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Strategy. Identify links between electricity needs in the future and available renewable resources.Optimize development and deployment of renewables based on their benefits to:Electricity systemEnvironmentLocal economiesDevelop a research tool that integrates spatial resource characteristics an
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1. Strategic Location of Renewable Generation Based on Grid Reliability PowerWorld Users Group Meeting
November 2-3, 2005
The CALIFORNIA ENERGY COMMISSION and DAVIS POWER CONSULTANTS contributed to the development of this analysis.
2. Strategy Identify links between electricity needs in the future and available renewable resources.
Optimize development and deployment of renewables based on their benefits to:
Electricity system
Environment
Local economies
Develop a research tool that integrates spatial resource characteristics and planning analysis.
3. Objectives Investigate the extent to which renewable distributed electricity generation can help address transmission constraints
Determine performance characteristics for generation, transmission and renewable technology
Identify locations within system where sufficient renewable generation can effectively address transmission problems
4. Objectives We want to determine the impact of large-scale distributed projects on grid security.
We need to:
Identify weak transmission elements and define metrics that assess system security.
Find locations where new generation would enhance the security of the grid.
Combine maps of beneficial locations with maps of energy resources.
5. Methodology Simulation
Power Flow
Contingency Analysis
Security Metrics
Results
Weak Elements
Security Indices
Visualization
6. Power flow Simulation Identify weak elements in the system by simulating impacts from lost transmission or capacity (NERC N-1 contingency)
More importantly, can identify locations in system where new generation can provide grid reliability benefits. Included project just to center the presentationIncluded project just to center the presentation
7. Normal Operation Example Mention here that putting generation at bus # 3 requires reducing generation somewhere else.Mention here that putting generation at bus # 3 requires reducing generation somewhere else.
8. Contingency Example Mention here that putting generation at bus # 3 requires reducing generation somewhere else.Mention here that putting generation at bus # 3 requires reducing generation somewhere else.
9. Contingency Analysis Security is determined by the ability of the system to withstand equipment failure.
Weak elements are those that present overloads in the contingency conditions (congestion).
Standard approach is to perform a single (N-1) contingency analysis simulation.
A ranking method will be demonstrated to prioritize transmission planning.
11. Weak Element Visualization
12. Determination of Good Locations
13. Determination of Good Locations Generation could be located to produce counter-flows that mitigate weak element contingency overloads.
The new injection of power requires decreasing generation somewhere else.
A good assumption is that generation will be decreased across the system or each control area using participation factors.
14. TLR for Normal Operation Need to know how the new generation at a certain bus will impact the flows in a transmission element.
? Transmission Loading Relief (TLR)
16. TLR for Contingencies Need to consider contingencies
Contingency Transmission Loading Relief (TLR) Sensitivity is the change in the flow of a line due to an injection at a bus assuming a contingency condition.
17. Determination of Good Locations Equivalent TLR (ETLR):
18. Determination of Good Locations Weighted TLR (WTLR) using post-contingency TLRs:
19. Weighted TLR (WTLR) Complexity: A TLR is computed for each bus, to mitigate a weak element, under a contingency.
We want a single weighted TLR for each bus.
20. Calculating WTLRs The contingency information (severity and number) of a weak element can be captured by calculating the Aggregate MW Contingency Overload (AMWCO).
This effectively converts the cube to a table.
21. Calculating WTLRs Need to mitigate the weakest elements first
Weight the TLR by the weakness of each element, which is given by the AMWCO.
22. Meaning of the WTLR A WTLR of 0.5 at a bus means that 1MW of new generation injected at the specific bus is likely to reduce 0.5 MW of overload in transmission elements during contingencies.
Thus, if we inject new generation at high impact buses, re-dispatch the system, and rerun the contingencies, the overloads will decrease.
Note that the units of the WTLR are:
23. Large Case Example Project for the California Energy Commission (CEC).
Needed to simulate N-1 contingencies (about 6,000 for California)
Simulation developed for 2003, 2005, 2007 and 2017 summer peak cases.
In 2003, there were 170 violating contingencies, 255 contingency violations, and 146 weak elements.
24. Process Overview
25. Result: Weak Element Distribution This is a terrific result that shows both the increase in number of hot spots and their severity
It also indicates that considerable mitigation can be achieved by attaching the most severe hot spots (that is why we need to weight the TLRs later on.This is a terrific result that shows both the increase in number of hot spots and their severity
It also indicates that considerable mitigation can be achieved by attaching the most severe hot spots (that is why we need to weight the TLRs later on.
