PLC & DCS power supply

Iron and steel enterprise industrial upgrading Large steel groups have newly built cold-rolled and hot-rolled plants with high technological content. Most of the rolling mills use imported equipment and the degree of automation is quite high. There are a large number of PLCs or DCS systems. UPS, capacity from 3kVA to 80kVA.

UPS redundancy scheme selection In the PLC or DCS system, in order to ensure the reliability of the system and power supply security, it is recommended to use 1+1 parallel redundant centralized power supply scheme. In this scheme, when the two UPSs work normally, they bear the average total system load, each bear 50%, and their work reliability is 5.5 times that of the stand-alone system. For example, if the MTBF of a single UPS is 300,000 hours, the MTBF of the 1+1 system is 1.65 million hours, which greatly improves the reliability.

Battery Selection To ensure system reliability, battery reliability is one of the key indicators. Emerson recommends users to use UPS + battery integration design program, choose Emerson UPS battery UH series, can achieve the best UPS and battery coordination, and fully extend the battery life and ensure uninterrupted power supply control system.

Battery Capacity Calculations The battery backup time is typically 30 minutes for each UPS fully loaded. Two 1+1 parallel UPS systems For a 60kVA UPS, the battery configuration is 60 12V 100AH ​​batteries per UPS.

Converter oxygen system power supply

Steel converter emergency converter converter emergency gun motor needs UPS power supply. When the main power supply circuit is cut off, the oxygen lance in the steelmaking converter needs to be rapidly increased, the molten steel flows out, and the molten steel is prevented from solidifying, causing the converter to be scrapped. Therefore, the lance motor must be configured with a UPS to ensure normal operation during a power outage, with capacities ranging from 40 kVA to 200 kVA.

Taking a 75kW motor as an example, suppose the motor capacity power is 75kW, the inverter power is 150kW, it is used for 75kW motor, and the commercial power is three-phase 380V, 50Hz, all the way. Power supply requirements In the event of a mains power outage, reliable power supply to the lance motor can be guaranteed.

The working principle is that when the mains 1 is normal, the power supply path is mains → KM3 → motor, mains → KM1 → UPS battery charging; when the mains 1 power outage, the power supply path is mains → KM1 → UPS → Inverter → Motor.

The motor starting current is 6 to 7 times the rated current, the duration of light load 1 to 2 minutes, heavy load ≤ 5 minutes. The instantaneous current at the start of the motor is maximum, and then gradually decreases to the rated value as the start-up time increases.
Adding a frequency converter in front of the motor can realize the motor soft start function and limit the starting current to less than twice. Take the starting current coefficient as 6.5, 75kW motor starting power is 75kW × 6.5 = 487.5kW. Add the frequency converter, take the starting current coefficient as 2, then 75kW motor starting power is 75kW×2=150kW. If the frequency converter is not added, it can work for 1 minute when the rated load is 150%. With a 75kW motor, the required active power for the UPS is 487.5kW/150% = 325kW, and the UPS nominal power is 325/0.8 = 406.25kW, with 400kVA selected. If inverter is added, the UPS nominal power is 150/0.8=187.5kVA, and 200kVA UPS is selected.

It is recommended to use the Emerson H12500/A UPS+ frequency converter solution, which can greatly save investment and improve system reliability. The UPS backup time is 15 minutes.

Large fan excitation system power supply

Blast Furnace Fan Excitation System The blast furnace fan is responsible for supplying oxygen to supply air. It plays an important role in steel making. Once it is interrupted, it will cause huge losses. In severe cases, the entire blast furnace will be scrapped. The main power of the fan is generally MW pole, and the excitation system is generally independent power supply. It is required to configure a high power double UPS system with 120kVA to 400kVA.

UPS chooses single machine or 1+1 parallel redundant system.

Group Company Information Center

The iron and steel enterprise information center is based on the concept of centralized management and collaborative commerce. It is characterized by integrated management and control, and the smooth flow of three streams. According to the typical requirements of the steel industry system, the product basic data description is established through advanced procurement, sales, production, quality, and equipment. , inventory and financial management functions build the best business processes of core companies, rationalize the allocation of corporate resources, improve the company’s core competitiveness and market resilience through the collaboration of information flows with the business flows, logistics and capital flows of various production and business units and departments. Improve business-to-customer service levels and quality, and increase customer satisfaction and loyalty to the company.

The information center is the nerve center of the group company, and it concentrates a large number of servers, magnetic media, communication routing equipment, and monitoring equipment. The area of ​​the computer room in the information center is about 100 to 500 m2, and the standard rack is less than or equal to 150.

Low voltage distribution system

The low-voltage power distribution system provided by Emerson is tailored to meet the needs of users in the information center room and tailored to meet the needs of users and actual equipment.

All switches use ABB switch to provide high reliability and high quality power supply for the information center; important switches have dry junction monitoring output, real-time monitoring of switch on and off status; reactive power compensation cabinet uses ABB original power factor measurement, controller RVC, accurately measure and control power factor, improve power utilization; optional liquid crystal display unit TEEMC, set display telemetry, communication in one, widely used in low-voltage power systems, is the preferred product of the power monitoring system; low voltage distribution system The size is usually 600 (w) × 600 (d) × 2000 (h), but it can also be customized according to the power room space.

UPS system

In the information center room, data devices such as servers usually have a total capacity of <400 KVA. Taking a load of 400KVA as an example, the Emerson Hipulse series 120KVA 12-pulse direct parallel-redundancy scheme is recommended. To ensure the reliability of the information center room, battery reliability is one of the key indicators. Emerson recommends users to use UPS and battery integration design options, select Emerson UPS battery UPStar series, can achieve the best UPS and battery coordination, and fully extend the battery life, to protect the center of information center power supply.

Usually, the battery backup time of the information center room is 30 minutes for each UPS. Two 1+1 parallel UPS systems for the 120KVA UPS, the battery configuration for each UPS 96 12V80AH battery.

Air conditioning system

In an information center room, the data equipment room usually has an area of ​​less than 200 square meters. Before the heat of data equipment and equipment room is determined, it can be estimated according to the general estimation method of the computer room: 600W/m2, some high-capacity rooms reach 800W/m2.

For example, if the data room has an area of ​​200 m2, the required cooling capacity is about 100 kW. Two CM+60 air conditioners with a single unit cooling capacity of 58.4 kW are used, and the total cooling capacity is 116.8 kW, which meets the requirements. In order to ensure the reliability of the equipment, a redundant unit is added for a total of three units. After the equipment room and maintenance structure of the equipment room are determined, the heat quantity of the equipment and the maintenance area are calculated and the configuration of the air conditioner is adjusted.

The main heat source in the power room comes from UPS, power supply and other equipment, and its heat capacity is low. You can select two CM+20 air-conditioning 1+1 redundant arrangements with a single unit cooling capacity of 19.1kW.

Power and Environmental Monitoring System

The monitored equipment mainly includes power equipment, air-conditioning equipment and equipment room environment. The types of equipment to be monitored include: low-voltage equipment, input AC voltage, current, and power frequency measurement power factor, output AC voltage and current, and four status signals on the low-voltage distribution panel (determined according to site requirements); Oil generator sets are used as smart devices; smart air conditioners (two types) are used as smart devices; and smart UPS devices are used as smart devices.
Shanghai Xingbai Automation Technology Co., Ltd. provides you with comprehensive UPS solutions. Welcome to inquire Fax Mr. Wang Miss Liu