Power System Blocks

Sensitivity computation

The sensitivity computation module is dedicated to compute linearized impact of network small variations on some elements state variables.

A sensitivity value is the numerical estimation of the partial derivative between the variable of impact and the function observed. Sensitivity computation can also be seen as partial derivatives computation on the network model.

Sensitivity computation inputs

Network

The main input for sensitivity computation module is an IIDM network.

Sensitivity factors

Sensitivity factors are the expected partial derivatives to be extracted from the input network.

A standard sensitivity computation input is composed of a list of sensitivity factors, each one composed of a sensitivity variable (variable of impact) and a sensitivity function (function observed).

Currently available sensitivity factors are:

JSON format

Sensitivity computation module provides a JSON mapping to sensitivity factors that can be used as a sensitivity factors provider. The file is a list of JSON objects each one representing a sensitivity factor:

[ {
  "@c" : ".factors.BranchFlowPerInjectionIncrease",
  "function" : {
    "@c" : ".BranchFlow",
    "id" : "BRANCH_FLOW_ID",
    "name" : "My monitored branch",
    "branchId" : "BRANCH_ID_IN_NETWORK"
  },
  "variable" : {
    "@c" : ".InjectionIncrease",
    "id" : "INJECTION_INCREASE_ID_1",
    "name" : "My impacting injection 1",
    "injectionId" : "INJECTION_1_ID_IN_NETWORK"
  }
}, {
  "@c" : ".factors.BranchFlowPerInjectionIncrease",
  "function" : {
    "@c" : ".BranchFlow",
    "id" : "BRANCH_FLOW_ID",
    "name" : "My monitored branch",
    "branchId" : "BRANCH_ID_IN_NETWORK"
  },
  "variable" : {
    "@c" : ".InjectionIncrease",
    "id" : "INJECTION_INCREASE_ID_2",
    "name" : "My impacting injection 2",
    "injectionId" : "INJECTION_2_ID_IN_NETWORK"
  }
} ]

Sensisitivity computation outputs

Sensitivity values

The outputs of sensitivity computation are sensitivity values. It is a list of objects associated to each sensitivity factors:

Example of interpretation

Let’s imagine that one want to get the impact of an increase on active power generation on generator G on branch B active flow. The sensitivity computation input will contain one sensitivity factor.

After computation, the result is a sensitivity value object composed of three elements:

That means that: