As conventional electricity generation is increasingly supplanted by intermittent renewable sources, maintaining steady grid operations is becoming more complex. It is due to the reduced reactive power and short-circuit levels that were previously supplied by synchronous generators. Grid operators are investigating various solutions to address this issue. One of which includes the implementation of the synchronous condenser market.
The synchronous condenser market is not a recent innovation. It has been part of electricity grids since its inception. It was commonly used in power stations or substations during the mid-twentieth century. However, its use declined with the rise of bigger generating turbines and industrial machinery that offered sufficient reactive and inertia power.
The introduction of power electronics including STATCOMs and SVCs which are more cost-effective to operate has led to the replacement of synchronous condensers in electrical networks. Nevertheless, the decline in grid inertia has reached a point where these systems alone cannot effectively stabilize the networks. It sparks an increased focus on synchronous condensers.
The synchronous condenser market functions as a motor without a load. It can also work as a generator without having a prime mover. It generates or absorbs reactive power. This also enhances short-circuit strength and offers essential mechanical inertia. This is due to its large size and synchronous rotation with the grid.
The Advantages
The synchronous condenser market size has seen substantial expansion in recent years thanks to its many advantages. The main advantages are that it is a technology that has been long recognized and is well-understood. It offers inertia because it operates as a heavy rotating device.
It delivers enhanced short-term overload capacity by being able to exceed its rating by over two times in a few seconds. This strengthens system support in emergencies or unforeseen events. There is the capacity to maintain a connection and deliver reliable performance even in conditions of significantly low voltage. It also has the capability to deliver rapid dynamic frequency response through the use of advanced excitation and control technologies.
Another advantage of the synchronous condenser market is that this system contributes to the grid a significant short-circuit strength. It also avoids generating harmonics and can take in harmonic currents effectively.
Nevertheless, they come with certain drawbacks. It is mainly higher losses and more mechanical wear. It also has slower reaction times than power electronic systems.
Several synchronous condensers introduced into electricity grids are newly developed systems from turbine manufacturers. Yet there is also potential in repurposing current thermal generators to act as synchronous condensers. They may also be modified for generations typically peaking power and synchronous condensing. It is by adding a synchronous self-shifting clutch which is installed between the generator and the turbine. In this situation, the turbine accelerates the generator. It enables synchronization with the grid. Once synchronized, the turbine detaches from the generator. This then relies on grid power to continue spinning.
The clutch separates the prime mover from the generator if reactive power is necessary. It reconnects for power generation if real power is needed. To provide sufficient space for the clutch between the generator and the turbine, the footing and foundation were extended by several feet. There was also installation for shaft couplings.
