Dictionary of Electrical Engineering

Commonly used terms in the Electrical industry.

asynchronous bus
a bus in which the timing of bus transactions is achieved with two basic "handshaking" signals, a request
signal from the source to the destination and an acknowledge signal from the destination to the source. The transaction begins with the request to the destination. The acknowledge signal is generated when the destination is ready to accept the transaction. Avoids the necessity to know system delays in advance and allows different timing for different transactions.

See synchronous bus
boundary bus
one of a set of buses which define the boundary between the portion of a power system to be analyzed and the rest of the system. Boundary buses are connected to both the internal and external systems.
bus
(1) a data path connecting the different subsystems or modules within a computer system. A computer system will usually have more than one bus; each bus will be customized to fit the data transfer needs between the modules that it connects.
(2) a conducting system or supply point, usually of large capacity. May be composed of one or more conductors, which may be wires, cables, or metal bars (busbars).
(3) a node in a power system problem
(4) a heavy conductor, typically used with generating and substation equipment.
bus admittance matrix

See Y-bus
bus differential relay
a differential relay specifically designed to protect high power buses with multiple inputs.
bus impedance matrix

See Z-bus
bushing
a rigid, hollow cylindrical insulator which surrounds a conductor and which extends through a metal plate such as a the wall of a transformer tank so as to insulate the conductor from the wall.
bushing transformer
a potential transformer which is installed in a transformer bushing so as to take advantage of the insulating qualities of that bushing.
fluidized bed combustion
a method of solid-fuel combustion in which the fuel, usually coal, is pulverized and mixed with a ballasting substance and burned on a bed of pressurized air. If the ballasting agent is crushed limestone, sulfur from the coal is absorbed and carried out as solid ash.
infinite bus
an electrical supply with such large capacity that its voltage (and frequency, if AC) may be assumed constant, independent of load conditions. If a machine's capacity is small relative to the electric supply system to which it is connected, it may be assumed to be operating on an infinite bus.
robust control
control of a dynamical system so that the desired performance is maintained despite the presence of uncertainties and modeling inaccuracies.
robust controller design
a class of design procedures leading to control systems that are robust in the sense of required performance. Robust design is a feedback process involving robustness analysis. A specific technique used in robust controller design depends on the type of model describing a system and its uncertainty, control objective, and a set of admissible controllers. The first requirement is to ensure robust stability; this could be followed by guaranteed cost, disturbance rejection, robust poles localization, target sets or tubes reachability, or other demands.

Ackermann's three basic rules of robust controller design are as follows:

1. Require robustness of control system only for physically motivated parameter values and not with respect to arbitrarily assumed uncertainties of the model.

2. When you close a loop with actuator constraints, leave a slow system slow and leave a fast system fast.

3. Be pessimistic in analysis; then, you can afford to be optimistic in design.
single machine infinite bus system
a model of a power system consisting of a single generator working into an infinite bus which represents the remainder of the system.
swing bus
in power-flow studies, a bus in the power system which is assigned unknown real and reactive power so as to compensate for losses in the system.
terminal bushing

See bushing
voltage-controlled bus
in power-flow analysis of an electric power system, a bus at which the real power, voltage magnitude, and limits on reactive power are specified. A bus connected to a generator will be so represented.
Z-bus
matrix which contains the impedance of each element in an electric power system.
Powered by The Filipino Engineer