A grid-connected control method and system for a desulfurization wastewater power generation system

Abstract

The embodiment of this specification discloses a grid-connected control method and system for a desulfurized wastewater power generation system, which relates to the field of ship technology and is used to solve the problem that the existing desulfurization method is prone to grid-connected impact. The method is applied to a desulfurized wastewater power generation system consisting of a power generation unit and a grid-connected unit connected to the power generation unit; the grid-connected unit includes a grid-connected synchronization device, a circuit breaker connected to the grid-connected synchronization device, and a control unit, and the method includes: the grid-connected unit detects the electric energy information based on the grid-connected synchronization device to obtain the detection result, and determines whether to start the circuit breaker to close based on the detection result and the preset grid-connected condition; the electric energy information is based on the power generation unit to recover the head potential energy to generate the recovered head potential energy; if yes, then the circuit breaker is controlled to start closing based on the control unit; if not, then the grid-connected synchronization device calls the corresponding grid-connected control strategy to feedback and adjust the power generation unit to promote the synchronous grid connection of the desulfurized wastewater power generation system.

Description

Technical Field

[0001] The present specification relates to the field of ship technology, and in particular to a grid-connected control method and system for a desulfurization wastewater power generation system. Background Art

[0002] With the rapid development of the shipping industry, most ships at the current stage use diesel engines as the mainstream power and main power generation device. When diesel engines generate electricity with fuel oil, the exhaust gas contains a large amount of sulfur oxides. These sulfur oxides need to be strictly controlled, which has a significant impact on the shipping industry. Therefore, in order to meet the requirements of the current marine fuel sulfur limit implementation plan and reduce the emission of sulfur oxides from ships, ship desulfurization devices that have an emission reduction effect have become an indispensable part of ships.

[0003] At present, some ships will adopt the method of installing exhaust gas desulfurization equipment for the main and auxiliary engines to reduce emissions. The desulfurization device uses the desulfurization tower as the core equipment, and uses seawater as a coolant and detergent to absorb sulfur oxides in the flue gas. However, in an open system, if there is no need to achieve uninterrupted absorption of sulfur oxides, it is necessary to continuously use seawater pumps to pump seawater into the desulfurization tower. The desulfurization tower is tall and installed at a high position, which causes a large amount of seawater to spray downward from the top of the desulfurization tower, with large kinetic energy and potential energy. However, based on the current desulfurization device, the desulfurization wastewater after flue gas flushing cannot be used for kinetic energy and potential energy when it is discharged overboard through a pipeline, resulting in a certain amount of energy waste. In addition, the electricity generated by the existing desulfurization wastewater power generation system is different from that of the main power grid. When the difference is large, the grid connection will have an impact on the main power grid system and will also have an adverse effect on the main power grid equipment. Summary of the invention

[0004] In order to solve the above technical problems, one or more embodiments of this specification provide a grid-connected control method and system for a desulfurization wastewater power generation system.

[0005] One or more embodiments of this specification adopt the following technical solutions:

[0006] One or more embodiments of the present specification provide a grid-connected control method for a desulfurized wastewater power generation system, which is applied to a desulfurized wastewater power generation system including a power generation unit and a grid-connected unit connected to the power generation unit; the grid-connected unit includes a grid-connected synchronization device, a circuit breaker connected to the grid-connected synchronization device, and a control unit connected to the grid-connected synchronization device in communication, and the method includes:

[0007] The grid-connected unit detects the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determines whether to start the closing of the circuit breaker based on the detection result and the preset grid-connected condition; wherein the electric energy information is generated based on the recovery of the head potential energy by the power generation unit;

[0008] If yes, controlling the circuit breaker to start closing based on the control unit;

[0009] If not, the grid-connected synchronization device calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit to promote the synchronous grid-connected of the desulfurization wastewater power generation system.

[0010] Optionally, in one or more embodiments of the present specification, the desulfurization wastewater power generation system further includes: a desulfurization unit connected to the power generation unit; the desulfurization unit includes: a seawater pump and a desulfurization tower; the desulfurization tower includes: a water inlet, a wastewater outlet, a flue gas inlet, and a tail gas outlet;

[0011] Wherein, the desulfurization unit is used for:

[0012] Pumping seawater into the water inlet of the desulfurization tower based on the seawater pump;

[0013] The seawater introduced into the water inlet is sprayed by a pre-installed spraying device, and the waste gas introduced into the flue gas inlet of the desulfurization tower is washed to obtain desulfurization waste water and washing waste gas;

[0014] The scrubber waste gas is discharged to the flue based on the tail gas outlet, and the desulfurization waste water flows into the power generation unit based on the waste water outlet.

[0015] Optionally, in one or more embodiments of the present specification, the grid-connected unit detects the electric energy information based on the grid-connected synchronization device, and before obtaining the detection result, the method further includes:

[0016] The power generation unit divides the desulfurized wastewater into two paths based on the main pipeline and the bypass pipeline; wherein the main pipeline is provided with a main proportional regulating valve, a turbine and a generator, and the bypass pipeline is provided with a bypass proportional regulating valve;

[0017] The power generation unit converts the head potential energy of the desulfurized wastewater into mechanical energy based on the turbine in the main pipeline;

[0018] The power generation unit adjusts the water flow of the main pipeline and the bypass pipeline based on the main proportional control valve and the bypass proportional control valve to obtain the desired rotation speed of the turbine, and drives the generator to rotate based on the desired rotation speed to convert the mechanical energy into electrical energy.

[0019] Optionally, in one or more embodiments of the present specification, the grid-connected unit detects the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determines whether to start closing the circuit breaker based on the detection result and a preset grid-connected condition, specifically including:

[0020] Based on the built-in frequency difference control unit and voltage difference control unit of the grid-connected synchronization device, the power information of the power generation unit is detected to obtain the detection result; wherein the detection result includes: frequency difference data and voltage difference data;

[0021] If the built-in closing control unit of the grid-connected synchronization device determines that the frequency difference data meets the preset grid-connected condition, and the voltage difference data meets the preset grid-connected condition, then it is determined to start closing the circuit breaker;

[0022] If the built-in closing control unit of the grid-connected synchronization device determines that the frequency difference data does not meet the preset grid-connected condition, or the voltage difference data does not meet the preset grid-connected condition, it determines not to start closing the circuit breaker.

