Development of load frequency control simulation tool

In Japan, each electric power company is required to maintain the supply and demand balance in its own area individually for the network adequacy and security. That is, each electric power company has a responsibility to strictly control tie-line power flow. On the other hand, base load power plants, such as nuclear power plants, and renewable energy sources whose outputs are difficult to control are increasing. This trend will be accelerated in order to realize the low-carbon society. Therefore, it is becoming essential to properly evaluate the performance of the supply and demand control. The authors have been studying dynamic simulation of load frequency control (LFC). This paper presents a LFC simulation tool that reproduces the LFC operation of the actual power system in Tohoku area. The simulation tool is composed mainly of thermal power plant models and a model of the LFC section of the central load dispatching center. The thermal power plant models are suitable for LFC simulation. The parameters of the plant models can be adjusted automatically using measurements. In the central load dispatching center model, only LFC section is modelled and it is quite faithful to the actual equipment. The simulation is conducted based on the measured supply-and-demand data. That is, simulation condition, such as operational mode of generators, and input data, such as system load variation, are set based on the measured data. Furthermore, the tool can simulate hypothetical cases by modifying the simulation condition or the input data. The accuracy of each component of the tool and the entire tool was verified by comparing simulation results with measurements. The simulation tool will be utilized for the evaluation of the LFC performance and its improvement by modifying the control scheme.