Factory power supply control system based on uninterruptible power supply

Abstract

The utility model discloses a factory power supply control system based on an uninterruptible power supply (UPS), which adopts two sets of UPS equipment to supply power to a field DSC system load in a centralized manner, replaces a traditional dispersed UPS independent power supply mode, and saves the investment of the UPS equipment of each site on site. And the concentration of the UPS equipment facilitates the management, maintenance and monitoring of the equipment, and fault hidden dangers can be found and eliminated in time through background monitoring. Meanwhile, storage battery maintenance and UPS equipment maintenance problems are considered in the design, a parallel operation mode is adopted, when one set of UPS equipment is out of fault, the other set of UPS equipment is seamlessly connected with a conversion power supply for power supply through STS static change-over switches of all sites on site, load disturbance-free and uninterrupted power supply of the DCS on site is achieved, the maintenance efficiency of the equipment is effectively improved, and the service life of the UPS equipment is prolonged. And stable operation of an enterprise production control system is ensured, production is not interrupted, and production cost is reduced.

Description

Technical Field

[0001] This utility model relates to a factory power supply control system based on an uninterruptible power supply. Background Technology

[0002] The power supply design of distributed control systems (DCS) is a key aspect of industrial automation, and its core lies in ensuring the continuous operation of the system in complex industrial environments through redundancy, modularity, and reliability.

[0003] In typical manufacturing enterprises, distributed control system sites typically use a single UPS configuration. A malfunction in this configuration can cause power loss to the control system, particularly affecting critical production processes and potentially leading to serious safety incidents. Replacing the UPS necessitates a complete shutdown of the associated production systems, affecting operations for two to three hours and resulting in lost production output and profits.

[0004] Therefore, it is necessary to design a factory power supply control system based on an uninterruptible power supply. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a factory power supply control system based on an uninterruptible power supply, which can ensure a stable power supply to the factory and has strong risk resistance.

[0006] The technical solution of the utility model is as follows:

[0007] A factory power supply control system based on an uninterruptible power supply includes two power supply branches that supply power to the distribution cabinets at the field sites: a first power supply branch and a second power supply branch.

[0008] First power supply branch:

[0009] The first power supply branch is equipped with a first UPS; the first UPS includes a connected rectifier unit and an inverter unit;

[0010] An external first AC power supply is connected to the input bus I via switch QF1; the input bus I is connected to the AC terminal of the rectifier unit of the first UPS via switch QF4 and the first isolation transformer in sequence; the inverter unit is connected to the output bus I via switch QF16; the connection point between the rectifier unit and the inverter unit in the first UPS is also connected to the first battery pack via switches QF11 and QF13 connected in series in sequence.

[0011] Second power supply branch:

[0012] The second power supply branch is equipped with a second UPS; the second UPS includes a connected rectifier unit and an inverter unit;

[0013] An external second AC power supply is connected to the input bus II via switch QF2; the input bus II is connected to the AC terminal of the rectifier unit of the second UPS via switch QF6 and the second isolation transformer; the inverter unit is connected to the output bus II via switch QF17; the connection point between the rectifier unit and the inverter unit in the second UPS is also connected to the first battery pack via switches QF12 and QF14 connected in series.

[0014] The site distribution cabinet is equipped with an STS static transfer switch; the output side of the STS static transfer switch is connected to the site power supply line.

[0015] Input bus I is connected to the STS static changeover switch via switch group 1QF1;

[0016] Input bus II is connected to the STS static transfer switch via switch group 2QF1.

[0017] A switch QF15 is connected across the connection point between switches QF12 and QF14 and the connection point between switches QF11 and QF13.

[0018] It also includes bypass power supply branches;

[0019] In the bypass power supply branch, the bypass AC input power is connected to the bypass isolation transformer via switch QF3 and to the static switch in the first UPS and the second UPS via switch QF8.

[0020] Input bus I is connected to active filter APF1 via switch QF5; input bus II is connected to active filter APF2 via switch QF7.

[0021] Beneficial effects:

[0022] This utility model discloses a factory power supply control system based on uninterruptible power supplies (UPS). This solution uses two UPS units to centrally supply power to the load of the on-site DSC system, replacing the traditional distributed UPS independent power supply mode, thus saving investment in UPS uninterruptible power supply equipment at each on-site site. Centralized UPS equipment facilitates equipment management, maintenance, and monitoring; backend monitoring allows for timely detection and elimination of potential faults. Simultaneously, the design considers battery and UPS equipment maintenance, employing a parallel operation mode. When one UPS unit fails and goes offline, the other UPS unit seamlessly connects to switch power supply through the STS static transfer switches at each on-site site, achieving uninterrupted power supply to the on-site DCS system load without disturbance. This effectively improves equipment maintenance efficiency, ensures stable operation of the enterprise's production control system, uninterrupted production, and reduces production costs. It provides a novel uninterruptible power supply method for production enterprises with unstable power supply and harsh on-site environments. Attached Figure Description

[0023] Figure 1 This is a UPS power supply system equipment configuration diagram;

[0024] Figure 2 This is a schematic diagram of the STS static transfer switch connection at the site.

