Electrical Power System Essentials

1.1 INTRODUCTION

As electricity comes out of the AC outlet every day, and has already been doing so for more than 100 years, it may nowadays be regarded as a commodity. It is a versatile and clean source of energy; it is fairly cheap and ‘always available’. In the Netherlands, for instance, an average household encountered only 35 minutes' interruption to their supply in the year 2006 [7] out of a total of 8760 hours, resulting in an availability of 99.99334 %!

Society's dependence on this commodity has become critical and the social impact of a failing power system is beyond imagination:

• cars would not be refueled as gas station pumps are driven by electricity;
• the sliding doors of shops and shopping malls would not be able to open or close and people would therefore be locked out or in;
• electrified rail systems, such as subways and trains, would come to a standstill;
• traffic lights would not work;
• refrigerators would stop;
• heating/cooling installations would fail;
• cash dispensers would be offline;
• computers would serve us no longer;
• water supplies would stop or run out.

Many more examples may be given, but the message is clear: electric power systems are the backbone of modern society (see Figure 1.1) and chaos would result if the electricity supply failed for an extended period.

Our society needs engineers who know how to design, build and operate an electrical power system. So let's discover what lies beyond the AC outlet and enter the challenging world of power system analysis... ...