* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Idaho Power Nomogram
Survey
Document related concepts
Stray voltage wikipedia , lookup
Pulse-width modulation wikipedia , lookup
Electric power system wikipedia , lookup
Three-phase electric power wikipedia , lookup
Electrification wikipedia , lookup
Variable-frequency drive wikipedia , lookup
Life-cycle greenhouse-gas emissions of energy sources wikipedia , lookup
Buck converter wikipedia , lookup
Switched-mode power supply wikipedia , lookup
Amtrak's 25 Hz traction power system wikipedia , lookup
Voltage optimisation wikipedia , lookup
Mains electricity wikipedia , lookup
Alternating current wikipedia , lookup
Transcript
A new Nomogram Development POMbased tool - Application results in the Idaho Power System. Orlando Ciniglio, IPC Marianna Vaiman, V&R Energy WECC TSS Meeting, Salt Lake City, UT January 20 - 22, 2015 1 OUTLINE 1. 2. 3. 4. Some background information What is a Nomogram? Basic Approach Case Studies – Midpoint West Vs COI Idaho – NW Vs Limiting element 5. Conclusions 2 Background Information • Large GI work prompted need to study interaction between existing path. • It was determined that new project could be accommodated on Midpoint West path and not impact existing transfer commitments as long as heavy COI flows N-S were not concurrent. • A 90% value for COI (only 10% of the time were COI flows greater than this value) was determined, for the time period of interest, based on historical records • It was determined that a Nomogram between these two Paths would help assess the potential interaction. 3 Generic Problem Outline • Want to find a Nomogram relation (boundary of operation) between two “Paths” subject to thermal, voltage, flowability and/or stability constraints. – “Paths” can be • • • • paths Single Line Generator(s) output Load(s) level – And observing limits in all other paths inside areas of interest • By controlling load and generation within pre-specified constraints in the areas of interest. • For points at or inside the Nomogram boundaries, system performance is acceptable (marginal at the boundaries) for all 4 credible outages. Generic Problem Outline (Basic Case) 5 Generic Problem Outline (Basic Case – cont) 6 The Concept of a Nomogram • Given: – The paths of interest (x & y axes), and • By utilizing: – A specified set of generators/loads in pre-defined areas • In general, all of the generators/loads in the areas; • The generation and loads in the selected areas are allowed to vary within a pre-defined range ( i.e., [Pmax,Pmin], [Lmax,Lmin], for each generator and load in the areas); • Determine: – The boundary of operation for simultaneous flows on both paths. Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 7 Basic Approach • Constraints for Source/Generators: Pmin for the generators (normally set to zero in the power flow cases) need to be adjusted so that the following condition is met: if(MinGenMW = 0, if(MaxGenMW > 0, min ( 0.5*MaxGenMW,MWGen),MinGenMW),MinGenMW) – where if(( condition=true) x,y), means logical statement is evaluated to x if condition is true, and to y otherwise. • Establishes [Pmax, Pmin] for generators to that may be adjusted in the process. 8 Basic Approach (cont) • Constraints for Sink/Loads: Load min, for each load in the areas of interest is defined as: • if(MinLoadMW=0,LDMIN*MIN(MaxLoadMW,MW),MinLoadMW) • Where LDMIN is a factor, normally set to 0.8 • MW = actual load level Load max, for each load in the areas of interest is defined as: • if(MaxLoadMW>0,LDMAX*MaxLoadMW,MaxLoadMW) • Where LDMAX is a factor, normally set to 1.15 • Establishes [Lmin,Lmax] for loads that may be adjusted in the process 9 How the Nomogram is Constructed in POM? • For a Path X flow that is not less than a given value: – Determines the required generation/load adjustments within their limits in the user-defined areas, to cause Path Y to be maximally increased until a violation (voltage/thermal/other path flows/stability) is found. – This will define one point on the nomogram. • Changes Path X flow by a given amount, and repeats this process to determine the corresponding Path Y level that can be reached before a violation is found. • Computes actual path flow limitations by using available generators/loads, within their user-defined limits Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 10 Nomograms vs. Boundary of Operating Region (BOR) • Two different computations: – BOR is AC transfer analysis simulation for 2 (or 3) simultaneous transfers – Nomograms is an optimization