An emergency protection device and automatic control method for power failure of an electrodeposition tank

Abstract

The present application relates to hydrometallurgy electric power protection technical field, more specifically, it relates to a kind of emergency protection device and automatic control method of power failure of electrodeposition tank accident, device includes polar rectifier, emergency generator set and monitoring unit;The direct current output end of the polar rectifier is used for parallel with the direct current output end of main rectifier for the power supply of series electrodeposition tank group, the polar rectifier is configured to output positive slot voltage to the series electrodeposition tank group after the main rectifier power failure, the positive slot voltage is the voltage distributed to each electrodeposition tank in the series electrodeposition tank group, and it is lower than the normal electrodeposition working voltage of single electrodeposition tank in the series electrodeposition tank group, to inhibit the original cell reverse reaction in the series electrodeposition tank group;The present application can realize that emergency power supply below normal production load is specially used for polar rectifier to output positive slot voltage, so as to long-term inhibit original cell reverse reaction under the premise of economy, security.

Description

Technical Field

[0001] This invention relates to the field of power protection technology in hydrometallurgical processes, and more specifically, to an emergency protection device and automatic control method for power outages caused by electrosinking accidents. Background Technology

[0002] In hydrometallurgical electrowinning processes, multiple electrowinning cells are typically connected in series and powered by a high-power main rectifier. When a prolonged power outage occurs on the external grid or the main rectifier fails and shuts down, the deposited metal plating, acidic electrolyte, and insoluble anode in the electrowinning cells spontaneously form a galvanic cell. This causes reverse electrochemical dissolution of the metal plating on the cathode starting plate and reduction corrosion of the anode plate. Existing busbar short-circuit protection measures can only cope with short-term shutdowns and cannot provide continuous and effective protection under prolonged power outage conditions. While configuring large-capacity backup generators to maintain the entire production line at full load can restore production, the equipment investment is huge and fuel consumption is extremely high, making it uneconomical in scenarios where only electrode plate protection is needed rather than production restoration. Therefore, there is an urgent need for an emergency protection solution that can economically and automatically suppress the reverse reaction of the galvanic cell in the electrowinning cells during prolonged power outages. Summary of the Invention

[0003] To address the problems of high cost and low automation in corrosion protection of electrode plates in electrowinning cells during long-term power outages in existing technologies, this invention provides an emergency protection device and automatic control method for electrowinning cell power outages. This device enables the polarization rectifier to output a positive cell protection voltage at an emergency power supply below the normal production load, thereby effectively suppressing reverse reactions of the galvanic cell in a long-term manner while being economical and safe.

[0004] To at least partially solve the above problems, the present invention provides an emergency protection device for power outages in electrowinning cells, comprising a polarized rectifier, an emergency generator set, and a monitoring unit; the DC output terminal of the polarized rectifier is connected in parallel with the DC output terminal of the main rectifier supplying power to the series electrowinning cell group; the polarized rectifier is configured to output a positive cell-protection voltage to the series electrowinning cell group after the main rectifier loses power; the positive cell-protection voltage is the voltage distributed to each electrowinning cell in the series electrowinning cell group, and is lower than the normal electrowinning operating voltage of a single electrowinning cell in the series electrowinning cell group, so as to suppress the reverse reaction of the galvanic cells in the series electrowinning cell group; The AC output terminal of the emergency generator set is configured to be connected to the AC input terminal of the polarized rectifier for power supply. The emergency generator set is configured to automatically start after the main rectifier loses power to supply power to the polarized rectifier. The rated output capacity of the emergency generator set is greater than or equal to the tank protection load required to maintain the positive tank protection voltage, and less than the load required for normal electrowinning production of the series electrowinning tank group. The monitoring unit is connected to the emergency generator set and the polarized rectifier respectively, and is configured to control the emergency generator set to start automatically after determining that the main rectifier has lost power, and control the polarized rectifier to output the positive tank protection voltage.

[0005] Optionally, the monitoring unit is configured to: control the polarized rectifier to continuously output the positive slot protection voltage when the cumulative duration of the main rectifier power failure does not exceed a preset duration threshold; and control the polarized rectifier to switch from continuous output to intermittent output of the positive slot protection voltage when the cumulative duration of the main rectifier power failure exceeds the preset duration threshold, so as to reduce the average output power of the emergency generator set while keeping the slot voltage of the series electrolytic cell group positive. The intermittent output is a pulse output, and during the pulse interval, the slot voltage of the series electrolytic cell group is not lower than a preset protection threshold.

[0006] Optionally, the monitoring unit is configured to: control the polarization rectifier to increase the positive tank voltage when the temperature of the electrolyte in the series electrodeposition cell group is lower than a preset temperature threshold and / or the circulation flow rate of the electrolyte is lower than a preset flow rate threshold; and control the polarization rectifier to reduce the positive tank voltage back to the value before the increase after the temperature of the electrolyte is no longer lower than the preset temperature threshold and the circulation flow rate of the electrolyte is no longer lower than the preset flow rate threshold.

[0007] Optionally, it also includes an electrolyte circulation pump and an auxiliary power supply branch; the electrolyte circulation pump is configured to drive the electrolyte circulation of the series electrodeposition cell group; the auxiliary power supply branch is electrically connected to the electrolyte circulation pump and is configured to supply power to the electrolyte circulation pump by the emergency generator set after the main rectifier loses power, so as to maintain the circulation of the electrolyte during the power failure of the main rectifier.

[0008] Optionally, it also includes a dual power switching cabinet, a polarized DC disconnect switch, and a main DC disconnect switch; the AC output terminal of the emergency generator set and the mains circuit are both connected to the dual power switching cabinet, the first output terminal of the dual power switching cabinet is electrically connected to the AC input terminal of the polarized rectifier, and the second output terminal of the dual power switching cabinet is electrically connected to the electrolyte circulation pump via the auxiliary power supply branch. The dual power switching cabinet is configured to switch the AC power supply of the polarized rectifier to the emergency generator set and the power supply of the electrolyte circulation pump to the emergency generator set after the main rectifier loses power; the DC output terminal of the polarized rectifier is connected to the DC bus supplying power to the series electrolytic cell group via the polarized DC disconnect switch, and the DC output terminal of the main rectifier is connected to the DC bus via the main DC disconnect switch. The polarized DC disconnect switch and the main DC disconnect switch are mechanically interlocked; the monitoring unit is also configured to interlock the electrolyte circulation pump to maintain a minimum circulation flow rate after determining that the main rectifier has lost power.

[0009] Optionally, the monitoring unit is configured to: first disconnect the main DC disconnect switch after the emergency generator set supplies power to the polarized rectifier, then close the polarized DC disconnect switch after a preset delay, and then start the polarized rectifier to output the positive tank protection voltage to the series electrolytic cell group, so as to avoid the main rectifier and the polarized rectifier operating in parallel with each other as two DC power supplies; wherein, both the main DC disconnect switch and the polarized DC disconnect switch are equipped with electric operating mechanisms, and the monitoring unit disconnects or closes the corresponding disconnect switches via the electric operating mechanisms; wherein, a thyristor bypass branch is connected in parallel at both ends of the polarized DC disconnect switch, and the thyristor bypass branch is configured to be conductive during the closing of the polarized DC disconnect switch, so as to suppress the operating overvoltage generated during the switching process.

