阅读说明：本技术 一种应用于电解法压载水处理系统的大功率恒流源系统及其控制方法 (High-power constant current source system applied to electrolytic ballast water treatment system and control method thereof ) 是由 孙前刚 张彦 刘刚 祝新 潘李云 李兵 于 2019-09-12 设计创作，主要内容包括：本发明涉及一种应用于电解法压载水处理系统的大功率恒流源系统及控制方法。包括：功率输入单元、功率变换单元、功率输出单元和控制单元,其特征在于,所述功率输入单元与电网交流端连接；所述功率变换单元的输入端与功率输入单元的输出端连接,所述功率变换单元由至少两个电源模块组成,所述电源模块之间通过电流信号线和通讯信号线连接；所述功率输出单元与电源模块的输出端连接；所述控制单元通过通讯信号线与电源模块连接。本发明实现了电解法压载水处理系统需要的大功率恒流输出,输出电流稳定且连续可调,具有控制精度高,可靠性高,控制实现简单,运行成本低等优点。(The invention relates to a high-power constant current source system applied to an electrolytic ballast water treatment system and a control method. The method comprises the following steps: the power conversion device comprises a power input unit, a power conversion unit, a power output unit and a control unit, and is characterized in that the power input unit is connected with an alternating current end of a power grid; the input end of the power conversion unit is connected with the output end of the power input unit, the power conversion unit is composed of at least two power supply modules, and the power supply modules are connected with each other through a current signal wire and a communication signal wire; the power output unit is connected with the output end of the power supply module; the control unit is connected with the power module through a communication signal wire. The invention realizes the high-power constant current output required by the ballast water treatment system by the electrolytic method, has stable and continuously adjustable output current, and has the advantages of high control precision, high reliability, simple control realization, low operation cost and the like.)

1. a high-power constant current source system applied to an electrolytic ballast water treatment system is characterized by comprising a control unit, a power conversion unit, a power input unit and a power output unit;

the control unit is used for calculating a total output current set value of the constant current source system, issuing a control instruction to the power conversion unit, outputting a current reference value to each power supply module and monitoring state parameters of the power conversion unit; the power conversion unit is formed by connecting at least two power modules in parallel and outputs corresponding current according to a total output current set value; the power input unit is used for realizing the parallel connection of the input ends of all power modules in the power conversion unit; the power output unit is used for realizing the parallel connection of the output ends of all the power modules in the power conversion unit.

2. the high power constant current source system of claim 1, wherein the control unit performs the following operations:

Sampling a detection signal of the microbial quantity of ballast water to be treated, and carrying out piecewise linearization operation processing according to the optimal curve of the microbial killing effect to obtain a rough adjustment reference of the total output current of the constant current source system;

Sampling the active substance concentration signal of the ballast water pipeline after the processing, calculating the difference value between the active substance concentration signal and the active substance concentration set value, performing PID (proportion integration differentiation) operation, and performing real-time fine adjustment on the gross output current coarse adjustment reference of the constant current source system to obtain the total output current set value;

issuing a power-on command to each power module in the power conversion unit, starting each power module after receiving the power-on command, and enabling the power module to be in a standby state but not in an output state;

Circularly sending a state query command to each power supply module at certain intervals, and feeding back self state parameters to a control unit by the power supply module receiving the state query command;

counting the number of the current online normal working power modules according to the state parameters;

Distributing the output current reference value of each power module according to the number of the power modules which normally work on line currently and the total output current set value, wherein the power modules output current according to the output current reference value; the output current reference value of each power supply module is a value obtained by dividing the total output current set value by the number of the current online normal working power supply modules.

