UPS power shared battery pack solution

　　Author ：Iflowpower – UMboneleli weSikhululo saMandla esiphathwayo

1. Introduction In order to improve system reliability, the current machine room uses N + X parallel redundancy or dual-bobs UPS configuration method. In the previous method, the number of UPS hosts is much, and the number of batteries is also often added to the proportion, which increases investment in money, space, load-bearing, maintenance, etc.

, sometimes even UPS host. Several times. So is there a reason to do with a battery if there is a system backup time or less affected? Is there a way to have a battery pack so that the battery pack is not required to follow redundancy without the redundancy of the UPS host Yes, shared battery pack is a good solution.

Second, the theoretical basis of shared battery pack method and its superiority so-called shared battery pack method refers to the solution of two or more UPS hosts to utilize a group or multi-set battery solution. When the main electricity is normal, each UPS is charged to the battery pack. When the market is abnormal, each UPS also uses the energy inversion of the battery pack to an alternating current supply load.

The system architecture of the shared battery pack method is as follows: In the N + X parallel redundancy or the double-phase configuration system, the UPS host must have redundancy, such as: 2 + 1 and contact, redundancy accounts for 33% of total capacity 1 + 1 and the redundancy is 50%, 1 + 2, and the redundancy is 67% of the total capacity, accounting for at least 50% of the total capacity in the double bus system. etc. According to the conventional battery configuration method, each UPS host is equipped with the respective battery packs.

If the UPS host cannot be inverted, the battery pack it belongs will follow, although the battery is not faulty. Therefore, the UPS host redundancy, the battery is also redundant, the main unit redundancy accounts for a few percent of the total UPS total capacity, the battery redundancy is also followed by a few percent of the total battery capacity, only this can make the system backup Time is not affected, achieving real redundancy. Change ideas, when a UPS host fails, if it shifts it to other normal UPS, the battery is not necessarily redundant? Is the backup time of the entire system not affected? This is the theoretical basis for sharing battery pack methods.

The shared battery pack method has the following advantages: 1. Save the redundancy quantity of funds in the purchase of batteries accounting for a few percent of the total system, and can save a few percent of the total investment of battery. Today, the price of the battery is flying, this cost that can save is quite considerable.

At the same time, the number of batteries is reduced, and investments such as handling, installation, etc. will also be reduced. 2.

Saving the installation space of installation space investment is also very large, reducing the number of batteries, which reduces the investment in installation space in proportion. At the same time, the investment in rent, decoration fee, air conditioning configuration, etc. 3.

The investment battery pack in which it costs is very heavy. In order to solve the problem of floor load, the placement area of ​​the battery is generally expanded or the load bearing bracket. If the number of batteries is reduced, 8; 7787.

Six six six power. . Investment in, 5, 7, and investment will save accordingly.

4. Saving operating cost investment battery is less, the system itself and the electric energy consumed by the room air conditioner are less, and the maintenance cost to be put into the maintenance is small, and it will be more environmentally friendly. 5.

The system expansion is relatively convenient for shared battery pack UPS systems. When expansion of the battery, if there is a battery, if the backup time of the existing battery pack is still enough, directly add up the UPS host. Expansion will become very simple, convenient, save money.

6. To play the biggest performance of the battery, improve the battery utilization battery is maintained, if you do not discharge long, you will lose activity. About the traditional battery configuration method, due to the large amount of battery, the battery will be small current discharge, the battery capacity may not be removed, and the market is still recovered.

The shallow discharge of this small current is not good for the battery. For a long time, the battery performance will decline, once a UPS is broken, other UPS batteries will not reach the requirements. And about sharing the battery pack method, because the number of batteries is relatively small, the discharge current of the battery will be relatively large, and the battery capacity can also be put, which is conducive to improving the activity of the battery, extending the battery life.

Once a UPS is broken, the backup time of the system will not be affected because the battery will not be able to fill the UPS. From the above analysis, it can be seen that the shared battery pack method has a lot of advantages, especially when investment, load-bearing, installation space, etc., this method shows its superiority.

Third, several issues to be solved by sharing the battery pack method Since the shared battery pack method has many advantages, why have not been universal applications? Why many manufacturers usually promote their UPS has a shared battery pack function, but do not dare to use customers when practical applications? This is because every UPS can share battery packs, sharing battery packs to have certain technical support. Regarding the sharing of battery pack methods, everyone is more concerned about the following: 1. DC busbar is directly connected, will each UPS rectifier will be affected? Can the voltage stability of the DC bus bar ensure that the voltage barrier of DC parent roses is small enough? 2.

How do each UPS handle the unit of battery? 3. Whether the "Battery Online Test" function can be used when sharing the battery pack? 4. If one of the UPS rectifier is faulty, how will each UPS action? 5.

