Design of Test System for Generation of Harmonic Sinusoids
Södergård, Tomas (2012)
Södergård, Tomas
2012
Kuvaus
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Tiivistelmä
An essential component in monitoring of power systems is the protection relay. Since modern protection relays contain several advanced measuring functions test equipment for testing these internal functions is crucial both in the field and laboratory environments.
In this thesis a previously designed product is updated since many key components are obsolete and hence hard to find. Simultaneously, CE–certification and future hardware updates shall be simplified which is of great importance for manufacturers with smaller volumes. The key component in the updated system is an industrial PC, CX5010.
From the functional perspective the main functionality in this type of equipment is generation of sinusoidal waves to which harmonic frequency components potentially can be added. In this thesis, based on literature study, a few alternative approaches for sinusoidal generation is examined. Additionally, how to avoid overflow caused by interference between the harmonic frequency components is examined.
The result of this thesis is a wavetable based generator of sinusoidal waves where the frequency and phase accuracy and stability has been statistically examined. Additional-y, an algorithm for normalizing the harmonic energy has been developed. In the developed prototype, measurement of trip time and sequences for test of typical relay functions has been implemented. Finally, a user interface aimed for a touch screen has been developed.
In this thesis a previously designed product is updated since many key components are obsolete and hence hard to find. Simultaneously, CE–certification and future hardware updates shall be simplified which is of great importance for manufacturers with smaller volumes. The key component in the updated system is an industrial PC, CX5010.
From the functional perspective the main functionality in this type of equipment is generation of sinusoidal waves to which harmonic frequency components potentially can be added. In this thesis, based on literature study, a few alternative approaches for sinusoidal generation is examined. Additionally, how to avoid overflow caused by interference between the harmonic frequency components is examined.
The result of this thesis is a wavetable based generator of sinusoidal waves where the frequency and phase accuracy and stability has been statistically examined. Additional-y, an algorithm for normalizing the harmonic energy has been developed. In the developed prototype, measurement of trip time and sequences for test of typical relay functions has been implemented. Finally, a user interface aimed for a touch screen has been developed.