What type of compound generator is used for applications like railway and street lights where the generator is located far away from the load center to compensate for voltage drops along the line?

In a power plant, power is usually supplied from several lower-rated generators connected together instead of using one massive single generator. What is this configuration configuration called?

Which of the following conditions will NOT prevent a self-excited DC generator from building up its rated electromotive force (e.m.f.)?