A voltage regulation control system and method for an aluminum electrolysis control circuit

Abstract

The application discloses a voltage stabilizing control system and method for an aluminum electrolysis control circuit, and relates to the technical field of electronic control circuits.The voltage stabilizing control system comprises a voltage collecting module, a PID operation module and a control voltage output module connected in sequence.The input end of the voltage collecting module and the input end of the control voltage output module are connected with the voltage collecting end of the aluminum electrolysis control circuit.The output end of the control voltage output module is connected with the saturable reactor of the aluminum electrolysis control circuit.The voltage collecting module acquires the voltage at the current time and the voltage at the previous time of the voltage collecting end.The PID operation module generates a control signal according to the voltage at the current time and the voltage at the previous time.The control voltage output module generates a target voltage according to the control signal and the voltage at the current time, and takes the target voltage as the voltage of the saturable reactor, so that the aluminum electrolysis control circuit works.The application improves the quality of aluminum electrolysis.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic control circuits, and in particular to a voltage stabilization control system and method for an aluminum electrolysis control circuit. Background Art

[0002] The aluminum electrolysis stabilization control system regulates the 220kV three-phase high-voltage AC power provided by the power grid system into a stable DC current according to user needs. When the load or power supply voltage changes, the system can automatically adjust the output of the rectifier unit to ensure the stability of the series DC current. Most rectifier systems in China still use diode rectification, with on-load switches for coarse adjustment and saturated inductors for fine adjustment. The two are combined to achieve precise control of the series current.

[0003] PLC current stabilization control technology is now widely used in large-scale aluminum electrolysis production in China. As the size of electrolytic cells in China increases, the supply current and voltage of the cells also increase. Initially designed for electrolytic cells with a supply current below 300kA, the PLC current stabilization control system, when applied to large electrolytic cells with a supply current above 350kA, delayed current regulation. When the anode effect occurs in the electrolytic cell, the current cannot be adjusted in time. This causes large fluctuations in the electrolytic current under the influence of the anode effect voltage, affecting the stable power supply of the rectifier unit. This significantly affects the power supply to the rectifier unit and the production of the entire series of electrolytic cells, thus affecting process conditions and hindering the optimal operation of the entire electrolytic series. Current indicators are severely affected, production capacity is reduced, and power consumption is increased. Given this situation, it is necessary to re-analyze the various factors affecting the normal operation of the current stabilization system in order to design and manufacture a current stabilization system suitable for ultra-large electrolytic series.

[0004] After research and analysis, it was found that in the main circuit control loop of the current stabilization system, there are circuit components and loads with large inductance, such as smoothing reactors and saturation reactors. Due to the high-frequency current obstruction of the inductance, the current stabilization adjustment of the control loop is delayed. When the electrolytic cell of the electrolytic series takes effect, the current mutation of the electrolytic series cannot be suppressed in time; and the pure current control method cannot meet the power supply current requirements of the electrolytic cell production process, resulting in low quality of aluminum electrolysis.

[0005] Therefore, a voltage stabilizing control device and method for aluminum electrolysis control circuits have been developed: a main circuit voltage control circuit is added to the current stabilizing control system to control the voltage in the main circuit, making up for the shortcomings of pure current control and making the current stabilizing control more timely and accurate. Summary of the Invention

[0006] The purpose of the present invention is to provide a voltage stabilization control system and method for an aluminum electrolysis control circuit, which reduces the fluctuation of the voltage output by the aluminum electrolysis control circuit, meets the requirements of the electrolytic cell production process for the power supply current, and improves the quality of aluminum electrolysis.

[0007] To achieve the above object, the present invention provides the following solutions:

[0008] A voltage stabilization control system for an aluminum electrolysis control circuit, the voltage stabilization control system comprising: a voltage acquisition module, a PID operation module and a control voltage output module connected in sequence;

[0009] The input end of the voltage acquisition module and the input end of the control voltage output module are both connected to the voltage acquisition end of the aluminum electrolysis control circuit; the output end of the control voltage output module is connected to the saturated reactor of the aluminum electrolysis control circuit;

[0010] The voltage acquisition module is used to obtain the voltage at the current moment and the voltage at the previous moment of the voltage acquisition terminal, and send the voltage at the current moment and the voltage at the previous moment to the PID calculation module;

[0011] The PID operation module is used to generate a control signal according to the voltage at the current moment and the voltage at the previous moment;

[0012] The control voltage output module is used to generate a target voltage according to the control signal and the voltage at the current moment, and use the target voltage as the voltage of the saturated reactor to enable the aluminum electrolysis control circuit to operate.

