PPC
Power plant controller
The plant-level controller that measures at the connection point and sets inverter or turbine outputs to meet grid requirements.
SLD
Functional block · MDIA
Microgrid dispatch infeasibility alarm
Functional block · Microgrids
An independently authored application reference. The drawing shows the named function or circuit relationship; use the project legend and selected equipment documentation for its drafting form and connections.
Browse this installation focusIn plain English
What this block does
Reports that the requested allocation cannot satisfy the declared resource and operating constraints.
A simple example
In a microgrid with solar generation, a battery and generators, the controller can allocate an import/export target among the available resources while reserving the power needed for operating disturbances. For this reference, the drawing identifies “Target and resource constraints” at the input and “Dispatch infeasibility indication” at the output. The alarm must not imply a physically achievable target.
What the drawings help you do
Start at the named input: Target and resource constraints. Identify its source device or document and the state represented on the drawing. Follow the named output: Dispatch infeasibility indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- Input
- Target and resource constraints
- Output
- Dispatch infeasibility indication
- Application reference
- An explanation of a named drawing function or circuit relationship; the project documents define the equipment and its connections.
Read the source: Microgrid control systems
Schematic · MDIA
What it represents
Reports that the requested allocation cannot satisfy the declared resource and operating constraints. Active-power dispatch allocates the electrical work performed by the microgrid resources. A total site target, a resource power limit and the actual measured contribution are different quantities that must be connected clearly in the diagram.
In a microgrid with solar generation, a battery and generators, the controller can allocate an import/export target among the available resources while reserving the power needed for operating disturbances. For this reference, the drawing identifies “Target and resource constraints” at the input and “Dispatch infeasibility indication” at the output. The alarm must not imply a physically achievable target.
Identify the measurement boundary, power sign convention, resource limits and target priority. An original control block does not supply dispatch settings, a financial operating policy or proof of grid-code compliance. The functional block is an independent explanation of this named application. Equipment-specific ratings, terminal connections and operating conditions must be established in the project documentation.
How to read it
- Start at the named input: Target and resource constraints. Identify its source device or document and the state represented on the drawing.
- Follow the named output: Dispatch infeasibility indication. Cross-reference its destination and separate the command from confirmation that the equipment responded.
- The alarm must not imply a physically achievable target.
- Identify the measurement boundary, power sign convention, resource limits and target priority. An original control block does not supply dispatch settings, a financial operating policy or proof of grid-code compliance.
Information to show or reference
- Label the source and connection reference for target and resource constraints.
- Identify the destination and defined state of dispatch infeasibility indication.
- Record the equipment or control-document revision supporting this functional block.
- Check this application limit in the project design: The alarm must not imply a physically achievable target.
A distinction that matters
The alarm must not imply a physically achievable target. This reference describes the named application; it does not establish a new IEC graphical symbol, an ANSI device-function number or an exact manufacturer connection diagram.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
Microgrid control systems
Public technical context for microgrid active-power dispatch controls. Active and reactive power, generation, load control, operating reserves and system supervision. The application text and educational graphic are independently authored; the publisher does not certify this representation.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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Put the reference into a drawing workflow.
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