Power system frequency is an important indicator of the quality of power supply. As per the regulations of The Indian Electricity Act, the frequency has to be maintained within ±3% of the rated frequency, namely, 50 Hz. However, in India, the frequency is always low and this causes severe problems to the connected load and power generating equipment. In the electricity grid code introduced recently in India, the Free Governor Mode of Operation (FGMO) has been made mandatory for power generating companies. With this, the frequency profile is expected to improve considerably. The success of the FGMO depends on the capabilities of power plants to respond to the frequency changes. A mathematical simulation can provide an insight to the response behavior of various types of power plants and their turbine governing systems. In this paper, the response characteristics of thermal and hydro power plants are studied by simulating the detailed mathematical models of their turbine governing systems.
Frequency regulation is an important task in the power system operation and control. Though
The Indian Electricity Act, 2003 stipulates frequency to be maintained within ±3% of the
rated 50 Hz, it is always less than 48 Hz in most of the grids; resulting in severe losses to
industrial users and the generating plants. In India, the responsibility of maintaining grid
frequency is entrusted to the regional electricity boards who coordinate with state electricity
boards, and central generating stations. Maintaining the frequency is difficult as the demand
for power is always more than that is generated.
The concept of frequency regulation in power systems has changed with the introduction
of new Electricity Grid Code [1] in India. It is now mandatory to follow the Free Governor
Mode of Operation (FGMO), according to which the generating units are required to increase
their generations by at least 10 %, for 5 min when the system frequency falls. The success of
the FGMO depends on the response capability of the generating unit. It is necessary to
understand the response capabilities of the thermal and hydro generating units for better
grid frequency management. |