[0010] Optionally, it also includes an uninterruptible power supply for powering the monitoring unit; the monitoring unit is configured to determine that a power outage fault has occurred when it simultaneously receives a power failure signal from the external power grid and a power failure signal from the high-voltage switchgear, and detects that the total voltage of the DC bus supplying power to the series electrosink group is lower than the voltage threshold for a preset duration, and outputs a start signal to the emergency generator set.

[0011] Optionally, the series electrodeposition cell group is used for electrodeposition of nickel and / or cobalt, the electrolyte of the series electrodeposition cell group is an acidic sulfate electrolyte containing nickel and / or cobalt ions, the anode of the series electrodeposition cell group is a lead-based insoluble anode, the cathode of the series electrodeposition cell group is a titanium or stainless steel starting plate, and the normal electrodeposition operating voltage of a single electrodeposition cell in the series electrodeposition cell group is 3.0~4.2V.

[0012] Furthermore, the present invention also provides an emergency protection automatic control method for electrowinning cell power outages, applied to the emergency protection device for electrowinning cell power outages described in any of the above claims, comprising: determining a power outage fault after the main rectifier supplying power to the series electrowinning cell group loses power; automatically starting an emergency generator set in response to the determination of the power outage fault, wherein the emergency generator set supplies power to the polarization rectifier; controlling the polarization rectifier to output a positive cell-holding voltage to the series electrowinning cell group to suppress reverse reactions of the galvanic cells in the series electrowinning cell group, wherein the positive cell-holding voltage is the voltage distributed to each electrowinning cell in the series electrowinning cell group and is lower than the normal electrowinning operating voltage of a single electrowinning cell in the series electrowinning cell group; wherein the rated output capacity of the emergency generator set is greater than or equal to the cell-holding load required to maintain the positive cell-holding voltage and less than the load required for normal electrowinning production of the series electrowinning cell group.

[0013] Optionally, the determination of a power outage fault includes: when simultaneously receiving a power failure signal from the external power grid and a power failure signal from the high-voltage switchgear, and detecting that the total voltage of the DC bus supplying power to the series electrolytic cell group is lower than a voltage threshold for a preset duration, the power outage fault is determined to have occurred; the method further includes: in response to the determination of a power outage fault, outputting a start signal to the emergency generator set to start the emergency generator set, and interlocking the electrolyte circulation pump of the series electrolytic cell group to maintain a minimum circulation flow rate; after the voltage and frequency output by the emergency generator set stabilize, switching the AC power supply of the polarized rectifier from the mains power to the emergency generator set; first disconnecting the main DC disconnect switch in the DC output circuit of the main rectifier, and closing the polarized DC disconnect switch in the DC output circuit of the polarized rectifier after a preset delay, and then controlling the polarized rectifier to output the positive cell-holding voltage to the series electrolytic cell group.

[0014] Optionally, the method further includes: when the temperature of the electrolyte in the series electrodeposition cell group is lower than a preset temperature threshold and / or the circulation flow rate of the electrolyte is lower than a preset flow rate threshold, controlling the polarization rectifier to increase the positive cell holding voltage; after the temperature of the electrolyte is no longer lower than the preset temperature threshold and the circulation flow rate of the electrolyte is no longer lower than the preset flow rate threshold, controlling the polarization rectifier to reduce the positive cell holding voltage back to the value before the increase.

[0015] Optionally, controlling the polarized rectifier to output a positive slot protection voltage to the series electrodeposition group includes: controlling the polarized rectifier to continuously output the positive slot protection voltage when the cumulative duration of the main rectifier's power failure does not exceed a preset duration threshold; and controlling the polarized rectifier to switch from continuous output to intermittent output of the positive slot protection voltage when the cumulative duration of the main rectifier's power failure exceeds the preset duration threshold, so as to reduce the average output power of the emergency generator set while keeping the slot voltage of the series electrodeposition group positive, wherein the intermittent output is a pulse output, and during the pulse interval, the slot voltage of the series electrodeposition group is not lower than a preset protection threshold.

[0016] Optionally, the method further includes: after detecting the restoration of external power grid and the high-voltage switchgear being energized, controlling the polarized rectifier to gradually reduce the positive protection voltage to zero at a preset rate; after the positive protection voltage is reduced to zero, disconnecting the polarized DC disconnect switch, closing the main DC disconnect switch, and restoring the normal electrowinning operating voltage of a single electrowinning cell in the series electrowinning cell group to be output by the main rectifier to the series electrowinning cell group; and outputting a shutdown signal to the emergency generator set to shut down the emergency generator set.

[0017] Compared with the prior art, the present invention has at least the following beneficial effects: The emergency protection device and automatic control method for electrowinning cell power outages of the present invention, through a dedicated matching architecture of an emergency generator set and a polarized rectifier, ensures that the rated output capacity of the emergency generator set only matches the cell protection load required to maintain the positive cell protection voltage, without having to meet the high load required for normal electrowinning production of the series-connected electrowinning cell group. This significantly reduces the purchase cost and operating energy consumption of emergency power equipment. Simultaneously, since the positive cell protection voltage is controlled at a level lower than the normal electrowinning operating voltage, this voltage is sufficient to offset the reverse electromotive force of the galvanic cell to suppress plate corrosion, but will not trigger a continuous metal electrowinning reaction. This achieves the economical protection goal of preventing cell production, enabling plate protection for several days with low fuel consumption during prolonged power outages, avoiding the problems of short-term effectiveness of traditional short-circuit protection methods and high investment costs of full-load standby generator solutions. Furthermore, the automatic start / stop, power switching, and DC circuit interlock control implemented through the monitoring unit eliminate the safety hazards and response delays of manual operation, ensuring the reliability and automation level of the emergency protection process.

[0018] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0019] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the system structure of the electrosink accident power outage emergency protection device of the present invention.

[0020] Icons: 10-Series electrolytic cell group; 20-Main rectifier; 30-Polarized rectifier; 40-Emergency generator set; 50-Monitoring unit; 60-Dual power supply switch cabinet; 70-Electrolyte circulation pump; 80-Auxiliary power supply branch; 91-Main DC disconnect switch; 92-Polarized DC disconnect switch. Detailed Implementation

[0021] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions in the embodiments of this invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] The following is in conjunction with the appendix Figure 1 The present invention will be described in detail below.

[0023] Example 1:

[0024] like Figure 1As shown, this embodiment provides an emergency protection device for power outages in electrowinning cells. The device includes a polarized rectifier 30, an emergency generator set 40, and a monitoring unit 50. The DC output terminal of the polarized rectifier 30 is connected in parallel with the DC output terminal of the main rectifier 20, which supplies power to the series electrowinning cell group 10. The polarized rectifier 30 is configured to output a positive cell-protection voltage to the series electrowinning cell group 10 after the main rectifier 20 loses power. This positive cell-protection voltage is the voltage distributed to each electrowinning cell in the series electrowinning cell group 10 and is lower than the normal electrowinning operating voltage of a single electrowinning cell in the series electrowinning cell group 10, in order to suppress the reverse reaction of the galvanic cells within the series electrowinning cell group 10. Specifically, in the hydrometallurgical electrowinning process, when the main rectifier 20 stops outputting due to a power outage or malfunction of the external grid, the deposited metal plating, acidic electrolyte, and insoluble anode in the series electrowinning cell group 10 spontaneously form a galvanic cell, generating a reverse electromotive force that leads to the dissolution of the cathode plating and anodic corrosion. In this embodiment, the positive cell protection voltage is not used to maintain normal metal electrowinning production, but is specifically used to counteract the reverse electromotive force of the aforementioned galvanic cell. From an electrochemical mechanism perspective, as long as the applied cell voltage can maintain the electrode surface in a slightly positive potential state, the formation of reverse current can be effectively blocked, thereby inhibiting electrochemical corrosion. At the same time, since this voltage is strictly controlled at a level lower than the normal electrowinning operating voltage, its energy is insufficient to drive the metal ions in the electrolyte to undergo a continuous reduction deposition reaction on the cathode surface. This function of inhibiting corrosion and not producing metal allows the device to achieve plate protection with extremely low energy consumption during long-term power outages, avoiding the problems of ineffective electrowinning due to excessively high voltage or protection failure due to excessively low voltage.