3. The high power constant current source system according to claim 1, wherein the control unit comprises a data processing circuit, a grid voltage sampling circuit, a total output current sampling circuit, an output voltage sampling circuit and a communication circuit;

The data processing sampling circuit is used for calculating a set value of the total output current of the constant current source system and an output current reference value of each power supply module in the power conversion unit; the power grid voltage sampling circuit is used for monitoring the input voltage of the power input unit in real time; the total output current sampling circuit is used for sampling the output current of the power output unit; the output voltage sampling circuit is used for sampling the output voltage of the power output unit; the communication circuit comprises two parts, namely CAN bus communication between the control unit and the power conversion unit, and MODBUS communication between the control unit and a ballast water management system controller PLC; the control unit communicates with a CAN bus of the power conversion unit to realize the issuing of a power module control instruction and an output current reference value and the monitoring of the state parameters of the power module; and the control unit is communicated with the MODBUS of the ballast water management system controller PLC to realize remote monitoring and control of the high-power constant-current source system.

4. The high power constant current source system of claim 1, wherein the communication signal line between the control unit and the power module has a broadcast mode for the control unit to send the output current reference and control command of the power module and the feedback of the state parameter of the power module.

5. The high power constant current source system of claim 1, wherein the control unit is in polling communication with each power module to monitor the status parameters of each power module in real time; when the power module reports a fault or communication loses connection, the power module is considered to be in fault, and the number of the power modules which normally work online at present is counted according to the judgment; and distributing the output current reference value of each power module according to the number of the currently working power modules and the total output current set value, wherein the output current reference value of each power module is a value obtained by dividing the total output current set value by the number of the currently online normally working power modules.

6. the high-power constant current source system as claimed in claim 1, wherein the high-power constant current source system is in a water-cooling heat dissipation form, circulating water is input from the water inlet and distributed to each power module through the water distribution module, the power modules are used for heat dissipation in a water-cooling plate manner, the input ports of the water-cooling plate are connected with the circulating water through the quick water connectors, and the output ports of the water-cooling plates of the power modules are gathered to the water distribution module and then output to the water outlet.

7. The control method of the high-power constant current source system based on any one of claims 1 to 6 is characterized by comprising the following specific steps:

Step S101: the control unit samples a rapid detection signal of the microbial quantity of ballast water to be treated, and performs piecewise linearization operation processing according to an optimal curve of a microbial killing effect to obtain a rough adjustment reference of the total output current of the constant current source system;

Step S102: the control unit calculates the difference value between the active substance concentration signal and the active substance concentration set value through sampling the active substance concentration signal of the ballast water pipeline, performs PID (proportion integration differentiation) operation, and performs real-time fine adjustment on the total output current coarse adjustment reference of the constant current source system to obtain the total output current set value;

Step S103: the control unit issues a power-on command to the power supply modules of the power conversion unit through the CAN bus, the N power supply modules are started after receiving the power-on command, and the power supply modules are in a standby non-output state;

step S104: the control unit sends a power module state query command to the CAN bus in a cycle of every 10ms, and the power module receiving the power module state query command feeds back a message of self state parameters to the control unit;

step S105: the control unit counts the number of the power modules which normally work on line currently according to the state parameter message;

Step S106: the control unit distributes the output current reference value of each power module according to the number of the power modules which work currently and the total output current set value, and the power modules output current according to the output current reference value, so that high-power output of the constant current source system is realized.

8. The method as claimed in claim 7, wherein the output current reference value of each power module is the total output current setting value divided by the number of power modules in normal operation.

Technical Field

The invention belongs to the technical field of power supplies, and particularly relates to a high-power constant current source system applied to an electrolytic ballast water treatment system and a control method thereof.

background

According to International Maritime Organization (IMO) statistics, over 80% of global commodity transportation is undertaken by ocean-going vessels. During navigation, the ship ballast water is used for adjusting the self attitude of the ship so as to meet good maneuverability of the ship. The ballast water transferred by ships every year all over the world is more than 100 hundred million tons, which brings great threat to marine ecological environment and makes ecological invasion particularly serious. To solve this problem, International Maritime Organization (IMO) requires that each country must enforce ships to install satisfactory ballast water treatment devices to kill microbes to avoid the marine pollution problem caused by ballast water.

The treatment method for the field of ship ballast water mainly comprises a mechanical treatment method, a physical treatment method and a chemical treatment method.

the technology of treating ballast water by electrolysis method belongs to chemical treatment method, and utilizes electrolysis base treatment to make oxidation and reduction reactions respectively occur on anode and cathode so as to convert harmful substance into harmless substance. The method can kill most aquatic organisms, bacteria and pathogenic microorganisms in ballast water.

