Power supply method for water electrolysis hydrogen production control system

Abstract

The invention discloses a power supply method for a water electrolysis hydrogen production control system, which adopts two paths of AC220V power supplies to supply power to a UPS (Uninterrupted Power Supply) through a double-throw power supply switching device, the UPS is rectified and inverted to provide an AC220V voltage-stabilized power supply, the voltage-stabilized power supply and the other path of AC220V power supply supply power to a main controller and an auxiliary controller of the water electrolysis hydrogen production control system, and supply power to a 24V direct current load through a 220V AC / 24V DC module; carrying out three-power separation on a system power supply, a field power supply and an auxiliary power supply on the 24V direct current load; a transformer for isolation is additionally arranged at the wire inlet end of a control power supply, a filter capacitor is connected between a control signal wire and the ground in parallel, and a filter is additionally arranged between two poles of a signal; and a star-shaped double-network structure is adopted to receive operation or fault alarm signals of the power supply module. According to the invention, a stable and uninterrupted power supply can be provided for the water electrolysis hydrogen production control system, the signal interference of the DCS control system is reduced, and the reliability and safety of the operation of the DCS control system are improved, so that the stability of the water electrolysis hydrogen production operation is ensured.

Description

Technical Field

[0001] The invention relates to the technical field of water electrolysis hydrogen production, and in particular to a power supply method for a water electrolysis hydrogen production control system. Background Art

[0002] With the rapid development of new energy industries such as photovoltaics and wind power, clean energy hydrogen production technology continues to improve, and green hydrogen direct reduction ironmaking will become an important direction. Hydrogen production by water electrolysis is one of the important technologies for industrial hydrogen production at present. It is a relatively mature process technology, which is characterized by high purity of hydrogen production, simple operation and no pollutant emissions. Under the conditions of forced circulation of electrolyte and direct current passing through the electrolyzer, oxygen and hydrogen are produced in the positive and negative chambers of the electrolyzer. After separation and liquid removal by their respective gas-liquid separators, the produced hydrogen and oxygen are cooled by the cooler and continuously sent out of the system for use in downstream processes. The control system for hydrogen production by water electrolysis consists of a distributed control system (DCS) and an emergency shutdown system (ESD). The process automatic control system automatically controls the set system pressure, tank temperature, separator liquid level balance, timely replenishes the raw water consumed by electrolysis, collects gas samples in real time for analysis, guides process operations, and realizes automatic monitoring and control of various operating parameters.

[0003] The various production links of hydrogen production by water electrolysis are directly interdependent. The production process is restricted by many factors such as temperature and pressure. It is flammable and explosive. The control information requires to be timely, stable and reliable. It is crucial to improve the reliability of the DCS control system. If the key control point modules such as the electrolyzer and gas purification are offline, there will be malignant accidents such as rupture and explosion of the production device container and leakage of a large amount of alkali solution and hydrogen at the same time, which will pose a great threat to personal safety and stable production operation. Therefore, it is necessary to provide a stable and uninterrupted power supply to the water electrolysis hydrogen production control system to ensure the stability of the system operation, realize real-time monitoring and control of the water electrolysis hydrogen production process, effectively ensure the safe, stable and long-term operation of the water electrolysis hydrogen production device, and avoid the waste of manpower, material and financial resources caused by failure start-up and shutdown.

[0004] Through the search, some relevant documents and patents were retrieved, such as patent CN112968605B, which discloses a hydrogen production power supply with a dual interlaced BUCK topology and a control method thereof. The hydrogen production power supply disclosed in this invention patent includes a pre-charging circuit, a DC circuit breaker, a DC bus capacitor, a fuse, two groups of interlaced BUCK circuits, two groups of filter circuits, three current sampling units, and two voltage sampling units. The two groups of interlaced BUCK circuits in this invention patent are connected in series, the midpoint of the BUCK circuit is connected to the midpoint of the bus capacitor and the midpoint of the hydrogen production electrolyzer and is grounded, and the capacitor output is filtered using an LC filter circuit. The topology of BUCK series connection can increase the input voltage level of the power supply, and each group of BUCK circuits adopts an interlaced parallel structure to achieve power transmission with a higher power level. The problem with this method is that it does not consider the impact of power outages caused by controller, control module, card failure or grounding failure of the field instrument circuit on the control system. If there is a problem with the control system, it will have a huge impact on production and may even cause production and equipment accidents.

