·Application fields:

Communication system;

■ financial system;

■ industrial automation system;

■ Internet Data Center (IDC);

■ multimedia data center (MDC);

■ other important load systems.

·Features of the scheme:

■ appearance design: standard 19 inch black cabinet;

■ Maintainability: hot plug-in on-line, no bypass is required;

■ scalability: realize online capacity expansion, online upgrade and online maintenance;

■ green energy saving: high efficiency, low heat loss, no pollution to the power grid;

■ high cost performance: reduce the initial purchase cost and future expansion maintenance and operation cost of users;

■ high reliability: solve the bottleneck of single point fault and provide reliable power protection for key load;

■ high anti-interference: ensure that "power interference" from municipal power supply or UPS power supply itself is eliminated as far as possible, including conduction interference and radiation interference.

·The general introduction of the dual bus modular (n+x) scheme:

Internet Data Center (IDC) and multimedia data center (MDC) are the control centers of high-speed Internet. The user has a high requirement of "timeliness" for the remote processing, storage and transfer of information resources (data, voice and image information) they undertake. Even if it is only a few seconds of "downtime" will bring immeasurable losses to the safe operation of the Internet and the production and operation of users. When serious, it will even cause serious paralysis of social and economic life. Therefore, IDC must provide users with 365 × 24h continuous high-speed, safe and reliable value-added information services. To achieve this goal, in principle, the whole power supply system which is responsible for power supply to IDC room must adopt redundant power supply scheme with high fault tolerance function to ensure whether it is in the event of failure of municipal power grid or failure of any module (including system control module), daily maintenance / maintenance operation or fuse caused by some reasons When the breaker switch is "tripped", the interconnection equipment shall be powered by the inverter power supply of "online ups", instead of entering the state of power supply by the common municipal power supply / emergency standby generator set via the AC bypass of ups. This is because only the inverter power supply of "online ups" can provide high-quality sine wave power supply with stable voltage, no frequency "mutation", no interference and minimal waveform distortion to the load of users. For "non online ups" including backup ups and Online Interactive UPS, they mainly adjust the voltage of input power supply, and there is no "substantial" improvement in the frequency fluctuation of input voltage, interference of various power sources and voltage distortion. This means that there should be no single "bottleneck" fault potential in the whole power supply system. Therefore, redundant UPS power supply system with high fault tolerance function should be configured as much as possible. That is, in the operation of this UPS power supply system, the whole UPS power supply system must still work normally even when some "components" happen "failure".

Compared with the traditional UPS, it has higher advantages to adopt modular (n+x) UPS configuration in dual bus system. In the construction of information network power supply system of industry users, the capacity of high-end UPS is often mispredicted, or too low or too high. The result may lead to the high procurement cost, unable to meet the load demand or cause resource, space and energy waste. The dual bus modularization (n+x) solves this problem effectively through the expandable module structure, which can help the user to construct and invest in phases in the uncertain development of the future. When the demand of the user's power load increases, only the power module needs to be increased according to the stage of power consumption planning. At the same time, through modular integration, it can fully meet the needs of power supply system expansion, and has more flexibility and better reliability, which is the trend and milestone of the future development of power protection. In addition, in the traditional high-end UPS products, there are always problems that single ups are prone to single point failure. In the past, the user's safety measures are to adopt the traditional redundancy mechanism of "1+1" or "n+1", which not only increases the cost of procurement, installation and maintenance, but also can only fault-tolerant once. In the dual bus modular (n+x) system, each parallel module is an intelligent independent individual with built-in redundancy, without the need for the system controller to control the parallel system centrally. When any module (including system control module) fails, the redundancy design will achieve the maximum fault redundancy, and can also allow users to choose redundancy with more than one fault tolerance rate according to their own needs. That is to say, in the dual bus modular (n+x) system, users can realize fault redundancy and upgrade and expansion of "n+x" by purchasing the corresponding power module. The dual bus modular (n+x) system can effectively solve the constraints existing in traditional UPS, and make the user obtain excellent scalability, and can independently allocate and integrate the system when necessary. It not only meets the expansion of the later equipment, but also reduces the initial purchase cost of users.

According to the technical development level of UPS industry, it is advisable to select modular (n+x) UPS redundant power supply system with "dual bus input" and "dual bus output" power supply function. It is composed of the following parts of power supply system:

1) Dual bus input power supply system

The basic configuration of dual bus input power supply system is: municipal power input power supply + standby generator set + automatic switch control cabinet + input distribution cabinet. The automatic switching control system monitors the real-time operation status of various input power sources at all times, and ensures that the most reliable power supply is always sent to the input end of ups. For some important IDC rooms, the "emergency generator" power supply is actually a redundant generator power supply system composed of multiple diesel generators + generators and control cabinet.

