Current stabilization control system for connecting photovoltaic direct current to electrolytic aluminum direct current bus

Abstract

The utility model discloses a current stabilization control system for connecting a photovoltaic direct current to an electrolytic aluminum direct current bus. The current stabilization control system for connecting the photovoltaic direct current to the electrolytic aluminum direct current bus comprises an electrolytic aluminum power supply rectification part and a photovoltaic station part, the photovoltaic station part further comprises a photovoltaic monitoring system which is connected with all Hall current sensors and a current stabilization control system in the photovoltaic station part and the electrolytic aluminum power supply rectification part. All Hall current sensors in the photovoltaic field station part and the electrolytic aluminum power supply rectification part are used for measuring current data at different positions and sending the current data to the photovoltaic monitoring system, and the photovoltaic monitoring system carries out mutual verification and comparison on the current data, gives an alarm when the current data exceed the limit, and is also used for carrying out communication and interaction with the current stabilization control system. According to the utility model, accurate, safe and reliable operation of the current stabilization control system for accessing the photovoltaic direct current into the electrolytic aluminum direct current bus can be realized, and the constant current of the electrolytic aluminum direct current bus is further maintained.

Description

TECHNICAL FIELD

[0001] The utility model embodiment relates to electrolytic aluminium power supply technical field, especially relate to a kind of photovoltaic direct current access electrolytic aluminium direct current bus's current stabilizing control system. BACKGROUND

[0002] In 2022, the global electrolytic aluminium production was 68.02 million tons, and China's electrolytic aluminium production was 40.21 million tons, accounting for 59% of the global electrolytic aluminium production, ranking first in the world. In 2022, China's average electrolytic aluminium power consumption per ton of aluminium was 13522 kWh, which was the optimal energy consumption level in the world, but the electricity consumption of the electrolytic aluminium industry in 2022 still exceeded 540 billion kWh (among which, the proportion of non-water renewable energy utilization was only 4.1%), accounting for about 6% of the total electricity consumption of the whole society, and the total carbon emission was about 4% of the total social amount.

[0003] At present, domestic photovoltaic stations mainly transport to the power grid for consumption through alternating current mode, but in the northwest region with rich light resources, the power grid structure is relatively weak, and it is difficult to realize full consumption of photovoltaic power generation capacity, resulting in some photovoltaic stations abandoning light, which seriously affects the economy of photovoltaic stations.

[0004] Using direct current transmission system to supply green electricity generated by photovoltaic stations to nearby electrolytic aluminium plants in direct current mode can not only increase the proportion of green electricity in the electrolytic aluminium production process and reduce carbon emissions, but also solve the problem of photovoltaic consumption, which has significant economic and social benefits. A few small-scale (the proportion of photovoltaic power to electrolytic aluminium load is less than 5%) photovoltaic direct current access electrolytic aluminium bus related demonstration projects have been built and put into operation in China, such as 2 MW photovoltaic of Yunnan Aluminium Yangzonghai Aluminium Industry, 1500V low-voltage direct current access electrolytic aluminium, 3.1 MW photovoltaic of Yunnan Hongtai, ±10kV medium-voltage direct current access electrolytic aluminium, 1.7 MW photovoltaic of Yunnan Aluminium Zexin Aluminium Industry, ±10kV medium-voltage direct current access and 5 MW photovoltaic, 1500V low-voltage direct current access electrolytic aluminium project, etc. The successful operation of related demonstration projects proves that photovoltaic direct current access electrolytic aluminium is a technically feasible and potentially huge route.

[0005] In the electrolytic aluminium production process, the current of the direct current bus is maintained constant, which is beneficial to the improvement of the current efficiency of the aluminium electrolysis cell, the reduction of the work intensity of the front-line operators and the probability of anode effect. Therefore, it is necessary to maintain the constant current of the direct current bus in the electrolytic aluminium production process as much as possible.

[0006] After the photovoltaic direct current is connected to the aluminum electrolysis direct current bus, the green electricity delivered by the photovoltaic direct current and the direct current rectified from the high-voltage power grid are combined and supplied to the electrolytic cell. Because of the volatility and randomness of the photovoltaic power supply, significant disturbance and impact on the current constant state of the aluminum electrolysis direct current bus will be caused, especially when the proportion of the photovoltaic direct current connected to the aluminum electrolysis direct current bus is increased, the disturbance and impact will be very obvious, which puts higher requirements and challenges on the current stabilizing control system of the aluminum electrolysis.