[0005] Patent CN212463075U discloses a power supply device suitable for high-power and ultra-high-power water electrolysis to produce hydrogen. The invention provides a power supply device suitable for high-power and ultra-high-power water electrolysis to produce hydrogen, which is composed of a power output circuit composed of an inductor, a capacitor, a transformer, an inverter, etc. The control part adopts a DSP+FPGA and DSP+CPLD architecture. Through the advantages of topology and control strategy, the harmonics and power factor generated by high-power power electronic equipment are reduced to pollute the power grid, effectively reduce grid-side harmonics, improve power factors, and improve system efficiency to meet the current urgent application of high-power electrolysis to produce hydrogen. The problem with this method is that the power supply of the automatic control system does not consider the redundant design of dual power supplies and dual circuits. Once the control system loses power, it is easy to cause the production device to stop. In severe cases, explosions and other severe accidents may occur, causing damage to equipment and personal injury.

[0006] Patent CN114726241B discloses a water electrolysis hydrogen production power supply device based on IGBT technology. The invention includes a series-connected rectifier module and a buck module, wherein the rectifier module includes a plurality of parallel rectifier modules, and the buck module includes a plurality of parallel buck modules; the rectifier module is used to access three-phase electricity and filter and rectify to output a DC voltage of a first amplitude; the buck module is connected to the rectifier module to lower the amplitude of the DC voltage and output a DC voltage of a second amplitude after filtering; each of the rectifier modules and each of the buck modules includes an input switch, an output switch and a plurality of IGBT tubes, which can improve the stability and reliability of the output voltage. The invention does not consider the impact of power grid fluctuations, harmonic pollution and other conditions on the water electrolysis hydrogen production control system. The production process control is highly dependent on automation technology. Once there is a problem with the control system, it will have a huge impact on production.

[0007] In summary, the control system is the core to ensure the reliable operation of the water electrolysis hydrogen production device, and the stability of the automatic control system operation mainly depends on the continuity of the power supply. Therefore, it is very necessary to explore a more effective power supply method for the water electrolysis hydrogen production control system, provide a stable and uninterrupted power supply for the water electrolysis hydrogen production control system, realize real-time monitoring and control of the water electrolysis hydrogen production process, and ensure the stable operation of the water electrolysis hydrogen production system. Summary of the invention

[0008] The present invention proposes a power supply method for a water electrolysis hydrogen production control system, which can provide a stable and uninterrupted power supply for the water electrolysis hydrogen production control system, reduce the signal interference of the DCS control system, improve the reliability and safety of the DCS control system operation, control, operate and monitor the water electrolysis hydrogen production device, thereby ensuring the stability of the water electrolysis hydrogen production operation and creating greater economic benefits for the enterprise.

[0009] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0010] The present invention is achieved through the following technical scheme: a power supply method for a water electrolysis hydrogen production control system, which adopts two AC220V power supplies to power a UPS through a double-throw power supply switching device, and the UPS power supply provides an AC220V regulated power supply after rectification and inversion. The regulated power supply and another AC220V power supply are used to power a main controller and a sub-controller of the water electrolysis hydrogen production control system, and a 24V DC load is powered through a 220VAC / 24VDC module; the 24V DC load is electrically separated into a system power supply, a field power supply and an auxiliary power supply; an isolation transformer is added at the incoming line end of the control power supply, a filter capacitor is connected in parallel between the control signal line and the ground, and a filter is installed between the two poles of the signal; and a star-type dual network structure communication is adopted to receive the operation or fault alarm signal of the power module.

[0011] Furthermore, bypass switches are installed in the power supply input and output lines of the UPS, the UPS inlet and outlet are respectively provided with an inlet switch and an outlet switch, and the bypass switch is connected in parallel to the outside of the UPS inlet and outlet switches.

[0012] Furthermore, a high-power decoupling diode is installed at the positive pole of the 220VAC / 24VDC DC power supply output terminal to achieve isolation between the two power supplies, and the power is provided to the 24V DC load through the DC power distribution module.

[0013] Furthermore, the system power supply is used for the controller, input and output module, and communication module, the field power supply is used for the transmitter, A / D conversion, and line diagnosis, and the auxiliary power supply is used for switch quantity query, relay, and safety barrier.

[0014] Furthermore, the three-power separation adopts AC distribution module, DC distribution module and auxiliary distribution module to distribute power. The AC distribution module has a built-in redundant high-performance filter, the DC distribution module has a built-in branch fuse, and the auxiliary distribution module has a built-in recoverable fuse and indicator light.

