tabulations of relay, circuit breaker trip settings. 5. Relays specifications. 6. Parameters of models used in various studies. 7. Copy of model(s) used to perform studies. Page 10

11 Evaluation and Qualification Criteria Composition of Consultancy Team The team shall consist of the following experts with the relevant experience and tools at its disposal to achieve the objectives of the project. 1. Project Manager 2. Power System Protection Specialist Qualification of Consultants Consultant team shall have the following expertise: Software 1. Minimum of 15 years working experience in conducting electric power system studies, power system protection and coordination studies and generator interconnection studies. Preference shall be given to organization that has been involved entirely in power system protection studies, especially in the area of generator protection and control, and transmission protection schemes. 2. Certified Professional education in the aforementioned technical areas. 3. Minimum of 15 years working experience in power system protection coordination in power plant, utility transmission and distribution system. 4. Experience in international electric projects (preferably in developing/emerging economies) 5. Proficiency (oral and written) in English Language. All software modeling and simulations shall be performed and completed using PSS Sincal 12. During the review stages GPL should be able to utilize the model(s) developed by the Consultant to explore, analyze and compare results obtained from the study. Project Duration The expected duration of this project should not exceed 120 working days. Bidder s submission must have a detail work schedule, clearly indicating start and end period for each scope of work. Page 11

12 Commercial Terms Budget The proposed tasks described above shall be performed on a fixed price basis. The analyses described in Scope of Consultancy Service will be performed for a fixed price of US$..., ( Dollars) Schedule The base schedule for this study project assumes, for scheduling purposes, that. will be the start date and that the project has a total duration of weeks. Bill of Quantities Item No. Task Initial Scope meeting / Preparatory 1 Activities 2 Short circuit Analysis Coordinating Generator Protection with 3 Transmission Protection and Generator Control Coordination of Generator and Transmission 3.1 System Protections Coordination of Generator Protection with 3.2 Generator Control 4 Final Report 5 Project Management Total Amount (US$) Week Page 12