[0007] At present, the main rectification mode of the aluminum electrolysis plant is diode rectification, and the current stabilizing control system mainly realizes the constant of the aluminum electrolysis direct current bus current by adjusting the coarse adjustment of the on-load tap changer and the fine adjustment of the saturation reactor. However, the existing current stabilizing control system does not consider the influence of the photovoltaic direct current connected to the aluminum electrolysis direct current bus, therefore, it is necessary to improve the existing current stabilizing control system to realize the goal of keeping the aluminum electrolysis direct current bus current constant after the photovoltaic direct current is connected to the aluminum electrolysis. Practical new type content

[0008] The utility model provides a kind of current stabilizing control system of photovoltaic direct current connection aluminum electrolysis direct current bus, to realize the accurate, safe and reliable operation of current stabilizing control system of photovoltaic direct current connection aluminum electrolysis direct current bus, to maintain the constant of aluminum electrolysis direct current bus current further.

[0009] According to an aspect of the utility model, a kind of current stabilizing control system of photovoltaic direct current connection aluminum electrolysis direct current bus is provided, and current stabilizing control system of photovoltaic direct current connection aluminum electrolysis direct current bus includes: aluminum electrolysis power supply rectification part and photovoltaic field station part;

[0010] The aluminum electrolysis power supply rectification part includes: a current stabilizing control system, multiple rectifier units connected between the alternating current bus and the aluminum electrolysis direct current bus, each rectifier unit includes at least two diode rectifiers;

[0011] The aluminum electrolysis power supply rectification part further includes: a direct current bus Hall current sensor arranged on the aluminum electrolysis direct current bus, and multiple rectifier outlet Hall current sensors arranged on the direct current transmission line after the diode rectifiers;

[0012] The photovoltaic field station part includes: a photovoltaic monitoring system and two photovoltaic subsystems, each photovoltaic subsystem includes: multiple photovoltaic strings, at least two intelligent combiner boxes, a boost energy router, a buck energy router and a negative electrode protection cabinet, the intelligent combiner box is connected between the multiple photovoltaic strings and the boost energy router, the boost energy router is connected with the buck energy router, the negative electrode protection cabinet and the aluminum electrolysis direct current bus in sequence;

[0013] The photovoltaic station part further comprises: a photovoltaic string Hall current sensor arranged on a cable of the plurality of photovoltaic string, a Hall current sensor arranged inside the intelligent combiner box, a first Hall current sensor arranged inside the boost energy router, a second Hall current sensor arranged inside the buck energy router, a photovoltaic branch Hall current sensor arranged on a DC transmission line behind the negative electrode protection cabinet, and a photovoltaic system collection circuit Hall current sensor arranged on a DC bus of the photovoltaic system.

[0014] The photovoltaic station part further comprises: a photovoltaic monitoring system connected with all Hall current sensors in the photovoltaic station part and the electrolytic aluminum power supply rectification part and the current stabilizing control system, the Hall current sensors in the photovoltaic station part and the electrolytic aluminum power supply rectification part for measuring current data at different positions and sending the current data to the photovoltaic monitoring system, the photovoltaic monitoring system for mutual checking and comparison of the current data, alarming when the current data is out of limit, and communicating and interacting with the current stabilizing control system.

[0015] Optionally, each rectifier unit further comprises: a current transformer and a step-down transformer.

[0016] A first end of the current transformer is connected with the AC bus, a second end of the current transformer is connected with the step-down transformer, and the step-down transformer is connected with the diode rectifier.

[0017] Optionally, each rectifier unit further comprises: at least two current transformers, at least two rectifier transformers, and at least two saturable reactors.

[0018] The two current transformers are connected with the step-down transformer, the two rectifier transformers are connected with the two current transformers, and the two saturable reactors are connected between the two rectifier transformers and the two diode rectifiers.

[0019] Optionally, each rectifier unit further comprises: a short-circuit device and a filter device.

