Energy storage and power supply method for data center

Abstract

The invention discloses an energy storage and power supply method for a data center, which does not comprise a UPS (Uninterrupted Power Supply) and comprises a transformer, an energy storage inverter, an energy storage battery, a distributed green energy source and an IT (Information Technology) load, wherein the input end of the transformer is connected with a high-voltage alternating-current power distribution network, the output end of the transformer is connected with the energy storage inverter, and the output end of the energy storage inverter is connected with a low-voltage direct-current micro-grid bus; the energy storage battery, the distributed green energy and the IT load are respectively connected with the low-voltage direct-current micro-grid bus through independent DC / DC converters; the output voltage of the high-voltage alternating-current power distribution network is transmitted to the low-voltage direct-current micro-grid bus after passing through the transformer and the energy storage inverter; the distributed green energy transmits voltage to the low-voltage direct-current micro-grid bus; and when the energy storage battery or the IT load has a charging demand, the low-voltage direct-current micro-grid bus supplies power to the energy storage battery or the IT load. According to the energy storage and power supply method, efficient, reliable, distributed green energy consumption and 0ms seamless switching power supply can be achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of energy storage and power supply, and in particular to an energy storage and power supply method for a data center. Background Art

[0002] In recent years, the scale of data centers and communication rooms, as core infrastructure supporting the storage, processing and transmission of massive data, has expanded rapidly to meet the huge demand in emerging technology fields such as Internet services, cloud computing, big data analysis and artificial intelligence.

[0003] However, this also brings several major challenges, especially the issue of power supply and energy efficiency. The surge in electricity demand requires more reliable grid support and more efficient energy storage and energy utilization strategies, while also prompting the industry to explore and adopt solutions such as renewable energy, optimized cooling systems, and intelligent energy management to reduce dependence on traditional energy and reduce carbon footprint.

[0004] At present, the existing energy storage power supply systems used for data center power supply mainly include: UPS AC power supply, Panama power supply. Among them, the traditional data center and communication room power supply and distribution system using UPS AC power supply generally includes 10kV high-voltage distribution system, transformer, low-voltage distribution, uninterruptible power supply system and its input and output distribution, and internal distribution of the room. The detailed circuit diagram can be found in Figure 1 ; The second Panama power supply uses the magnetic saturation characteristics of the rectifier transformer and connects an AC / DC converter at the back end for rectification and conversion. The advantage is that the efficiency will be relatively high, but the surplus power cannot be connected to the grid, the rectified voltage is relatively low (336V / 240V), the access to green energy is limited, and the cost is relatively high. At the same time, the green energy access is through 10kV, and the utilization efficiency of photovoltaics is not high.

[0005] Therefore, whether using the traditional UPS AC power supply solution or the Panama power supply developed in recent years, there will be the following problems: (1) The seamless on-grid and off-grid switching time is long, and the UPS AC power supply solution requires the use of STS static transfer switches for STS switching, which is difficult to meet the switching time of 5 / 15ms; (2) Energy management is poor, and the access and absorption efficiency of green energy (such as solar energy, wind energy, thermal energy storage, hydrogen energy storage, pumped energy storage) is low; (3) The battery utilization rate is low and cannot create added value; (4) It is a passive load with low power quality and requires additional SVG (Static Var Generator) equipment to supplement it.

[0006] Therefore, there is an urgent need to build a new power architecture and design a new energy storage power supply method for data centers to achieve efficient and reliable, distributed green energy consumption, and seamless switching of power supply. Summary of the invention

[0007] The technical problem to be solved by the present invention is to design a method for powering a data center with energy storage to solve the problems of the inability to achieve seamless on-grid and off-grid switching and low efficiency of green energy consumption in the existing traditional energy storage power supply method for powering a data center.