[0025] Figure 3 This is a schematic diagram of the communication between various devices in a UPS power supply system. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0027] Example 1: As Figure 1-3 As shown, for the distributed control system configured for the enterprise, all sites are powered by two centralized, completely independent UPS units. These two UPS units operate in parallel online to supply power to external loads. The specific configuration of the UPS equipment is as follows: Figure 1 As shown.

[0028] During normal operation, the load is powered by AC380V mains power through two converters: AC to DC and then back to AC. Simultaneously, the battery is charged. Mains power I is input to input bus I via QF1 (closed), then through switch QF4 (closed) and the isolation transformer to UPS1. UPS1 then undergoes internal rectification and inversion to output AC380V to switch QF16, which (closed) outputs to output bus I. Finally, the power is distributed to the load via branch switches. Simultaneously, the rectified output from UPS1 charges battery pack 1 via QF11 and QF13 (closed). Similarly, mains power II is input to input bus II via QF2 (closed), then via switch QF6 (closed) through the isolation transformer to UPS2. UPS2 then undergoes internal rectification and inversion to output AC380V to switch QF17, which (closed) outputs to output bus II. Finally, the power is distributed to the load via various branch switches, for example: Figure 1 UPS1's 1QF1 and 2QF1 (closed) simultaneously power one site, and a field static switch selects one circuit to supply power to the load at that site. Meanwhile, the rectified output of UPS1 charges battery pack 1 via QF11 and QF13 (closed).

[0029] In bypass operation mode, if an overload or short circuit occurs at the UPS output, or if the inverter malfunctions, the UPS switches to bypass operation mode. At this time, another AC power source is input to the UPS bypass circuit input terminal via QF3 (closed state) and an isolation transformer. The power is then switched by an internal static switch and output to the output bus via QF16 and QF17 (closed state) to power the load.

[0030] In normal operation, if a mains power failure occurs, the UPS switches to battery operation mode. The load is powered by the battery pack (discharging) through the inverter via QF16 and QF17 (closed state) outputting AC380V to the output bus.

[0031] Improve input power quality

[0032] The UPS input is equipped with isolation transformers (isolation transformers 1, 2, and a bypass isolation transformer) and active power filters (APF1, APF2) to improve the quality of the UPS incoming power supply, protect the internal electronic components, and extend the UPS's lifespan. The output of the isolation transformers is completely isolated from the input, effectively filtering the AC input power voltage. The active power filters are connected in parallel to detect harmonics of different magnitudes and frequencies in the AC input power current in real time. They inject compensation currents of equal amplitude but opposite phase into the input bus, achieving real-time dynamic harmonic filtering and ensuring that the current on the input bus is a standard sine wave.

[0033] UPS and battery redundancy configuration

[0034] This power supply solution employs a dual-UPS online parallel operation mode. Under normal conditions, the two completely independent UPSs provide power to different loads respectively. If one UPS fails, the other UPS will meet the power needs of all loads and operate stably for an extended period. Each UPS is equipped with a separate static switch and bypass, and includes a built-in isolation transformer and a Class D surge protector. The rated capacity of the bypass is the same as that of the rectifier-inverter circuit, and its power supply is connected to a different busbar than the main power supply.

[0035] Two backup battery packs (battery pack 1 and 2) provide DC inverter power to UPS1 and UPS2. Through different switching combinations of five circuit breakers (QF11-15), any battery pack can flexibly provide DC power to any UPS, so that one of the UPS and battery packs can be used for UPS maintenance, battery charging and discharging and repair operations at any time without affecting the normal operation of the other UPS.

[0036] When battery pack 1 requires maintenance, close switch QF15 and open switch QF13. At this time, battery pack 2 supplies power to UPS1 and UPS2, allowing battery pack 1 to undergo maintenance, battery charging / discharging, and repair operations. After maintenance, close switch QF13 and open switch QF15. Similarly, when battery pack 2 requires maintenance, close switch QF15 and open switch QF14. At this time, battery pack 1 supplies power to UPS1 and UPS2, allowing battery pack 2 to undergo maintenance, battery charging / discharging, and repair operations. After maintenance, close switch QF14 and open switch QF15.