[0025] The AC output terminal of the emergency generator set 40 is configured to connect to the AC input terminal of the polarized rectifier 30 for power supply. The emergency generator set 40 is configured to automatically start after the main rectifier 20 loses power, supplying power to the polarized rectifier 30. The rated output capacity of the emergency generator set 40 is greater than or equal to the tank protection load required to maintain the positive tank protection voltage, and less than the load required for normal electrowinning production of the series electrowinning tank group 10. This capacity matching relationship constitutes the core architectural feature of the emergency protection device of this invention. In engineering practice, the power required to maintain the positive tank protection voltage is usually only a few percent or even lower than the normal electrowinning production power, because there is no need to overcome high electrowinning overpotentials and line voltage drops under tank protection conditions. By selecting the capacity of the emergency generator set 40 according to the tank protection load rather than the production load, the equipment purchase cost of the generator set, the machine room footprint, and the fuel consumption during operation can be significantly reduced. For example, for an electrowinning production line with a normal production load of several megawatts, its tank protection load may only require several hundred kilowatts. Using a dedicated small-capacity emergency generator set 40 instead of a traditional large-capacity backup power supply can achieve an optimal balance between economy and safety. Furthermore, the emergency generator set 40's design specifically for the polarized rectifier 30 means that in emergency protection mode, power resources are precisely allocated to the critical task of corrosion protection, rather than being diverted to unnecessary production loads, thus ensuring a longer protection duration even with limited fuel.

[0026] The monitoring unit 50 is connected to the emergency generator set 40 and the polarized rectifier 30 respectively. It is configured to automatically start the emergency generator set 40 and control the polarized rectifier 30 to output a positive protection voltage after the main rectifier 20 is determined to have lost power. As the control center of the entire emergency protection device, the monitoring unit 50 undertakes the dual functions of status perception and command execution. When the main rectifier 20 is operating normally, the monitoring unit 50 is in a real-time monitoring standby state. Once a preset power failure condition is detected, the monitoring unit 50 immediately triggers the emergency response process. First, it sends a start signal to the emergency generator set 40. After the generator set establishes a stable AC output, it then controls the polarized rectifier 30 to start operation and adjust to the target protection voltage. This fully automatic control configuration eliminates the response lag and risk of misoperation in emergency situations caused by manual operation, ensuring that the time window between the occurrence of power failure and the establishment of the protection voltage is minimized, thereby reducing the time the plates are exposed to an unprotected state to the greatest extent possible. In this embodiment, the specific hardware form of the monitoring unit 50 can be a programmable logic controller (PLC), an industrial computer, or a dedicated control board. As long as it has the corresponding signal acquisition interface and control output capability, it can realize the linkage control of the emergency generator set 40 and the polarized rectifier 30.

[0027] Example 2:

[0028] like Figure 1As shown in Example 1, this example further explains the intelligent adjustment strategy of the monitoring unit 50. The monitoring unit 50 is configured to: control the polarized rectifier 30 to continuously output a positive slot protection voltage when the cumulative duration of power failure of the main rectifier 20 does not exceed a preset duration threshold; and control the polarized rectifier 30 to switch from continuous output to intermittent output of the positive slot protection voltage when the cumulative duration of power failure of the main rectifier 20 exceeds the preset duration threshold. This aims to maintain the slot voltage of the series electrolytic capacitor bank 10 in a positive direction while reducing the average output power of the emergency generator set 40. The intermittent output is a pulse output, and during the pulse interval, the slot voltage of the series electrolytic capacitor bank 10 is not lower than a preset protection threshold. This dual-mode control strategy based on cumulative duration aims to solve the balance between protection effectiveness and energy consumption under long-term power outage conditions. Specifically, in the initial stage of a power outage, the reverse electromotive force of the galvanic cells in the series electrodeposition tank group 10 has not yet reached a steady state, and the electrochemical state of the electrode surface is in a period of drastic change. At this time, the continuous output mode can quickly establish a stable positive electric field, effectively suppressing the initial reverse dissolution trend of the coating. When the cumulative power outage time exceeds the preset time threshold, the galvanic cell reaction in the tank gradually tends to dynamic equilibrium, and the reverse corrosion rate slows down relatively. If continuous constant voltage output is maintained, it will not only cause ineffective consumption of fuel in the emergency generator set 40, but may also cause changes in the state of the electrode surface due to prolonged constant polarization. At this time, switching to the intermittent pulse output mode utilizes the double-layer capacitance effect of the electrode / solution interface to maintain a certain positive potential by relying on the interface charge storage during the pulse turn-off period. As long as this potential is not lower than the preset protection threshold, the formation of reverse current can be continuously suppressed. This adjustment method allows the emergency generator set 40 to provide energy only during the pulse conduction period, significantly reducing the average output power, thereby extending the protection endurance time under limited fuel. It should be understood that the preset duration threshold and preset protection threshold can be set according to the specific process characteristics of the series electrodeposition tank group 10. For example, the preset duration threshold can be set to several hours, and the preset protection threshold should be higher than the open circuit voltage of the galvanic cell but lower than the metal deposition potential to ensure that reverse corrosion does not occur and no invalid electrodeposition is generated at any time.

[0029] Furthermore, the monitoring unit 50 is also configured to: control the polarization rectifier 30 to increase the forward tank voltage when the temperature of the electrolyte in the series electrowinning cell group 10 is lower than a preset temperature threshold and / or the electrolyte circulation flow rate is lower than a preset flow rate threshold; and control the polarization rectifier 30 to reduce the forward tank voltage back to the value before the increase after the electrolyte temperature is no longer lower than the preset temperature threshold and the electrolyte circulation flow rate is no longer lower than the preset flow rate threshold. This adaptive voltage regulation mechanism is an important supplement to the dual-mode control, used to cope with changes in protection requirements caused by the deterioration of electrolyte conditions during power outages. From an electrochemical mechanism perspective, when the electrolyte temperature decreases, the ion migration rate slows down, the solution resistance increases, and the concentration polarization on the electrode surface intensifies, resulting in an increase in the tank voltage required to offset the same reverse electromotive force. Similarly, when the electrolyte circulation flow rate is insufficient, the thickness of the diffusion layer on the electrode surface increases, the mass transfer process is hindered, and fluctuations in the reverse potential are also caused. If the reference tank voltage is maintained at this time, it may not be able to completely overcome the increased reverse driving force, leading to corrosion in local areas. Therefore, the monitoring unit 50 actively increases the forward protection tank voltage by sensing temperature and flow signals in real time, which is essentially a dynamic compensation for changes in the reverse potential of the concentration cell. When the operating conditions return to normal, the voltage is promptly reduced back to the reference value, avoiding the risk of side reactions caused by excessive voltage and further saving energy. In practical applications, the increase can be a fixed voltage increment or a function based on the degree of deviation, as long as a closed-loop regulation that increases voltage when operating conditions are poor and decreases voltage when operating conditions are good is achieved. This multi-dimensional intelligent adjustment strategy demonstrates the monitoring unit 50's comprehensive perception capability of operating conditions and duration, ensuring that the emergency protection device can achieve reliable plate protection with optimal energy efficiency ratio in various complex environments.