In electrolytic ballast water treatment system applications, the electrolytic cell used to generate the biocide inactivator is a key component of the system. The concentration of the inactivator has obvious difference on the killing effect of plankton, spore, larva and pathogen in the ballast water, and in order to meet the killing effect of the system and reduce energy consumption as much as possible, the concentration of the inactivator generated by the electrolytic cell needs to be dynamically adjusted in a wide range, and a corresponding electrolytic power supply needs to be matched with the concentration. It is necessary to design a high-power constant current source system and a control method thereof, and the high-power constant current source system can generate a high-reliability continuously adjustable electrolytic power supply, so as to ensure the stable output and accurate adjustment of the inactivating agent.

in the existing ballast water treatment system by an electrolytic method, an electrolytic power supply has the following problems:

(1) A single closed loop feedback control is employed. In the prior art, the output current of the electrolytic power supply is changed by taking a concentration signal of an active substance of the ballast water after sampling treatment as feedback, and because of the hysteresis effect of the oxidation-reduction reaction, the energy consumption is increased, and the operation cost is increased.

(2) And the single power supply module supplies power. The single power module is limited by power devices and power electronic technology, the output power of the single power module is limited, the output current requirement cannot be met, the result that the concentration of the active substance cannot reach the standard can be caused, and the defects of low system reliability, low maintainability and the like are caused by the power supply mode of the single power module.

(3) And air cooling heat dissipation. The power supply equipment has large volume and poor noise and environmental adaptability.

Disclosure of Invention

in view of the above, the invention provides a high-power constant-current source system applied to an electrolytic ballast water treatment system and a control method thereof, the high-power constant-current source system and the control method thereof adopt a feedforward-feedback cascade control technology, a digital bus control technology and a water-cooling heat dissipation technology, realize the high-power constant-current output required by the electrolytic ballast water treatment system, and have the advantages of high control precision, high reliability, simple control realization, low operation cost and the like.

the invention is realized by the following technical scheme: a high-power constant current source system applied to an electrolytic ballast water treatment system comprises a control unit, a power conversion unit, a power input unit and a power output unit;

The control unit is used for calculating a total output current set value of the constant current source system, issuing a control instruction to the power conversion unit, outputting a current reference value to each power supply module and monitoring state parameters of the power conversion unit; the power conversion unit is formed by connecting at least two power modules in parallel and outputs corresponding current according to a total output current set value; the power input unit is used for realizing the parallel connection of the input ends of all power modules in the power conversion unit; the power output unit is used for realizing the parallel connection of the output ends of all the power modules in the power conversion unit.

Preferably, the control unit performs the following operations:

sampling a detection signal of the microbial quantity of ballast water to be treated, and carrying out piecewise linearization operation processing according to the optimal curve of the microbial killing effect to obtain a rough adjustment reference of the total output current of the constant current source system;

Sampling the active substance concentration signal of the ballast water pipeline after the processing, calculating the difference value between the active substance concentration signal and the active substance concentration set value, performing PID (proportion integration differentiation) operation, and performing real-time fine adjustment on the gross output current coarse adjustment reference of the constant current source system to obtain the total output current set value;

Issuing a power-on command to each power module in the power conversion unit, starting each power module after receiving the power-on command, and enabling the power module to be in a standby state but not in an output state;

Circularly sending a state query command to each power supply module at certain intervals, and feeding back self state parameters to a control unit by the power supply module receiving the state query command;

Counting the number of the current online normal working power modules according to the state parameters;

Distributing the output current reference value of each power module according to the number of the power modules which normally work on line currently and the total output current set value, wherein the power modules output current according to the output current reference value; the output current reference value of each power supply module is a value obtained by dividing the total output current set value by the number of the current online normal working power supply modules.

