Power generators are classified as synchronous and asynchronous according to their operation.
The synchronous generator maintains a frequency synchronized with the motor rotation, offers fixed frequency regardless of load, and is used in hydroelectric plants, but requires direct current and maintenance of mechanical contacts.
The asynchronous generator has a simpler and more robust construction, without mechanical contacts in the rotor, and is used in wind turbines, but demands reactive power and stops operating if the load exceeds its capacity.
Both convert mechanical energy into electrical energy for critical applications in hospitals, industries, and events.
Have you ever heard of synchronous and asynchronous generators?
Responsible for meeting the energy needs of any establishment that depends entirely on energy to be fully operational, the power generator is a piece of equipment that transforms mechanical or chemical energy into electrical energy.
It is an effective and safe solution for places that require uninterrupted electricity, such as hospitals, large industries, shopping malls, and large-scale events.
In general, the electric generator can be classified as synchronous or asynchronous, according to the way its motor works.
What are Synchronous and Asynchronous Machines?
Before we understand synchronous and asynchronous generators, we need to know a little about synchronous and asynchronous machines, and what the difference is between them:
Synchronous and asynchronous machines are electrical machines that transform energy from a primary source into electrical energy.
Synchronous Machines
The synchronous machine is most used in electrical power generation systems, where it functions as a generator or as a reactive power compensator.
Currently, the use of this converter also extends to high-power drive systems, pumping, and electric traction.
They are rotary electromechanical converters that operate at constant speed when in steady sinusoidal state and are mainly used to convert certain mechanical energy sources into electrical energy.
Asynchronous Machines
Induction asynchronous motor is an electric motor of three-phase, two-phase, or single-phase current, whose rotor is excited by the stator and the rotation speed is not proportional to the frequency of its power supply (the rotor speed is less than that of the rotating field, due to slip).
Main components of the synchronous generator
The efficiency and control of a synchronous generator depend on an internal architecture where each part plays a strategic role.
The operation is based on the interaction of three main elements:
- Stator: fixed structure of the generator, which houses the coils where the alternating current is induced to supply the load.
- Rotor: moving part that, when rotating, creates the magnetic field necessary for induction. Depending on the application and speed, it can have a salient or smooth pole shape.
- Excitation system: heart of the generator control, responsible for providing direct current to the rotor to generate the magnetic flux and stabilize the operation.
What is the difference between synchronous and asynchronous generators?
The main difference between the two models lies in autonomy and how they interact with the power grid.
The synchronous generator acts as a “leader”: it has full control over its own voltage and maintains the frequency strictly constant, regardless of variations.
The asynchronous generator, on the other hand, functions more like a “follower”: it generally needs a portion of the grid’s energy for its magnetization before it starts supplying electricity.
In summary, while the synchronous helps sustain the grid, the asynchronous depends on it to operate.
How does a synchronous generator work?
Its operation is based on the precise interaction between magnetic fields, ensuring that the energy produced is stable and predictable.
According to the technical literature of electrical engineering, synchronous speed is a physical law for these devices.
- Magnetic field in the rotor: an external source feeds the rotor (rotating part) with direct current, creating a constant magnetic field that rotates with the shaft. This is important because it allows full control over the output voltage.
- Induction in the stator: the movement of the rotor’s magnetic field crosses the stator’s conductors (fixed part), generating electricity by induction. This action is fundamental to ensure that energy conversion is efficient and of high quality.
- Frequency and voltage: the speed is calculated by the formula N = 120 × f / p (N: RPM; f: frequency in Hz; p: poles). As a result, it ensures that the equipment operates in full harmony with the power grid requirements.
Advantages of synchronous generators
It has the advantage of the alternating current frequency remaining fixed, regardless of the load the generator is supplying.
This feature makes this type of generator used in large hydroelectric plants.
Synchronous generators are also more efficient than asynchronous ones when used on a large scale.
Disadvantages of synchronous generators
The need for direct current to power the rotor’s electromagnets is a disadvantage, in cases where permanent magnets are not used.
This direct current can come from a battery, or in the case of alternators, from a secondary generator that shares the same shaft as the main generator.
Another negative point is the fact that they are more complex than asynchronous motors, with mechanical contacts that require maintenance.
How does an asynchronous generator work?
The asynchronous generator uses the same principle as asynchronous motors (also known as induction motors) to produce energy.
When used as a motor, electrical energy is converted into mechanical energy, causing the rotor to spin.
The rotation speed depends on the motor’s characteristics, but it will always be below the so-called synchronous frequency.
When used as a generator, the rotor must be spun above this synchronous frequency to convert mechanical energy into electrical energy.
Advantages of asynchronous generators
The main advantages of an asynchronous generator are its simpler and more robust construction, the absence of mechanical contacts in the rotor, reducing maintenance due to wear, and the independence from synchronism with the rotor speed, which makes it widely used in applications such as wind farms.
Disadvantages of asynchronous generators
The disadvantage of this type of generator is that in addition to requiring the rotor to spin faster than the synchronous frequency, the generator also needs reactive power to generate active power.
This can be overcome by using a capacitor bank connected to the generator.
