Delta UPS application in Haikou People's Hospital

1. Customer Demand

The UPS construction of Haikou People's Hospital is mainly to ensure the long-term, stable and uninterrupted operation of the core equipment of the weak current system in the computer room. On the one hand, the UPS power system is used to stabilize the voltage signal of the power grid to provide a more stable working voltage for the core equipment. At the same time, during the power outage and before the generator starts, the core equipment in the weak current room cannot stop running, and the UPS needs to provide timely power supply to ensure the uninterrupted operation of the core equipment. Due to the importance of the load, the customer requires the use of 1+1 redundant parallel connection to provide a highly reliable power supply system for the load during planning.

2. 1+1 Redundancy System Solution Based on HIFT UPS

2.1 User Demand Analysis

Hainan Provincial People's Hospital built a data room and configured a UPS system. The actual load is about 25KW, as shown in the following table:

In the "Communication Industry Standard YD/T1095-2000 Uninterruptible Power Supply for Communications - UPS" standard, Item 17 of Table 1 proposes the "Output Power Factor" project, and the technical requirement is that the output power factor is ≤0.8.

At the same time, the UPS should have a 20% to 30% reserve. The total capacity of the UPS can be calculated as:

UPS capacity (KVA) = 23.36KW/0.8/0.8=36.5KVA. Therefore, the recommended UPS capacity is 40KVA.

Since IT applications are relatively important, the system needs to run continuously and uninterruptedly at ordinary times, but it can be planned for power outage maintenance, but it needs to be notified in advance. During business operation, power outages are absolutely not allowed, so the system needs to adopt redundant power supply. The backup time is 4 hours. The entire system requires extremely high reliability and availability.

Based on the above analysis, we recommend customers to choose HIFT UPS. Delta HIFT UPS has the following four advantages:

1. MTTR is close to 0, modular hot-swap online maintenance, greatly shortening maintenance time

2. N+X redundancy provides the highest system reliability.

3. Expand capacity on demand and provide the most flexible and economical investment and configuration strategies

4. High efficiency and energy saving, providing the lowest operating cost

Generally, the lower the load, the lower the UPS efficiency. However, for HIFT UPS, even if the load is only 15% of the rated capacity, the overall efficiency is over 90%; when the load reaches 27%, the efficiency is as high as 94%. Every small step increase in efficiency is a big step in saving energy expenditure.

2.2 Schemes and Scheme Analysis:

2.2.1 Redundancy Configuration Scheme of HIFT UPS

The current actual load is 25KW. Due to the performance advantage of HIFT UPS's on-demand capacity expansion, it can be configured according to the current actual load. Therefore, the load capacity is configured according to 25KW.

25KW/(0.8*0.8)≈40KVA. According to customer needs, a redundant parallel solution is required.

2.2.2 Solution

2 HIFT 40KVA systems in parallel Total capacity 80KVA

The parallel system is as follows:

The configuration list is as follows:

Two 40KVA systems are connected in parallel, each UPS has two modules, a total of four modules, and a total capacity of 80KVA. When the system is operating normally, each module shares the load equally. The current load is 25KW, and the four modules share the load equally, with each module running at 6.4KW.

When the mains power is normal, if any module fails, it will automatically exit the system under the command of the system control program, and the remaining modules will automatically and evenly share the load brought by the failed module.

Since the actual load capacity is 25KVA, the actual power capacity only occupies 2 power modules, and the redundant 2 power modules are a 2+2 system. That is to say, only when 3 modules fail at the same time, the UPS will switch to bypass operation and operate in an unprotected state.

When the system is operating normally, if the mains fails (power outage or voltage exceeds the limit), the two UPSs will switch to battery inverter operation at the same time. During this period, if one of the modules fails, the faulty module will be removed from the system, and the remaining modules will evenly share the load of the faulty module and continue to operate in normal battery inverter mode.

As customer loads grow, power modules can be added online at any time (each module is 20KVA), and the maximum capacity can be expanded to 240KVA, which far exceeds customers' future expansion requirements.

2.2.3 Comparison of configuration between common UPS 1+1 redundant parallel system and HIFT UPS solution

2.2.3.1 Reliability comparison

In this case, the reliability calculation formula of the common UPS 1+1 parallel redundant system is as follows:

In the formula:

R: represents system reliability

F(t): probability of failure

If the reliability of a single machine is R(t)=0.99, substituting it into the formula, the reliability of the 1+1 parallel system is: R (1+1)=0.9999

In Solution 1, HIFT UPS also uses the host 40KVA system parallel redundancy, but due to its modular structure design, it can form an N+X parallel system, that is, redundancy in the case of system redundancy, forming a 2+2 system. According to the system reliability model, the calculation is as follows:

Where m=2, n=2, the calculated value is R(2+2)=0.999996

System solution reliability comparison

Through the above reliability analysis and comparison of the common UPS 1+1 parallel connection and HIFT UPS N+X redundancy solution, the following conclusions can be drawn:

The redundant power supply system is composed of a single machine 1+1. When the reliability of a single machine is 0.99, the reliability of the parallel system can reach 0.9999.

