Application of modular power distribution system in high-density data center

Traditional data center power distribution architecture

In the traditional power distribution system, the main incoming line of the data center first reaches the distribution cabinet (the distribution cabinet is generally rated at 50~500kW), which is generally equipped with a large power transformer to convert voltage or improve power quality. Then, the distribution cabinet distributes the main incoming line into a certain number of branch circuits (generally rated at 1.5~15kW) to distribute power to IT equipment. Each IT cabinet uses one or more branch circuits. The wiring of IT cabinets usually requires the use of hard pipes or hoses, which are generally deployed under the raised floor.

When traditional power distribution systems were introduced, there were very few large IT devices in data centers. At that time, changes were rarely made except for planned downtime when major upgrades were made to the IT equipment.

Challenges

At present, data centers have undergone tremendous changes in electricity consumption, especially facing the problems of increased power density, increasing number of independent IT equipment, and the need to add or remove equipment based on the deployment of existing IT facilities. These problems have brought great challenges to traditional power distribution systems. Compared with the few large IT equipment in the past data centers, modern data centers may be equipped with thousands of plug-in devices with independent power cords, which requires more power sockets.

During the life cycle of a data center, IT equipment in the cabinet is frequently replaced, often requiring changes in power or the addition or removal of sockets in the cabinet. Due to changes in power demand, operating data centers often have to add circuits without interfering with nearby IT loads. The power density per cabinet has increased significantly, and the number of branch circuits inside the cabinet has also increased accordingly. A large number of wire ducts fill the ventilation space under the floor, which will cause airflow obstruction and increase the difficulty of changing wiring. The number of IT devices connected to a branch circuit breaker is often far more than one, which makes it difficult to estimate the size of the branch circuit or determine whether it is critically overloaded. Modern data centers generally install dual-circuit power supply systems, and it must be ensured that all circuit loads do not exceed 50%.

However, there is no way to monitor or plan for this. Although people are generally aware of these problems and various corresponding products have appeared on the market, the traditional power distribution architecture is still used, which leads to the following dilemmas for some newly built data centers: data center operators have to replace circuits with power (hot work); operators cannot judge which circuits are critically overloaded or which circuits may be overloaded when one circuit is powered off; the cooling space under the floor is blocked by a large number of cables, which reduces the ventilation of modern IT equipment; the floor space of the distribution cabinet is too large, and the load-bearing capacity of the floor is too high; the distribution cabinet with large transformers cannot be fully utilized because there are not enough branch circuits; the distribution cabinet with large transformers generates a lot of waste heat, which must be cooled, resulting in reduced data center efficiency.

[[178581]]

Optimizing power distribution architecture to meet data center development needs

Optimization goals

Through optimization, an efficient, scalable, and reconfigurable data center power distribution architecture can be created, which has the following features: circuits can be safely added or changed in a running system; there is no need to lay cables under the floor; the power of all circuits can be monitored; the status of all circuit breakers can be monitored remotely; the IT area or related power distribution area can be deployed at any time; the IT cabinet meets all power requirements with only one cable; IT personnel can change the socket model on the IT cabinet by themselves; the capacity and redundancy of each branch circuit can be managed; there is no need to use excessive copper wire; and the efficiency is high.

Large data center scenario

For larger data centers, when installing a group of cabinets, small modular power distribution cabinets are also installed at the same time and plug into the bus duct above. Unlike traditional circuit breaker panels, where the wire ends are not processed in advance, modular power distribution cabinets use backplanes with pre-terminated anti-electric circuit breaker modules installed. Branch circuit modules are not installed in the modular power distribution cabinets at first. The power circuits from the modular power distribution cabinet to the IT cabinets are connected using flexible cables, which need to be plugged into the front of the modular power distribution cabinet on site to meet the different needs of each cabinet. The branch circuit cables of the IT cabinets are pre-terminated and equipped with circuit breaker modules that can be plugged into the anti-electric backplane of the modular power distribution cabinet. For equipment that requires dedicated branch circuits, such as most blade servers, a power distribution cabinet cable contains 1 to 3 branch circuits, which are directly plugged into the blade server without the need for additional cabinet-level power distribution cabinets (such as distribution panels). When the equipment in the cabinet is deployed in a mixed manner, a cabinet-type power distribution cabinet with rated current and replaceable sockets can be used. In this system, new IT cabinet rows are equipped with distribution cabinets and all supporting branch circuit wires and strip cabinet sockets, which can be installed within 1 hour without any wire cutting or termination operations.

Small data center scenario

Small data centers below 300kW can use a simplified architecture with the same components and working principles as large data centers. For small data centers that are only allowed to use one or two distribution cabinets, it is often more economical to connect the modular distribution cabinets directly to the key bus with traditional conduits and wires. Small data centers can also adopt a more simplified solution, that is, to integrate the modular distribution cabinets directly into the UPS system, forming a compact deployment solution that can be placed in the IT room and lined up with the IT cabinets. This saves the use of main bus wiring links and does not require additional space for power supply placement. As for very small data centers or irregularly shaped data centers, the use of small modular distribution units is extremely suitable.

Renovation and upgrading application scenarios

The upgrade of an existing data center often involves many data center projects, with expansion or installation of high-density area projects being the most common. Compared to installing traditional distribution cabinets, the installation process of modular distribution systems is much simpler and more convenient, especially for these renovation projects. When installing new traditional distribution cabinets for existing data centers, there will be a series of challenges, but modular distribution systems can "solve" most of these challenges at the same time. As the data center grows, modular distribution cabinets can coexist and operate with existing traditional distribution cabinets. In these renovation plans, the installation of traditional distribution cabinets is often limited by various historical limitations. Ceiling bus duct elements are not used, and each distribution cabinet is connected to the main bus by traditional pipes and wires. The most important advantage of modular distribution cabinets when upgrading traditional data centers is that since the cables are placed in the ceiling cable trough, their installation will not aggravate the airflow obstruction under the floor.

Power distribution monitoring

In the data center power distribution system, there may be hundreds of circuit breakers under load. The optimized power distribution system uses higher capacity cabinets to power the power, and the number of circuit breakers is reduced by 20% to 40% compared with the general system. Even so, there are still many circuits in the system, which can be divided into 4 levels: UPS main bus, distribution cabinet input, branch circuit, and socket. The modular power distribution system uses built-in current and energy monitoring to know every line at each level. In addition, the branch circuit breakers of the distribution cabinet are also monitored to grasp their working status in real time. All monitoring communicates through the open standard protocol of Simple Network Management Protocol (SNMP). Capacity management software can monitor each circuit in the system, enhance safety factors, verify redundancy and confirm existing capacity.