[0023] Optionally, in one or more embodiments of the present specification, the grid-connected synchronization device calls a corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition to perform feedback adjustment on the power generation unit, specifically including:

[0024] The grid-connected synchronization device determines the current deviation grid-connected parameter based on the detection result and the preset grid-connected condition;

[0025] The frequency difference control unit is used to control and adjust the opening of the main proportional control valve and the bypass proportional control valve based on the frequency difference data and the preset frequency difference grid control strategy when the frequency difference data is determined to be the current deviation grid-connected parameter;

[0026] The voltage difference control unit is used to adjust the excitation current of the power generation unit based on the voltage difference data and a preset voltage difference grid-connected control strategy when it is determined that the voltage difference is a current deviation grid-connected parameter.

[0027] Optionally, in one or more embodiments of the present specification, based on the basic information of the frequency difference and the preset frequency difference grid-connected control strategy, controlling and adjusting the opening of the main proportional control valve and the bypass proportional control valve specifically includes:

[0028] The frequency difference control unit is used to calculate the currently required frequency change and the turbine speed change corresponding to the frequency change if it is determined based on the basic information of the frequency difference that the frequency difference is less than a preset frequency difference threshold;

[0029] The frequency difference control unit determines the relationship between the generator set speed and the frequency of the power generation unit and the relationship between the desulfurization wastewater flow rate and the turbine speed, so as to obtain the main pipeline change of the desulfurization wastewater flow rate corresponding to the turbine speed change;

[0030] The frequency difference control unit determines the bypass pipeline change amount according to the total flow of desulfurization wastewater and the main pipeline change amount, so as to control the opening adjustment of the main proportional control valve and the bypass proportional control valve based on the main pipeline change amount and the bypass pipeline change amount.

[0031] Optionally, in one or more embodiments of the present specification, adjusting the excitation current of the power generation unit based on the voltage difference data and a preset voltage difference grid-connected control strategy specifically includes:

[0032] If the voltage difference control unit determines, based on the voltage difference, that the voltage difference is less than a preset voltage threshold and that the voltage of the generator set is less than the voltage of the main grid, then the induced electromotive force corresponding to the current required voltage boost is determined, so as to adjust the magnetic current of the power generation unit according to the relationship between the induced electromotive force and the excitation current, so as to increase the voltage of the generator set;

[0033] If the voltage difference control unit determines, based on the voltage difference, that the voltage difference is less than a preset voltage threshold and that the voltage of the generator set is greater than the voltage of the main power grid, it determines the induced electromotive force corresponding to the currently required voltage reduction amount, and adjusts the magnetic current of the generating unit according to the relationship between the induced electromotive force and the excitation current to reduce the voltage of the generator set.

[0034] Optionally, in one or more embodiments of the present specification, the grid-connected unit detects the electric energy information based on the grid-connected synchronization device, and before obtaining the detection result, the method further includes:

[0035] The control unit obtains the operating status information of each hardware device in the desulfurization wastewater power generation system to determine whether there is a device failure based on the operating status information;

[0036] If so, the control unit controls the circuit breaker to open, and controls the power generation unit to close the main proportional regulating valve and fully open the bypass proportional regulating valve.

[0037] Optionally, in one or more embodiments of the present specification, the grid-connected unit further includes: a voltage transformer and a current transformer; the voltage transformer and the current transformer are used to respectively detect voltage changes and current changes on both sides of the grid-connected point to monitor the impact of the grid-connected process on the main power grid.

[0038] One or more embodiments of this specification provide a grid-connected control system for a desulfurization wastewater power generation system, the system comprising:

[0039] The system comprises: a desulfurization wastewater power generation system consisting of a power generation unit and a grid-connected unit connected to the power generation unit; the grid-connected unit comprises a grid-connected synchronization device, a circuit breaker connected to the grid-connected synchronization device, and a control unit connected to the grid-connected synchronization device in communication;

[0040] The grid-connected unit is used to detect the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determine whether to start the closing of the circuit breaker based on the detection result and the preset grid-connected condition; wherein the electric energy information is generated based on the recovery of the head potential energy by the power generation unit;

[0041] If yes, controlling the circuit breaker to start closing based on the control unit;

[0042] If not, the grid-connected synchronization device calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit to promote the synchronous grid-connected of the desulfurization wastewater power generation system.

[0043] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects:

[0044] The power generation unit recovers the head potential energy in the desulfurization wastewater, so that the energy that might have been wasted is effectively converted into electrical energy, thereby improving the energy utilization efficiency of the entire system. This helps to reduce energy waste and maximize the utilization of resources. A grid-connected unit is set after the power generation unit so that the grid-connected synchronization device can use the frequency difference control unit and the voltage difference control unit to adjust the power generation unit to monitor the power generation unit in real time, and then adjust the turbine flow and excitation current to adjust the power generation frequency and voltage. The system can quickly connect to the grid through simple proportional control valves and excitation current control, so that it can keep synchronization with the ship's main power grid, reducing the impact on the stability of the power grid when connected to the grid. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0046] Figure 1 A schematic flow chart of a grid-connected control method for a desulfurization wastewater power generation system provided in an embodiment of this specification;

[0047] Figure 2 An overall schematic diagram of a grid-connected control system for a desulfurization wastewater power generation system provided in an embodiment of this specification;

[0048] Figure 3 An implementation roadmap for the grid-connected control process of a desulfurization wastewater power generation system provided in the embodiments of this specification;

[0049] Figure 4 A schematic diagram of a power generation side control strategy based on frequency difference control in an application scenario provided by an embodiment of this specification;

[0050] Figure 5 A schematic diagram of a power generation side control strategy based on voltage difference control in an application scenario provided by an embodiment of this specification;

[0051] Figure 6 An overall schematic diagram of a grid-connected control system for another desulfurization wastewater power generation system provided in an embodiment of this specification.

[0052] In the figure: 1 is seawater, 2 is seawater pipeline, 3 is seawater pump, 4 is seawater inlet, 5 is overboard opening, 6 is desulfurization tower, 7 is main proportional control valve, 8 is turbine, 9 is generator, 10 is wastewater outlet, 11 is grid-connected synchronization device, 12 is voltage transformer, 13 is current transformer, 14 is circuit breaker, 15 is ship electrical equipment, 16 is control unit, 17 is bypass proportional control valve, 18 is bypass pipeline, 19 is three-way valve, 20 is buffer water tank, 21 is bypass turbine, 22 is bypass generator, 23 is battery, 24 is supply valve, 25 is supply pipeline, and 26 is supply seawater pump. DETAILED DESCRIPTION

[0053] The embodiments of this specification provide a grid-connected control method and system for a desulfurization wastewater power generation system.