[0020] The short-circuit device is connected between the AC bus and the current transformer, and the filter device is connected with the step-down transformer.

[0021] Optionally, each rectifier unit further comprises: a first disconnector and a second disconnector.

[0022] The first end of the first disconnector is connected with one of the AC busbars, the first end of the second disconnector is connected with another of the AC busbars, and the second end of the first disconnector is connected with the second end of the second disconnector and then connected with the short circuit device.

[0023] Optionally, each of the photovoltaic subsystems further comprises a positive electrode protection cabinet connected between the voltage reduction energy router and the direct current bus of electrolytic aluminum.

[0024] Optionally, the number of the rectifier outlet Hall current sensors comprises 14.

[0025] Optionally, the number of the photovoltaic string Hall current sensors comprises 96.

[0026] Optionally, the number of the Hall current sensors comprises 4.

[0027] Optionally, the number of the first Hall current sensors comprises 2, and the number of the second Hall current sensors comprises 2.

[0028] The technical scheme of the utility model embodiment provides a current stabilization control system of photovoltaic direct current access electrolytic aluminum direct current bus based on Hall sensors, in the direct current transmission line of the photovoltaic direct current access electrolytic aluminum system, a plurality of Hall sensors are reasonably arranged to measure current values at different positions, the collected current data is summed and compared, the accuracy of the measured current is ensured, reliable basic data is provided for the accurate, safe and reliable operation of the current stabilization control system, data misreading and false reporting and problems such as over-regulation and under-regulation of the current stabilization control system are avoided, through setting data out-of-limit alarm, the current stabilization control system of photovoltaic direct current access electrolytic aluminum direct current bus is accurately, safely and reliably operated, and then the constant of the electrolytic aluminum direct current bus current is maintained.

[0029] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the utility model, nor is it used to limit the scope of the utility model. Other features of the utility model will become easy to understand through the following description. BRIEF DESCRIPTION OF DRAWINGS

[0030] In order to more clearly illustrate the technical scheme in the embodiments of the present application, the drawings needed to be used in the following embodiment description will be briefly introduced, obviously, the drawings in the following description are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0031] Figure 1 It is a technical scheme schematic diagram of the photovoltaic direct current access electrolytic aluminum direct current bus provided by the embodiment of the present application.

[0032] Figure 2 It is a structure schematic diagram of the current stabilizing control system of the photovoltaic direct current access electrolytic aluminum direct current bus provided by the embodiment of the present application. DETAILED DESCRIPTION

[0033] In order to make the personnel in the technical field better understand the present application scheme, the technical scheme in the embodiments of the present application will be clearly and completely described below in combination with the drawings in the embodiments of the present application, obviously, the described embodiments are only some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0034] It should be noted that the terms "first", "second" and the like in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and do not have to be used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0035] Figure 1 It is a technical scheme schematic diagram of the photovoltaic direct current access electrolytic aluminum direct current bus provided by the embodiment of the present application, referring to Figure 1 The scheme mainly consists of power grid, on-load voltage regulating transformer, rectifier, saturable reactor, rectifier unit, photovoltaic group string, current collection box, boost DC / DC converter, direct current cable, step-down DC / DC converter, current stabilizing control system, bus protection cabinet and direct current bus, and the specific connection relationship is as shown in Figure 1The green electricity generated by the photovoltaic is boosted to a 20kV level by the boost DC energy router, then transmitted to the vicinity of the aluminum electrolysis plant through the DC transmission line of the ±20kV voltage level, and then directly connected to the aluminum electrolysis DC bus after being stepped down to 1500V by the step-down DC energy router. The limitation of the small proportion of the AC load of the aluminum electrolysis plant (usually the AC load accounts for less than 5% of the total load of the aluminum electrolysis plant) and the weak green electricity consumption capacity of the AC system can be broken, the green electricity consumption capacity of the aluminum electrolysis industry can be improved, the proportion of green electricity in the aluminum electrolysis production process can be improved, and the carbon emission can be further reduced.