[0008] In order to solve the above technical problems, the technical solution adopted by the present invention is: a method for energy storage power supply for a data center, which does not include a UPS power supply, and includes: a transformer, an energy storage inverter, an energy storage battery, distributed green energy and an IT load; wherein the input end of the transformer is connected to a high-voltage AC distribution network, the output end of the transformer is connected to an energy storage inverter, and the output end of the energy storage inverter is connected to a low-voltage DC microgrid bus; the energy storage battery, distributed green energy and IT load are respectively connected to the low-voltage DC microgrid bus through independent DC / DC converters; the output voltage of the high-voltage AC distribution network is transmitted to the low-voltage DC microgrid bus after passing through the transformer and the energy storage inverter; the distributed green energy transmits voltage to the low-voltage DC microgrid bus; when the energy storage battery or IT load has a charging demand, the low-voltage DC microgrid bus supplies power to the energy storage battery or IT load.

[0009] Furthermore, in the energy storage power supply method described in the present invention, two groups of transformers, energy storage inverters, energy storage batteries and distributed green energy are included, and the low-voltage DC microgrid bus includes a first low-voltage DC microgrid bus and a second low-voltage DC microgrid bus; the input ends of the two groups of transformers are connected to the high-voltage AC distribution network, and the output ends are respectively connected to the energy storage inverters of each group, the output end of one group of energy storage inverters is connected to the first low-voltage DC microgrid bus, and the output end of the other group of energy storage inverters is connected to the second low-voltage DC microgrid bus; wherein, the first low-voltage DC microgrid bus and the second low-voltage DC microgrid bus are connected to the IT load through a DC / DC converter.

[0010] Furthermore, in the energy storage and power supply method described in the present invention, one group of the energy storage batteries and distributed green energy are connected to the first low-voltage DC microgrid bus through independent DC / DC converters; another group of the energy storage batteries and distributed green energy are connected to the second low-voltage DC microgrid bus through independent DC / DC converters.

[0011] Furthermore, in the energy storage power supply method described in the present invention, the input end of the transformer is connected to the high-voltage AC distribution network through a frame-type circuit breaker.

[0012] Furthermore, in the energy storage and power supply method described in the present invention, the output voltage of the high-voltage AC distribution network is 10 kV, 20 kV or 35 kV.

[0013] Furthermore, in the energy storage and power supply method described in the present invention, the distributed green energy includes solar energy, wind energy, thermal energy storage energy, hydrogen energy storage energy, and pumped energy storage energy.

[0014] Furthermore, the energy storage power supply method described in the present invention also includes a water cooling unit, and the low-voltage DC microgrid bus is connected to the water cooling unit through a DC / AC inverter.

[0015] Furthermore, in the energy storage and power supply method described in the present invention, the energy storage battery is a string-type energy storage battery, which includes multiple clusters of batteries, and the multiple clusters of batteries are respectively connected to multiple independent DC / DC converters to be connected to the low-voltage DC microgrid bus through the DC / DC converter.

[0016] Furthermore, in the energy storage power supply method described in the present invention, the IT load includes a plurality of load units, and the low-voltage DC microgrid bus is respectively connected to the plurality of load units through a single DC / DC converter.

[0017] The beneficial effect of the present invention is that the inventor has optimized and designed a method for energy storage and power supply for data centers, which can achieve efficient and reliable, distributed green energy consumption, and seamless switching of power supply through a new design of its own power architecture.

[0018] In the energy storage power supply method designed by the present invention, a new energy storage system and a PCS flexible networking system with a DC networking design are adopted, that is, the energy storage inverter is used to convert the high-voltage AC power received from the transformer into low-voltage DC power, and input it to the low-voltage DC microgrid bus for power supply; at the same time, by setting a low-voltage DC microgrid bus to connect the energy storage battery, distributed green energy and IT load respectively, the power supply of the low-voltage DC microgrid bus with multiple voltage input sources (including at least one energy storage inverter input source and a distributed green energy input source) can be realized. When any input source is abnormal, the low-voltage DC microgrid bus can provide voltage to achieve 0ms seamless backup power switching.