[0054] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0055] like Figure 1 As shown, the present specification embodiment provides a schematic flow chart of a grid-connected control method for a desulfurization wastewater power generation system. Figure 1 It can be seen that in one or more embodiments of this specification, a grid-connected control method for a desulfurization wastewater power generation system is applied to Figure 2The application shown is a desulfurization wastewater power generation system comprising a power generation unit and a grid-connected unit connected to the power generation unit; the grid-connected unit comprises a grid-connected synchronization device 11, a circuit breaker 14 connected to the grid-connected synchronization device 11, and a control unit 16 communicatively connected to the grid-connected synchronization device 11, and the method comprises:

[0056] S101: The grid-connected unit detects the electric energy information based on the grid-connected synchronization device 11 to obtain a detection result, and determines whether to start the circuit breaker 14 to close based on the detection result and the preset grid-connected condition; wherein the electric energy information is generated based on the recovery of the head potential energy by the power generation unit.

[0057] like Figure 2 As shown, the desulfurization wastewater power generation system of the embodiment of this specification includes a power generation unit and a grid-connected unit connected to the power generation unit. Among them, the power generation unit can use the head potential energy generated by the desulfurization process to recover part of the energy for power generation, and the grid-connected unit integrates the electric energy generated by the power generation unit into the main power grid of the ship. Further, in one or more embodiments of this specification, the desulfurization wastewater power generation system also includes: a desulfurization unit connected to the power generation unit; the desulfurization unit includes: a seawater pump 3 and a desulfurization tower 6; and the desulfurization tower 6 includes: a water inlet, a wastewater outlet 10, a flue gas inlet, and a tail gas outlet; wherein the desulfurization unit is used to: pump seawater 1 into the water inlet of the desulfurization tower 6 based on the seawater pump 3, that is, under the action of the seawater pump 3, the seawater 1 is pumped into the water inlet of the desulfurization tower 6 from the seawater inlet 4 through the seawater pipeline 2, and because the water inlet is connected to the spray device at the top of the desulfurization tower 6. Therefore, the seawater 1 introduced into the water inlet is sprayed by the pre-set spray device, and the exhaust gas introduced into the flue gas inlet of the desulfurization tower 6 is washed to obtain desulfurized wastewater and washed exhaust gas. That is, the exhaust gas generated by the main diesel engine and / or auxiliary engine of the ship enters the flue gas inlet of the desulfurization tower 6 through the desulfurization pipeline, and absorbs sulfur oxides in the exhaust gas in the tower by spraying downward. After being washed with seawater, the washed exhaust gas is discharged to the flue through the tail gas outlet at the top of the desulfurization tower 6, and the desulfurized waste water flows downward into the power generation unit based on the waste water outlet 10, so that the power generation unit uses the head potential energy of the desulfurization unit to recover part of the energy for power generation, thereby reducing the energy waste problem in the existing method.

[0058] After the desulfurization unit flows the desulfurized wastewater into the power generation unit through the wastewater outlet 10, the power generation unit will use the head potential energy of the desulfurization unit to recover part of the energy for power generation. Then, in order to avoid the difference between the electric energy generated by the current desulfurization wastewater power generation system and the main power grid, when the difference is large, the grid connection will have an impact on the main power grid system and thus cause the grid connection problem, the grid connection unit in the embodiment of this specification will detect the electric energy information generated by the power generation unit based on the grid connection synchronization device 11 to obtain the detection result. Then, according to the detection result and the preset grid connection conditions, it is determined whether to start the circuit breaker 14 to close the switch for grid connection to reduce the negative impact of the grid connection process on the ship's main power grid.

[0059] Furthermore, in one or more embodiments of the present specification, the grid-connected unit detects the electric energy information based on the grid-connected synchronization device 11. Before obtaining the detection result, the power generation unit needs to recover the head potential energy in the desulfurization wastewater generated by the desulfurization unit to improve the energy utilization rate, and the following process needs to be implemented:

[0060] Firstly based on Figure 2 It can be seen that the power generation unit includes: a main proportional regulating valve 7, a turbine 8, a generator 9, a bypass proportional regulating valve 17 and a bypass pipeline 18. In the embodiment of this specification, the power generation unit will divide the desulfurized wastewater into two paths through the main pipeline and the bypass pipeline 18; wherein, the main pipeline is provided with a main proportional regulating valve 7, a turbine 8 and a generator 9, and the bypass pipeline 18 is provided with a bypass proportional regulating valve 17. After the wastewater flowing out of the desulfurization device is divided into two paths, the power generation unit converts the head potential energy of the desulfurized wastewater into mechanical energy based on the turbine 8 in the main pipeline. It can be understood that the wastewater enters the turbine 8 through the main pipeline, and the excess head potential energy of the wastewater is converted into the mechanical energy of the turbine 8, which can drive the turbine 8 to rotate. In the other path, the wastewater enters the bypass pipeline 18, bypasses the turbine 8, and does not participate in the driving of the turbine 8. After the main pipeline converts the head potential energy of the desulfurized wastewater into mechanical energy based on the turbine 8, the power generation unit adjusts the water flow of the main pipeline and the bypass pipeline 18 according to the main proportional regulating valve 7 and the bypass proportional regulating valve 17, thereby obtaining the desired speed of the turbine 8, and driving the generator 9 to rotate based on the desired speed to convert the mechanical energy into electrical energy. In addition, it should be noted that the main pipeline and the bypass pipeline 18 are discharged from the outboard opening 5 after merging downstream of the turbine 8. Among them, it should be noted that the turbine 8 and the turbine generator 9 are connected in a mechanical transmission manner to form a turbine generator set. The turbine 8 rotates using the head potential energy, and the output shaft of the turbine 8 is connected to the rotor input shaft of the turbine generator 9 to convert the mechanical energy into electrical energy. The turbine 8 is arranged directly below the wastewater outlet 10 and at a height similar to the outboard opening 5 to obtain the maximum available head height and have greater potential energy; the turbine 8 adopts a pipeline vertical turbine 8, and the minimum caliber can be as low as 200mm, which can flexibly adapt to the compact equipment installation environment of the ship.

[0061] In this process, by recovering the head potential energy in the desulfurization wastewater, the energy that might have been wasted is effectively converted into electrical energy, thereby improving the energy utilization efficiency of the entire system. This helps to reduce energy waste and maximize the utilization of resources. And through the flexible adjustment of the main proportional control valve 7 and the bypass proportional control valve 17, the water flow of the main pipeline and the bypass pipeline 18 can be accurately controlled to obtain the desired speed of the turbine 8. This flexibility enables the system to be adjusted according to actual needs to ensure the efficiency and stability of energy recovery.