Another disadvantage is that once the load powered by the generator exceeds its capacity, the generator immediately stops generating power.
Final comparison
These are very similar pieces of equipment, but the asynchronous model is generally simpler and more robust, requiring capacitors to balance the power factors resulting from the lack of synchronism between rotation and frequency.
In general, the asynchronous generator is very economical and requires less maintenance than synchronous generators, in addition to being more adaptable to different applications and energy specifications.
Applications and advantages of the synchronous generator
Synchronous generators are preferred in sectors where continuity and quality of energy are non-negotiable. They act as the backbone of backup systems in large infrastructures that operate 24 hours a day.
Here are some of these sectors:
- Data Centers: ensures stable frequency to protect sensitive servers against power fluctuations, which is important to prevent data loss and hardware damage.
- Hospitals: provides reliable power to surgical centers and ICUs in case of utility grid failure, a fundamental aspect for preserving lives.
- Events: supports large sound and lighting systems without voltage drops, ensuring the audience’s experience and the integrity of the equipment.
Tecnogera, a reference in power generation and with the most modern fleet in the country, offers the rental of high-performance synchronous generators, ensuring full technical support.
Our solutions eliminate risks of electrical instability with modern equipment and rigorous preventive maintenance.
Discover Tecnogera’s energy solutions.
How to identify if the generator is synchronous or asynchronous?
Differentiating these devices is essential to ensure that the technical application is correct and safe for your installation.
- Check the nameplate: verify if the term “Synchronous” or “Induction” is listed in the manufacturer’s specifications. This is important to immediately identify the nature of the machine.
- Check the excitation system: observe if the equipment has brushes or a brushless excitation unit. This is relevant because synchronous generators require this power supply for the rotor field.
- Analyze the rotation: check if the rotation is fixed (e.g., 1800 RPM for 60Hz) or if it shows slip under load. This confirms whether the frequency remains constant regardless of demand.
- Consult a specialist: in case of doubt, request a technical analysis from the Tecnogera team for an accurate diagnosis and to avoid connection errors that can damage your electrical system.
How to choose between synchronous and asynchronous generator?
The decision depends on the load stability and the autonomy your project requires. In practice, the synchronous generator is the ideal choice when the goal is to have full control over voltage and reactive power supply.
Getting this choice right ensures operational safety and avoids oversizing, reducing unnecessary fuel and maintenance costs.
In critical applications, the investment in renting a synchronous machine pays off by protecting your assets.
To ensure the best configuration for your project, request specialized service from our team.
Variety of power solutions for every operation
In addition to synchronous and asynchronous generators, Tecnogera offers load bank and battery storage systems. This variety allows you to compose the most suitable solution, integrating different technologies to maximize your business’s energy security.
Having access to a complete portfolio under a single supplier facilitates the balance between stability and operational cost.
Combine a power generator synchronous with state-of-the-art accessories ensures that your plant supports any load profile.
Sustainability in generator choice
At Tecnogera, we combine high technology with environmental commitment through battery energy storage systems (BESS).
This zero-emission solution works in synergy with synchronous generators, taking on demand during peak hours and significantly reducing fossil fuel burning.
The result is a cleaner operation for construction sites and temporary projects. In practice, this technological integration has already allowed our clients to reduce diesel consumption by up to 30%, impacting both the environment and the project budget.
Innovation in power generation systems
The complexity of a modern generation system demands the advanced technical expertise that Tecnogera delivers end-to-end.
Our engineering customizes projects that strictly meet reactive power and frequency stability requirements.
Our innovation is validated by the delivery of hundreds of critical energy projects annually, with real-time remote monitoring.
We use proprietary technologies to ensure that each power generator operates at its maximum energy efficiency and operational efficiency.
Rent the right generator for your operation with Tecnogera
Count on specialized technical support to size the ideal power generator for your operation, whether synchronous or asynchronous.
Our team analyzes your actual demand to offer the technology that best balances performance and economy.
The rental with Tecnogera ensures immediate access to a modern fleet, eliminating concerns about asset depreciation and maintenance.
We focus on the resilience of your electrical system so you can focus on growing your business.
Frequently asked questions about synchronous generators
Can an asynchronous generator be used as the main generator?
Although technically possible, its use as the main generator is rare and complex, as it requires an external magnetization source to maintain voltage stability.
In a synchronous machine, the rotor rotates in synchronism with which element?
In a synchronous machine, the rotor rotates in sync with the rotating magnetic field generated by the electric currents circulating in the stator coils.
Which generator is best suited for rental in hospitals and industries?
The synchronous generator is the most suitable due to its superior ability to regulate frequency and support complex loads with total safety.
Is it better to buy or rent a synchronous generator?
Renting is usually more advantageous as it eliminates the need for a high investment in the asset and ensures access to 24-hour technical support, updated equipment, and immediate replacement in case of failures.
Does Tecnogera offer synchronous and asynchronous generators for rent?
Yes, we have synchronous and asynchronous generators to meet everything from complex industrial applications to simple network support needs with maximum efficiency.
How does synchronous generator rental work with Tecnogera?
The rental process includes sizing consultancy, installation logistics, assisted operation, and complete maintenance throughout the contract period.