[0030] Example 3:

[0031] like Figure 1As shown, based on Embodiment 1 or Embodiment 2, this embodiment further constructs a physical-level safety switching architecture and auxiliary power system to ensure equipment safety and process stability during emergency protection. The device also includes an electrolyte circulation pump 70 and an auxiliary power supply branch 80. The electrolyte circulation pump 70 is configured to drive the electrolyte circulation of the series-connected electrodeposition cell group 10; the auxiliary power supply branch 80 is electrically connected to the electrolyte circulation pump 70 and is configured to supply power to the electrolyte circulation pump 70 from the emergency generator set 40 after the main rectifier 20 loses power, so as to maintain electrolyte circulation during the power outage of the main rectifier 20. Specifically, during the power outage emergency protection period, although metal electrodeposition production has stopped, the continuous circulation of the electrolyte is crucial for maintaining a uniform temperature field within the cell, preventing the aggravation of local concentration polarization, and ensuring the effectiveness of the aforementioned adaptive voltage regulation strategy. If the electrolyte remains stagnant, the ion concentration on the electrode surface will rapidly become unbalanced, leading to an abnormal increase in the reverse electromotive force and even causing local corrosion. By setting up an independent auxiliary power supply branch 80, the electrolyte circulation pump 70 can be disconnected from the main production power grid and directly obtain power from the emergency generator set 40, thereby ensuring that the series electrowinning tank group 10 is always in a controlled hydrodynamic environment throughout the entire emergency protection cycle. It should be understood that the specific implementation of the auxiliary power supply branch 80 can be a combination of dedicated power distribution cables, circuit breakers, and contactors, as long as it can establish a reliable electrical path from the emergency generator set 40 to the electrolyte circulation pump 70 when the main power supply fails.

[0032] To further enhance the system's power supply reliability and operational safety, the device also includes a dual power switching cabinet 60, a polarized DC disconnect switch 92, and a main DC disconnect switch 91. The AC output of the emergency generator set 40 and the mains circuit are both connected to the dual power switching cabinet 60. The first output of the dual power switching cabinet 60 is electrically connected to the AC input of the polarized rectifier 30, and the second output of the dual power switching cabinet 60 is electrically connected to the electrolyte circulation pump 70 via the auxiliary power supply branch 80. The dual power switching cabinet 60 is configured to switch the AC power supply of the polarized rectifier 30 to the emergency generator set 40 and the power supply of the electrolyte circulation pump 70 to the emergency generator set 40 after the main rectifier 20 loses power. This dual power switching design on the AC side constitutes the first line of defense for the emergency protection system. The dual power switching cabinet 60 typically has both electrical and mechanical interlocking mechanisms inside, which can strictly prevent grid connection conflicts between the mains power and the output power of the emergency generator set 40, ensuring physical isolation and absolute safety during the power switching process. Meanwhile, by unifying the emergency power supply of the polarization rectifier 30 and the electrolyte circulation pump 70 into the management of the dual power supply switching cabinet 60, the on-site power distribution topology is simplified, fault nodes are reduced, and the system's response speed and overall reliability in emergency situations are improved.

[0033] Regarding safety protection on the DC side, the DC output terminal of the polarized rectifier 30 is connected to the DC bus supplying power to the series electrolytic capacitor bank 10 via the polarized DC disconnect switch 92, and the DC output terminal of the main rectifier 20 is connected to the DC bus via the main DC disconnect switch 91. The polarized DC disconnect switch 92 and the main DC disconnect switch 91 are mechanically interlocked. This mechanical interlock refers to a forced constraint achieved through physical linkages, latches, or transmission mechanisms, preventing the two disconnect switches from being simultaneously closed in their physical structure. Compared to soft interlocks achieved solely through software logic or electrical contacts, mechanical interlocks fundamentally eliminate the risk of malfunctions caused by control program malfunctions, relay sticking, or signal interference, and completely avoid the potential for massive circulating currents and equipment burnout accidents caused by accidental parallel connection of the two DC power supplies of the main rectifier 20 and the polarized rectifier 30. Furthermore, the monitoring unit 50 is also configured to interlock the electrolyte circulation pump 70 to maintain a minimum circulation flow rate after determining that the main rectifier 20 has lost power. This interlocking mechanism ensures that even in the event of an abnormal automatic control signal, the electrolyte circulation pump 70 can be forced to maintain the minimum operating condition for safe operation, preventing heat accumulation or sediment buildup in the tank due to pump stoppage, and providing the necessary process basis for subsequent emergency protection operations.

[0034] In the specific execution of DC power supply switching, the monitoring unit 50 is configured to: first disconnect the main DC disconnector 91 after the emergency generator set 40 supplies power to the polarized rectifier 30; then close the polarized DC disconnector 92 after a preset delay; and finally start the polarized rectifier 30 to output a positive tank protection voltage to the series electrolytic capacitor bank 10, so as to avoid the parallel operation of the two DC power supplies, the main rectifier 20 and the polarized rectifier 30. This timing control of disconnecting before closing is the core logic of safe DC side switching. The preset delay setting fully considers the time required for the arc to extinguish when the DC disconnector is disconnected and the process of the bus parasitic capacitance discharge, ensuring that the polarization protection circuit is connected only after the main circuit is completely disconnected and the insulation is restored, thereby further eliminating the risk of power supply overlap in the time dimension. Both the main DC disconnector 91 and the polarized DC disconnector 92 are equipped with electric operating mechanisms, and the monitoring unit 50 disconnects or closes the corresponding disconnectors via these electric operating mechanisms. The introduction of the electric operating mechanism not only enables remote automated control of the switching process, avoiding the safety hazards of manual on-site operation of high-voltage DC switches, but also allows for precise control of the speed and force of opening and closing, ensuring the reliable operation of the mechanical interlock mechanism.

[0035] To suppress damage to precision power electronic devices caused by transient overvoltages during switching, a thyristor bypass branch is connected in parallel across the two ends of the polarized DC disconnector 92. This thyristor bypass branch is configured to conduct during the closing of the polarized DC disconnector 92 to suppress operational overvoltages generated during switching. Specifically, at the instant the contacts of the polarized DC disconnector 92 are about to make contact but have not yet fully stabilized, stray inductance and capacitance in the circuit are highly susceptible to high-frequency oscillating overvoltages due to sudden current changes. At this time, the monitoring unit 50 triggers the thyristor bypass branch to conduct in advance, allowing it to act as a low-impedance buffer channel to carry the current and absorb surge energy. After the main contacts of the polarized DC disconnector 92 are fully closed and stably contacted, the thyristor bypass branch is then naturally turned off or actively turned off, smoothly transferring the current back to the main disconnector path. This soft-landing switching method effectively clamps the amplitude of operational overvoltages, protecting the power modules inside the polarized rectifier 30 and the electrode surfaces of the series electrodeposition tank group 10 from voltage surges, significantly extending the service life of critical equipment. It should be understood that although this embodiment uses a thyristor as a bypass buffer element, in other embodiments, zinc oxide surge arresters, RC absorption circuits, or other power electronic components with similar transient suppression functions can also be used to achieve the same technical effect.

