Consider the DC machine cross section shown in Figure 2. The machine has a gap length...

 

Transcribed Image Text:

Consider the DC machine cross section shown in Figure 2. The machine has a gap length g of 1.25 mm, an armature radius re of 50 cm, and a depth d of 40 cm into the page. There are N = 175 total field turns wound across two poles. The pole faces span an angle ß = 110°. Assume the iron permeability is very high such that the iron reluctance can be ignored. Also, ra is large enough compared to g such that the air gap cross sectional area can be assumed uniform. Calculate the reluctance of each airgap Rg. Then use magnetic circuit theory to calculate the field current If required to establish a field flux linkage λ = 20 Wb-t. (14 points) Rg If H-¹ A Consider the DC machine cross section shown in Figure 2. The machine has a gap length g of 1.25 mm, an armature radius re of 50 cm, and a depth d of 40 cm into the page. There are N = 175 total field turns wound across two poles. The pole faces span an angle ß = 110°. Assume the iron permeability is very high such that the iron reluctance can be ignored. Also, ra is large enough compared to g such that the air gap cross sectional area can be assumed uniform. Calculate the reluctance of each airgap Rg. Then use magnetic circuit theory to calculate the field current If required to establish a field flux linkage λ = 20 Wb-t. (14 points) Rg If H-¹ A