[0062] Furthermore, in one or more embodiments of the present specification, the grid-connected unit detects the electric energy information based on the grid-connected synchronization device 11, and before obtaining the detection result, the method further includes:

[0063] The control unit 16 obtains the operating status information of each hardware device in the desulfurization wastewater power generation system to determine whether there is a device failure based on the operating status information. If there is a device failure, the control unit 16 controls the circuit breaker 14 to open, and controls the power generation unit to close the main proportional control valve 7 and fully open the bypass proportional control valve 17. The washing wastewater is discharged into the sea through the bypass pipeline 18; Figure 3 As shown, when there is no fault in the relevant equipment, the grid-connected synchronization device 11 further detects whether the grid-connected conditions are met. When a device fails, the power supply of the faulty device is cut off in time and the water flow path is adjusted to avoid further damage that may be caused by the continued operation of the faulty device. For example, by closing the main proportional control valve 7 and fully opening the bypass proportional control valve 17, it can be ensured that the desulfurized wastewater bypasses the faulty turbine 8, thereby protecting the turbine 8 from unnecessary wear or damage. When there is no fault in the equipment, the system can continue to operate normally and perform energy recovery and electrical energy conversion of the desulfurized wastewater. This fault detection and response mechanism ensures the continuity and stability of the system, reduces the system downtime caused by equipment failure, and improves the overall operating efficiency of the system.

[0064] Specifically, in one or more embodiments of the present specification, the grid-connected unit detects the electric energy information based on the grid-connected synchronization device 11 to obtain a detection result, and determines whether to start the circuit breaker 14 to close based on the detection result and the preset grid-connected condition, specifically including:

[0065] First, the power information of the power generation unit is detected based on the built-in frequency difference control unit 16 and the voltage difference control unit 16 of the grid-connected synchronization device 11 to obtain the detection results; wherein, the detection results include: frequency difference data and voltage difference data. If the built-in closing control unit 16 of the grid-connected synchronization device 11 determines that the frequency difference data meets the preset grid-connected conditions, and the voltage difference data meets the preset grid-connected conditions, then it is determined to start the circuit breaker 14 in the grid-connected synchronization termination to close. If the built-in closing control unit 16 of the grid-connected synchronization device 11 determines that the frequency difference data does not meet the preset grid-connected conditions, or the voltage difference data does not meet the preset grid-connected conditions, then it is determined not to start the circuit breaker 14 to close. In this way, the preset grid-connected conditions are judged before the grid-connected connection is carried out, avoiding the problem that the electric energy generated by the current existing desulfurization wastewater power generation system is different from the main grid. When the difference is large, the grid connection will have an impact on the main grid system and will also have an adverse effect on the main grid equipment.

[0066] S102: If yes, the control unit 16 controls the circuit breaker 14 to start closing.

[0067] If it is determined that the circuit breaker 14 can be started to close based on the detection result and the preset grid connection condition in step S101, the control unit 16 controls the circuit breaker 14 to start closing, so that after the hydroelectric power generation equipment is connected to the grid, it can provide power to the ship's electrical equipment 15 together with the main diesel generator, auxiliary machine and other power generation equipment. It should be noted that the preset grid connection condition is to obtain the frequency difference between the power generation unit and the ship's main grid. and the frequency difference direction, and the frequency difference allowable value compare; when , and when other grid-connected conditions meet the requirements, the grid-connected synchronization device 11 controls the circuit breaker 14 to close and connect to the grid. Or detect the voltage difference and the direction of the voltage difference, the voltage of the 9 turbine generators is Ug, the voltage of the ship grid is Us, and the set grid-connected voltage difference is ;when , and when other grid-connected conditions meet the requirements, the grid-connected synchronization device 11 controls the circuit breaker 14 to close and connect to the grid. In this process, the grid-connected synchronization device 11 can monitor and adjust the output parameters of the power generation unit in real time to synchronize it with the ship's main power grid, reducing the impact on the stability of the power grid during grid connection. Especially under complex sea conditions and variable load conditions, it is crucial to maintain the stable operation of the ship's power system.

[0068] S103: If not, the grid-connected synchronization device 11 calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit to promote the synchronous grid-connected of the desulfurization wastewater power generation system.

[0069] If it is determined that the circuit breaker 14 cannot be started to close based on the detection results and the preset grid-connected conditions in step S101, then the grid-connected synchronization device 11 calls the corresponding grid-connected control strategy based on the detection results and the preset grid-connected conditions, and performs feedback adjustment on the power generation unit, thereby promoting the synchronous grid connection of the desulfurization wastewater power generation system. Figure 2 As shown, the grid-connected unit includes a grid-connected synchronization device 11, a voltage transformer 12, a current transformer 13, a circuit breaker 14, a control unit 16, etc. The grid-connected unit is used to adjust the electric energy generated by the power generation unit and connect it to the main power grid. The electricity generated by the power generation unit is detected by the grid-connected synchronization device 11. When the grid-connected conditions meet the standards, the grid-connected synchronization device 11 controls the circuit breaker 14 to close, and the electric energy generated by the power generation unit is connected to the ship's main power grid. The voltage transformer 12 and the current transformer 13 detect the impact of the grid-connected process on the ship's main power grid; when the grid-connected conditions do not meet the standards, the grid-connected synchronization device 11 sends data to the control unit 16, and the control unit 16 automatically adjusts the power generation unit to meet the grid-connected requirements and then connect to the grid. The electric energy after the grid-connected is used to power the electrical equipment of the main power grid.

[0070] Specifically, in one or more embodiments of the present specification, the grid-connected synchronization device 11 calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit, which specifically includes the following process:

[0071] First, the grid-connected synchronization device 11 will determine the current deviation grid-connected parameters based on the detection results and the preset grid-connected conditions; for example: frequency difference, voltage difference, so as to control and adjust the frequency and voltage of the power generation unit so that the desulfurization wastewater power generation meets the grid-connected conditions and fully recycles the surplus energy. Then the frequency difference control unit 16 will be used to control and adjust the opening of the main proportional control valve 7 and the bypass proportional control valve 17 based on the frequency difference data and the preset frequency difference grid-connected control strategy when the frequency difference data is determined to be the current deviation grid-connected parameter. The voltage difference control unit 16 is used to adjust the excitation current of the power generation unit based on the voltage difference data and the preset voltage difference grid-connected control strategy when the voltage difference is determined to be the current deviation grid-connected parameter. This process is achieved by adjusting the flow and excitation current of the turbine 8 to adjust the power generation frequency and voltage, so that the system can promote rapid grid connection through simple proportional control valves and excitation current control.