[0036] Example 4:

[0037] like Figure 1As shown, based on the above embodiments, this embodiment further describes the power failure judgment logic of the system and a specific application field. The device also includes an uninterruptible power supply (UPS) to power the monitoring unit 50. The UPS ensures that the monitoring unit 50 can still obtain a continuous and stable power supply at the moment when the main rectifier 20 loses power, causing a power outage in the plant, thereby preventing the entire emergency protection logic from paralyzing or resetting due to the loss of control power. Based on this, the monitoring unit 50 is configured to determine a power outage fault when it simultaneously receives a power failure signal from the external power grid and a power failure signal from the high-voltage switchgear, and detects that the total voltage of the DC bus supplying power to the series electrolytic capacitor bank 10 is lower than the voltage threshold for a preset duration (operating status and various feedback signals), and outputs a start signal to the emergency generator set 40. Specifically, this three-signal joint judgment mechanism constitutes multiple safety defenses to prevent malfunctions of the emergency protection device. In the actual operating environment of a hydrometallurgical plant, power grid fluctuations, the start-up and shutdown of large equipment, or lightning strikes can all cause momentary voltage drops on the bus. Relying solely on a single voltage threshold as a trigger condition can easily lead to frequent false starts of the emergency generator set 40. This not only shortens the unit's lifespan and wastes fuel but may also cause unnecessary impacts on the power grid. By introducing external power grid power failure signals and high-voltage switchgear power failure signals as pre-verification conditions, and combining them with duration window filtering logic, the monitoring unit 50 can effectively distinguish between momentary interference and real systemic power outages. Only when the three conditions logically intersect in time sequence is it confirmed as a power outage fault requiring intervention, thereby greatly improving the system's environmental adaptability and operational reliability. It should be understood that although this embodiment lists three specific judgment signals, in other embodiments, other signal sources capable of characterizing the system's power failure state can be added or replaced according to the on-site power distribution architecture, as long as the function of accurately identifying real power outage faults can be achieved.

[0038] Furthermore, as a preferred application scenario, the series electrodeposition cell group 10 in this embodiment is used for the electrodeposition of nickel and / or cobalt. The electrolyte of the series electrodeposition cell group 10 is an acidic sulfate electrolyte containing nickel and / or cobalt ions. The anode of the series electrodeposition cell group 10 is a lead-based insoluble anode, and the cathode of the series electrodeposition cell group 10 is a titanium or stainless steel starting plate. The normal electrodeposition voltage of a single electrodeposition cell in the series electrodeposition cell group 10 is 3.0~4.2V. In the nickel and cobalt hydrometallurgical process, because the electrolyte is strongly acidic and contains a high concentration of metal ions, once the power is cut off and the cell voltage disappears, the reverse electromotive force of the galvanic cell formed between the deposited metal coating and the lead-based anode is extremely high, and the corrosion rate is much faster than in neutral or alkaline systems. At the same time, the lead-based insoluble anode is very prone to reduction corrosion under the action of reverse current, resulting in excessive lead impurities in the electrolyte; while the back dissolution of the coating on the surface of the titanium or stainless steel starting plate will directly damage the passivation film of the substrate, causing permanent damage. The emergency protection device provided by this invention addresses the specific process pain points mentioned above by matching parameters. Its output positive cell protection voltage effectively counteracts the back potential of the galvanic cell in this system, while strictly controlling it within the non-deposition range below 3.0V, perfectly meeting the protection requirements of nickel / cobalt electrowinning cells to prevent corrosion and gold production. However, it should be specifically noted that the above description of the nickel / cobalt electrowinning system is merely an exemplary application case, intended to help those skilled in the art better understand the implementation details and technical effects of the present invention under specific working conditions, and does not constitute a limitation on the scope of protection of this invention. In fact, the emergency protection device of this invention is also applicable to other metal electrowinning processes using sulfate acidic electrolyte systems, such as copper, zinc, and manganese, as long as they have similar reverse corrosion problems due to power outages and require protection through low-voltage polarization, they can be included within the scope of protection of this invention.

[0039] Example 5:

[0040] like Figure 1 As shown, this embodiment provides an automatic control method for emergency protection against electrolytic cell power outages. This method is applied to the emergency protection device for electrolytic cell power outages described in any of the above embodiments. By combining this control method with specific hardware entities, a fully automated closed-loop process from fault detection to emergency protection execution is achieved. Figure 1 As shown, the method mainly includes the following steps: In step S100, after the main rectifier 20, which supplies power to the series electrodeposition cell group 10, loses power, the monitoring unit 50 determines that a power outage fault has occurred. Specifically, this step is the logical trigger point of the entire emergency protection method. The monitoring unit 50 converts the power outage state in the physical world into a fault flag bit inside the control system by collecting electrical parameters in real time. Although the specific implementation method based on multi-signal joint determination was mentioned in the previous embodiment, the core of the basic process of this method lies in establishing the causal relationship between "power outage" and "fault". Only when the monitoring unit 50 confirms that the main rectifier 20 has lost its driving capability to the series electrodeposition cell group 10 will the subsequent emergency protection sequence be activated, thereby avoiding malfunctions caused by transient interference.

[0041] In step S200, in response to the determination of a power outage fault, the monitoring unit 50 automatically starts the emergency generator set 40, which supplies power to the polarization rectifier 30. In this step, the monitoring unit 50 sends a start command to the emergency generator set 40, causing it to transition from standby to operation and establishing a stable AC power output. Subsequently, this power is delivered to the AC input terminal of the polarization rectifier 30, providing an energy source for subsequent DC-DC conversion. It should be understood that this automatic start-up refers not only to the issuance of signals at the software level but also to the timing management of physical processes such as unit preheating, speed-up, and voltage build-up. Through this step, the system quickly establishes an independent internal microgrid in the event of a loss of external power grid support, specifically serving the critical load of polarization protection without involving unnecessary production loads, thereby ensuring the efficient utilization of emergency energy.

[0042] In step S300, the monitoring unit 50 controls the polarization rectifier 30 to output a positive cell protection voltage to the series electrodeposition cell group 10 to suppress the reverse reaction of the galvanic cells within the series electrodeposition cell group 10. The positive cell protection voltage is the voltage distributed to each electrodeposition cell in the series electrodeposition cell group 10, and is lower than the normal electrodeposition operating voltage of a single electrodeposition cell in the series electrodeposition cell group 10. Specifically, the monitoring unit 50 precisely sets the DC output voltage value of the polarization rectifier 30 by adjusting its control angle or chopper duty cycle. The selection of this voltage value follows the principle of "suppressing corrosion and preventing metal formation": on the one hand, it must be high enough to offset the reverse electromotive force of the galvanic cells generated by the electrode potential difference within the cell, preventing reverse dissolution of the cathode plating and reduction corrosion of the anode; on the other hand, it must be strictly lower than the sum of the decomposition voltage and overpotential required for normal electrodeposition to prevent ineffective metal deposition reactions during the protection period. This precise control of the voltage window is the core difference between this method and conventional backup power supply recovery schemes, and is also a key technical means to achieve long-term low-power cell protection.

