Because power systems are complex and multi-variable, it is very difficult to realize automatic secondary load-frequencycontrol.
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。
2
The industrial frequencycontrol technique lor power load control is introduced .
本文介绍了电力负荷的工频控制技术。
3
Then the principles of hierarchical estimation and feed forward compensation are applied to derive the power system state estimation and loadfrequencycontrol equations.