[0072] Further, in one or more embodiments of the present specification, based on the basic information of the frequency difference and the preset frequency difference grid-connected control strategy, the opening of the main proportional control valve 7 and the bypass proportional control valve 17 is controlled and adjusted, specifically including:

[0073] The frequency difference control unit 16 is used to calculate the current required frequency change and the speed change of the turbine 8 corresponding to the frequency change if it is determined based on the basic information of the frequency difference that the frequency difference is less than the preset frequency difference threshold. Then the frequency difference control unit 16 determines the relationship between the speed and frequency of the generator 9 group of the power generation unit and the relationship between the desulfurization wastewater flow rate and the speed of the turbine 8, so as to obtain the main pipeline change of the desulfurization wastewater flow rate corresponding to the speed change of the turbine 8. Then the frequency difference control unit 16 determines the bypass pipeline change based on the total flow of the desulfurization wastewater and the main pipeline change, and controls the opening adjustment of the main proportional regulating valve 7 and the bypass proportional regulating valve 17 based on the main pipeline change and the bypass pipeline change, so that it meets the grid connection requirements and is connected to the grid, and the electric energy after the grid connection is used to power the main grid power equipment.

[0074] In a certain application scenario, such as Figure 4 The grid-connected control strategy based on the basic information of the frequency difference and the preset frequency difference is shown to control and adjust the opening of the main proportional control valve 7 and the bypass proportional control valve 17. Among them, the grid-connected control strategy based on the frequency difference control is mainly formulated according to the operation law of the frequency difference control unit 16 in the grid-connected synchronization device 11. The speed of the turbine 8 is adjusted by the control unit 16 to drive the speed of the generator 9 to change, thereby changing the frequency of the turbine generator set. The specific control principle is as follows:

[0075] The frequency difference control unit 16 of the grid-connected synchronization device 11 detects the magnitude and direction of the frequency difference between the power generation unit and the ship's main power grid. The frequency of the turbine generator set of the power generation unit is recorded as , the ship main power grid frequency is , the grid-connected frequency difference allowable value is set as , the frequency difference detection is shown in formula (1).

[0076] (1)

[0077] when When the frequency difference between the current hydro-generator set and the ship power grid is within the grid-connected allowable range, and when other grid-connected conditions meet the requirements, the closing signal control unit 16 of the grid-connected synchronization device 11 will control the closing of the circuit breaker and grid connection;

[0078] when When the frequency difference between the current turbine generator set and the ship power grid does not meet the frequency difference requirement for grid connection, the frequency difference control unit 16 will continue to perform frequency difference direction detection. When the frequency of the hydro-generator unit is Lower than the ship's main power grid frequency , the frequency difference control unit 16 sends a speed-up control signal through the control unit 16 to increase the frequency of the hydro-generator set; conversely, the frequency difference control unit 16 sends a speed-down control signal through the control unit 16 to reduce the frequency of the hydro-generator set. The frequency of the hydro-generator set after speed-up and after speed-down are respectively recorded as , ,but:

[0079] (2)

[0080] The frequency difference control unit 16 of the grid-connected synchronization device 11 sends a speed-up or speed-down control signal through the control unit 16. The control method for increasing or decreasing the frequency of the hydro-generator set specifically includes: the turbine 8 of the hydro-generator set rotates under the action of the water flow, and the speed of the turbine 8 is and the flow rate of desulfurized wastewater passing through turbine 8 The turbine 8 drives the generator 9 to rotate, and the power generation frequency of the power generation unit is affected by the speed of the generator 9. Therefore, in order to adjust the frequency difference between the turbine generator set and the ship power grid to meet the grid connection requirements, the flow rate of the desulfurized wastewater entering the turbine 8 must be changed by the control unit 16. To achieve, that is:

[0081] (3)

[0082] In the above formula (3), is the rotation speed of the generator 9; p is the number of pole pairs of the generator 9; is the frequency of the hydro-generator set; is the proportional coefficient between the flow rate of desulfurized wastewater and the speed of turbine 8; is the flow rate of desulfurized wastewater passing through the turbine 8; is the speed of turbine 8.

[0083] The expected flow rate of desulfurized wastewater passing through the turbine 8 can be obtained by formula (3): , and the control unit 16 changes the flow rate of desulfurized wastewater entering the turbine 8 This is achieved by adjusting the main proportional control valve 7 and the bypass proportional control valve 17. The wastewater flow distribution entering the main pipeline and the bypass pipeline 18 is shown in formula (4).

[0084] (4)

[0085] Among them, Q is the total flow of desulfurization wastewater; , It is the flow rate of desulfurization wastewater passing through the main pipeline before and after frequency modulation; , It is the wastewater flow through the bypass pipe before and after frequency modulation; The change in the flow rate of desulfurization wastewater in the main pipeline; is the proportional coefficient between the flow rate of desulfurized wastewater and the speed of turbine 8; is the change in turbine speed; is the frequency change; is the frequency of the hydro-generator set.

[0086] The opening adjustment of the main proportional regulating valve 7 and the bypass proportional regulating valve 17 is controlled in linkage. When the main proportional regulating valve 7 on the main pipe is fully opened, its opening is 1, and the bypass proportional regulating valve 17 on the bypass pipe 18 is fully closed, its opening is 0, and all the desulfurized wastewater passes through the main pipe; as the main proportional regulating valve 7 is gradually closed, the bypass proportional regulating valve 17 will gradually open until the main proportional regulating valve 7 on the main pipe is fully closed, its opening is 0, at which time the bypass proportional regulating valve 17 is fully opened, its opening is 1, and all the desulfurized wastewater passes through the bypass pipe 18. When the seawater flow rate is When , the opening of the proportional control valve on the main pipeline and the proportional control valve on the bypass pipeline 18 is:

[0087] (5)

[0088] In the formula, , They are the opening degrees of the main proportional control valve 7 on the main pipe and the bypass proportional control valve 17 on the bypass pipe 18 respectively.