[0019] Furthermore, when designing the present invention, the distributed green energy is directly connected to the above-mentioned low-voltage DC microgrid bus through a DC / DC converter. The present invention adopts a centralized DC architecture to absorb and store green energy such as photovoltaics without the need for 10kV side-down rectification. The overall efficiency is higher than that of traditional UPS power supply systems and Panama power supplies, and can effectively improve the utilization rate of green energy.

[0020] In addition, the traditional UPS power supply system solution or Panama power supply solution requires 15 minutes of power protection, and the energy storage battery is basically not used after backup. The energy storage power supply method of the present invention adopts DC grid construction technology, which, combined with the energy storage system, can achieve peak shaving and valley filling in the energy storage industry.

[0021] In addition, in actual application, the energy storage power supply method of the present invention can use a large-capacity energy storage battery, and at the same time use a diesel generator as the power supply of an external high-voltage AC distribution network to provide backup power for the data center. The large-capacity battery can also provide a longer backup power time for the data center. To a certain extent, it can reduce the proportional capacity of diesel power generation.

[0022] It can be seen that the energy storage power supply method designed by the present invention can achieve 0ms seamless direct switching when powering the data center and realize distributed green energy consumption. It has strong reliability and excellent practical application effect, and has good promotion prospects and application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The following is a system circuit architecture diagram of an existing UPS power supply system in one implementation mode.

[0024] Figure 2 A system circuit architecture diagram of the energy storage and power supply method described in the present invention in one implementation manner.

[0025] Figure 3 This is an equivalent circuit control diagram of the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus in one implementation manner of the energy storage power supply method described in the present invention. DETAILED DESCRIPTION

[0026] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0027] like Figure 1 As shown, the current traditional data center and communication room power supply and distribution system usually adopts a UPS power supply system, which includes not only a high-voltage distribution system and a transformer, but also multiple uninterruptible power supplies (UPS) and IT loads and air conditioners in the room; wherein the input ends of the above-mentioned multiple uninterruptible power supplies are connected to the above-mentioned high-voltage distribution system through a transformer, and the output ends of the above-mentioned multiple uninterruptible power supplies are connected to the IT loads and air conditioners through a UPS bus to distribute power to the IT loads and air conditioners.

[0028] The traditional UPS power supply system and the existing Panama power supply have the following problems when applied: long time for seamless on-grid and off-grid switching, poor access and absorption of green energy, low battery utilization, etc., and their actual application effect is not good. Therefore, in view of the problems existing in the above-mentioned existing power supply systems, the present invention adopts a new energy storage power supply method to design a grid-type energy storage power supply system for data centers.

[0029] In the present invention, the energy storage power supply method removes the STS static transfer switch when designing the system circuit architecture. The STS static transfer switch is no longer used to switch power between two independent power sources to achieve 0ms backup power fast switching; at the same time, the system circuit architecture is connected to distributed green energy to improve the utilization rate of green energy, thereby utilizing the new power supply architecture to increase the life and utilization rate of energy storage batteries, improve the quality of power, and reduce the use of power grid management equipment such as SVG (dynamic reactive power compensation and harmonic control device).

[0030] See also Figure 2 As shown, in the present invention, the energy storage power supply system does not include a UPS power supply, and specifically includes: a transformer, an energy storage inverter, an energy storage battery, distributed green energy and an IT load; wherein the input end of the transformer is connected to a high-voltage AC distribution network, the output end of the transformer is connected to an energy storage inverter, and the output end of the energy storage inverter is connected to a low-voltage DC microgrid bus; the above-mentioned energy storage battery, distributed green energy and IT load are respectively connected to the low-voltage DC microgrid bus through independent DC / DC converters.

[0031] Of course, in actual application, the power supply architecture of the energy storage power supply system using the energy storage power supply method can specifically set two sets of transformers, energy storage inverters, energy storage batteries and distributed green energy. At the same time, the above-mentioned low-voltage DC microgrid bus includes a first low-voltage DC microgrid bus (i.e. Figure 2 The DC microgrid bus I shown in the figure) and the second low-voltage DC microgrid bus (i.e. Figure 2 The DC microgrid bus II is shown.

