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-SQA- SCOTTISH QUALIFICATIONS AUTHORITY
HIGHER NATIONAL UNIT SPECIFICATION
GENERAL INFORMATION
-Unit Number-
2400040
-Superclass-
XJ
-Title-
Electrical Principles
-DESCRIPTIONGENERAL COMPETENCE FOR UNIT: Applying
electrical
principles
to
transmission line, steady state and
transient circuit problems.
CREDIT VALUE:
1
ACCESS:
Access to this Unit is at the discretion of
the Centre.
However, it would be
beneficial, if the student had a
knowledge of
fundamental circuit
theorems, Ohms's and Kirchhoff's laws
and alternating circuit theory.
This may be evidenced by possession
of:
National Certificate Modules 2160030
Single Phase A.C., 2160080 Network
Analysis and 2160090 D.C. and A.C.
Circuit Responses or similar
qualifications or experience.
Unit No.2400040
Continuation
OUTCOMES AND PERFORMANCE CRITERIA
OUTCOME 1
Apply complex notation to phasor quantities.
PERFORMANCE CRITERIA
(a)
Performance of addition, subtraction and multiplication using cartesian and
polar expressions is correct.
(b)
The conjugate of a complex quantity is applied to the division of complex
numbers correctly.
(c)
Phasor quantities are accurately expressed mathematically and displayed
diagrammatically in cartesian and polar form with respect to a reference
phasor in any quadrant.
OUTCOME 2
Solve a.c. network problems using complex notation.
PERFORMANCE CRITERIA
(a)
Complex notation is correctly applied to impedance, voltage, current and
power components.
(b)
Voltages, currents, power factor and all power components are accurately
calculated for a series circuit containing one resistor, one inductor and one
capacitor, and a parallel network with two branches, one having an inductor
and resistor connected in series and the other having a single capacitor.
(c)
Currents, voltages, power and power factor in a series-parallel network are
accurately measured and recorded.
OUTCOME 3
Evaluate the response of a circuit to a transient disturbance.
PERFORMANCE CRITERIA
(a)
The responses of RL and RC series circuits, to both the application and
removal of a direct voltage, are correctly predicted and the formulae for one
condition are accurately described.
(b)
The response curves of RL and RC series circuits, to both the application
and removal of a d.c. voltage are drawn correctly.
(c)
The responses of RL and RC series circuits, to the application of a
sinusoidal voltage are correctly predicted for specified conditions and the
formulae for one condition are accurately described.
(d)
The labelled waveform sketch showing the response of an RL or RC series
circuit to the application of a sinusoidal waveform is correct.
Page 2 of 4
Unit No.2400040
Continuation
OUTCOME 4
Evaluate the performance of transmission lines using distributed parameters.
PERFORMANCE CRITERIA
(a)
The secondary parameters (characteristic impedance Z 0 , propagation
coefficient γ, attenuation coefficient α, phase shift
coefficient ß, wavelength λ, velocity of propagation u) of
a transmission line are correctly calculated from given primary
parameters.
(b)
Voltage and current, at a given distance from the sending and receiving end
of a transmission line, are correctly calculated using given formulae.
(c)
The incident, reflected and transmitted values of voltage, current and power
for a source and matched line of characteristic impedance Z 0
terminated in an impedance Z L are correctly calculated for the case
where Z L is greater than Z 0 and the case where Z L is smaller than Z 0 .
(d)
Z L = ∞, Z L 〉 Z 0 , Z L 〈 Z 0 and Z L = 0
Page 3 of 4
Unit No.2400040
Continuation
CONTEXT
The following information gives further clarification regarding the context in which
the outcomes and performance criteria are to be achieved.
Corresponding to the Outcomes:
2.
Performance criterion (a): power components are: apparent power, reactive
power and real power.
4.
Performance criterion (b), calculations are performed by application of the
formulae:
v χ = Vs e − χ
y
and i χ = I s e − χ y
where χ is the distance from
the sending end
and
v χ = Vr e
χy
and i χ = I r e
χy
where χ is the distance from
the receiving end
AWARD OF PASS
A student who achieves all performance criteria for all outcomes will be awarded
a Pass in the Unit.
AWARD OF PASS WITH MERIT
Pass with Merit may be awarded to a student who achieves all outcomes and in
so doing consistently demonstrates superior performance when, for example:
(a)
relating theory to practice;
(b)
performing calculations.
 Copyright SQA 1990
20/12/01
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