What is testing of dc machine?
The load testing of DC machine is needed to determine the rating of a machine. When we run a machine, then some energy is lost in the machine, which converts into the heat and cause temperature rise.
What are the different types of tests done on DC motor?
Testing of DC motor, dc motor testing direct and indirect method
- Indirect method of testing. This method consists of measuring the losses and then calculating the efficiency.
- Swinburne’s test (No load test)
- Hopkinson’s Test (Back-to-back test or Regenerative test)
How do you test the performance of a DC motor?
Swinburne’s test is the most commonly used and simplest method of testing of shunt and compound wound dc machines which have constant flux. In this test the efficiency of the machine at any load is pre-determined. We can run the machine as a motor or as a generator.
How many tests are there in DC motor?
Basically, the testing of DC machines classified into two types. Namely, direct and indirect tests. The indirect test is further classified into two. They are Swinburne and Hopkinson’s Test.
What is Swinburne test?
The Swinburne test is an indirect method for determining the efficiency of DC motors. It works by finding the no-load losses experimentally and then estimating additional losses from the rated motor data. Because the motor is running at no-load condition, the net output is zero.
What are losses in dc machine?
Magnetic Losses or Core Losses or Iron Losses in dc machine The core losses are the hysteresis and eddy current losses. These losses are considered almost constant as the machines are usually operated at constant flux density and constant speed. These losses are about 20 per cent of the full load losses.
What are the methods of indirect testing of dc machine efficiency?
Swinburne’s test is the simplest indirect method of testing dc machines. In this method, the dc machine(generator or motor) is run as a motor at no-load and losses of the machine are determined. Once the losses of the machine are known, its efficiency at any desired load can be determined in advance.
What is regenerative test?
Hopkinson’s test of dc machine also known as a Regenerative Test. This test is also one of the efficient ways of determining the losses and efficiency of a dc machine. The test is performed by mechanical coupling of two identical dc machines. In which one machine works as a generator and the other as a motor.
What is Hopkinson test?
Hopkinson’s Test is another useful method of testing the efficiency of a DC machine. It is a full load test and it requires two identical machines which are coupled to each other. If there are no losses in the machine, then no external power supply would have needed.
What is the use of brushes in DC Machine?
Brushed DC motors are one of the simplest types of DC motor. It uses brushes to deliver current to the motor windings through mechanical commutation. The number of coils wound around the motor and the density of the coils determine the properties of the motor. The armature or rotor is an electromagnet.
What is Swinburne test in DC machine?
The Swinburne test is an indirect method for determining the efficiency of DC motors. It works by finding the no-load losses experimentally and then estimating additional losses from the rated motor data. From this information, the efficiency can be determined at any applied load.
What are the different types of testing of DC machines?
Testing of DC machines: Swinburne’s test, brake test, regenerative testing, Hopkinson’s test, field’s test, retardation test and separation of stray losses, problems.
What is a DC machine?
Introduction DC machine can be used as a motor or as a generator. DC Machine is most often used for a motor. Cutaway view of a dc motor
What is the objective of the DC machine lab?
Speed control techniques of DC motor using programmable logic controller and Lab VIEW PSO2, 3 Page | 5 DC MACHINES LABORATORY OBJECTIVE: The objective of the DC Machine Lab is to expose the students to the operation of DC machines and give them experimental skill.
How does a DC motor work?
DC Machines Construction DC machines, like other electromechanical energy conversion devices have two sets of electrical windings field windings – on stator amarture windings – on the rotor. 7 DC Machines Construction The stator of the dc motor has poles, which are excited by dc current to produce magnetic fields.