Paralleling diesel generators is a complex but highly effective approach for meeting high - power demands while ensuring reliability and flexibility in power supply systems. As a trusted diesel generator supplier, we understand the complexities involved in this process and the critical requirements that must be met. In this blog, we will delve into the key aspects that need to be considered when paralleling diesel generators.
Electrical Characteristics
Voltage
One of the fundamental requirements for paralleling diesel generators is to match the output voltage. When connecting multiple generators, the voltage of each unit must be set to the same level. A slight difference in voltage can lead to circulating currents between the generators, which not only causes unnecessary power losses but also may damage the generator windings over time. Modern diesel generators, such as our High - Efficiency Industrial Diesel Generator with Wheels, are equipped with advanced voltage regulators that can precisely adjust the output voltage. These regulators continuously monitor and control the voltage to ensure that it remains stable and consistent with other paralleled generators.
Frequency
Frequency is another crucial electrical parameter. The frequency of all paralleled diesel generators must be synchronized. In a standard electrical grid in most countries, the frequency is typically 50 Hz or 60 Hz. Any deviation from this set frequency can cause power quality issues and disrupt the operation of connected electrical equipment. To achieve frequency synchronization, generators are usually equipped with a governor system. The governor controls the engine speed to maintain a constant frequency. For example, in our Small Diesel Back Up 5 Kva Silent Soundproof Generators for Home Use, the governor system is designed to respond quickly to load changes and keep the frequency within an acceptable range, facilitating seamless paralleling with other generators.
Phase Relationship
The phase relationship between the output voltages of the paralleled diesel generators must be identical. If the phases are not aligned correctly, large inrush currents can occur when the generators are connected, which can cause significant stress on the generators and associated electrical components. This requires precise synchronization equipment. Synchronizing panels are commonly used in parallel generator systems. These panels monitor the phase angles of the generators and provide signals to control when the generators can be safely connected. Our experienced technicians can help customers select the appropriate synchronizing panels and configure them correctly for their specific paralleling requirements.
Load Sharing
Proper load sharing is essential for the stable operation of paralleled diesel generators. Each generator in the parallel system should share the total load in proportion to its rated capacity. Uneven load sharing can result in some generators being overloaded while others are under - utilized. This not only reduces the overall efficiency of the system but also shortens the lifespan of the overloaded generators.
Real - Power Sharing
For real - power sharing, the governor systems of the generators work together. They communicate with each other through a load - sharing control system. When the load on the system changes, the governor adjusts the fuel supply to the engine of each generator to ensure that the real - power is divided equally among the generators based on their rated capacities.
Reactive - Power Sharing
Reactive - power sharing is related to the voltage and power factor of the system. Automatic voltage regulators (AVRs) play a key role in reactive - power sharing. By adjusting the excitation of the generator's alternator, the AVR can control the reactive - power output of each generator. This helps to maintain a balanced power factor across the parallel system and ensures that each generator contributes its fair share of reactive power.
Control and Monitoring
To ensure the safe and efficient operation of paralleled diesel generators, a comprehensive control and monitoring system is required.
Control System
A centralized control system can manage the starting, stopping, and synchronization of the generators. It can also control the load - sharing process and adjust the electrical parameters as needed. Modern control systems often use microprocessors and advanced algorithms to provide accurate and reliable control. They can communicate with the generators and other electrical equipment in the system through a network, enabling remote operation and control.
Monitoring System
Monitoring is equally important. A monitoring system can continuously collect data on the performance of the generators, such as voltage, current, frequency, temperature, and oil pressure. This data can be used to detect any potential problems early and take preventive measures. For example, if the temperature of a generator exceeds the normal range, the monitoring system can send an alarm to the operator, who can then take appropriate action to avoid equipment damage.
Physical and Mechanical Considerations
Location and Installation
The location of the diesel generators is critical. They should be installed in a well - ventilated area to ensure proper cooling and prevent the accumulation of exhaust gases. Adequate space should be provided around the generators for maintenance and access. Additionally, the generators should be installed on a stable and level foundation to minimize vibration and ensure smooth operation.
Exhaust System
A proper exhaust system is necessary to safely remove the exhaust gases from the generators. When paralleling multiple generators, the exhaust system must be designed to handle the increased volume of exhaust gases. It should also be installed in a way that minimizes the back - pressure on the generators, as high back - pressure can reduce the engine's performance and efficiency.
Protection and Safety
Over - Current Protection
Over - current protection devices, such as circuit breakers, are essential for protecting the generators and the connected electrical equipment from excessive current. These devices can automatically disconnect the generator from the system in the event of a short - circuit or over - load condition, preventing damage to the equipment.
Over - Voltage and Under - Voltage Protection
Over - voltage and under - voltage protection systems monitor the output voltage of the generators. If the voltage exceeds or falls below the acceptable range, the protection system can take appropriate actions, such as adjusting the voltage regulator or disconnecting the generator from the system.
Emergency Stop
An emergency stop mechanism should be installed on each generator and at a central location in the parallel system. In case of an emergency, such as a fire or a serious equipment malfunction, the operator can quickly stop all the generators to prevent further damage or danger.
In conclusion, paralleling diesel generators requires careful consideration of electrical characteristics, load sharing, control and monitoring, physical and mechanical aspects, as well as protection and safety measures. As a professional diesel generator supplier, we have a wide range of products, including the 10kva Heavy Duty Diesel Generator, and the expertise to help you meet all the requirements for successful generator paralleling. If you are interested in purchasing diesel generators or need more information on generator paralleling, we encourage you to contact us for a detailed discussion and customized solutions.
References
- [Electrical Power Systems: Operation and Control] by J. Wesley Hettle
- [Diesel Generator Handbook] by various industry experts