[0043] In the method of this invention, the rated output capacity of the emergency generator set 40 is greater than or equal to the tank protection load required to maintain the positive tank protection voltage, and less than the load required for normal electrowinning production of the series electrowinning tank group 10. Although this characteristic is manifested as a selection parameter for the equipment, it constitutes a substantial constraint on power supply behavior at the method level. It means that when executing steps S200 and S300, the system is physically limited to providing only the energy required to maintain protection, and cannot support full-line resumption of production. This methodological capacity matching strategy fundamentally eliminates the risk of emergency power supply overload attempting to resume production due to human error or control logic error, while also ensuring that with limited fuel reserves, the emergency generator set 40 can support the continuous output of the tank protection voltage with a longer operating time, achieving a balance between safety and economy. It should be understood that the execution order of the above steps is determined based on the electrochemical protection mechanism and the power electronic conversion law, and there is a close physical correlation and temporal dependence between the steps, which together constitute an inseparable technical whole.

[0044] Example 6:

[0045] like Figure 1 As shown, based on the above embodiments, this embodiment further provides a complete timing chain for an automatic control method for emergency protection against electrosink failures. This method is applied to the emergency protection device for electrosink failures described in any of the above embodiments, demonstrating a closed-loop control process covering the entire lifecycle from fault occurrence and emergency protection execution to automatic system recovery. Unlike the basic method flow described in Embodiment 5, this embodiment focuses on the logical connections between control links, state transition conditions, and coordinated hardware execution.

[0046] During the fault diagnosis and emergency start-up phase, the monitoring unit 50 executes a strict three-signal joint judgment logic. Specifically, determining a power outage fault includes: simultaneously receiving a power failure signal from the external power grid and a power failure signal from the high-voltage switchgear, and detecting that the total voltage of the DC bus supplying power to the series electrolytic capacitor bank 10 is lower than the voltage threshold for a preset duration. This judgment mechanism effectively eliminates false power failure signals caused by instantaneous grid flicker, large equipment start-up / shutdown, or lightning interference through logical AND operations and time window filtering of multiple signals, ensuring that the emergency generator set 40 is only triggered during a real systemic power outage, avoiding life loss and fuel waste caused by frequent false starts of the unit. In response to the determination of a power outage fault, the monitoring unit 50 outputs a start signal to the emergency generator set 40 to start the emergency generator set 40 and interlocks the electrolyte circulation pump 70 of the series electrolytic capacitor bank 10 to maintain a minimum circulation flow rate. The interlock control of the electrolyte circulation pump 70 is moved to the unit startup stage because, in the initial stage of a power outage, although the main rectifier 20 has stopped outputting, residual heat and concentration gradients still exist in the tank. If the electrolyte immediately becomes still, it will lead to localized overheating or ion concentration imbalance on the electrode surface, exacerbating the risk of reverse corrosion. Therefore, before the emergency generator set 40 has fully established a stable power supply, the monitoring unit 50 maintains power supply to the control circuit of the electrolyte circulation pump 70 through an uninterruptible power supply, or utilizes the pump's inertia and backup energy storage to ensure the continuity of the fluid dynamic environment, creating a stable process foundation for subsequent polarization protection.

[0047] During the power switching and safety switching phase, the monitoring unit 50 performs precise timing control to ensure electrical safety. After the voltage and frequency output by the emergency generator set 40 stabilize, the AC power supply of the polarized rectifier 30 is switched from the mains power to the emergency generator set 40. Stability here means that the generator's output voltage amplitude, frequency, and waveform distortion rate all reach the allowable input range of the polarized rectifier 30, typically requiring tens of seconds of warm-up and excitation setup time. Premature switching may cause the rectifier to undervoltage protection or excessive output ripple. Subsequently, the monitoring unit 50 executes the DC-side safety switching sequence: first, the main DC disconnect switch 91 in the DC output circuit of the main rectifier 20 is disconnected; after a preset delay, the polarized DC disconnect switch 92 in the DC output circuit of the polarized rectifier 30 is closed; then, the polarized rectifier 30 is controlled to output a positive tank protection voltage to the series electrolytic capacitor bank 10. This disconnect-then-close timing sequence, combined with the mechanical interlock structure described in Embodiment 3, constitutes a double insurance against the parallel operation of the two DC power supplies. The preset delay setting fully considers the time required for arc extinguishing and bus parasitic capacitance discharge when the main DC disconnector 91 is disconnected, ensuring that the polarization protection circuit is not connected until the main circuit is completely disconnected and insulation is restored. During this process, the thyristor bypass branch conducts at the instant the polarization DC disconnector 92 closes, absorbing operational overvoltage and achieving a smooth transition of the DC bus, avoiding voltage spikes from impacting the power devices of the polarization rectifier 30 and the electrode surfaces of the series electrolytic cell group 10.

[0048] During the emergency protection operation phase, the monitoring unit 50 dynamically adjusts its output strategy based on changes in operating conditions and duration to achieve an optimal balance between protection effectiveness and energy efficiency. On one hand, the monitoring unit 50 monitors the electrolyte status in real time: when the temperature of the electrolyte in the series electrodeposition cell group 10 is lower than a preset temperature threshold and / or the electrolyte circulation flow rate is lower than a preset flow rate threshold, the polarization rectifier 30 is controlled to increase the forward cell protection voltage; after the electrolyte temperature is no longer lower than the preset temperature threshold and the electrolyte circulation flow rate is no longer lower than the preset flow rate threshold, the polarization rectifier 30 is controlled to reduce the forward cell protection voltage back to its pre-increase value. This adaptive voltage regulation mechanism is based on the principle of electrochemical concentration cells: when the temperature decreases or the flow rate is insufficient, the diffusion layer on the electrode surface thickens, and ion migration is hindered, leading to an increase in the cell voltage required to offset the same reverse electromotive force. Actively increasing the voltage at this time is essentially a dynamic compensation for the increased reverse driving force under deteriorating operating conditions, preventing localized corrosion caused by insufficient fixed voltage to overcome the reverse electromotive force; and promptly reducing the voltage after the operating conditions recover avoids side reactions and ineffective energy consumption caused by overprotection. On the other hand, the monitoring unit 50 switches the polarization mode according to the cumulative power outage duration: when the cumulative power outage duration of the main rectifier 20 does not exceed the preset duration threshold, the polarization rectifier 30 is controlled to continuously output a positive tank voltage; when the cumulative power outage duration of the main rectifier 20 exceeds the preset duration threshold, the polarization rectifier 30 is controlled to switch from continuous output to intermittent output of the positive tank voltage, so as to keep the tank voltage of the series electrowinning tank group 10 positive while reducing the average output power of the emergency generator set 40. The intermittent output is a pulse output, and during the pulse interval, the tank voltage of the series electrowinning tank group 10 is not lower than the preset protection threshold. In the early stage of power outage, the electrochemical state in the tank is unstable, and continuous constant voltage output helps to quickly establish a stable positive electric field; when the power outage time is prolonged and the galvanic cell reaction tends to be steady, the double-layer capacitance effect of the electrode / solution interface is used to maintain the positive potential by relying on the interface stored charge during the pulse turn-off period. As long as this potential is not lower than the preset protection threshold, the reverse current can be continuously suppressed. This mode switching allows the emergency generator set 40 to provide energy only during the pulse conduction period, significantly reducing fuel consumption in long-term shutdown scenarios and extending the protection range under limited fuel reserves.

