Transcript load model - Department of Electrical and Computer Systems

Dynamic Load Modelling
Author’s Name
Murali Venkata
1276 2873
Supervisor Dr. Qi Su
Associate supervisor
Prof. Bob Morrison
What is a LOAD, a LOAD MODEL & TYPES of LOAD MODELS?
Load can have several meanings in a power system including:
• A device that consumes power
• Total power (active and/or reactive) consumed by all devices
• Power output of generating plant
• A portion of system that is not explicitly represented in a system model, but rather treated as a single powerconsuming device connected to a bus.
A load model is a mathematical representation of relationship between a bus voltage (magnitude and frequency) and
the power (active and reactive) or current flowing into the busload.
Load models are classified into two broad categories: static and dynamic models.
Why ?
 Any accurate description of a power system phenomenon in time-domain requires dynamic load representation
 Any load parameters depending on the past instants of time also require dynamic modelling.
The following studies prefer dynamic load modelling: First swing stability, Small signal (damping and synchronising power)
stability, Induction motor stability, Voltage stability & Dynamic over-voltages
How?
Current practices: Measurement based approach & Component based approach.
Need for research:
the needs for using extensive non-linear mathematical tools for large-signal load modelling & the errors which may be
introduced if it is linearized.
the component-based and measurement-based methods to be used in complimentary or a supplementary manner ?

Introduce models and data for load behaviour for low voltages and over long time periods, incorporating self-tripping
& auto-control mechanisms during low voltage and under-frequency conditions for ex, low voltage stall, trip and recovery
behaviour.

Methods for measuring load characteristics.
Electrical and Computer Systems Engineering
Postgraduate Student Research Forum 2001