26. Identification of Weak Elements I like this one, is better than just mentioning the participation of everybody.I like this one, is better than just mentioning the participation of everybody.
27. Good Locations New generation at green locations will tend to reduce the overloads.
New generation at red-yellow locations will tend to increase the overloads.
Note that higher imports would worsen system security.
28. Local WTLR Visualization
30. Towards a Locational Value Determination of locations where new generation would enhance security needs to be combined with availability and economics of energy resources.
Valuation requires monetizing the security benefits.
31. Towards a Locational Value GIS spatial analysis techniques are needed to determine feasible generation alternatives for each location in a large-scale system.
32. Towards a Locational Value Units of WTLR are [AMWCO/MW installed].
The security cost/benefit can be obtained as follows:
Assume WTLR is negative: Injection reduces the AMWCO
33. Security-Penetration Curves Once a set of proposed sites is defined, the effect of simultaneous distributed injections with different levels of penetration can be simulated using security-penetration curves.
The effectiveness of the solution is affected for large injections due to:
Local transfer capability of the grid
Reversed flows
This is the most important result of the whole presentation. So we need to take time here.
We define the penetration index as the fraction of the WTLR sensitivity per bus, in those that have a high WTLR.
This results in a certain amount of generation installed in the system. The balancing generation will be reduces proportionally to participation factors in all California.
The system reliability indicator is the System Aggregate MW Overload.
Note that the new generation increases LINEARLY because it is proportional. The effectiveness though is NONLINEAR. We can explain why this is the case.This is the most important result of the whole presentation. So we need to take time here.
We define the penetration index as the fraction of the WTLR sensitivity per bus, in those that have a high WTLR.
This results in a certain amount of generation installed in the system. The balancing generation will be reduces proportionally to participation factors in all California.
The system reliability indicator is the System Aggregate MW Overload.
Note that the new generation increases LINEARLY because it is proportional. The effectiveness though is NONLINEAR. We can explain why this is the case.
34. Security-Penetration Curves This is the most important result of the whole presentation. So we need to take time here.
We define the penetration index as the fraction of the WTLR sensitivity per bus, in those that have a high WTLR.
This results in a certain amount of generation installed in the system. The balancing generation will be reduces proportionally to participation factors in all California.
The system reliability indicator is the System Aggregate MW Overload.
Note that the new generation increases LINEARLY because it is proportional. The effectiveness though is NONLINEAR. We can explain why this is the case.This is the most important result of the whole presentation. So we need to take time here.
We define the penetration index as the fraction of the WTLR sensitivity per bus, in those that have a high WTLR.
This results in a certain amount of generation installed in the system. The balancing generation will be reduces proportionally to participation factors in all California.
The system reliability indicator is the System Aggregate MW Overload.
Note that the new generation increases LINEARLY because it is proportional. The effectiveness though is NONLINEAR. We can explain why this is the case.
35. Policy Analysis A fundamental goal of integrated electricity systems is to ensure dependable supply to customers.
This goal cannot be achieved if the system consistently exhibits overloaded elements and congestion.
System AMWCO can be utilized to:
Evaluate system security for different seasons/years
Design policy goals regarding security
Can use security-penetration curves
This is the most important result of the whole presentation. So we need to take time here.
We define the penetration index as the fraction of the WTLR sensitivity per bus, in those that have a high WTLR.
This results in a certain amount of generation installed in the system. The balancing generation will be reduces proportionally to participation factors in all California.
The system reliability indicator is the System Aggregate MW Overload.
Note that the new generation increases LINEARLY because it is proportional. The effectiveness though is NONLINEAR. We can explain why this is the case.This is the most important result of the whole presentation. So we need to take time here.
We define the penetration index as the fraction of the WTLR sensitivity per bus, in those that have a high WTLR.
This results in a certain amount of generation installed in the system. The balancing generation will be reduces proportionally to participation factors in all California.
The system reliability indicator is the System Aggregate MW Overload.
Note that the new generation increases LINEARLY because it is proportional. The effectiveness though is NONLINEAR. We can explain why this is the case.
36. Policy Analysis
37. Policy Analysis
38. Integrated Model