In today's digital era, data centers have become the core infrastructure for enterprise operations. Whether in finance, internet services, or traditional manufacturing, data centers are responsible for massive volumes of data storage, processing, and transmission. Within this complex and precise system, power supply is undoubtedly the lifeline that ensures the normal operation of data centers. Once the power supply is interrupted, data loss or service disruption can cause enormous economic losses and damage to a company's reputation. Therefore, diesel generator sets, as emergency power supplies for data centers, are of undeniable importance.
A data center is a complex system composed of numerous devices, including computer servers, storage devices, network communication equipment, and more. These devices require continuous and stable power supply to operate normally. As data volumes continue to grow and business complexity increases, the power demand of data centers has also become increasingly significant. It is estimated that a medium-sized data center's power consumption may be equivalent to the total electricity usage of thousands of households. Therefore, ensuring the stability and reliability of the power supply is a key factor for data center operations.
Within the power supply system of a data center, diesel generator sets are indispensable emergency power sources. When utility power fails or is interrupted, diesel generator sets can start quickly and take over the power supply, ensuring that the data center's equipment does not stop operating due to power outages.
Selecting a suitable diesel generator set is the first step to ensure stable operation of a data center. When choosing, the following key factors must be considered:
- Generating Capacity: Calculating the required generating capacity based on the actual power consumption of the data center is the foundation of selection. Not only must the operating power of the equipment be considered, but the starting power must also be accounted for, with additional margin reserved to handle emergencies. For example, equipment such as servers may require several times more power at startup than during operation. Therefore, these factors must be fully considered when calculating the generator's power.
- Purpose: It is important to clarify whether the diesel generator set will serve as a backup power source or a primary power source. If it is used as a backup power source, it must ensure rapid restoration of electricity in the event of a power outage. This involves technical parameters such as generator startup speed and parallel operation time.
- Fuel Supply: The availability of diesel may vary across industries and regions. When selecting a diesel generator set, the stability of local diesel supply, price, and ease of transportation must all be considered.
- Noise Level: Data centers are often located in urban areas or near residential communities, so the noise level of diesel generator sets must comply with local environmental regulations. Excessive noise can disturb surrounding areas and may even lead to complaints.
- Generator Type: According to the needs of the data center, diesel generator sets can be divided into the following types:
- Open-type diesel generator sets: These lack protective enclosures and are generally used in fixed environments and for large-scale equipment. This type of generator is relatively inexpensive but requires good airflow and maintenance.
- Silent diesel generator sets: These reduce noise through enclosures and soundproofing equipment and are suitable for areas with strict noise regulations.Mobile diesel generator sets: Equipped with wheels or trailers, they can be moved at any time, suitable for emergency or temporary power supply needs.
Well-known brands often represent higher quality products and more complete after-sales service. When selecting, attention can be paid to some industry-recognized brands such as Cummins and Caterpillar. Additionally, understanding brand market feedback and user evaluations can provide important references for selection.
Selecting a suitable diesel generator set is only the first step; subsequent maintenance and upkeep are equally important. Proper maintenance can extend the service life of the generator and ensure it can start normally and operate stably at critical moments.
- Prohibition of shutdown under load: Before shutting down, the load must first be gradually removed. Then the generator output circuit breaker should be turned off, and the diesel engine should continue to operate at idle speed for about 3–5 minutes before complete shutdown. This prevents equipment damage caused by sudden shutdown.
- Load bank maintenance: To avoid exposure to sun and rain, protective covers are usually installed on load banks. Therefore, regular waterproofing and anti-rust treatment must be conducted annually. Additionally, since load banks generate high internal temperatures during operation, proper heat dissipation is required. If rainwater enters the ventilation holes, it can cause excessive moisture inside, which over time may reduce the insulation of resistance wires. Therefore, regular maintenance of load banks is also necessary, including dust removal, component inspection, and insulation monitoring.
Regular comprehensive inspections of diesel generator sets should include, but are not limited to, the following:
- Fuel system inspection: Ensure normal fuel supply without leakage.
- Lubrication system inspection: Check oil level and quality, and replace lubricating oil in a timely manner.
- Cooling system inspection: Ensure coolant level is normal and the cooling system is leak-free.
- Electrical system inspection: Check generator output voltage, frequency, and other parameters; inspect battery capacity and condition.
- Starting system inspection: Ensure that the starter motor and battery can reliably start the generator.
In practical data center applications, multiple diesel generators often operate in parallel to meet the power demand of the data center. The stability and reliability of parallel operation are key to the data center's power supply. However, parallel systems also face several technical challenges.
- Control of voltage difference, frequency difference, and phase difference: At the moment of parallel operation, the differences in voltage, frequency, and phase among generators must be controlled within a narrow range (e.g., phase difference <10°). This requires high-performance digital parallel controllers (such as Woodward, ComAp). Controllers must achieve even distribution of active and reactive power, with unbalance less than 3%. Unequal distribution may cause generators to compete or back-feed, damaging the equipment.
- Rapid startup and synchronization: The ATS (Automatic Transfer Switch) detects utility failure and simultaneously starts all backup generators. Once the generators reach rated speed and voltage, the controllers adjust them to synchronize before closing the generator bus circuit breaker. The ATS then switches to the generator bus, and the control system sequentially applies load according to a preset order to avoid impact on the generators and UPS. The entire process typically completes within 30–60 seconds, with online UPS ensuring “zero-millisecond” interruption for IT equipment.
- Parallel operation time: The time from utility power failure to the completion of generator parallel operation and the start of power supply. Generally, the shorter this time, the less impact on data center equipment.
- Power distribution uniformity: After parallel operation, whether the active and reactive power among generators is evenly distributed. Uneven distribution may lead to overload of certain generators, affecting stability and service life.
- System stability: Whether the parallel system can maintain stability during operation without voltage fluctuations or frequency changes. High-performance controllers and precise synchronization technology are required to ensure this.
The stable operation of a data center depends on reliable power supply, and diesel generator sets play a critical role as emergency power sources. Selecting a suitable diesel generator set requires comprehensive consideration of generating capacity, purpose, fuel supply, noise level, generator type, brand, and after-sales service. At the same time, proper maintenance is key to ensuring long-term stable operation. The stability and reliability of parallel operation systems are central to data center power supply, requiring high-performance controllers and precise synchronization technology. In the future, with technological advancements, diesel generator sets will move toward intelligence, high efficiency, modular design, and scalability. Only by thoroughly understanding the fundamentals, type selection, brand evaluation, and subsequent maintenance management of diesel generator sets can decision-makers make wiser choices, ensuring the stability and safety of data center operations.