[0036] Figure 2 It is a structure diagram of a steady flow control system for connecting photovoltaic DC to aluminum electrolysis DC bus according to the embodiment of the utility model, referring to Figure 2 The embodiment of the utility model provides a kind of steady flow control system for connecting photovoltaic DC to aluminum electrolysis DC bus, and steady flow control system for connecting photovoltaic DC to aluminum electrolysis DC bus includes: electrolytic aluminium power supply rectification part 100 and photovoltaic station part 200;

[0037] Electrolytic aluminium power supply rectification part 100 includes: steady flow control system 21, multiple rectifier units connected between AC bus and electrolytic aluminium DC bus, and each rectifier unit includes at least two diode rectifiers 10;

[0038] Electrolytic aluminium power supply rectification part 100 further includes: DC bus hall current sensor 12 arranged on electrolytic aluminium DC bus, and multiple rectifier outlet hall current sensors 11 arranged on DC transmission line after diode rectifier 10;

[0039] Photovoltaic station part 200 includes: photovoltaic monitoring system 22 and two photovoltaic subsystems 23, each photovoltaic subsystem 23 includes: multiple photovoltaic group strings, at least two intelligent combiner boxes 14, boost energy router 15, step-down energy router 16, negative electrode protection cabinet 17, intelligent combiner box 14 is connected between multiple photovoltaic group strings and boost energy router 15, boost energy router 15 is sequentially connected with step-down energy router 16, negative electrode protection cabinet 17 and electrolytic aluminium DC bus;

[0040] Photovoltaic station part 200 further includes: photovoltaic group string hall current sensor 13 arranged on cable of multiple photovoltaic group strings, hall current sensor arranged in intelligent combiner box 14, first hall current sensor arranged in boost energy router 15, second hall current sensor arranged in step-down energy router 16, photovoltaic branch hall current sensor 19 arranged on DC transmission line after negative electrode protection cabinet 17, and photovoltaic system collection circuit hall current sensor 20 arranged on DC bus of photovoltaic system;

[0041] The photovoltaic power station part 200 further comprises a photovoltaic monitoring system 22 connected with all the Hall current sensors in the photovoltaic power station part 200 and the electrolytic aluminum power supply rectification part 100 and the current stabilizing control system 21, the Hall current sensors in the photovoltaic power station part 200 and the electrolytic aluminum power supply rectification part 100 are used to measure current data at different positions and send to the photovoltaic monitoring system 22, the photovoltaic monitoring system 22 is used to check and compare the current data, alarm when the current data is out of limit, and communicate and interact with the current stabilizing control system 21.

[0042] Specifically, Figure 2 Exemplarily, 15 Hall current sensors are arranged in the electrolytic aluminum power supply rectification part 100 in total, and the electrolytic aluminum power supply rectification part 100 comprises 7 rectifier units. Rectifier outlet Hall current sensors 11 are arranged on the direct current transmission line after the diode rectifier 10 in each rectifier unit of the electrolytic aluminum power supply rectification part 100, and 14 rectifier outlet Hall current sensors 11 are arranged in total in the 7 rectifier units. One direct current bus Hall current sensor 12 is arranged on the electrolytic aluminum direct current bus.

[0043] Figure 2 Exemplarily, 107 Hall current sensors are arranged in the photovoltaic power station part 200 in total. The photovoltaic power station part 200 (total capacity about 12 MW) is divided into two photovoltaic subsystems 23. The green electricity generated by the photovoltaic modules is collected to the intelligent combiner box 14 through the cable (photovoltaic string Hall current sensor 13 is arranged on the string cable), and each intelligent combiner box 14 corresponds to 24 photovoltaic string inputs. Two intelligent combiner boxes 14 (with Hall current sensors) are arranged in a single photovoltaic subsystem 23, and the photovoltaic green electricity output by the two intelligent combiner boxes 14 is collected into a single-capacity 6 MW boost energy router 15 (with a first Hall current sensor) at a voltage level of 1500 V, and the voltage of the photovoltaic green electricity is raised to 20 kV by the boost energy router 15, and then transmitted to a single-capacity 6 MW step-down energy router 16 (with a second Hall current sensor) near the power supply workshop of the electrolytic aluminum plant through the direct current transmission line, and the voltage is reduced to about 1500 V by the step-down energy router, and then passes through the negative electrode protection cabinet 17, and the photovoltaic branch Hall current sensor 19 is arranged on the direct current transmission line after the negative electrode protection cabinet 17. Finally, the photovoltaic green electricity generated by the two photovoltaic subsystems 23 is collected, and then injected into the electrolytic aluminum direct current bus at 1250 V through the direct current bus of the photovoltaic system. The photovoltaic system collection circuit Hall current sensor 20 is arranged on the direct current bus of the photovoltaic system. Therefore, 107 Hall current sensors are arranged in the photovoltaic power station part 200 in total.