computation • BOR: – Sources and sinks are defined – Changes load/generation in sources and sinks until a violation of monitored constraints occurs – Computes flows on the interfaces (paths) • Nomograms: – Selects which combination of generators/loads to adjust and by how much from the specified list – Maximizes the interface (path) Y flow, while keeping interface (path) X greater than a given value, before reaching a violation Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 11 Input Data to Build a Nomogram • The following information is necessary to build a Nomogram: – – – – A Power Flow Case. Description of the two paths; flow on one of them is maximized. Description of other limiting paths with their flows limits. List of generators/loads that can be adjusted in order to maximize flows on selected paths, as well as their allowed variation range. • For example, for generators Pmin/Pmax specified in the base case can be used – Monitored elements (for voltage and thermal constraint monitoring) and limits. – Contingency list. – Solution options (enable/disable control of ULTCs, phase shifters, SVDs, etc.) Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 12 Output Files • Program outputs results of computations to four files • File #1: – The file contains information about the calculation step at which power flow through Path 1 reaches its maximum for a given limit value of power flow through Path 2. 1450 34 1280.77 1500 34 1280.77 – Each record contains three 1550 9 1277.86 space-delimited fields: 1600 27 1274.35 • Limit value of power flow through Path 2; • Step number; • Power flow through Path 1 calculated by script BuildNomogramFinal.txt. Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 13 Output Files (cont.) • File #2: – The file contains detailed information about the calculation step at which power flow through Path 1 reaches its maximum for a given limit value of power flow through Path 2. – The file consists of several types of records: • The first record contains: – Limit value of power flow through Path 2; – Step number; – Power flow through Path 1 calculated by script BuildNomogramFinal.txt. • The second record contains information about particular loads/generators used at calculation step listed in the first record, including bus number, generator/load ID, and the value of real power at this calculation step. • The last record contains a list of violations that limit increase in power flow through Result for 1000 15 1319.76 Path 1. 1 60077 1 56.52 1 60100 1 137.5 2 60151 1 76.68 Violation: Midpoint-Hemingway 500kV -1514.4 MW (not in -1500.0..1500.0) Swing Bus 1046.3 MW (not in 0.0..710.0) Copyright © 1997-2016 V&R Energy Systems Research, 14 Output Files (cont.) • File #3: – The file contains computation results for all steps at which power flow through Path 1 is computed for a given limit value of power flow through Path 2. – File format is the same as the file format shown above. • Program also creates and saves new Power Plow Cases in .epc format for each point on the nomogram: – User defines which point(s)/step(s) to save. Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 15 Graphical Output: POM Nomograms • Nomograms are built automatically: – In this example, computations are done with a 50 MW step Voltage/Thermal Constraint Not Monitored Voltage Constraint Monitored / Thermal Constraint Not Monitored Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 16 Conclusions • The process is automated • Computes and plots the entire boundary, not just one single point • Identifies the mix of generation and loads that should be used to maximize the path flow – Optimization algorithm allows to maximize path flow Copyright © 1997-2016 V&R Energy Systems Research, Inc. All rights reserved. 17 18 Case Study #1 • Want to find a Nomogram relation between Midpoint West and COI (N-S) flows, subject to: – Midpoint – Hemingway < 1500MW – Hemingway – Summer Lake < 1500MW – COI flow >= 1920MW ( North to South). – And observing limits in all other Paths inside areas of interest • By controlling load and generation within pre-specified constraints in the areas of interest: 19 – – – – – – – – 60 Idaho 62 Montana 64 Sierra 65 Pace 40 Northwest 30 PG & E 26 LADWP 73 WAPA R.M. Midpoint West Vs COI 20 COI flows > ~1930MW (10% of the time under light load hours) 21 Midpoint West / COI Nomogram (no voltage/no thermal constraints) 22 Midpoint West / COI Nomogram (voltage/no thermal constraints) 23 Midpoint West / COI Nomogram (voltage and thermal constraints) 24 Questions ? 25