[0032] Among them, the input ends of the above-mentioned two groups of transformers are both connected to the high-voltage AC distribution network, and the output ends are respectively connected to the energy storage inverters of each group, the output end of one group of energy storage inverters is connected to the first low-voltage DC microgrid bus, and the output end of the other group of energy storage inverters is connected to the second low-voltage DC microgrid bus; and the above-mentioned first low-voltage DC microgrid bus and the second low-voltage DC microgrid bus are both connected to the IT load through a DC / DC converter.

[0033] Based on this setting, Figure 2 In the power architecture shown, one group of energy storage batteries and distributed green energy can be connected to the first low-voltage DC microgrid bus through independent DC / DC converters; another group of energy storage batteries and distributed green energy can be connected to the second low-voltage DC microgrid bus through independent DC / DC converters; wherein the distributed green energy can specifically include solar energy, wind energy, thermal energy storage energy, hydrogen energy storage energy, and pumped storage energy.

[0034] See also Figure 2It can be seen that in this embodiment, the energy storage inverters of the above two groups are both PCS grid-type flexible direct current stack architectures, and the energy storage inverter includes two AC / DC inverters, and the two AC / DC inverters are respectively connected to two high-voltage AC distribution networks through transformers, and the input end of the transformer is connected to the high-voltage AC distribution network through a frame circuit breaker, so that the two high-voltage AC distribution networks can output AC voltage to the two AC / DC inverters, that is, output Figure 2 "AC 1" and "AC 2" shown.

[0035] In this embodiment, the output voltage of the two high-voltage AC distribution networks can be selected as at least one of 10kV, 20kV or 35kV according to the actual application situation; the two 10 / 20 / 35kV voltages are stepped down to 380V through the high-voltage distribution room and the transformer, and the two AC voltages (AC 1 and AC 2) 380V are respectively introduced into the two AC / DC converters of the energy storage inverter, and connected to the first low-voltage DC microgrid bus (i.e. Figure 2 The DC microgrid bus I shown in the figure); at this time, the first low-voltage DC microgrid bus can provide the first power supply for the IT load and the water cooling unit through the DC / DC converter.

[0036] Similarly, repeating the above content can form a second low-voltage DC microgrid bus (i.e. Figure 2 The DC microgrid bus II shown provides a second power supply for IT loads and water cooling units.

[0037] It should be noted that, in this embodiment, both the first power supply and the second power supply include three voltage input sources, which specifically include: two high-voltage AC distribution networks that input two AC voltages (AC 1 and AC 2), and distributed green energy connected to the low-voltage DC microgrid bus. When any two of the three input sources are abnormal, the low-voltage DC microgrid bus can provide voltage to achieve 0ms seamless backup power switching.

[0038] Also, see further Figure 2 It can be seen that in this embodiment, the energy storage battery is a string type energy storage battery, which includes multiple clusters of batteries (such as Figure 3 The multiple battery clusters are connected to multiple independent DC / DC converters respectively, so as to be connected to the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus through the DC / DC converters. The IT load can also include multiple load units (such as Figure 2 The loads 1 to N are shown, and the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus are respectively connected to multiple load units through a single DC / DC converter.

[0039] Furthermore, the water cooling unit for cooling the IT load may be specifically connected to the first low-voltage DC microgrid bus and the second low-voltage DC microgrid bus via a DC / AC inverter.

[0040] It can be seen that based on the above Figure 1 The power supply architecture design of the energy storage power supply system shown can specifically implement the following energy storage power supply method, namely: the output voltage of two high-voltage AC distribution networks is transmitted to the low-voltage DC microgrid bus after passing through a transformer and an energy storage inverter; the distributed green energy transmission voltage is transmitted to the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus; when the energy storage battery or IT load has a charging demand, the above-mentioned first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus supplies power to the energy storage battery or the IT load.

