CHP Ramp Rate Limitation Option

[Bill-Becker]

This pull request introduces a new ramp rate constraint for Combined Heat and Power (CHP) systems, improves result reporting for curtailed electricity, and adds a new test scenario to validate these changes. The most significant updates are the implementation of CHP ramp rate constraints, enhancements to input parsing and result reporting, and the addition of a comprehensive nuclear battery scenario test.

CHP Ramp Rate Constraints:

• Added a new parameter ramp_rate_fraction_per_hour to the CHP struct and input parsing, allowing users to specify the maximum rate of change in CHP electric production per hour as a fraction of capacity. [1] [2]
• Implemented add_chp_ramp_rate_constraints in chp_constraints.jl to enforce ramp up and ramp down limits on CHP production between consecutive timesteps.
• Integrated ramp rate constraints into the main CHP constraint setup, activating them only when the ramp rate is less than the maximum possible per timestep.

Result Reporting Improvements:

• Updated add_chp_results to report curtailed electric output from CHP (electric_curtailed_series_kw) and subtract curtailment from the calculated CHP-to-load values for more accurate reporting.

Input Handling Enhancements:

• Improved the dictkeys_tosymbols utility to robustly convert numeric boolean values (0.0/1.0) to proper Bool types, preventing errors during input parsing.

Testing and Validation:

• Added a new test scenario file nuclear_battery.json and a comprehensive test script test_ramp.jl to simulate a nuclear-as-CHP system with ramp rate constraints and battery support, including plotting and result summaries. [1] [2]