Power Systems
The grid is a single machine spanning a continent, held at one frequency by second-to-second balancing. These topics animate the path power takes and what each transformation along it is buying.
Start from the beginning →8 topics you can watch now, 13 still to come.
The system end to end
Generation, transmission, distribution — and why they differ.
- From Generator to SocketStart here. Send the same power down the same line at two voltages and watch ninety-nine per cent of the loss disappear.
- The Per-Unit SystemA normalisation that looks like bookkeeping and is not — chosen correctly, it makes every transformer in the network disappear from the diagram.
- Generating stations and their roles
- Load curves, load factor and diversity
Transmission lines
A conductor long enough that its own geometry matters.
- Line parameter calculation from geometry
- Long line equations and the ABCD form
Distribution and cables
The last few kilometres, where most of the network actually is.
- Radial and ring main distributors
- Underground cables and grading
- Substation layouts
- Earthing systems
Fault analysis
What happens in the first cycle after something goes wrong.
- Fault AnalysisFifty times rated current, doing damage on two different clocks — and symmetrical components turning one unbalanced problem into three balanced ones.
- Protection and DiscriminationTwo requirements that fight each other: be fast, and trip nothing unnecessary. Every scheme in the topic is a different resolution of that conflict.
- Circuit breaker types and arc interruption
- Fuses and their time-current characteristics
Analysis and operation
Running the network, not just building it.
- Load FlowThe most-run calculation in the industry, and it needs iteration for one reason: what is specified is power, not current, which makes the equations non-linear.
- Power System StabilityWhy a grid can fall apart in under a second, read off one sine curve — and why fast protection is a stability requirement rather than damage limitation.
- Economic Dispatch and Frequency ControlFrequency is the supply-demand balance made visible everywhere at once. Then the cheapest fleet is not the one that runs the cheapest units first.
- Unit commitment algorithms
- State estimation and SCADA
- Voltage stability and reactive planning
About Power Systems
Power systems is the engineering of the largest machine ever built, operated under a constraint most systems never face: generation must match consumption continuously, because the grid stores almost nothing. Every topic here is downstream of that.
The subject introduces its own arithmetic first, and for good reason. Per-unit normalisation makes transformers disappear from calculations and turns a network of mismatched voltage levels into one comparable set of numbers. Load flow then answers the everyday question of what voltage appears where, given who is generating and who is drawing.
The rest is about things going wrong and the system surviving anyway. Fault analysis asks how much current flows when a line shorts; protection asks which device should open, how fast, and how to ensure the nearest one acts before its backup.
What to know first
- Electric Circuit Analysis, including three-phase AC
- Electrical Machines, particularly transformers
Where it gets used
- Reading a single-line diagram of a substation or industrial plant
- Understanding why grid frequency is watched as a measure of balance
- Grasping how protection coordination localises a fault to one section