How will the UPS will move? 6. If the shared battery pack part is faulty, such as short-circuited, how to self-protection? These problems are directly related to the security and stability of the entire system, very important, different manufacturers have different ways, so choose sharing batteries When grouping methods, you must choose a strong technical strength, manufacturing related experience - rich UPS manufacturers. IV.

Delta NT series UPS shared battery pack solutions DAD series UPS can be multi-machine sharing battery pack, in series, parallel, double busbar Can be used under architecture. At present, there are two 30kva's UPS sharing battery pack in the Shanghai Railway Bureau dispatching control center in normal operation; two 320kva UPS sharing battery packs in Jiujiang Telecom are operating in normal operation; two 40kva in the Shandong Provincial Committee The UPS shared battery pack is operating normally; two 30kva UPS sharing battery packs in Shandong TV station are running normal; there are three 40kVA UPS sharing battery packs in Yingtan Telecom, these cases have never been shared by sharing battery packs. Faulty.

On the UPS production line of Delta also tests the shared battery pack to test parallel. Therefore, it is quite reliable in sharing battery pack technology in sharing battery pack, and related experience is still very rich. The Delta NT Series UPS is important to handle the above problems: About Question 1: After the Directory of each UPS is connected, the rectifier work is substantially unaffected, because the SCR opening of each rectifier is driven The control of the signal is not related to whether the DC bus bar is connected.

As long as the direct-current feedback signal is accurate and timely, the drive signal is correct, the SCR work will not be affected. Therefore, 12 pulse rectifiers, 18 pulse rectifiers can safely and stable operation, and even dozens of rectifying modules of switching power supplies can be directly connected and safely running directly. Take a deeper step, if the control is good, the rectifier will not only have a bad place but also benefits, because they can counteract some low harmonics to make the DC voltage wavy smaller, and the DC voltage is more stable.

The rectifier of the Delta NT series UPS is controlled by a special CPU. The acquisition signal is accurate and timely, the drive signal is correct, and the anti-interference ability is strong. The UPS also has an automatic average flow function, which not only guarantees the three-phase input current per UPS, but also adjusts the current difference between the rectifiers of each parallel UPS, which will not be too large, otherwise the current UPS will be limited to the limit.

To improve the security of the entire system. The Delta NT Series UPS is still <± 1% of the DC voltage stability regardless of the single-machine operation or sharing battery pack. About Question 2: Delta NT Series UPS can set battery capacity, all / floating voltage, charging current, battery low voltage alarm point, battery cutoff, battery cutoff, battery cutoff point according to battery capacity sizes and load.

If the shared battery pack is set, the "shared battery pack" on the operation panel is set to "YES", and the battery capacity and charging current are set to 1 / n of the battery to be 1 / n (n is the number of hosts). After the main power is powered off, each UPS starts discharging, when the battery voltage is lower than the charging pressure point, each UPS simultaneously activates the full charge function, when the cutoff voltage point or deadline is reached, each UPS simultaneously Floating. At normal operation, if artificially starting a single UPS full-speed function, the unit UPS is maximizing the set charging current, and it is automatically converted to floating, which will not affect the system.

About Questions 3: When the Delta NT Series UPS shared battery pack, the "battery online test" function is invalid, because the single detection "battery" is meaningless. According to the needs, the software can also be modified. When the "battery online test" function is started, the UPS is simultaneously moved.

About Question 4: During the operation, if a UPS rectifier is faulty, the fault will alarm and go to the battery operating state until the battery pack voltage dropped to 330V, the lock machine protection (normal UPS battery protection lock machine Voltage is generally 300V). Other UPS will work in a normal working state, and the maximum charge is charged with the set charging current. If the rectifier is damaged seriously, even short-circuited, the fuse of the fault rectifier and the direct current parent row will quickly blow, and the single fault point does not affect the entire system.

About the problem 5: In the operation, if a UPS inverter is faulty, the fault will alert, about the parallel system, the fault UPS will lock the output, the load is borne by another UPS. If additional UPS is overloaded, all UPS is transferred to the bypass working state and continue to power the load. Regarding the series or double bus system, the fault UPS will transfer directly to the bypass working state and continue to power the load.

If the inverter is damaged seriously, even short-circuit, the fuse of the fault inverter is connected to the DC parent row quickly blows, and the single fault point does not affect the entire system. About Question 6: The battery pack with the Delta NT series UPS is electromagnetic contactor and fuse protection, when the UPS detects the battery pack leakage, the battery polarity is reversed, the battery voltage is too low, etc. The electromagnetic contactor will not suck it.

When the battery pack is short-circuited, there will be fused fuse to protect the entire system. 5. The problem that the shared battery pack method should be careful, pay attention to the following two points when using the shared battery pack method: 1.

Try to prevent only one set of batteries from being used because there is a single point failure, once this set of batteries fail, all UPs have no batteries available. If this time, the market is powered out, the entire system will stop. According to relevant experience, it is best to use 2-5 sets of battery sharing, as this can prevent battery packs from single-point failure, and can be used for battery packs.