| Units: | - |
| Default Value: | 1 |
| Validation Rule: | ≥1 |
| Description: | Reduce the number of simulated periods by this factor in the first pass of a two-pass decomposition |
A two-pass temporal decomposition of the LT Plan optimization problem is available using this setting. The default value of one (1) means no decomposition is performed. Values greater than one trigger the decomposition, which proceeds as in two passes:
The 'high resolution' pass is performed at the resolution set out in the general LT Plan settings. For example, if you choose Sampled Chronology with one week per quarter, and hourly resolution, the high resolution pass will run at this resolution. The low resolution pass uses the same sampling but reduces the number of simulated blocks by the Decomposition factor. Continuing the example, if you set Decomposition to eight (8) then each modeled week in the low resolution run will have 168/8 = 21 periods.
Information is passed between the low resolution and high resolution passes that speeds up the solution search i.e. the low resolution pass should yield a feasible expansion solution which is a high quality starting point for the second pass. This can yield significant speed up to LT Plan especially for high temporal resolution models and difficult integer problems e.g. when Unit Commitment is co-optimized or the expansion tree search is difficult to solve.
This decomposition uses the same mechanism as Hint Units Built and Hint Units Retired on expansion classes like Facility, Generator, Battery, Line etc but automates the production of those hints using the low resolution pass. Hence the Performance Hint Mode applies.
Notes: