Discussion on online maintenance and management of uninterruptible power supply and DC power supply

UPS is a third-generation power frequency pure online intelligent UPS developed with brand-new digital technology to meet the power supply reliability requirements of China's power grid environment, network monitoring, network systems, medical systems, etc., and to overcome the increasingly harsh power grid environment caused by the centralized power supply of medium and large computer network systems. DC power supply is a device that maintains a steady current in the circuit, such as dry batteries, storage batteries, DC generators, etc.

UPS and DC power supply are important power supply guarantee equipment for enterprises. Traditional maintenance management includes: ① Daily inspection of appearance, regular replacement of batteries, filter capacitors, fans and other wearing parts, battery activation during overhaul, etc.; ② Modification or use of replacement equipment, and use of advanced tools to test battery performance. This management method has high investment costs for enterprises, heavy workload for maintenance personnel, and it is not easy to grasp the equipment operation status and key data in real time, and the ability to prevent equipment accidents is low. Implementing online maintenance management can avoid the shortcomings of traditional methods and obtain good benefits.

1. System composition

1. Master control station (backstage)

It consists of a monitoring station, an engineering maintenance station, and a system interface. It uses management and analysis software to process the received data and publish it through the Web. Engineering maintenance personnel can log in to the server to view the operating status of all online equipment in the factory and complete historical and real-time data analysis and statistics.

2. Field equipment control station (ES)

According to the needs of the on-site equipment, you can choose a monitoring function instrument or an equipment operation status information color collection instrument (EII). EII communicates with power meters, battery acquisition modules , DC panels, UPS and other intelligent devices through RS-232/485 ports, converts monitoring data into data packets that comply with the communication protocol, connects to the local area network, and transmits it to the main control room server. An independent and complete ES includes the following parts.

2.1. System host. It consists of a downlink serial port channel, a data processor, a display, and an uplink serial port channel. The downlink serial port channel accesses the battery voltage acquisition module through the RS-485 bus, collects data, and manages the voltage acquisition module. The data processor completes data decompression, data calculation, and storage management, and sends part of the processed data to the display, and the other part is sent to the protocol processor through the uplink serial port channel, or transmitted to the upper layer management system .

2.2. Data acquisition module group. The data acquisition requirements and corresponding acquisition instruments can be determined according to user needs. Generally, it consists of battery voltage acquisition modules, current, temperature, power, etc. The modules are well isolated and have strong insulation, high reliability and safety. Data acquisition can be grouped. Each module can collect voltage for a certain number of batteries. It can be equipped with current and temperature sensors. The modules are generally connected to the system host using RS-485.

2.3. Protocol processor. The interface board with protocol processing program can process various communication protocols. It can realize: ① Encode, package and send the battery voltage, current, temperature and other information sent by the host to the remote server according to the agreed protocol; ② Decode the remote control and remote adjustment instructions sent by the remote server to the host for real-time control.

2.4. Discharge module. It can quickly measure the DC internal resistance of the battery and instantly test the battery performance. The high-power discharge module can provide instantaneous high-current impact load.

2.5. Remote server. Realize computer data communication within the local area network, remotely access the on-site battery monitoring system through the local area post, receive and analyze data, and publish data through the Web server.

3. Communication network

The networked field equipment substations (collection monitoring stations) use optical fiber as the data communication backbone to form a local area network for online monitoring of UPS and DC power supply throughout the plant.

2. Main functions of the system

1. Ledger management

Integrate the UPS, DC system, battery information equipment and query functions of each station. You can query the real-time and historical data of each UPS and DC equipment, such as each battery voltage, average voltage, whole group voltage, charge and discharge current, ambient temperature, etc., and display them in curve and bar graph form, or generate reports for printing.

2. Real-time analysis

The battery operating status and historical data within the selected time period are analyzed. When a battery is discharged and meets a certain current range and time (greater than the set value), the system will evaluate the battery capacity (capacity estimation).

3. Alarm indication and inquiry

It can alarm for each UPS and DC power supply failure and provide alarm query for timely processing.

4. Networking

The system has remote communication, telemetry, telesignaling and remote control functions, which enable the remote server to monitor and manage the UPS, DC power supply and battery monitoring system of each station in real time through Ethernet. It can also be connected to other systems according to the needs of the enterprise, collect information of some important equipment and realize more functions.

5. System application precautions

Carefully investigate the current status of the enterprise's internal UPS and DC power supply as well as the scale of the enterprise's existing network, and configure them reasonably based on the function and importance of the equipment.

5.1. Determine the network architecture plan, that is, whether the enterprise needs to establish a complete network system or build on the existing network to achieve complete and independent online maintenance and management of a single battery pack.

5.2. With the online management system as the core and supplemented by necessary manual testing, management costs can be reduced. Large stations and key equipment directly adopt the complete system, and small stations, single UPS, etc. are processed by the background machine to form an overall maintenance management system.

5.3. Some UPS and DC power supplies already have multiple management functions, such as status parameters, status records, alarms, etc. Reasonable configuration can not only reduce development costs, but also reduce the hidden dangers of failure caused by too many lines.

5.4. The maintenance management system only performs monitoring. It is recommended that control instructions (such as fault handling, switching, activation, etc.) be issued manually.

5.5. After the system is established, a monitoring station can be set up in a manned place, and the operator can monitor the operating status around the clock. Maintenance personnel should check and manage it regularly.

5.6. Interfaces and protocols should be reserved to facilitate compatibility with other systems. The upper-level management of the system can also be built on the company's existing website.

5.7. It is recommended that the state management system be separated from the process control or execution system, and attention should be paid to their independence and avoid mutual interference.

5.8. After the system is established, there must be a work system and management mechanism to ensure normal use.

The UPS and DC power supply online maintenance management system ensures the safe and stable production of the enterprise, transforms traditional maintenance into condition-based maintenance, reduces a lot of maintenance costs, and increases enterprise benefits.