In the 1+1 redundant system composed of HIFT UPS, when the reliability of a single module is also 0.99, the reliability of the 2+2 system composed of two systems in parallel is 0.9999999995, which is 200,000 times higher than that of the 1+1 system.

In addition, the redundant power supply system is composed of a single machine 1+1. When the reliability of a single machine is 0.99, the reliability of the parallel system reaches 0.9999. This value has nothing to do with the load. In other words, no matter how much the actual load of the system is, the system is always 1+1 redundant, and two machines are not allowed to fail at the same time. The reliability is always 0.9999.

However, in the N+X redundant power supply system composed of HIFT UPS, the actual load of the system accounts for the equipment capacity and is closely related to the reliability of the system. The lower the actual load, the higher the system reliability. Customers can improve the system reliability by adding power modules online to ensure safe operation of the system.

2.2.3.2 Economic comparison

(1) Equipment purchase cost

As for future capacity expansion, it is very difficult to expand the capacity of ordinary UPS, which involves the distribution capacity, cable capacity, location and area, and customer requirements for the availability of system operation. When the actual load increases, it becomes almost impossible to expand the capacity. Therefore, in general, when purchasing UPS, customers will consider buying the capacity of the equipment to the estimated capacity in the future at one time to avoid the risk of future overload. In addition, the host configuration is a 25% margin, and the two UPSs are evenly divided into 50% load operation when the system is connected in parallel. The load capacity of a single UPS during actual operation is only 18% of the equipment capacity. This has caused a huge waste of initial purchase costs.

The total capacity of the HIFT UPS solution in the initial equipment purchase can be configured with a UPS system that is lower than the 1+1 redundant configuration. The reason is that the HIFT UPS N+X system can grow with the actual needs of customers. This expansion can be completely without downtime and is quick, simple and convenient to implement. Since the capacity can be expanded on demand, customers do not need to adopt a one-time configuration and can increase equipment investment in stages as the business volume grows.

In any case, compared with the traditional 1+1 redundant configuration solution, the HIFT UPS N+X power supply solution can save customers a lot of initial equipment procurement costs during the initial equipment procurement, and can provide customers with a more economical equipment investment method.

(2) Equipment operating costs

In the 1+1 redundant configuration power supply solution, a one-time investment method was adopted. When the two machines were running in parallel, the load capacity of each UPS was only about 18% of the equipment capacity, resulting in a significant reduction in the efficiency of the UPS, which was only 82%. The system operated inefficiently for a long time. The following is the average data of the relationship between load and efficiency of various UPS:

■Efficiency is 89% at 50% load

■ Efficiency is 88% at 40% load

■Efficiency is 86% at 30% load

■ Efficiency is 82% at 20% load

In the 1+1 redundant parallel solution, the single load is 12.5KW, the UPS capacity is 40KVA, the single load accounts for 39%, and the overall efficiency is 88%. The annual power consumption of the system is:

[(12.5KW/0.88-12.5KW)*8760h]*2=26280KWH (degrees)

If the industrial electricity cost is 1.5 yuan per kilowatt-hour, the annual electricity bill is 39,420 yuan

In the HIFT UPS solution, the load of a single unit is 12.5KW, the UPS capacity is 40KVA, and the load of a single unit accounts for 39%. Since the efficiency of the HIFT UPS can reach 94% when the load reaches 27%, the efficiency of the whole unit is 94% in the solution. The annual power consumption of the system solution equipment is:

[(12.5KW/0.94-12.5KW)*8760h]*2=13140KWH (degrees)

If the industrial electricity cost is 1.5 yuan per kilowatt-hour, the annual electricity bill is: 19710 yuan

Comparison of operating costs:

2.2.3.3 Comprehensive comparison

3. Conclusion

Delta's HIFT UPS has the flexibility of on-demand capacity expansion, the reliability of N+X redundancy, the high efficiency at low loads, and the fastest maintenance time brought by module hot-swappable technology. It not only brings the highest availability and convenient future expansion to Haikou People's Hospital, but also brings the lowest operating costs to customers.