[0044] The photovoltaic monitoring system 22 of the photovoltaic station part 200 collects current data of all Hall current sensors in the photovoltaic station part 200, all the Hall current sensors including the photovoltaic string Hall current sensor 13 on the multi-channel photovoltaic string cable, the Hall current sensor arranged in the intelligent combiner box 14, the first Hall current sensor arranged in the boost energy router 15, the second Hall current sensor arranged in the step-down energy router 16, the photovoltaic branch Hall current sensor, and the photovoltaic system collection circuit Hall current sensor 20, and sums and compares all the current data. The data out-of-limit alarm is arranged to avoid data reading errors, and is helpful for safe and reliable operation of the entire photovoltaic direct-current access electrolytic aluminum current stabilization control system.

[0045] The monitoring data of the photovoltaic monitoring system 22 is communicated and interacted with the current stabilization control system 21 of the electrolytic aluminum plant, and according to photovoltaic current fluctuation, the electrolytic aluminum power supply rectification part 100 can realize flexible distribution of load, realize common adjustment of online single rectifier unit according to different current stabilization operation modes, adapt to photovoltaic output fluctuation, and finally realize constant current control function of the electrolytic aluminum direct-current bus under the joint action of the photovoltaic green power branch and the electrolytic aluminum power supply rectification part 100.

[0046] It should be noted that the current stabilization control system 21 can belong to the electrolytic aluminum power supply rectification part 100, but the current stabilization control system 21 also controls the photovoltaic station part 200.

[0047] The current stabilization control system of the photovoltaic direct-current access electrolytic aluminum direct-current bus realizes constant current of the electrolytic aluminum direct-current bus after the photovoltaic direct-current access electrolytic aluminum bus, which is conducive to efficient and stable production of the electrolytic aluminum and maximally reduces the influence of anode effect.

[0048] The current stabilization control system of the photovoltaic direct-current access electrolytic aluminum direct-current bus can maximally avoid overshoot and undershoot problems, reduce the number of actions of the on-load tap changer, and prolong the service life and maintenance cycle of the on-load voltage regulating switch.

[0049] The current stabilization control system of the photovoltaic direct-current access electrolytic aluminum direct-current bus realizes intelligent current stabilization control of the photovoltaic direct-current access electrolytic aluminum direct-current bus system, maximally reduces data misreading and misreporting, and reduces manual operation workload.

[0050] The utility model discloses a technical scheme of an embodiment provides a kind of current stabilizing control system of photovoltaic direct current access electrolytic aluminium direct current bus based on hall sensor, in the direct current transmission line of photovoltaic direct current access electrolytic aluminium system, multiple hall sensors are reasonably arranged to measure the current value at different positions, the current data collected is summed and compared and checked, to ensure the accuracy of the current measured, provide reliable basic data for the accurate, safe and reliable operation of current stabilizing control system, avoid the misreading of data and the problem such as over-regulation and under-regulation of current stabilizing control system, by setting data out-of-limit alarm, so that the current stabilizing control system of photovoltaic direct current access electrolytic aluminium direct current bus is accurately, safely and reliably operated, and then maintain the constant of electrolytic aluminium direct current bus current. In summary, the utility model solves the problem that the existing current stabilizing control system does not consider the influence of photovoltaic direct current access electrolytic aluminium direct current bus, and the electrolytic aluminium direct current bus current cannot be kept constant after photovoltaic direct current access electrolytic aluminium.

[0051] With reference still to Figure 2 Optionally, each rectifier unit further comprises a current transformer 4 and a step-down transformer 5.

[0052] The first end of the current transformer 4 is connected with the AC bus, the second end of the current transformer 4 is connected with the step-down transformer 5, and the step-down transformer 5 is connected with the diode rectifier 10.