[0089] The grid-connected control strategy based on frequency difference control adjusts the desulfurized wastewater flow distribution of the two pipelines by changing the opening of the main proportional regulating valve 7 and the bypass proportional regulating valve 17 on the main pipeline and the bypass pipeline 18, so as to change the speed of the generator 9. Based on the above analysis and the operation method of the frequency difference control unit 16 of the grid-connected synchronization device 11, when the frequency difference between the hydro-generator set and the ship's main power grid does not meet the frequency difference requirement required for grid connection, the frequency difference control unit 16 will send a speed-up pulse or a speed-down pulse through the control unit 16. When the frequency difference control unit 16 sends a speed-up pulse, the speed of the turbine 8 increases, the opening of the main proportional regulating valve 7 on the main pipeline increases, and the wastewater flow through the main pipeline below the wastewater outlet 10 increases; the opening of the bypass proportional regulating valve 17 on the bypass pipeline 18 decreases, and the wastewater flow through the bypass pipeline 18 decreases. When the frequency difference control unit 16 sends a deceleration pulse, the speed of the turbine 8 decreases, the opening of the bypass proportional control valve 17 on the bypass pipeline 18 increases, the wastewater flow through the bypass pipeline increases, the opening of the proportional control valve on the main pipeline decreases, and the wastewater flow through the main pipeline below the wastewater outlet 10 decreases.

[0090] Further, in one or more embodiments of the present specification, adjusting the excitation current of the power generation unit based on the voltage difference data and the preset voltage difference grid-connected control strategy specifically includes:

[0091] If the voltage difference control unit 16 determines that the voltage difference is less than the preset voltage threshold value based on the voltage difference, and the voltage of the generator set is less than the voltage of the main grid, then the induced electromotive force corresponding to the current required voltage boost can be determined, so as to adjust the magnetic current of the generating unit according to the relationship between the induced electromotive force and the excitation current to increase the voltage of the generating unit. In addition, if the voltage difference control unit 16 determines that the voltage difference is less than the preset voltage threshold value based on the voltage difference, and the voltage of the generator set is greater than the voltage of the main grid, then the induced electromotive force corresponding to the current required voltage reduction can be determined, so as to adjust the magnetic current of the generating unit according to the relationship between the induced electromotive force and the excitation current to reduce the voltage of the generating unit.

[0092] like Figure 5 As shown, in a certain application scenario, the grid-connected control strategy based on voltage difference control is mainly formulated according to the operation law of the voltage difference control unit 16 in the grid-connected synchronization device 11. By adjusting the excitation of the generator 9, the output voltage of the generator 9 is changed, thereby changing the output power of the hydro-generator set.

[0093] The voltage difference control unit 16 of the grid-connected synchronization device 11 detects the voltage difference and the direction of the voltage difference, and the voltage of the hydro-generator set is recorded as , the ship grid voltage is , the grid-connected voltage difference allowable value is set as , the voltage difference detection is shown in formula (6).

[0094] (6)

[0095] when When the voltage difference between the current turbine generator set and the ship power grid is within the grid-connected allowable range, and when other grid-connected conditions meet the requirements, the closing signal control unit 16 of the grid-connected synchronization device 11 will control the closing of the circuit breaker and grid connection; when When the voltage difference between the current hydro-generator set and the ship power grid does not meet the voltage difference requirement for grid connection, the voltage difference control unit 16 will continue to perform voltage difference direction detection. When the voltage of generator 9 is Lower than the ship's grid voltage , the voltage difference control unit 16 sends a boost pulse through the control unit 16 to increase the voltage of the generator 9; conversely, the voltage difference control unit 16 sends a buck pulse through the control unit 16 to reduce the voltage of the generator 9. The voltage of the generator 9 after boosting and after bucking is respectively recorded as Ug1 and Ug2, then:

[0096] (7)

[0097] For the power generation side, when the generator is connected to the grid, the voltage at the generator terminal 9 is and induced electromotive force Equal, induced electromotive force With magnetic flux , Coil turns ,frequency is proportional, that is:

[0098] (8)

[0099] In the above formula, is the magnetic flux; is the magnetic induction intensity; S is the area; For example, the vacuum permeability ; is the magnetic field strength; is the frequency; is the number of coil turns; is the effective magnetic circuit length; is the excitation current; is the voltage of the generator 9; is the induced electromotive force; is the proportionality coefficient between voltage and excitation current.

[0100] It can be seen from formula (8) that when connected to the grid, in order to adapt to the voltage on the main grid side, the generator side should timely adjust the excitation current of the hydropower generator set , so that the voltage difference is within the allowable value range.

[0101] In the excitation current When the electromagnetic torque of the generator 9 changes Change accordingly, namely:

[0102] (9)

[0103] In the above formula, is the proportionality coefficient, is the excitation current and induced electromotive force Since the grid-connected control strategy based on voltage difference control only adjusts the voltage amplitude and does not affect the phase, that is, before and after voltage regulation is a fixed value. Combined with formula (8), formula (9) can be simplified as follows:

[0104] (10)

[0105] in, is the intermediate coefficient.

[0106] When adjusting the voltage difference, fix the speed of turbine 8 unchanged, that is, the speed of generator 9 is a constant. At this time, when the electromagnetic torque of the generator 9 When the generator 9 generates Will change accordingly, namely:

[0107] (11)

[0108] The output power of the turbine generator set before and after voltage regulation can be calculated , Respectively, then:

[0109] (12)

[0110] in, is the intermediate coefficient; , It is the voltage of the generator 9 after voltage increase or decrease.

[0111] Among them, it should be noted that M1 is the electromagnetic torque constant, which is the motor's own parameter, related to the motor's own design, and determined by the motor structure. M2 and M3, as described in the formula in the text, are calculated from a series of parameter constants, which are essentially simplified integration of multiple constant parameters. In order to facilitate the clarification of the relationship between key variables, weaken the influence of irrelevant constant parameters, avoid too many parameters, and make the patent content easy to read, the results of the series constant calculation are simplified to M2 and M3. The difference between the intermediate coefficients M2 and M3 is: when analyzing and discussing the grid-connected control strategy based on voltage difference control, in order to clarify the relationship between voltage and electromagnetic torque, the constant parameters that are irrelevant to voltage are extracted and integrated, and the above calculation results are set to M2; in order to clarify the relationship between power and voltage, the constant parameters that are irrelevant to voltage are integrated and extracted, and the above calculation results are set to M3. Based on the above analysis and the operation method of the voltage difference control unit 16 of the grid-connected synchronization device 11, when the voltage difference between the hydro-generator set and the ship's main power grid does not meet the voltage difference requirements required for grid connection, the voltage difference control unit 16 will send a boost pulse or a buck pulse through the control unit 16. When a boost pulse is issued, the grid-connected synchronization device 11 increases the excitation current of the generator 9, thereby increasing the torque of the generator 9 and improving the output power. When a step-down pulse is issued, the grid-connected synchronization device 11 reduces the excitation current of the generator 9, and the power generation of the desulfurization wastewater power generation system will decrease accordingly.