[0037] Battery pack 1 supplies power to UPS2. With switches QF13 and QF15 closed, switch QF11 open, then switch QF14 open, and switch QF12 closed, battery pack 1 now supplies power to UPS2. Alternatively, battery pack 1 supplies power to both UPS1 and UPS2. With switches QF13, QF15, QF11, and QF12 closed, and switch QF14 open, battery pack 1 now supplies power to both UPS1 and UPS2.

[0038] Similarly, when battery pack 2 supplies power to UPS1, close switches QF14 and QF15, open switch QF12, then open switch QF13, and close switch QF11. At this time, battery pack 2 supplies power to UPS1. When battery pack 2 supplies power to both UPS1 and UPS2, close switches QF14, QF15, QF11, and QF12, and open switch QF13.

[0039] like Figure 1 As shown, the output side of the isolation transformer adopts a star connection, and there is a neutral point (N) at the output end, which is led to the output bus. The UPS output is three-phase power, and the output bus is three-phase plus neutral line (N). The single-phase voltage used by the power supply output from the output bus to each branch load is AC220V (i.e., ABC phase voltage).

[0040] STS static transfer switch configuration at each site

[0041] To ensure power supply reliability, UPS1 and UPS2 each provide two AC220V power supplies to each site, connected to the STS static transfer switch (STS) in the distribution cabinet of each site (e.g., ...). Figure 2 (As shown). The STS static transfer switch is used to switch power supply between two power sources. If the first power source fails, the STS automatically switches to the second power source to supply power to the load; if the second power source fails, the STS automatically switches back to the first power source to supply power to the load. The static transfer switch provides fast power switching (≤5ms), meeting the DCS power supply interruption time requirements and ensuring uninterrupted operation of electronic equipment at each DCS site.

[0042] Remote monitoring function

[0043] This design scheme achieves intelligent computer monitoring, automatic fault diagnosis, and advanced maintenance management functions. The remote monitoring equipment can display the UPS system in a structural block diagram, and graphically display its operating status, voltage, current, frequency, etc.; UPS start-up, shutdown, and power supply switching can all be displayed online; it can monitor the operating status and load of equipment such as battery banks, active filters, and input / output cabinets, and update the data synchronously; it records the operation and accidents of each device; and it has report generation, graphical display, and printing functions.

[0044] like Figure 3 As shown, the active power filter (APF), UPS host, battery pack, and integrated input / output cabinet upload data to the serial port server via the RS485 interface provided by an external serial interface card or the built-in serial port module, using the MODBUS communication protocol. The computer can access the operating parameters of each device in the serial port server through monitoring software.

[0045] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A factory power supply control system based on an uninterruptible power supply, characterized in that, It includes two power supply branches that supply power to the distribution cabinets at the site: the first power supply branch and the second power supply branch; First power supply branch: The first power supply branch is equipped with a first UPS; the first UPS includes a connected rectifier unit and an inverter unit; An external first AC power supply is connected to the input bus I via switch QF1; the input bus I is connected to the AC terminal of the rectifier unit of the first UPS via switch QF4 and the first isolation transformer in sequence; the inverter unit is connected to the output bus I via switch QF16; the connection point between the rectifier unit and the inverter unit in the first UPS is also connected to the first battery pack via switches QF11 and QF13 connected in series in sequence. Second power supply branch: The second power supply branch is equipped with a second UPS; the second UPS includes a connected rectifier unit and an inverter unit; An external second AC power supply is connected to the input bus II via switch QF2; the input bus II is connected to the AC terminal of the rectifier unit of the second UPS via switch QF6 and the second isolation transformer; the inverter unit is connected to the output bus II via switch QF17; the connection point between the rectifier unit and the inverter unit in the second UPS is also connected to the first battery pack via switches QF12 and QF14 connected in series. The site distribution cabinet is equipped with an STS static transfer switch; the output side of the STS static transfer switch is connected to the site power supply line. Input bus I is connected to the STS static changeover switch via switch group 1QF1; Input bus II is connected to the STS static transfer switch via switch group 2QF1.

2. The factory power supply control system based on an uninterruptible power supply according to claim 1, characterized in that, A switch QF15 is connected across the connection point between switches QF12 and QF14 and the connection point between switches QF11 and QF13.

3. The factory power supply control system based on an uninterruptible power supply according to claim 1, characterized in that, It also includes bypass power supply branches; In the bypass power supply branch, the bypass AC input power is connected to the bypass isolation transformer via switch QF3 and to the static switch in the first UPS and the second UPS via switch QF8.

4. The factory power supply control system based on an uninterruptible power supply according to any one of claims 1 to 3, characterized in that, Input bus I is connected to active filter APF1 via switch QF5; input bus II is connected to active filter APF2 via switch QF7.

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