[0013] A voltage stabilization control method for an aluminum electrolysis control circuit, the voltage stabilization control method being implemented based on the above-mentioned voltage stabilization control system for an aluminum electrolysis control circuit, the voltage stabilization control method comprising:

[0014] Obtain the current voltage and the previous voltage of the voltage acquisition terminal of the aluminum electrolysis control circuit;

[0015] Generate a control signal based on the voltage at the current moment and the voltage at the previous moment;

[0016] A target voltage is generated according to the control signal and the voltage at the current moment, and the target voltage is used as the voltage of the saturated reactor to operate the aluminum electrolysis control circuit.

[0017] According to the specific embodiments provided by the present invention, the present invention discloses the following technical effects:

[0018] The present invention discloses a voltage stabilization control system and method for an aluminum electrolysis control circuit. PID calculation is performed based on the voltage at the previous moment and the current moment of a voltage acquisition terminal of the aluminum electrolysis control circuit to obtain a control signal, thereby adjusting the current moment voltage and inputting the signal into a saturated reactor of the aluminum electrolysis control circuit. This reduces fluctuations in the voltage output by the aluminum electrolysis control circuit, meets the power supply current requirements of the electrolytic cell production process, and improves the quality of aluminum electrolysis. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic structural diagram of a voltage stabilization control system for an aluminum electrolysis control circuit provided in Example 1 of the present invention;

[0021] Figure 2 This is a schematic diagram of the location of the voltage stabilization control system in the aluminum electrolysis control circuit;

[0022] Figure 3 This is a schematic flow chart of a voltage stabilization control method for an aluminum electrolysis control circuit provided in Example 2 of the present invention.

[0023] Explanation of symbols:

[0024] Voltage acquisition module—1, PID operation module—2, control voltage output module—3. DETAILED DESCRIPTION

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0026] The purpose of the present invention is to provide a voltage stabilization control system and method for an aluminum electrolysis control circuit, aiming to meet the requirements of the electrolytic cell production process for power supply current and improve the quality of aluminum electrolysis.

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0028] Example 1

[0029] Figure 1 This is a schematic diagram of the structure of a voltage stabilizing control system for an aluminum electrolysis control circuit provided in Example 1 of the present invention. Figure 1 As shown, the voltage stabilization control system for the aluminum electrolysis control circuit in this embodiment includes: a voltage acquisition module 1, a PID operation module 2 and a control voltage output module 3 connected in sequence.

[0030] The input end of the voltage acquisition module 1 and the input end of the control voltage output module 3 are both connected to the voltage acquisition end of the aluminum electrolysis control circuit; the output end of the control voltage output module 3 is connected to the saturated reactor of the aluminum electrolysis control circuit;

[0031] The voltage acquisition module 1 is used to obtain the current voltage and the voltage at the previous moment of the voltage acquisition terminal, and send the current voltage and the voltage at the previous moment to the PID calculation module 2;

[0032] The PID operation module 2 is used to generate a control signal according to the voltage at the current moment and the voltage at the previous moment;

[0033] The control voltage output module 3 is used to generate a target voltage according to the control signal and the voltage at the current moment, and use the target voltage as the voltage of the saturated reactor to enable the aluminum electrolysis control circuit to operate.

[0034] like Figure 2 As shown, the voltage stabilization control system is set inside the aluminum electrolysis control circuit. Figure 2 In the figure, except for the second dotted box from the left to the right, which is the voltage stabilization control system, the rest are the structure of the aluminum electrolysis control circuit. The working process of the aluminum electrolysis control circuit after adding the voltage stabilization control system is as follows:

[0035] The 380V AC power generated by the power supply is converted to 18V after passing through a three-phase isolation transformer (not shown in the figure), and then converted into DC power after entering the rectifier unit (i.e., V042 three-phase rectifier bridge). The positive and negative poles of the DC power are both connected to the voltage stabilization control system. The voltage stabilization control device collects the voltage signal of the aluminum electrolysis control circuit during this period (the collection points are 04.51 and 04.92). When the voltage fluctuates (i.e., the current value of the collected voltage is inconsistent with the value at the previous moment), the voltage stabilization control device performs PID calculation to achieve the generation of the target voltage (i.e., stable voltage), and then controls the saturated reactor control winding through the first smoothing reactor L041 and the second smoothing reactor L042 to ensure that a stable voltage can be output. Figure 2 The middle resistors R041, R042 and R043 are all aluminum shell resistors. They play the role of reducing the impact of power supply output fluctuations and field induced voltage on the voltage stabilization control system and some power supply components in the circuit, protecting the components in the circuit and reducing the chance of damage.

[0036] Example 2

[0037] Figure 3 This is a flow chart of a voltage stabilization control method for an aluminum electrolysis control circuit provided in Example 2 of the present invention. Figure 3 As shown, the voltage stabilization control method for the aluminum electrolysis control circuit in this embodiment is implemented based on the voltage stabilization control system for the aluminum electrolysis control circuit in Example 1. The voltage stabilization control method includes:

[0038] Step 101: Obtain the current voltage and the previous voltage of the voltage acquisition terminal of the aluminum electrolysis control circuit.

[0039] Step 102: Generate a control signal according to the voltage at the current moment and the voltage at the previous moment.

[0040] Step 103: Generate a target voltage based on the control signal and the voltage at the current moment, and use the target voltage as the voltage of the saturated reactor to enable the aluminum electrolysis control circuit to operate.

[0041] Specific, combined Figure 2 , voltage stabilization control methods include:

[0042] Step 1: Obtain the voltage between 04.51 and 04.92 in the aluminum electrolysis control circuit.

[0043] Step 2: Compare the voltage value of the voltage between 04.51 and 04.92 at the previous moment with the voltage value at the current moment. For the generated voltage difference, control the output through PID operation (P, I, D represent proportional, differential, and integral respectively), and quickly adjust the fluctuation of the series voltage in electrolysis production so that it quickly approaches the given value, ensuring the stable output of the electrolysis series voltage.

[0044] Step 3: The voltage at the voltage acquisition end is changed by the control signal output by the PID operation to obtain the target voltage, and the target voltage is applied to the saturated reactor control winding through the first smoothing reactor L041 and the second smoothing reactor L042 to improve the voltage regulation response speed and control accuracy.

[0045] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0046] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only intended to help understand the system, method, and core concept of the present invention. At the same time, those skilled in the art will find that the specific implementation methods and application scopes may vary based on the concept of the present invention. In summary, the contents of this specification should not be construed as limiting the present invention.

Claims

1. A voltage stabilization control system for an aluminum electrolysis control circuit, characterized in that: The voltage stabilization control system comprises: a voltage acquisition module, a PID operation module and a control voltage output module connected in sequence; The input end of the voltage acquisition module and the input end of the control voltage output module are both connected to the voltage acquisition end of the aluminum electrolysis control circuit; the output end of the control voltage output module is connected to the saturated reactor of the aluminum electrolysis control circuit; The voltage acquisition module is used to obtain the voltage at the current moment and the voltage at the previous moment of the voltage acquisition terminal, and send the voltage at the current moment and the voltage at the previous moment to the PID calculation module; The PID operation module is used to generate a control signal according to the voltage at the current moment and the voltage at the previous moment; The control voltage output module is used to generate a target voltage according to the control signal and the voltage at the current moment, and use the target voltage as the voltage of the saturated reactor to enable the aluminum electrolysis control circuit to operate.

2. A voltage stabilization control method for an aluminum electrolysis control circuit, characterized in that: The voltage stabilization control method is implemented based on the voltage stabilization control system for an aluminum electrolysis control circuit according to claim 1, and the voltage stabilization control method includes: Obtain the current voltage and the previous voltage of the voltage acquisition terminal of the aluminum electrolysis control circuit; Generate a control signal based on the voltage at the current moment and the voltage at the previous moment; A target voltage is generated according to the control signal and the voltage at the current moment, and the target voltage is used as the voltage of the saturated reactor to operate the aluminum electrolysis control circuit.

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