The practical operation proves that the automatic variable-load control system works well.

实际运行证明，自动变负荷控制系统运行效果较好。

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Because power systems are complex and multi-variable, it is very difficult to realize automatic secondary load-frequency control.

电力系统一般都很复杂且变量又多，实现二阶负载—频率自动控制也相应变得很困难。

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