[0112] Under different operating conditions, the exhaust emissions and harmful gas generation of the ship's power unit are significantly different. In order to save energy, the seawater pump 3 of the desulfurization unit of the present application is automatically adjusted by the control unit 16 according to the operating conditions of the ship's power unit. Therefore, the wastewater flow rate used for the power generation unit is not stable. This results in that under certain operating conditions or changes in operating conditions, the wastewater flow rate is insufficient to maintain the grid-connected power supply of the power generation unit, resulting in decreased stability of the power system, insufficient power supply load, etc.; when the operating conditions change frequently, frequent fluctuations in the power supply load will have an adverse effect on electrical equipment. In addition, short-term system failures such as the seawater pump 3 will also lead to short-term disconnection from the grid. Therefore, in order to overcome the occurrence of the above situation, such as Figure 6 As shown, in another embodiment of the present specification, based on the previous implementation, the bypass pipeline 18 is optimized and improved, and the technical problems such as insufficient wastewater flow supply from the short-term power generation unit leading to decreased stability of the power system and insufficient power supply load are solved through structures such as the buffer water tank 20.

[0113] The bypass proportional regulating valve 17 on the bypass pipeline 18 is set as a three-way valve 19, the inlet end of the three-way valve 19 is connected to the main pipeline under the wastewater outlet 10 of the desulfurization unit, the first outlet of the three-way valve 19 is connected to the buffer water tank 20, and the second outlet of the three-way valve 19 is connected to the bypass turbine 21. By adjusting the three-way valve 19, the wastewater of the desulfurization unit can flow into the buffer water tank 20 and / or the bypass turbine 21. The buffer water tank 20 is used to temporarily store excess wastewater. When the wastewater flow required by the turbine 8 of the power generation unit is insufficient, the wastewater stored in the buffer water tank 20 is supplemented into the main pipeline through the replenishment pipeline 25. The replenishment valve 24 adjusts the opening based on the control unit 16 to supply an appropriate amount of replenishment wastewater flow. The wastewater of the desulfurization unit flows into the buffer water tank 20 using its own potential energy. The bypass pipeline 18 is connected to the main pipeline near the wastewater outlet 10 of the desulfurization unit, so that the position of the buffer water tank 20 can be set relatively higher to store higher potential energy.

[0114] When there is enough desulfurized wastewater stored in the buffer water tank 20, the excess wastewater flows into the bypass turbine 21 through the second outlet of the three-way valve 19, driving the bypass turbine 21 to rotate. The output shaft of the bypass turbine 21 is connected to the rotor input shaft of the bypass generator 22, and the electric energy generated by the bypass generator 22 is stored in the battery 23 after being processed.

[0115] Preferably, the present application further includes a replenishment seawater pump 26, and the battery 23 provides energy for the replenishment seawater pump 26, and the replenishment seawater pump 26 replenishes seawater into the buffer water tank 20. When the control unit 16 continuously opens the replenishment valve 24, and the water level of the buffer water tank 20 drops to the set value, the replenishment seawater pump 26 starts to work to replenish water for the buffer water tank 20; when the desulfurization unit continues to have insufficient or unstable seawater supply, and the replenishment seawater pump 26 works for more than the set time, it means that the operating condition of the ship power unit is long-term unstable or there are other faults in the system. At this time, the main proportional regulating valve 7 is closed, the power generation unit stops working, and the grid-connected unit is disconnected from the grid. After the operating condition of the ship power unit is stable or the fault is eliminated, the power generation and grid connection work continues.

[0116] In this embodiment, other system structures and grid-connected control strategies are the same as those in the previous embodiment.

[0117] Preferably, when the control unit 16 determines that there is a short-term wastewater supply shortage in the power generation unit or the short-term seawater demand of the desulfurization unit changes frequently, the control unit 16 controls the speed of the seawater pump 3 to increase or maintain stability to maintain grid connection stability.

[0118] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device, equipment, and non-volatile computer storage medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment.

[0119] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0120] The above description is only one or more embodiments of this specification and is not intended to limit this specification. For those skilled in the art, one or more embodiments of this specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of one or more embodiments of this specification shall be included in the scope of the claims of this specification.

Claims

1. A grid-connected control method for a desulfurization wastewater power generation system, characterized in that: Applied to a desulfurization wastewater power generation system comprising a power generation unit and a grid-connected unit connected to the power generation unit; the grid-connected unit comprises a grid-connected synchronization device, a circuit breaker connected to the grid-connected synchronization device, and a control unit communicatively connected to the grid-connected synchronization device, the method comprising: The grid-connected unit detects the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determines whether to start the closing of the circuit breaker based on the detection result and the preset grid-connected condition; wherein the electric energy information is generated based on the recovery of the water head potential energy by the power generation unit; If yes, controlling the circuit breaker to start closing based on the control unit; If not, the grid-connected synchronization device calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit to promote the synchronous grid-connected of the desulfurization wastewater power generation system; The grid-connected unit detects the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determines whether to start the closing of the circuit breaker based on the detection result and the preset grid-connected condition, specifically including: Based on the built-in frequency difference control unit and voltage difference control unit of the grid-connected synchronization device, the power information of the power generation unit is detected to obtain the detection result; wherein the detection result includes: frequency difference data and voltage difference data; If the built-in closing control unit of the grid-connected synchronization device determines that the frequency difference data meets the preset grid-connected condition, and the voltage difference data meets the preset grid-connected condition, then it is determined to start closing the circuit breaker; If the built-in closing control unit of the grid-connected synchronization device determines that the frequency difference data does not meet the preset grid-connected condition, or the voltage difference data does not meet the preset grid-connected condition, it is determined not to start closing the circuit breaker; The grid-connected synchronization device calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit, specifically including: The grid-connected synchronization device determines the current deviation grid-connected parameter based on the detection result and the preset grid-connected condition; The frequency difference control unit is used to control and adjust the opening of the main proportional control valve and the bypass proportional control valve based on the frequency difference data and the preset frequency difference grid control strategy when the frequency difference data is determined to be the current deviation grid-connected parameter; The voltage difference control unit is used to adjust the excitation current of the power generation unit based on the voltage difference data and a preset voltage difference grid-connected control strategy when it is determined that the voltage difference is a current deviation grid-connected parameter.

