Calculation of Efficiency
Let I0 be the no-load current (which may be measured by an ammeter A1).
Ish is the shunt field current (it may be measured with ammeter A2).
The no-load armature current = ( I0 – Ish)
The supply voltage (V). As a result, the power input with no load equals V I0 watts.
Swinburne’s test requires no load power input, merely to provide losses. The losses that occur in the machine mostly include:
- Iron loss in the core
- Friction and winding losses.
- Armature copper loss.
Swinburne’s test determines that the machine’s no load mechanical output is zero, hence the no load input power is simply utilized to provide losses.
The armature copper loss is = ( I0 – Ish)2 Ra
the armature resistance (Ra).
Now, to calculate the constant losses, we must remove the armature copper loss from the no-load power input.
Constant losses Wc = V I0 – ( I0 – Ish )2 Ra
After computing the no-load constant losses, we may compute the efficiency at any load.
Let I be the load current used to calculate the machine’s efficiency.
When the machine is running, the armature current (Ia) will equal (I – Ish). When the machine motoring
And Ia = ( I + Ish ) when the machine is generating.
Swinburne Test of DC Machine
The Swinburne Test is a method for determining the performance characteristics of direct current (DC) devices like generators and motors. This test, named for its author, Thomas Swinburne, a renowned electrical engineer from the early twentieth century, gives useful information on the efficiency and overall health of DC equipment. If you are interested in electrical engineering, particularly DC machines, this test is very important. In this essay, we will go over the Swinburne Test, including its aim, methodology, and significance in the evaluation of direct current machines.
Table of Content
- Swinburne’s Test
- Calculation of Efficiency
- Efficiency of Motor
- Efficiency of Generator
- Swinburne’s Test Vs Hopkinson’s Test
- Advantages and Disadvantages
- Applications