[0015] Furthermore, the signal is digitally filtered through filtering software, the reference point potential is regularly corrected, and a dynamic zero point is adopted.

[0016] Furthermore, the cabinet of the control system adopts a series single-point grounding method, and the central grounding points of the cabinets of each device are connected with a copper busbar, and the grounding busbar is directly connected to the grounding electrode, and the grounding resistance of the grounding electrode is less than 2Ω.

[0017] Furthermore, the star-shaped dual network communication structure ensures that the power module has an independent dual transceiver communication circuit, and has the fault alarm and self-diagnosis functions of short circuit and open circuit of the power module.

[0018] Furthermore, there are 2 to 3 220VAC / 24VDC modules.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] The present invention provides a power supply method for a water electrolysis hydrogen production control system, which provides a stable and uninterrupted power supply for the water electrolysis hydrogen production control system, significantly improves the reliability of the entire power supply system, comprehensively improves the power supply quality of the control system, avoids the influence of a power outage due to a fault of a certain controller, a card component, or a terminal board, or a grounding fault of a field instrument on the water electrolysis hydrogen production control system, effectively ensures the safe, stable, and long-term operation of a water electrolysis hydrogen production device, and avoids production accidents and economic losses caused by faults of the water electrolysis hydrogen production device. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 , 220V UPS power supply electrical schematic diagram of water electrolysis hydrogen production control system;

[0022] Figure 2 , schematic diagram of three-electric separation power supply of water electrolysis hydrogen production control system. DETAILED DESCRIPTION

[0023] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other. The described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] To further describe the present invention, the present invention is described in more detail below in conjunction with embodiments: Figure 1 As shown, the power supply method of the present invention provides two 220VAC power supplies for the water electrolysis hydrogen production control system, which come from different power supply buses. Among them, the first 220VAC power supply adopts two AC220V power supplies to power the UPS through a double-throw power supply switching device. The UPS power supply is rectified and inverted, and four outputs are provided through the air switch to provide AC220V regulated power supply for the water electrolysis hydrogen production control system. A dual-circuit single UPS power supply mode is adopted, and the incoming lines are connected to different power supply buses respectively. The UPS power supply output supplies 24VDC power supply 1, CPU-1 and uninterruptible power supply load. The second 220VAC power supply is directly powered by the city power supply to the water electrolysis hydrogen production DCS control system. The UPS inlet and outlet in the first 220VAC power supply are provided with an inlet switch and an outlet switch, and a bypass switch is installed in the power supply input and output lines of the UPS. The bypass switch is connected in parallel to the outside of the UPS inlet and outlet switches. Once the UPS fails, the inlet and outlet switches are disconnected, and the maintenance bypass is closed to supply power normally. The bypass power supply and the second 220VAC power supply still have a double insurance function to continue to provide power for the 24VDC power supply 2, CPU-2 and some auxiliary loads. At this time, the UPS can be offline for repair, and after repair, it can be online, the maintenance bypass switch is disconnected, the inlet and outlet switches are closed, and power is supplied normally.

[0025] The DC part of the DCS control system for hydrogen production by electrolysis of water is powered by two 220VAC / 24VDC DC power supplies in parallel. The two 220VAC / 24VDC DC power modules are powered by 220VAC UPS and another 220VAC power supply respectively. If one DC power supply fails, the power supply is switched to the other power supply to carry all the loads. During the switching process, the other power supply is converted by the DC high-frequency power supply and then outputs DC power through the relay contacts. In the high-frequency isolation conversion system, the DC power is first inverted at high frequency, and then rectified and filtered after the high-frequency isolation conversion is completed. At the same time, this redundant 24V DC power supply is sent to different columns of terminal blocks in the control cabinet. The 24V DC power supply of the field equipment is distributed through different columns of terminal blocks, which improves the power supply reliability of the power supply and field equipment. A high-power decoupling diode is installed at the positive pole of the 220VAC / 24VDC DC power supply output end to achieve isolation between the two power supplies, and the DC power distribution module provides DC power for the input and output modules, transmitters, relays, communication modules, etc. The two DC power supply failure alarms are sent to the DCS control system. Once there is a DC power failure, the alarm notifies the operation post.