Preferably, the control unit comprises a data processing circuit, a grid voltage sampling circuit, a total output current sampling circuit, an output voltage sampling circuit and a communication circuit;

The data processing sampling circuit is used for calculating a set value of the total output current of the constant current source system and an output current reference value of each power supply module in the power conversion unit; the power grid voltage sampling circuit is used for monitoring the input voltage of the power input unit in real time; the total output current sampling circuit is used for sampling the output current of the power output unit; the output voltage sampling circuit is used for sampling the output voltage of the power output unit; the communication circuit comprises two parts, namely CAN bus communication between the control unit and the power conversion unit, and MODBUS communication between the control unit and a ballast water management system controller PLC; the control unit communicates with a CAN bus of the power conversion unit to realize the issuing of a power module control instruction and an output current reference value and the monitoring of the state parameters of the power module; and the control unit is communicated with the MODBUS of the ballast water management system controller PLC to realize remote monitoring and control of the high-power constant-current source system.

preferably, the communication signal line between the control unit and the power module has a broadcast mode, and is used for the control unit to send the output current reference and the control command of the power module and for the power module to feed back the state parameters of the power module.

Preferably, the control unit is in polling communication with each power supply module and monitors the state parameters of each power supply module in real time; when the power module reports a fault or communication loses connection, the power module is considered to be in fault, and the number of the power modules which normally work online at present is counted according to the judgment; and distributing the output current reference value of each power module according to the number of the currently working power modules and the total output current set value, wherein the output current reference value of each power module is a value obtained by dividing the total output current set value by the number of the currently online normally working power modules.

preferably, the high-power constant current source system adopts a water-cooling heat dissipation form, circulating water is input from the water inlet and distributed to each power module through the water distribution module, the power modules dissipate heat in a water-cooling plate mode, the input ports of the water-cooling plates are connected with the circulating water through the quick water connectors, and the output ports of the water-cooling plates of the power modules are gathered to the water distribution module and then output to the water outlet.

compared with the prior art, the invention has the following remarkable advantages:

(1) based on a feedforward-feedback cascade control structure, introducing a rapid detection signal of the amount of microorganisms in ballast water to be treated as a feedforward control signal of an electrolytic power supply, carrying out piecewise linearization operation processing according to an optimal killing effect curve of the microorganisms, providing a roughly adjusted current reference for the power supply, calculating a phase difference value between the processed ballast water active substance concentration signal and a set value by combining the processed ballast water active substance concentration signal, carrying out PID operation, and carrying out real-time fine adjustment on the power supply current rough adjustment reference, so that the control precision of a system on the concentration of active substances in a ballast water pipeline can be improved, the energy consumption can be reduced, and the operation cost can be saved;

(2) The high-power constant-current source system is formed by adopting a multi-module parallel technical scheme, so that the treatment effect of the ballast water treatment system is ensured, and the reliability and maintainability of the system are improved;

(3) The digital bus is adopted for control, the control is simple and flexible, the parallel connection mode without the current-sharing bus is adopted, the current-sharing circuit and the current-sharing controller are reduced, the manufacturing cost is saved, and meanwhile, the wiring process is simple;

(4) the power module has high power density, small volume and improved suitability for assembly by adopting a water-cooling heat dissipation mode; meanwhile, the electrolysis power supply equipment adopts a closed cabinet, so that the environmental adaptability is greatly improved.

drawings

Fig. 1 is a system block diagram of a high-power constant current source applied to an electrolytic ballast water treatment system of the present invention.

Fig. 2 is a circuit block diagram of a high-power constant current source system applied to an electrolytic ballast water treatment system of the present invention.

fig. 3 is a schematic block diagram of a high-power constant current source system control unit applied to an electrolytic ballast water treatment system of the present invention.

Fig. 4 is a logic flow diagram of the control method of the high-power constant current source system applied to the electrolytic ballast water treatment system of the present invention.

Detailed Description

the invention is described in detail below by way of example with reference to the accompanying drawings.

Fig. 1 is a system block diagram of a high-power constant current source applied to an electrolytic ballast water treatment system, and the composition and connection relationship thereof. The high-power constant current source system comprises a control unit 1, a power conversion unit 2, a power input unit 3 and a power output unit 4. The power conversion unit 2 converts the input alternating current into direct current required by the electrolytic cell.

