单项选择题 （） is a precaution which contributes to avoiding trouble under normal operating conditions.

单项选择题 Self-excited a-cgenerator with "error operated" voltage control systems draw the full excitation power for the machine terminalsThis dispenses with the current transformers, reactors and capacitors necessary for accurate compounding, but renders the excitation system vulnerable to variations in its output voltageWhich of the following is correct about the generator mentioned according to the sentences above （）.

单项选择题 Generators should have an excitation/voltage regulation system which will enable them to share the steady state reactive load （） no machine exceeds its proportional share of reactive load by more than 10% of the rated reactive load of the largest generator.