[0053] With reference still to Figure 2 Optionally, each rectifier unit further comprises at least two current transformers 7, at least two rectifier transformers 8 and at least two saturable reactors 9.

[0054] The two current transformers 7 are connected with the step-down transformer 5, the two rectifier transformers 8 are connected with the two current transformers 7, and the two saturable reactors 9 are connected between the two rectifier transformers 8 and the two diode rectifiers 10.

[0055] With reference still to Figure 2 Optionally, each rectifier unit further comprises a short-circuit device 3 and a filter device 6.

[0056] The short-circuit device 3 is connected between the AC bus and the current transformer 4, and the filter device 6 is connected with the step-down transformer.

[0057] With reference still to Figure 2 Optionally, each rectifier unit further comprises a first disconnector 1 and a second disconnector 2.

[0058] The first end of the first disconnector 1 is connected with one of the AC buses, the first end of the second disconnector 2 is connected with another of the AC buses, and the second end of the first disconnector 1 is connected with the second end of the second disconnector 2 and then connected with the short-circuit device 3.

[0059] Specifically, the first disconnector 1 can be a disconnector without grounding, and the second disconnector 2 can be a disconnector with grounding.

[0060] With reference to Figure 2 Optionally, the number of the rectifier outlet Hall current sensors includes 14.

[0061] Specifically, from Figure 2 It can be seen from the electrolytic aluminum plant power supply rectification system that there are 7 rectifier units. High-voltage alternating current from the alternating current bus (330kV power grid) passes through the first disconnector 1, the second disconnector 2, the short circuit device 3, the current transformer 4, and the step-down transformer 5, and then is divided into two paths, respectively passing through the current transformer 7 and the rectifier transformer 8, and then passing through the saturated reactor 9 and the diode rectifier 10, and is rectified into 1250V or so direct current, and then is merged into the electrolytic aluminum direct current bus of the 1250V voltage level. The rectifier outlet Hall current sensor 11 is arranged on the direct current transmission line after the diode rectifier 10 in each rectifier unit, and 14 rectifier outlet Hall current sensors 11 are arranged in total in the 7 rectifier units. The direct current bus Hall current sensor 12 is arranged on the electrolytic aluminum direct current bus, and a total of 15 Hall current sensors are arranged in the entire electrolytic aluminum power supply rectification part 100.

[0062] With reference to Figure 2 Optionally, each photovoltaic subsystem 23 further includes a positive electrode protection cabinet 18, which is connected between the step-down energy router 16 and the electrolytic aluminum direct current bus.

[0063] With reference to Figure 2 Optionally, the number of the photovoltaic group string Hall current sensors 13 includes 96.

[0064] Optionally, the number of the Hall current sensors includes 4.

[0065] Optionally, the number of the first Hall current sensors includes 2, and the number of the second Hall current sensors includes 2.

[0066] Specifically, the photovoltaic station part 200 (total capacity about 12MW) is divided into two photovoltaic subsystems 23. The green electricity generated by the photovoltaic components is collected through cables (photovoltaic string Hall current sensors 13 are arranged on the string cables) to the intelligent combiner box 14, and each intelligent combiner box 14 corresponds to 24 photovoltaic string inputs. A single photovoltaic subsystem 23 is configured with two intelligent combiner boxes 14 (with Hall current sensors), and the photovoltaic green electricity output by the two intelligent combiner boxes 14 is collected into a single machine capacity of 6MW boost energy router 15 (with a first Hall current sensor) at a voltage level of 1500V. The photovoltaic green electricity voltage is raised to 20kV by the boost energy router 15, and then transmitted to a single machine capacity of 6MW step-down energy router 16 (with a second Hall current sensor) near the power supply workshop of the electrolytic aluminum plant through a DC transmission line. The voltage is reduced to about 1500V by the step-down energy router, and then passed through the negative protection cabinet 17. The photovoltaic branch Hall current sensor 19 is arranged on the DC transmission line after the negative protection cabinet 17. Finally, the photovoltaic green electricity generated by the two photovoltaic subsystems 23 is collected, and then injected into the 1250V electrolytic aluminum DC bus through the DC bus of the photovoltaic system. The photovoltaic system collection circuit Hall current sensor 20 is arranged on the DC bus of the photovoltaic system. The photovoltaic station part 200 is provided with a total of 107 Hall current sensors.