[0049] During the mains power restoration and system reset phase, monitoring unit 50 executes a smooth and orderly automatic recovery process to ensure seamless connection of the production system. After detecting the restoration of external power and the high-voltage switchgear being energized, the control polarization rectifier 30 gradually reduces the positive protection tank voltage to zero at a preset rate. This soft-landing voltage reduction process avoids current surges caused by voltage jumps, preventing disturbance to the electrode surfaces that have just stabilized. After the positive protection tank voltage drops to zero, the polarization DC disconnect switch 92 is disconnected, and the main DC disconnect switch 91 is closed, restoring the normal electrowinning operating voltage of individual electrowinning tanks in the series electrowinning tank group 10 to be output by the main rectifier 20. The disconnect switch operation here also follows the safety sequence of disconnecting before closing, ensuring that the polarization circuit and the main production circuit are strictly physically isolated, eliminating grid connection risks. Finally, a shutdown signal is output to the emergency generator set 40 to shut it down. The entire recovery process requires no manual intervention, eliminating the safety hazards of manual operation and shortening the transition time from mains power restoration to normal production through precise timing control, thus minimizing the impact of power outages on production capacity. It should be understood that the parameters of each step in the above-mentioned full lifecycle control process (such as preset duration, voltage threshold, delay time, etc.) can be adaptively adjusted according to the specific process characteristics of the series electrolytic cell group 10 and the on-site power distribution conditions. This embodiment is merely illustrative and does not constitute a limitation on the scope of protection of this invention.

[0050] Example 7:

[0051] like Figure 1 As shown, to further verify the feasibility and technical effect of the present invention's technical solution in actual industrial production, this embodiment provides a specific application case in a nickel-cobalt hydrometallurgical production line. It should be understood that the specific process parameters, equipment selection, and operating data described below are merely illustrative examples intended to help those skilled in the art better understand the implementation methods of the present invention, and do not constitute a necessary limitation on the scope of protection of the present invention.

[0052] In a 10,000-ton-per-year electrolytic nickel-cobalt project of a hydrometallurgical enterprise, the emergency protection device and automatic control method for power outages in electrolytic cells provided by this invention are adopted. The project has two independent sulfuric acid-based hydrometallurgical production lines: a 48-cell series electrolytic cobalt line and a 48-cell series electrolytic nickel line. Each production line is equipped with an independent main rectifier 20 for normal production power supply, while sharing an emergency protection system designed based on the architecture of this invention. Specifically, the system includes a 1000kW diesel generator set as an emergency generator set 40, and two independent polarized rectifiers 30, corresponding to the nickel and cobalt lines respectively. The AC output of the emergency generator set 40 is connected to the AC input of the two polarized rectifiers 30 and the electrolyte circulation pumps 70 of each production line via a dual power switching cabinet 60. However, its electrical connection is strictly limited to supplying power only to the aforementioned cell-related loads and is never connected to the high-voltage input side of the main rectifier 20. This configuration intuitively reflects the core design concept of dedicated polarized rectifier generator sets: for two production lines with a total installed load of several megawatts, only one 1000kW generator set is needed to meet all emergency backup requirements. Compared with the traditional design that requires the configuration of generator sets of the same or even larger capacity to maintain the production of the entire line, the equipment purchase cost, machine room civil construction investment and supporting facility costs are reduced by about 70%.

[0053] Regarding process parameter settings, the pre-set tank protection voltage parameters in the monitoring unit 50 are configured differently for the lead-based insoluble anode and titanium / stainless steel starter plate system used in this production line. Specifically, the single-tank forward tank protection voltage reference value for cobalt wire is set to 0.7V, and for nickel wire it is set to 0.6V. Both of these values ​​are significantly lower than the single-tank operating voltage range of 3.0V to 4.2V during normal electrowinning production on this line. In actual operation testing, when a simulated long-term power outage occurs, the monitoring unit 50 completes the joint judgment of three signals within 200ms and automatically starts the emergency generator set 40; after the generator set output stabilizes, the system completes the AC power switching and the safe switching of the DC side from split to reconnect within 40 seconds, and then applies the aforementioned pre-set tank protection voltage to the series electrowinning cell group 10. During the entire 10-hour continuous power outage protection test, the system automatically performs mode switching according to the cumulative duration: maintaining continuous constant voltage output for the first 3 hours, and automatically switching to intermittent pulse output mode after 3 hours, effectively reducing fuel consumption. After testing, inspection revealed that the surfaces of the starter plates in all electrodeposition cells were smooth and clean, without any pitting, peeling, or plating re-dissolution. The lead anode surface was in good condition, and no abnormal increase in lead impurity content was observed in the electrolyte. Long-term tracking statistics show that after adopting the device of this invention, the average service life of the starter plates on this production line increased by approximately 40% compared to the previous operation relying solely on manual short-circuit rack protection, significantly reducing the frequency of plate replacement and maintenance costs.

[0054] Furthermore, compared to traditional manual short-circuit protection schemes, the solution shown in this embodiment also demonstrates superior adaptability to prolonged power outages. Traditional short-circuit protection systems can only handle short-term outages of up to 3 hours; beyond this time limit, the accumulation of back electromotive force in the galvanic cell often leads to protection failure. In contrast, this invention, relying on an independent emergency generator set 40 and fully automatic control logic, can theoretically provide continuous protection for several days as long as fuel supply is sufficient, without any manual intervention, completely eliminating the safety hazards of manually operating DC high-voltage equipment at night or in severe weather. In summary, this practical application case fully demonstrates the effectiveness, economy, and engineering feasibility of the technical solution of this invention in solving the corrosion problem of nickel-cobalt electrodeposition cells during prolonged power outages. It should be emphasized again that the 48-cell scale, 1000kW unit power, 0.6V / 0.7V cell protection voltage, and specific percentage data mentioned in the above embodiments are all measured or calculated results under specific project conditions. In other application scenarios, those skilled in the art can make adaptive adjustments to the above parameters according to the actual number of cells in the series electrowinning cell group 10, the characteristics of the electrolyte system, and the on-site power distribution conditions. Such adjustments should be considered to be covered within the protection scope of this invention.

[0055] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. Other modifications can be easily made by those skilled in the art. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and illustrations shown and described herein.

Claims

1. An emergency protection device for power outage due to an electrodeposition tank accident, characterized in that, Includes polarized rectifiers, emergency generator sets, and monitoring units; The DC output terminal of the polarized rectifier is used to connect in parallel with the DC output terminal of the main rectifier that supplies power to the series electrodeposition cell group. The polarized rectifier is configured to output a positive cell-holding voltage to the series electrodeposition cell group after the main rectifier loses power. The positive cell-holding voltage is the voltage distributed to each electrodeposition cell in the series electrodeposition cell group and is lower than the normal electrodeposition working voltage of a single electrodeposition cell in the series electrodeposition cell group, so as to suppress the reverse reaction of the galvanic cells in the series electrodeposition cell group. The AC output terminal of the emergency generator set is configured to be connected to the AC input terminal of the polarized rectifier for power supply. The emergency generator set is configured to automatically start after the main rectifier loses power to supply power to the polarized rectifier. The rated output capacity of the emergency generator set is greater than or equal to the tank holding load required to maintain the positive tank holding voltage, and less than the load required for normal electrowinning production of the series electrowinning tank group. The monitoring unit is connected to the emergency generator set and the polarized rectifier control respectively. It is configured to control the emergency generator set to start automatically after the main rectifier is determined to be de-energized, and to control the polarized rectifier to output positive protection voltage.

