Synchronizing Power Generators

Synchronization of electricity generators refers to the process of connecting individual generators to a larger power grid and ensuring that they all operate at the same frequency. This is critical for maintaining the stability and reliability of the power grid. In this article, we will explain how generators are synchronized and connected to the power grid.

First, let’s consider how an individual generator is synchronized with the power grid. To synchronize a generator with the power grid, it must be running at the same frequency as the rest of the generators in the grid. This is typically 50 Hz in most countries. To achieve this, the generator is spun up to the correct frequency using a prime mover, such as a gas turbine, steam turbine, or gas-fired internal combustion engine.

Once the generator is running at the correct frequency, it can be connected to the power grid. However, before it can be connected, several conditions must be met. The voltage and frequency of the generator must be the same as the voltage and frequency of the power grid. Additionally, the generator’s power factor must be in phase with the power grid. This is done with a synchronoscope, which is described later in this article.
Once these conditions are met, the generator can be connected to the power grid. However, it’s not as simple as flipping a switch. The process of connecting a generator to the power grid is carefully controlled to avoid any sudden changes in the power grid’s voltage or frequency. This process is typically controlled by a control system that monitors the power grid and makes adjustments as needed to ensure a smooth transition.


A synchronoscope is a device used to compare the phase relationship between two alternating current (AC) waveforms. The original synchronoscope was a cathode ray oscilloscope with a special sweep circuit that allowed the operator to compare the phase relationship between two inputs. The operator would adjust the phase of one input until the two waveforms appeared to be in phase with each other, as indicated by the lack of a difference in the position of the two traces on the oscilloscope screen.

Today, digital oscilloscopes with built-in synchronoscope functionality are widely available. These digital oscilloscopes use advanced signal processing techniques to automatically align the phase of the two inputs, making the comparison process much simpler and more accurate. These digital synchronoscopes also have a variety of advanced features such as the ability to display multiple waveforms simultaneously, and the ability to zoom in on specific sections of the waveform for a more detailed analysis. Additionally, digital synchronoscopes can be controlled and configured remotely via software, making it easy to use them in test and measurement applications in a variety of industries.

The specifics of renewables

Wind and solar power generators are important sources of renewable energy. These generators produce a constant current that is later converted into alternating current. To convert the constant current into alternating current, inverters are used. However, there are also generators that produce “dirty” alternating current, meaning that the frequency is not constant and fluctuates due to the varying speed of the wind or sun. In this case, the dirty alternating current is first converted into a constant current (rectified) and then converted into the desired frequency. Inverters for renewable energy sources are always connected to the grid and it is important for them to have a large source of alternating current to synchronize with.

In summary, synchronization of electricity generators is a critical process that ensures the stability and reliability of the power grid. It involves spinning up the generator to the correct frequency, ensuring that the voltage, frequency, and power factor match the power grid, and carefully controlling the process of connecting the generator to the grid.