2. The grid-connected control method of a desulfurization wastewater power generation system according to claim 1, characterized in that: The desulfurization wastewater power generation system further comprises: a desulfurization unit connected to the power generation unit; the desulfurization unit comprises: a seawater pump and a desulfurization tower; the desulfurization tower comprises: a water inlet, a wastewater outlet, a flue gas inlet, and a tail gas outlet; Wherein, the desulfurization unit is used for: Pumping seawater into the water inlet of the desulfurization tower based on the seawater pump; The seawater introduced into the water inlet is sprayed by a pre-installed spraying device, and the waste gas introduced into the flue gas inlet of the desulfurization tower is washed to obtain desulfurization waste water and washing waste gas; The scrubber waste gas is discharged to the flue based on the tail gas outlet, and the desulfurization waste water flows into the power generation unit based on the waste water outlet.

3. The grid-connected control method of a desulfurization wastewater power generation system according to claim 2, characterized in that: The grid-connected unit detects the electric energy information based on the grid-connected synchronization device, and before obtaining the detection result, the method further includes: The power generation unit divides the desulfurized wastewater into two paths based on the main pipeline and the bypass pipeline; wherein the main pipeline is provided with a main proportional regulating valve, a turbine and a generator, and the bypass pipeline is provided with a bypass proportional regulating valve; The power generation unit converts the head potential energy of the desulfurized wastewater into mechanical energy based on the turbine in the main pipeline; The power generation unit adjusts the water flow of the main pipeline and the bypass pipeline based on the main proportional control valve and the bypass proportional control valve to obtain the desired rotation speed of the turbine, and drives the generator to rotate based on the desired rotation speed to convert the mechanical energy into electrical energy.

4. The grid-connected control method for a desulfurization wastewater power generation system according to claim 1, characterized in that: Based on the basic information of the frequency difference and the preset frequency difference grid-connected control strategy, controlling and adjusting the opening of the main proportional control valve and the bypass proportional control valve specifically includes: The frequency difference control unit is used to calculate the currently required frequency change and the turbine speed change corresponding to the frequency change if it is determined based on the basic information of the frequency difference that the frequency difference is less than a preset frequency difference threshold; The frequency difference control unit determines the relationship between the generator set speed and the frequency of the power generation unit and the relationship between the desulfurization wastewater flow rate and the turbine speed, so as to obtain the main pipeline change of the desulfurization wastewater flow rate corresponding to the turbine speed change; The frequency difference control unit determines the bypass pipeline change amount according to the total flow of desulfurization wastewater and the main pipeline change amount, so as to control the opening adjustment of the main proportional control valve and the bypass proportional control valve based on the main pipeline change amount and the bypass pipeline change amount.

5. The grid-connected control method for a desulfurization wastewater power generation system according to claim 1, characterized in that: Based on the voltage difference data and the preset voltage difference grid-connected control strategy, adjusting the excitation current of the power generation unit specifically includes: If the voltage difference control unit determines based on the voltage difference that the voltage difference is less than a preset voltage threshold and the voltage of the generator set is less than the voltage of the main grid, then the induced electromotive force corresponding to the current required voltage boost is determined, so as to adjust the magnetic current of the power generation unit according to the relationship between the induced electromotive force and the excitation current, so as to increase the voltage of the generator set; If the voltage difference control unit determines, based on the voltage difference, that the voltage difference is less than a preset voltage threshold and that the voltage of the generator set is greater than the voltage of the main power grid, it determines the induced electromotive force corresponding to the currently required voltage reduction amount, and adjusts the magnetic current of the generating unit according to the relationship between the induced electromotive force and the excitation current to reduce the voltage of the generator set.

6. The grid-connected control method of a desulfurization wastewater power generation system according to claim 3, characterized in that: The grid-connected unit detects the electric energy information based on the grid-connected synchronization device, and before obtaining the detection result, the method further includes: The control unit obtains the operating status information of each hardware device in the desulfurization wastewater power generation system to determine whether there is a device failure based on the operating status information; If so, the control unit controls the circuit breaker to open, and controls the power generation unit to close the main proportional regulating valve and fully open the bypass proportional regulating valve.

7. The grid-connected control method for a desulfurization wastewater power generation system according to claim 1, characterized in that: The grid-connected unit further comprises: a voltage transformer and a current transformer; the voltage transformer and the current transformer are used to respectively detect the voltage change and the current change on both sides of the grid-connected point, so as to monitor the impact of the grid-connected process on the main grid.

8. A grid-connected control system for a desulfurization wastewater power generation system, the system comprising: A desulfurization wastewater power generation system consisting of a power generation unit and a grid-connected unit connected to the power generation unit; The grid-connected unit comprises a grid-connected synchronization device, a circuit breaker connected to the grid-connected synchronization device, and a control unit in communication connection with the grid-connected synchronization device; The grid-connected unit is used to detect the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determine whether to start the closing of the circuit breaker based on the detection result and the preset grid-connected condition; wherein the electric energy information is generated based on the recovery of the head potential energy by the power generation unit; If yes, controlling the circuit breaker to start closing based on the control unit; If not, the grid-connected synchronization device calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit to promote the synchronous grid-connected of the desulfurization wastewater power generation system; The grid-connected unit detects the electric energy information based on the grid-connected synchronization device to obtain a detection result, and determines whether to start the closing of the circuit breaker based on the detection result and the preset grid-connected condition, specifically including: Based on the built-in frequency difference control unit and voltage difference control unit of the grid-connected synchronization device, the power information of the power generation unit is detected to obtain the detection result; wherein the detection result includes: frequency difference data and voltage difference data; If the built-in closing control unit of the grid-connected synchronization device determines that the frequency difference data meets the preset grid-connected condition, and the voltage difference data meets the preset grid-connected condition, then it is determined to start closing the circuit breaker; If the built-in closing control unit of the grid-connected synchronization device determines that the frequency difference data does not meet the preset grid-connected condition, or the voltage difference data does not meet the preset grid-connected condition, it is determined not to start closing the circuit breaker; The grid-connected synchronization device calls the corresponding grid-connected control strategy based on the detection result and the preset grid-connected condition, and performs feedback adjustment on the power generation unit, specifically including: The grid-connected synchronization device determines the current deviation grid-connected parameter based on the detection result and the preset grid-connected condition; The frequency difference control unit is used to control and adjust the opening of the main proportional control valve and the bypass proportional control valve based on the frequency difference data and the preset frequency difference grid control strategy when the frequency difference data is determined to be the current deviation grid-connected parameter; The voltage difference control unit is used to adjust the excitation current of the power generation unit based on the voltage difference data and a preset voltage difference grid-connected control strategy when it is determined that the voltage difference is a current deviation grid-connected parameter.

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