2. The emergency protection device for power outage due to electrowinning tank accident as described in claim 1, characterized in that, The monitoring unit is configured as follows: When the cumulative duration of power failure of the main rectifier does not exceed the preset duration threshold, the control polarization rectifier continuously outputs positive holding voltage; When the cumulative duration of power failure of the main rectifier exceeds the preset duration threshold, the control polarization rectifier switches from continuous output to intermittent output of positive slot voltage to reduce the average output power of the emergency generator set while keeping the slot voltage of the series electrolytic cell group positive. The intermittent output is a pulse output, and during the pulse interval, the slot voltage of the series electrolytic cell group is not lower than the preset protection threshold.

3. The emergency protection device for power outage due to electrowinning tank accident as described in claim 1, characterized in that, The monitoring unit is configured as follows: When the temperature of the electrolyte in the series electrodeposition cell group is lower than the preset temperature threshold and / or the circulating flow rate of the electrolyte is lower than the preset flow rate threshold, the control polarization rectifier increases the positive cell holding voltage. Once the electrolyte temperature is no longer lower than the preset temperature threshold and the electrolyte circulation flow rate is no longer lower than the preset flow rate threshold, the control polarization rectifier will reduce the positive tank voltage back to the value before the adjustment.

4. The emergency protection device for power outage due to electrowinning tank accident as described in claim 1, characterized in that, It also includes an electrolyte circulation pump and an auxiliary power supply branch; The electrolyte circulation pump is configured to drive the electrolyte circulation of the series electrodeposition cell group; the auxiliary power supply branch is electrically connected to the electrolyte circulation pump and is configured to supply power to the electrolyte circulation pump by the emergency generator set after the main rectifier loses power, so as to maintain the circulation of electrolyte during the power failure of the main rectifier.

5. The emergency protection device for power outage due to electrowinning tank accident as described in claim 4, characterized in that, It also includes a dual power supply switching cabinet, a polarized DC disconnect switch, and a main DC disconnect switch; The AC output terminal of the emergency generator set and the mains circuit are both connected to the dual power switching cabinet. The first output terminal of the dual power switching cabinet is electrically connected to the AC input terminal of the polarization rectifier. The second output terminal of the dual power switching cabinet is electrically connected to the electrolyte circulation pump via the auxiliary power supply branch. The dual power switching cabinet is configured to switch the AC power supply of the polarization rectifier to the emergency generator set and the power supply of the electrolyte circulation pump to the emergency generator set after the main rectifier loses power. The DC output terminal of the polarized rectifier is connected to the DC bus supplying power to the series electrolytic cell group via a polarized DC disconnect switch, and the DC output terminal of the main rectifier is connected to the DC bus via a main DC disconnect switch. The polarized DC disconnect switch and the main DC disconnect switch are mechanically interlocked. The monitoring unit is also configured to interlock the electrolyte circulation pump to maintain a minimum circulation flow rate after the main rectifier is determined to be de-energized.

6. The emergency protection device for power outage due to electrowinning tank accident as described in claim 5, characterized in that, The monitoring unit is configured to operate after the emergency generator set supplies power to the polarized rectifier: First disconnect the main DC switch, then close the polarized DC switch after a preset delay, and then start the polarized rectifier to output a positive tank protection voltage to the series electrolytic cell group to avoid the two DC power supplies of the main rectifier and the polarized rectifier operating in parallel. Both the main DC disconnect switch and the polarized DC disconnect switch are equipped with electric operating mechanisms. The monitoring unit disconnects or closes the corresponding disconnect switches via the electric operating mechanisms. Among them, a thyristor bypass branch is connected in parallel at both ends of the polarized DC disconnector. The thyristor bypass branch is configured to be turned on during the closing of the polarized DC disconnector in order to suppress the operating overvoltage generated during the switching process.

7. The emergency protection device for power outage due to electrowinning tank accident as described in claim 1, characterized in that, It also includes an uninterruptible power supply for powering the monitoring unit; The monitoring unit is configured to determine a power outage fault and output a start signal to the emergency generator set when it simultaneously receives a power failure signal from the external power grid and a power failure signal from the high-voltage switchgear, and detects that the total voltage of the DC bus supplying power to the series electrolytic capacitor bank is lower than the voltage threshold for a preset duration.

8. The emergency protection device for power outage due to electrowinning tank accident as described in claim 1, characterized in that, The series electrodeposition cell array is used for the electrodeposition of nickel and / or cobalt. The electrolyte of the series electrodeposition cell array is an acidic sulfate electrolyte containing nickel and / or cobalt ions. The anode of the series electrodeposition cell array is a lead-based insoluble anode. The cathode of the series electrodeposition cell array is a titanium or stainless steel starting electrode. The normal electrodeposition operating voltage of a single electrodeposition cell in the series electrodeposition cell array is 3.0~4.2V.

9. An automatic control method for emergency protection against power outage due to an electrosink failure, applied to the emergency protection device for power outage due to an electrosink failure as described in any one of claims 1-8, characterized in that, include: A power outage fault was determined to have occurred after the main rectifier supplying power to the series electrodeposition cell array lost power. In response to the detection of a power outage fault, the emergency generator set is automatically started to supply power to the polarized rectifier. The control polarization rectifier outputs a positive cell holding voltage to the series electrodeposition cell group to suppress the reverse reaction of the galvanic cells in the series electrodeposition cell group. The positive cell holding voltage is the voltage distributed to each electrodeposition cell in the series electrodeposition cell group and is lower than the normal electrodeposition working voltage of a single electrodeposition cell in the series electrodeposition cell group. Among them, the rated output capacity of the emergency generator set is greater than or equal to the tank protection load required to maintain the positive tank protection voltage, and less than the load required for normal electrowinning production of the series electrowinning tank set.

10. The emergency protection automatic control method for power outage due to electrowinning tank accident as described in claim 9, characterized in that, Determining a power outage fault includes: When both the external power grid power failure signal and the high-voltage switchgear power failure signal are received simultaneously, and the total voltage of the DC bus supplying power to the series electrolytic cell group is detected to be lower than the voltage threshold for a preset duration, a power outage fault is determined to have occurred. The method also includes: In response to the determination of a power outage fault, a start signal is output to the emergency generator set to start the emergency generator set, and the electrolyte circulation pump of the series electrowinning tank group is interlocked to maintain the minimum circulation flow rate; After the voltage and frequency output by the emergency generator set stabilize, switch the AC power supply of the polarized rectifier from the mains power to the emergency generator set. First, disconnect the main DC switch in the DC output circuit of the main rectifier. After a preset delay, close the polarized DC switch in the DC output circuit of the polarized rectifier. Then, control the polarized rectifier to output a positive cell-holding voltage to the series electrolytic cell group.

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