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Electrical consumption

Given

If available, user should send the electrical consumption of his components or devices in Watt/hour (avg_power). Since the power will be extrapolated on the all duration, the power given should be the average power of the device or component over the given duration.

Completed from the archetype.

If available, the API will complete the missing electrical consumption by the electrical consumption of the archetype of the asset.

Modeling

Sometime user doesn't have access to the electrical consumption of their component or device, and we don't want to use a default value taken from an archetype.

If so, the API can use the percentage of component' or device' resource usage as a proxy for the electrical consumption. We refer to this percentage as a workload of the component or device. The API is able to convert a workload into a power consumption with consumption profiles.

To learn more about how we build consumption profile see consumption profile page.

Using consumption profile

Workload are given by the user as a percentage of the maximum workload.

An average workloads can be given. A workload of 10% will mean : "I used my component or device in average at 10% of its maximum workload"

A Workload can also be given as a dictionary to specify the percentage of time spent at each desired workload level. The following 

[
    {
        "load_percentage": 10,
        "time_percentage": 50
    },
    {
        "load_percentage": 50,
        "time_percentage": 20
    },
    {
        "load_percentage": 100,
        "time_percentage": 30
    }
]

This translates into using a component or a device:

  • 50% of the time at 10% ot its maximum workload,
  • 20% of the time at 50% of its maximum workload,
  • 30% of the time at the maximum workload

Example for a CPU

Taking the following load segmentation :

  • 100%
  • 50%
  • 10%
  • 0% (IDLE)
  • off

With the following time repartition

load_percentage high (100%) medium (50%) low (10%) idle off
time_percentage 15% 55% 10% 20% 0%

note : the sum of time ratio per load must be 100.

With the following consumption profile :

consumption_profile(workload) = 55.65 * ln(0.046 * (workload + 20.41)) + 4.24

Power consumptions :

load_percentage 100% 50% 10% idle off
Power (W) 260 182 77 36 0

avg_power is measured as follows :

avg_power = power(100%) * time_ratio(100%) + power(50%) * time_ratio(50%) + power(10%) * time_ratio(10%) + power(idle) * time_ratio(idle) + power(off) * time_ratio(off)

avg_power = 260 * 0.15 + 182 * 0.55 + 77 * 0.1 + 36 * 0.2 + 0 * 0
                             = 39 + 100.1 + 7,7 + 7,2 + 0
                             = 154 W/hour
                             = 1349 kwh/year

Result : 154 W/hour