Rts gmlc parser updates

[michaelbynum]

From @darrylmelander in the previous PR:

The new RTS-GMLC parser is targeted at reading a full set of data in RTS-GMLC format, and then generating multiple Egret models for various time spans within the read-in data.

Here are some of the parsing details:

• For branches, instead of using 'Cont Rating' for all three rating types, we now use:

  • rating_long_term: Cont Rating
  • rating_short_term: LTE Rating
  • rating_emergency: STE Rating

• For buses:

  • the bus name (system['bus'][{bus name}]) is 'Bus Name' (was 'Bus ID')
  • the bus "id" is now 'Bus ID' (was 'Bus Name')
  • generators now refer to the bus by name instead of ID (system['generator'][{gen name}]['bus'] = {bus name})

• Generators:

  • We omit the 'CSP' generator type
  • Because it only applies to CSP, we omit 'Natural Inflow' time series data

• Reserves:

  • Reserves are identified entirely by a naming convention. For system-wide reserves, we use this mapping:

  RTS-GMLC Name	Egret Name
  Spin_Up	spinning_reserve
  Reg_Up	regulation_up
  Reg_Down	regulation_down
  Flex_Up	flexible_ramp_up
  Flex_Down	flexible_ramp_down

  • For area-specific reserves, we add a suffix to the system-wide names, namely "_R{Area Name}", such as "Spin_Up_RArea1" for the spinning reserve for an area named Area1.
  • We don't get reserve information from anywhere other than timeseries_pointers.csv. We don't use reserves.csv. We could use the "Requirement (MW)" column in this file to populate the skeleton with static values, and then overwrite them if they have a timeseries associated with them. But we don't, so reserves are only included if they have a timeseries associated with them.

[michaelbynum]

From the previous PR, @bknueven said:

We don't get reserve information from anywhere other than timeseries_pointers.csv. We don't use reserves.csv. We could use the "Requirement (MW)" column in this file to populate the skeleton with static values, and then overwrite them if they have a timeseries associated with them. But we don't, so reserves are only included if they have a timeseries associated with them.

I would be in favor of this -- it's not necessarily unusual to carry static amounts of certain types of reserves, and I believe Egret should already support having a single MW value for every reserve type.