2) Dual bus output distribution system

In order to eliminate the potential trouble of "single bottleneck" between the output end and the user end of UPS parallel system, it is necessary to configure the output distribution system of dual bus modular (n+x) ups. The basic configuration is a UPS output power supply system composed of "n + 1" modular UPS redundant power supply system (preferably "1 + 1" or "2 + 1" parallel power supply scheme) + output distribution cabinet + load automatic switching switch (LTS). For some places with high requirements, a power supply system with high fault tolerance function composed of load synchronization controller (LBS) + two sets of "n + 1" modular (n+x) UPS redundant power supply system shall be configured. Since (30-50%) of the servers and disk array machines used in IDC room are products with the "dual power input power supply" system, for these devices, the power supply from two "n + 1" parallel systems can be directly connected to the two input terminals of the "dual power input equipment". For the key load with the mode of "single power input power supply", the power supply from two "n + 1" parallel systems is connected to the two input terminals of "load automatic switching switch" (the common static switch of STS type and SS type quick switch), and then the key equipment of the user is connected to the output end of the load automatic switching switch.

·Reliability analysis of dual bus modularization (n+x)

To evaluate the reliability of UPS system to perform its duties, not only the MTBF of UPS, but also the MTTR of ups and MTBF of power supply shall be considered. When UPS fails and power supply fails, the load will lose power, that is to say, the failure of UPS key responsibilities. The length of time the load is exposed to unprotected mains power depends on the length of maintenance time. If it takes one week to maintain a ups and the average time of no failure of the mains power is one week, the load will lose power when the ups fails. If the MTTR of UPS is 1 hour, MTBF of municipal power will not have a great impact on the failure probability of critical load. Obviously, reducing the MTTR of ups will reduce the failure probability for critical loads. The best way to reduce the MTTR of UPS is to minimize the factors that may affect UPS maintenance. Dual bus modular (n+x) UPS is the best choice because of its hot plug function on line.

In principle, the whole power supply system that undertakes the power supply task must adopt redundant power supply scheme with high "fault tolerance" function to ensure that whether it is in the event of failure of municipal power grid or any module (including system control module) failure, it is also in daily maintenance / maintenance operation or fuse burn out / breaker switch "trip" due to some reasons When the interconnection equipment is powered by inverter power supply of "online ups", it shall not enter the state of power supply by the common municipal power supply / emergency standby generator set via AC bypass of ups.

In summary, the dual bus modular (n+x) UPS has the longest average fault free time to perform its duties and the minimum average maintenance time (MTTR) and the strongest ability to resist the risk of market power interference and high "fault tolerance" function, the application of this scheme system will be supported by stable, efficient and safe 24-hour uninterruptible power supply, which can be regarded as the model of the latest professional power supply system in the computer room and the most reliable power guarantee.

·Select and match UPS redundant power supply system with "compatibility" of centralized monitoring system with IDC

In order to meet the needs of information network for the IDC and MDC computer rooms to realize unattended or few on duty management and remote centralized monitoring, thus improving the "manageability" of UPS power supply system, for Internet data center, in addition to the network management system which should be configured for real-time monitoring of all it equipment, a set of centralized monitoring system for "non it equipment" should be established to realize the centralized monitoring system of "non it equipment" Then, the real-time monitoring and analysis of the operation of such equipment as air conditioner, distribution cabinet, battery group, generator set, water leakage alarm, safety system and fire protection system are carried out. Therefore, the redundant power supply system of UPS selected shall be equipped with the following communication interfaces:

1) Rs232/rs485 interface, modem or SNMP adapter are configured on UPS;

2) Output communication interface of "relay dry contact" type used to display the working status / alarm information of UPS;

3) Input communication interface of "user defined" input signal (alarm signal of door access control, smoke, temperature, humidity, etc.);

4) Configure necessary data collectors for various "non it devices";

5) Configure the corresponding centralized monitoring and management software package or communication protocol.

By using the above-mentioned I / O communication interface and corresponding power management software or the existing centralized monitoring system of network management, the so-called intelligent IDC and MDC computer room centralized monitoring system can be formed. In such a network management system, the main control functions can be realized as follows:

1) Read the real-time operating parameters of UPS observed on led/lcd display of UPS (such as input / output voltage, current, frequency, active power / apparent power, power factor and charge discharge voltage / current of battery bank);

2) "Operation milestones" of various "room environment control equipment" used in "Internet data center" (information such as faults / alarms / user performed operations, etc.) arranged in time and in sequence since the start-up of various equipment;

3) In case of failure, the network broadcast alarm (pop-up alarm window) shall be performed, and the phone or mobile phone shall be automatically dialed, automatically paged or e-mail sent to inform the duty personnel to timely go to the site to eliminate the fault or repair;

4) Carry out the programmable "self test" operation for the standby battery pack of ups. If it is found that the "ah" of the battery is low, it shall also send out the warning signal of "battery needs to be replaced";

5) The "user defined" alarm signal (such as temperature / humidity, access control, fire protection and other alarm signals) is incorporated into the IDC room or the unified centralized monitoring system of intelligent buildings through the input communication interface of ups;

6) Personnel designated by the competent authorities of IDC and MDC, according to different authorization authority, grade "readjust" / set operation parameters of various corresponding devices or perform remote fault analysis / diagnosis operation.

·Simulation diagram of dual bus modularization (2+2):