[0067] The above specific embodiments do not constitute a limitation on the protection scope of the present application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A current stabilizing control system for photovoltaic direct current access to an electrolytic aluminum direct current bus, characterized by, The application relates to an electrolytic aluminum power supply rectification part and a photovoltaic station part. The electrolytic aluminum power supply rectification part comprises a current stabilizing control system, a plurality of rectifier units connected between an alternating current bus and a direct current bus of electrolytic aluminum, and each rectifier unit comprises at least two diode rectifiers. The electrolytic aluminum power supply rectification part further comprises a direct current bus Hall current sensor arranged on the direct current bus of electrolytic aluminum and a plurality of rectifier outlet Hall current sensors arranged on a direct current transmission line behind the diode rectifiers. The photovoltaic station part comprises a photovoltaic monitoring system and two photovoltaic subsystems, each photovoltaic subsystem comprises a plurality of photovoltaic groups, at least two intelligent combiner boxes, a boost energy router, a step-down energy router and a negative electrode protection cabinet, the intelligent combiner box is connected between the plurality of photovoltaic groups and the boost energy router, the boost energy router is connected with the step-down energy router, the negative electrode protection cabinet and the direct current bus of electrolytic aluminum in sequence. The photovoltaic station part further comprises a photovoltaic group Hall current sensor arranged on a cable of the plurality of photovoltaic groups, a Hall current sensor arranged in the intelligent combiner box, a first Hall current sensor arranged in the boost energy router, a second Hall current sensor arranged in the step-down energy router, a photovoltaic branch Hall current sensor arranged on a direct current transmission line behind the negative electrode protection cabinet and a photovoltaic system collection circuit Hall current sensor arranged on a direct current bus of the photovoltaic system. The photovoltaic station part further comprises a photovoltaic monitoring system, the photovoltaic monitoring system is connected with all Hall current sensors in the photovoltaic station part and the electrolytic aluminum power supply rectification part and the current stabilizing control system, all Hall current sensors in the photovoltaic station part and the electrolytic aluminum power supply rectification part are used for measuring current data at different positions and sending the current data to the photovoltaic monitoring system, the photovoltaic monitoring system is used for mutual checking and comparison of the current data, alarm when the current data is out of limit and communication and interaction with the current stabilizing control system. Each rectifier unit further comprises a current transformer and a step-down transformer.

2. The system of claim 1, wherein, A first end of the current transformer is connected with the alternating current bus, a second end of the current transformer is connected with the step-down transformer, and the step-down transformer is connected with the diode rectifier. Each rectifier unit further comprises at least two current transformers, at least two rectifier transformers and at least two saturated reactors.

3. The system of claim 2, wherein, The two current transformers are connected with the step-down transformer, the two rectifier transformers are connected with the two current transformers, and the two saturated reactors are connected between the two rectifier transformers and the two diode rectifiers. Each rectifier unit further comprises a short-circuit device and a filter device.

4. The system of claim 2, wherein, The short-circuit device is connected between the alternating current bus and the current transformer, and the filter device is connected with the step-down transformer. Each rectifier unit further comprises a first disconnecting switch and a second disconnecting switch.

5. The system of claim 4, wherein, ​ The first end of the first disconnector is connected with one of the AC busbars, the first end of the second disconnector is connected with another of the AC busbars, and the second end of the first disconnector is connected with the second end of the second disconnector and then connected with the short circuit device.

6. The system of claim 1, wherein, Each of the photovoltaic subsystems further comprises a positive electrode protection cabinet connected between the voltage reduction energy router and the direct current bus of electrolytic aluminum.

7. The system of claim 1, wherein, The number of the rectifier outlet Hall current sensors comprises 14.

8. The system of claim 1, wherein, The number of the photovoltaic group string Hall current sensors comprises 96.

9. The system of claim 1, wherein, The number of the Hall current sensors comprises 4.

10. The system of claim 1, wherein, The number of the first Hall current sensors comprises 2, and the number of the second Hall current sensors comprises 2.

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