CIM Issues #5099
Not possible to properly model variable shunt reactor
61970-301
Description
It is not possible to properly model variable shunt reactor which has “Large regulation ranges from 20% to 100%”. ShuntCompensator has implicit range 0% to 100% as only maximum sections are listed, while 0 section (or 0 Mvar) is presumed to be available. For VSR this is not true. Only way for a VSR to have 0 Mvar is to disconnect it using an external switch.
Files
| VSR – Variable Shunt Reactor Modeling.pptx | VSR – Variable Shunt Reactor Modeling.pptx | 1.32 MB | Long description of the problem | ||
| VSR proposed solution.png | View VSR proposed solution.png | 201 KB | Proposed change to the UML (note in proposed solution) |
Proposed Solution
Since variable shunt compensator cannot be linear because g=Re(1/(r+jx)) it is enough to specialize the NonlinearShuntCompensator class.
Proposed note for the specialized class VariableShuntCompensator:
A variable shunt compensator is a oil-filled reactor with discrete on-line regulation of reactive power. The regulation range typically varies between 30% and 100% of rated reactive power. When energized VSR cannot have a reactive output of 0 Mvar, so minimal valid section number is 1 with reactive power output at either 100% or at minimal reactive power output (reactive power can raise or fall with increasing section number).
Decision
Discussed on 15-Feb-2023 during in-person meetings in Richland. Agreed to apply the proposed UML updates and associated class description.
Release Notes
The class VariableShuntCompensator is added in Wires package. The class inherits from NonlinearShuntCompensator.
The description of the class is:
A variable shunt compensator (VSR) is an oil-filled reactor with discrete on-line regulation of reactive power. The regulation range typically varies between 30% and 100% of the rated reactive power. When energized VSR cannot have a reactive output of 0 Mvar, so minimal valid section number is 1 with reactive power output at either 100% or at minimal reactive power output. Note that reactive power can increase or decrease with increasing of the section number (NonlinearShuntCompensatorPoint.sectionNumber).
The class is also added to EQ profile in -452 and SSH profile in -456.