Generator excitation current and output voltage
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When a synchronous generator operates independently, adjusting the magnitude of its excitation current allows the output voltage of the generator to be changed flexibly. What is the principle behind this, and what are the quantitative relationships involved?
Excitation voltage and current refer to the voltage and current applied to the rotor coils, and they come in two types: self-excitation and externally excited. At the same output, the higher the excitation voltage, the greater the excitation current; at the same excitation voltage, the greater the output, the greater the excitation current. Additional note: The function of the excitation system is primarily to supply a direct current source to the excitation windings of synchronous motors. Its role in these motors can be reflected in the following aspects: (1) Regulating excitation to maintain a constant voltage. (2) It enables reasonable distribution of reactive power among various units. (3) The use of a sophisticated excitation system along with its automatic control devices can increase the limit of transmission power and expand the range of stable operation under static conditions. (4) During a short circuit, forced excitation also helps to improve dynamic stability. (5) During the transient process, the behavior of a synchronous motor depends to a large extent on the performance of the excitation system.