Ratings Provider Submitting Directional Ratings to TROLIE
Most lines only require a single set of rating values that apply irregardless of the direction that energy is flowing. However, for a some lines, Transmission Providers may require separate “directional” ratings that differ depending on the direction energy is flowing.
Directional ratings are supported in TROLIE by exposing separate
resources, both in terms of TransmissionFacilities and Segments, to
represent different rating directions. The names used for these resources are
ultimately up to the TROLIE implementation. The following two examples show some
contrasting styles for naming these resources. Both are equally valid, and are
provided here only as examples.
With “Named Direction”-Style Naming
One common style, such as that supported by the GE Vernova EMS, is to represent
rating directions by specifying an arbitrary in and out direction on a line,
typically representing the most common flow of energy in and out of a load pocket,
control area or other logical grouping of the transmission network.
This is illustrated by the following forecast proposal example:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
{
"proposal-header": {
"source": {
"last-updated": "2024-03-5T15:05:43.044267100-07:00",
"provider": "X-AMPL-TO"
},
"default-emergency-durations": [
{
"name": "emergency",
"duration-minutes": 60
}
],
"power-system-resources": [
{ "resource-id": "segmentA-in" },
{ "resource-id": "segmentA-out" }
]
},
"ratings": [
{
"resource-id": "segmentA-in",
"periods": [
{
"period-start": "2025-11-02T01:00:00-05:00",
"period-end": "2025-11-02T02:00:00-05:00",
"continuous-operating-limit": {
"mva": 160
},
"emergency-operating-limits": [
{
"duration-name": "emergency",
"limit": {
"mva": 165
}
}
]
}
]
},
{
"resource-id": "segmentA-out",
"periods": [
{
"period-start": "2025-11-02T01:00:00-05:00",
"period-end": "2025-11-02T02:00:00-05:00",
"continuous-operating-limit": {
"mva": 161
},
"emergency-operating-limits": [
{
"duration-name": "emergency",
"limit": {
"mva": 165
}
}
]
}
]
}
]
}
With “Point to Point”-Style Naming
An alternative style could be to name the resources as a concatenation
of the identifiers on each end, with the order of the identifiers indicating the
direction of the flow. Consider two substation buses, with the very simple identifiers
BusA and BusB. These are used to illustrate point-to-point naming in the following forecast
proposal example:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
{
"proposal-header": {
"source": {
"last-updated": "2024-03-5T15:05:43.044267100-07:00",
"provider": "X-AMPL-TO"
},
"default-emergency-durations": [
{
"name": "emergency",
"duration-minutes": 60
}
],
"power-system-resources": [
{ "resource-id": "BusA-BusB" },
{ "resource-id": "BusB-BusA" }
]
},
"ratings": [
{
"resource-id": "BusA-BusB",
"periods": [
{
"period-start": "2025-11-02T01:00:00-05:00",
"period-end": "2025-11-02T02:00:00-05:00",
"continuous-operating-limit": {
"mva": 162
},
"emergency-operating-limits": [
{
"duration-name": "emergency",
"limit": {
"mva": 165
}
}
]
}
]
},
{
"resource-id": "BusB-BusA",
"periods": [
{
"period-start": "2025-11-02T01:00:00-05:00",
"period-end": "2025-11-02T02:00:00-05:00",
"continuous-operating-limit": {
"mva": 163
},
"emergency-operating-limits": [
{
"duration-name": "emergency",
"limit": {
"mva": 165
}
}
]
}
]
}
]
}