[0026] like Figure 2As shown, three-electric separation power supply is adopted, namely system power supply, field power supply and auxiliary power supply. The transmitter, A / D conversion and field line diagnosis used to collect signals such as gas-liquid separator liquid level, EDI water supply flow, hydrogen outlet pressure are powered by the field power supply. The input and output modules, CPU controller and communication module are powered by the system power supply. Switch quantity query, relay and safety barrier are powered by the auxiliary power supply. AC power distribution module, DC power distribution module and auxiliary power distribution module are used for power distribution. The AC power distribution module has built-in redundant high-performance filters to prevent interference from the power grid and the inverter. The DC power distribution module has built-in branch fuses, and the auxiliary power distribution module has built-in recoverable fuses and indicator lights. The three-electric separation power supply can prevent the field wiring from mistakenly transmitting strong electricity, which affects the core circuit inside the electrolysis water hydrogen production control system.

[0027] The present invention adopts software and hardware anti-interference methods, adds an isolation transformer at the incoming line end of the water electrolysis hydrogen production control power supply, and weakens the transmission of high-noise signals in the external power grid to the inside of the DCS power supply circuit. A filter capacitor is connected in parallel between the control signal line and the ground to reduce common-mode interference, and a filter is installed between the two poles of the signal to reduce differential-mode interference. The signal is digitally filtered by filtering software, the reference point potential is corrected regularly, and a dynamic zero point is used to prevent potential drift. A series one-point grounding method is adopted, and the central grounding point of the cabinet of each device is connected with a copper busbar. The grounding busbar is directly connected to the grounding electrode. The grounding resistance of the grounding electrode is less than 2Ω, thereby enhancing the reliability of the power supply system.

[0028] The present invention adopts a star-shaped dual-network communication structure for the DCS control system for hydrogen production by electrolysis. The power module has an independent dual-transceiver communication circuit, and the communication bus goes deep into the module level. Any module failure does not affect the power module communication. Since the network adopts a redundant structure, if any communication line fails, the communication network still maintains normal data transmission, and has the fault alarm and self-diagnosis function of short circuit and open circuit of the power module.

[0029] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A power supply method for a water electrolysis hydrogen production control system, characterized in that: Two AC220V power supplies are used to power the UPS through a double-throw power switching device. The UPS power supply provides an AC220V regulated power supply after rectification and inversion. The regulated power supply and another AC220V power supply are used to power the main and sub-controllers of the water electrolysis hydrogen production control system, and the 24V DC load is powered by a 220VAC / 24VDC module. The 24V DC load is electrically separated into system power, field power and auxiliary power. An isolation transformer is added to the incoming end of the control power supply, a filter capacitor is connected in parallel between the control signal line and the ground, and a filter is installed between the two poles of the signal. A star-shaped dual network structure communication is used to receive the power module operation or fault alarm signal.

2. A power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: A bypass switch is installed in the power supply input and output lines of the UPS. The UPS inlet and outlet are respectively provided with an inlet switch and an outlet switch, and the bypass switch is connected in parallel to the outside of the UPS inlet and outlet switches.

3. A power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: A high-power decoupling diode is installed at the positive pole of the 220VAC / 24VDC DC power supply output end to achieve isolation between the two power supplies, and the power is provided to the 24V DC load through the DC power distribution module.

4. A power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: The system power supply is used for the controller, input and output modules, and communication modules; the field power supply is used for the transmitter, A / D conversion, and line diagnosis; the auxiliary power supply is used for switch quantity query, relays, and safety barriers.

5. The power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: The three-power separation adopts AC distribution module, DC distribution module and auxiliary distribution module to distribute power. The AC distribution module has a built-in redundant high-performance filter, the DC distribution module has a built-in branch fuse, and the auxiliary distribution module has a built-in recoverable fuse and indicator light.

6. A power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: The signal is digitally filtered through filtering software, the reference point potential is regularly corrected, and a dynamic zero point is adopted.

7. A power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: The cabinet of the control system adopts a series single-point grounding method, and the central grounding points of the cabinets of each device are connected with a copper busbar. The grounding busbar is directly connected to the grounding electrode, and the grounding resistance of the grounding electrode is less than 2Ω.

8. The power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: The star-shaped dual-network communication structure ensures that the power module has an independent dual-transceiver communication circuit and has the fault alarm and self-diagnosis functions of short circuit and open circuit of the power module.

9. A power supply method for a water electrolysis hydrogen production control system according to claim 1, characterized in that: There are 2 to 3 220VAC / 24VDC modules.

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