1.1 Load Frequency Control Problem If there is any sudden load change occurs in a control area of an interconnected power system then there will be frequency deviation as well as tie line power deviation. 1. To maintain the real frequency and the desired power output (megawatt) in the interconnected power system. 2.

Primary Frequency Response are actions to arrest and stabilize frequency in response to frequency deviations. Primary Response comes from generator governor response, load response (motors) and other devices that provide immediate response based on local (device- level) control.

– The Primary Frequency Control (PFC), an important way to maintain frequency stability, balances the power generation and load consumption in the grid. – PFC immediately activates when the Grid frequency limit is not in set dead band limits. Response delivered within 30 seconds.

To ensure stability, the Grid contracts power generators like Drax power station to provide frequency response services, so when frequency changes on the grid, Drax’s generating units can automatically respond. If the frequency rises, the turbine reduces its steam flow. If the frequency falls, steam flow will increase.

In an inductance, the lower the frequency, the lower its impedance. So having constant voltage over it, the current will rise if the frequency gets lower.

The relationship between power and frequency is inversely proportional to each other .

For example, the frequency variation has bad effects on the computer controlled modern control systems widely used in industrial applications because it can cause erratic operation, data loss, system crashes, and equipment damage of computer. Lamp flickering is another outcome of the frequency fluctuation.

The main reasons are uncertainties of wind and solar power generation, transactions in electricity market of distribution systems, severe load variations, etc.

At any instant, the frequency depends on the balance between the load and the capacity of the available generation. A frequency variation occurs if a generator becomes un-synchronous with the power system, causing an inconsistency that is manifested in the form of a variation.

As per the Indian Electricity Rules 1956 (amended up to 25th Nov 2000), the permissible range for grid frequency was +/- 3 % of nominal i.e. 48.5 Hz to 51.5 Hz. The permissible frequency ranges (by manufacturers) for operation of various makes of steam turbine are shown in Figure 1.

Frequency is a change in the way alternating current (AC) flows. Areas connected to a stable power grid do not typically experience frequency variations. Frequency variations normally affect areas using a dedicated power generator. High demand for power worsens the situation.