The control unit 1 is used for calculating a total output current set value of the constant current source system, issuing a control instruction to the power conversion unit 2 through the CAN bus, outputting a current reference value to each power module and monitoring state parameters of the power conversion unit 2; the power conversion unit 2 is formed by connecting at least two power modules in parallel, and outputs corresponding current according to a total output current set value transmitted on the CAN bus; the power input unit 3 is used for realizing the parallel connection of the input ends of all power modules in the power conversion unit 2; the power output unit 4 is used for realizing the parallel connection of the output ends of each power supply module in the power conversion unit 2.

as shown in fig. 2, which is a circuit block diagram of a high-power constant current source system applied to an electrolytic ballast water treatment system in an embodiment, the control unit 1 is connected to a power conversion unit 2 through a CAN bus, an input end of a power input unit 3 is connected to an ac end of a power grid, an input end of the power conversion unit 2 is connected to an output end of the power input unit 3, input ends of power modules in the power conversion unit 2 are connected in parallel, output ends of the power modules are connected in parallel, the power modules are connected through a CAN communication bus, and specifically, the power modules are connected through a current signal line and a communication signal line; the input end of the power output unit 4 is connected with the input and output end of the power conversion unit 2, and the output end of the power output unit 4 is connected with the rear end electrolytic cell.

The control unit 1 is a control and management center of the high-power constant current source system, and a structural block diagram is shown in fig. 3, and includes a data processing circuit 10, a grid voltage sampling circuit 11, a total output current sampling circuit 12, an output voltage sampling circuit 13, and a communication circuit 14.

the working process and principle are as follows: the data processing sampling circuit 10 is used for calculating a set value of the total output current of the constant current source system and an output current reference value of each power supply module in the power conversion unit; the grid voltage sampling circuit 11 is used for monitoring the input voltage of the power input unit 3 in real time; the total output current sampling circuit 12 is used for sampling the output current of the power output unit 4; the output voltage sampling circuit 13 is used for sampling the output voltage of the power output unit 4; the communication circuit 14 includes two parts of CAN bus communication between the control unit 1 and the power conversion unit 2, and MODBUS communication between the control unit 1 and the ballast water management system controller PLC. The control unit 1 communicates with the CAN bus of the power conversion unit 2 to realize the control instruction of the power supply module, and outputs the issuing of the current reference value and monitors the state parameters of the power supply module, wherein the state parameters comprise the voltage, the current, the fault, the overvoltage, the overcurrent and the like of each power supply module. The control unit 1 communicates with MODBUS of a ballast water management system controller PLC to realize remote monitoring and control of the high-power constant-current source system. Preferably, the communication signal line between the control unit and the power module has a broadcast mode, and is used for the control unit to issue the power module output current reference, the control command and the power module to feed back the self state parameter.

Aiming at killing effect curves of different water qualities and different concentrations of the inactivator, a curve with the best microorganism killing effect is selected for input control, a data processing circuit 10 of a control unit 1 carries out piecewise linearization operation processing, and tracking control is carried out on the great change of the microorganism species and concentration of the water quality, so that the generation amount of the concentration of the inactivator is basically ensured, and the water quality of ballast water to be treated is basically ensured. The piecewise linearization operation treatment enables the control unit to adjust the interval of the generation amount (total output current of the constant current source system) of the inactivating agent according to the types and the concentrations of the microorganisms in the water, thereby reducing the energy consumption and saving the operation cost.

the control unit 1 calculates a phase difference value between the concentration signal of the active substances in the treated ballast water pipeline and a set value of the concentration of the active substances, performs PID (proportion integration differentiation) operation to obtain a corresponding control increment, and controls the generation amount of the inactivating agent according to the control increment, so that the actually measured concentration of the active substances in the treated ballast water pipeline is always close to the set value, and the stability of the water quality of the ballast water is ensured. If the actual measured value of the concentration signal of the active substances of the ballast water pipeline after treatment is higher than the set value, the generation amount of the inactivator is reduced, namely the total output current of the constant current source system is reduced, and if the actual measured value of the concentration signal of the active substances of the ballast water pipeline after treatment is lower than the set value, the generation amount of the inactivator is increased, namely the output current of the constant current source system is increased. The control unit collects the concentration signal of the active substances in the treated ballast water pipeline, automatically adjusts PID loop control, and finely adjusts the generation amount of the inactivator (the total output current of the constant current source system) to obtain the set value of the total output current of the constant current source system.