[0041] In order to facilitate understanding of the power supply logic of the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus to the IT load, the present invention also provides Figure 3 The first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus (i.e. Figure 3 The equivalent circuit control diagram of the DC microgrid bus I / II) is shown.

[0042] like Figure 3 As shown, refer to Figure 2 After the two AC / DC converters of the energy storage inverter rectify the two AC voltages (AC 1 and AC 2) of 380V, the DC voltage is output to the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus, which is equivalent to the above Figure 3 The voltage source V1 and the voltage source V2 are shown; and the voltage source V1 is connected to the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus through the virtual resistor R1; similarly, the voltage source V2 is connected to the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus through the virtual resistor R2.

[0043] Where, I_load is the current provided by the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus to the IT load, and the unit parameter is A; I 绿色 is the current provided by distributed green energy, with a unit parameter of A; I_IT is the actual load consumption current of the IT load, with a unit parameter of A, which has the following relationship:

[0044] I_load=I 绿色 +I_IT

[0045] Combining the above relationship with Figure 3 , it can be seen that I 绿色≤0 means that the distributed green energy is discharged to the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus. And when I_load<0, it means that the current provided by the distributed green energy is greater than the actual load consumption current of the IT load. At this time, the energy storage battery of the energy storage power supply system can be used to absorb the green energy.

[0046] Accordingly, according to the Thevenin theorem, the reference current I_load required by the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus has the following relationship:

[0047]

[0048] Among them, V bus is the actual DC bus voltage of the DC microgrid; Vref1 is the output reference voltage of an AC / DC converter PCS1 (corresponding to AC 1) of the energy storage inverter, and R1 is the virtual resistance of PCS1; Vref2 is the output reference voltage of another AC / DC converter PCS2 (AC input II) of the energy storage inverter, and R2 is the virtual resistance of PCS2; VrefB(n) is the output voltage reference of the nth DC / DC converter connected to the battery, and RB(n) is the virtual resistance of the nth DC / DC converter connected to the battery.

[0049] Based on the above design principle, the PCS device can be adjusted and the DC / DC converter device can be set to R1, R2 and RB(n); and, when the virtual resistance R1=R2=RB(n) is set the same, the reference voltage (Vref1, Vref2, VrefB(n)) of the DC / DC converter corresponding to each battery of the energy storage battery can be adjusted, so as to realize the consumption of green energy and load power supply, and keep the voltage fluctuation of the first low-voltage DC microgrid bus / the second low-voltage DC microgrid bus within a certain range.

[0050] Accordingly, in order to verify that the energy storage power supply system designed by the present invention has the feature of high green energy utilization rate, the present invention also calculates and compares the green energy utilization efficiency of the energy storage power supply system, the traditional UPS power supply system and the existing Panama power supply:

[0051] (1) In the Panama power architecture: With the IT load as the end point, a rectifier transformer is used, and green energy can only be coupled on the 10kV side. The transmission path of green energy is: green energy → inverter → 10kV step-up transformer → 10kV Panama power → IT load. Among them, the typical transmission efficiency of the above inverter is 98% (from the specification), the efficiency of the 10kV step-up transformer is 97% (from the national standard), and the efficiency of the 10kV Panama power is 98.5% (specification). At this time, the utilization efficiency of green energy in the Panama power architecture is:

[0052] η 绿色 =98%*97%*98.5%=93.6%

[0053] (2) In the UPS power supply system, the optimal path for green energy is coupling on the 380V AC side, and its transmission path is: green energy → inverter → 380V AC grid → UPS → IT load. Among them, the typical transmission efficiency of the inverter is 98% (from the specification), and the efficiency of the UPS used in the data center is 94% (specification), so the utilization efficiency of green energy is:

[0054] η 绿色 =94%*98%=92.12%

[0055] (3) In the energy storage power supply system designed by the present invention, green energy is not coupled on the 10kV side, but on the low-voltage DC microgrid bus. The transmission path of green energy is: green energy → DC / DC converter boost → low-voltage DC microgrid bus → DC / DC converter buck → IT load. Among them, the transmission efficiency of DC / DC converter boost and DC / DC converter buck is 98.5% (from the specification), and the final green energy utilization efficiency is:

[0056] η 绿色 =98.5%*98.5%=97.02%

[0057] By comparing the green energy utilization efficiencies of the three architectures calculated above, it is not difficult to see that the power supply architecture using the energy storage power supply system of the present invention can achieve a higher green energy utilization efficiency of 97.02%, which is much higher than the 92.12% of the UPS power supply system and the 93.6% of the Panama power supply architecture.

