🔍 Key Concepts

• Stabilized shunt (compound) DC generator construction: shunt field plus a small series field • Difference between voltage regulation and speed regulation in DC generators • What commutating poles/interpoles and compensating windings actually correct in a DC machine

💭 Think About

• Ask yourself: In a stabilized shunt DC generator, why do we add a small series field to a shunt machine? What behavior are we trying to improve as load changes? • Consider whether the series field affects the mechanical speed of the prime mover, the electrical output voltage under load, or commutation/armature reaction directly. • Think about which parts of a DC machine are specifically designed to deal with armature reaction and commutation problems—are those normally series field, interpoles, or compensating windings?

✅ Before You Answer

• Be clear on the definition of voltage regulation (how terminal voltage changes from no-load to full-load at constant speed). • Be clear on the definition of speed regulation (how speed changes from no-load to full-load at constant applied voltage). • Verify which windings are normally used to correct armature reaction and commutation: interpoles (commutating poles) and/or compensating windings, not the stabilizing series field.