The control unit updates the set value of the total output current of the constant current source system in real time according to the optimal killing effect curve of the microorganisms and the set range of the concentration of the active substances by sampling the rapid detection signal of the microbial quantity of the ballast water to be treated and the concentration signal of the active substances in the ballast water pipeline after treatment; the control unit is in polling communication with each power supply module and monitors the state parameters of the power supply modules in real time; when the power module reports a fault or communication loses connection, the power module is considered to be in fault, and the number of the power modules which normally work online at present is counted according to the judgment; and distributing the output current reference value of each power module according to the number of the currently working power modules and the total output current set value, wherein the output current reference value of each power module is obtained by dividing the total output current set value by the number of the currently online normally working power modules.

the control unit sends the output current reference of the power supply module through bus broadcasting; and the power supply module outputs corresponding current according to the set value of the output current.

as shown in fig. 4, a logic flow chart of the control method of the high-power constant current source system applied to the electrolytic ballast water treatment system of the present invention is shown:

Step S101: the control unit 1 samples a rapid detection signal of the microbial quantity of ballast water to be treated, and according to an optimal microbial killing effect curve, the control unit 1 performs piecewise linearization operation processing to obtain a rough adjustment reference of the total output current of the constant current source system;

step S102: the control unit 1 calculates the difference value between the active substance concentration signal and the active substance concentration set value through sampling the active substance concentration signal of the ballast water pipeline, performs PID (proportion integration differentiation) operation, and performs real-time fine adjustment on the total output current coarse adjustment reference of the constant current source system to obtain the total output current set value;

step S103: the control unit 1 issues a power-on command to the power supply modules of the power conversion unit 2 through the CAN bus, the N power supply modules are started after receiving the power-on command, and the power supply modules are in a standby non-output state;

step S104: the control unit 1 sends a power module state query command to the CAN bus in a cycle of every 10ms, and the power module receiving the power module state query command feeds back a message of self state parameters to the control unit;

Step S105: the control unit 1 counts the number of the power modules which normally work on line currently according to the state parameter message;

step S106: the control unit 1 distributes the output current reference value of each power module according to the number of the power modules which work currently and the total output current set value, and the power modules output current according to the output current reference value, so that high-power output of the constant current source system is realized. The output current reference value of each power supply module is obtained by dividing the total output current set value by the number of the current online normal working power supply modules.

The high-power constant current source system adopts a water-cooling heat dissipation form, circulating water is input from a water inlet and distributed to each power module through the water distribution module, the power modules dissipate heat in a water-cooling plate mode, the input ports of the water-cooling plates are connected with the circulating water through the quick water connectors, and the output ports of the water-cooling plates of the power modules are gathered to the water distribution module and then output to the water outlet.

According to the invention, a rapid detection signal of the microbial quantity of the ballast water before treatment is introduced to serve as a feedforward control signal of an electrolytic power supply, a coarse adjustment current reference is provided for the power supply, and the control precision of the system on the concentration of active substances in a ballast water pipeline can be improved by combining a sampling signal of the concentration of the active substances of the ballast water after treatment, the energy consumption can be reduced, and the operation cost can be saved; a high-power constant current source system is formed by adopting a multi-module parallel technology, the output rated current reaches 1500A, the treatment effect of the ballast water treatment system is ensured, and the reliability and maintainability of the system are improved; the digital bus control is adopted, and the method belongs to a non-uniform current bus parallel connection mode, and is simple and flexible to control; the power supply modules are connected in parallel in a mode without a current-sharing bus, a current-sharing circuit and a current-sharing controller are reduced, the manufacturing cost is saved, and meanwhile, the wiring process is simple. And a water-cooling heat dissipation form is adopted, so that the power supply equipment has high power density, small occupied area and greatly improved environmental adaptability.