[0058] In summary, the energy storage system designed by the present invention can achieve efficient and reliable power supply with distributed green energy consumption and 0ms seamless switching. It can effectively meet the power supply needs of data centers and communication rooms. Its power supply architecture is superior to traditional UPS power supply systems and Panama power supply architectures, and it has good promotion prospects and application value.

[0059] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for power supply of energy storage for a data center, characterized in that: It does not include UPS power supply, and includes: transformer, energy storage inverter, energy storage battery, distributed green energy and IT load; wherein, the input end of the transformer is connected to the high-voltage AC distribution network, the output end of the transformer is connected to the energy storage inverter, and the output end of the energy storage inverter is connected to the low-voltage DC microgrid bus; the energy storage battery, distributed green energy and IT load are respectively connected to the low-voltage DC microgrid bus through independent DC / DC converters; the output voltage of the high-voltage AC distribution network is transmitted to the low-voltage DC microgrid bus after passing through the transformer and energy storage inverter; the distributed green energy transmits voltage to the low-voltage DC microgrid bus; when the energy storage battery or IT load has a charging demand, the low-voltage DC microgrid bus supplies power to the energy storage battery or IT load.

2. The energy storage power supply method according to claim 1, characterized in that: It comprises two groups of transformers, energy storage inverters, energy storage batteries and distributed green energy, wherein the low-voltage DC microgrid bus comprises a first low-voltage DC microgrid bus and a second low-voltage DC microgrid bus; the input ends of the two groups of transformers are connected to the high-voltage AC distribution network, and the output ends are respectively connected to the energy storage inverters of each group, the output end of one group of energy storage inverters is connected to the first low-voltage DC microgrid bus, and the output end of the other group of energy storage inverters is connected to the second low-voltage DC microgrid bus; wherein the first low-voltage DC microgrid bus and the second low-voltage DC microgrid bus are connected to the IT load through a DC / DC converter.

3. The energy storage power supply method according to claim 2, characterized in that: One group of energy storage batteries and distributed green energy are connected to the first low-voltage DC microgrid bus through independent DC / DC converters; another group of energy storage batteries and distributed green energy are connected to the second low-voltage DC microgrid bus through independent DC / DC converters.

4. The energy storage power supply method according to claim 1, characterized in that: The input end of the transformer is connected to the high voltage AC distribution network through a frame type circuit breaker.

5. The energy storage and power supply method according to claim 1, characterized in that: The output voltage of the high-voltage AC distribution network is 10 kV, 20 kV or 35 kV.

6. The energy storage and power supply method according to claim 1, characterized in that: The distributed green energy includes solar energy, wind energy, thermal storage energy, hydrogen storage energy, and pumped storage energy.

7. The energy storage and power supply method according to claim 1, characterized in that: It also includes a water cooling unit, and the low-voltage DC microgrid bus is connected to the water cooling unit through a DC / AC inverter.

8. The energy storage power supply method according to claim 1, characterized in that: The energy storage battery is a string type energy storage battery, which includes multiple clusters of batteries, and the multiple clusters of batteries are respectively connected to multiple independent DC / DC converters to be connected to the low-voltage DC microgrid bus through the DC / DC converters.

9. The energy storage and power supply method according to claim 1, characterized in that: The IT load includes a plurality of load units, and the low-voltage DC microgrid bus is respectively connected to the plurality of load units through a single DC / DC converter.

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