A permanent magnet type hydroelectric power generation method and system with a double closed-loop control strategy

Abstract

The application relates to a permanent magnet type hydraulic power generation method and system adopting a double closed loop control strategy and relates to the technical field of hydraulic power generation.The method comprises the following steps: obtaining a current scheduling instruction and a current motor number; obtaining a current flow, a given flow and a flow steady state threshold value according to the current motor number; calculating a flow deviation value according to the current flow and the given flow; adjusting a valve according to the flow deviation value and a preset flow PID control mode; adjusting the valve according to the flow deviation value and a preset flow hysteresis control mode; if the current scheduling instruction is a preset power scheduling instruction, obtaining a current power, a given power and a power steady state threshold value; calculating a power deviation value according to the current power and the given power; adjusting the valve according to the power deviation value and a preset power PID control mode; and adjusting the valve according to the power deviation value and a preset power hysteresis control mode.The application has the effect of realizing the collaborative control of the flow and the power.

Description

Technical Field

[0001] This invention relates to the field of hydropower technology, and in particular to a permanent magnet hydropower generation method and system with a dual closed-loop control strategy. Background Technology

[0002] A permanent magnet hydro generator is a type of hydro generator that uses permanent magnets to provide a magnetic field and does not require an additional excitation power source. The permanent magnets on the rotor rotate with the shaft to form a rotating magnetic field, which cuts the stator windings to induce alternating current, thereby converting the mechanical energy of the water flow into electrical energy.

[0003] In related technologies, permanent magnet hydro-turbine generator sets generally adopt a power single closed-loop control architecture, realize the conversion of generated electrical energy and grid connection output through hydro-electric converter, complete the power output regulation of the unit by relying on the guide vane actuator of the hydro-turbine generator, and are equipped with basic overcurrent and overvoltage protection units to ensure normal operation.

[0004] Regarding the aforementioned technologies, existing permanent magnet hydropower generation devices generally suffer from problems such as a single control dimension and a rigid control strategy, making it impossible to achieve precise coordinated control of flow and power simultaneously, and failing to adapt to the stable power generation needs under complex hydrological and grid fluctuation conditions. Summary of the Invention

[0005] To achieve coordinated control of flow and power, this invention provides a permanent magnet hydropower generation method and system with a dual closed-loop control strategy.

[0006] In a first aspect, the present invention provides a permanent magnet hydropower generation method with a dual closed-loop control strategy, employing the following technical solution: A permanent magnet hydropower generation method with a dual closed-loop control strategy includes: Step 1: In response to the scheduling signal, obtain the current scheduling instruction and the current motor number; Step 2: If the current scheduling instruction is a preset flow scheduling instruction, obtain the current flow, the given flow, and the steady-state flow threshold based on the current motor number; Step 3: Calculate the flow deviation value based on the current flow rate and the given flow rate; Step 4: When the flow deviation is less than the steady-state flow threshold, adjust the valve according to the flow deviation and the preset flow PID control mode; Step 5: When the flow deviation is not less than the steady-state flow threshold, adjust the valve according to the flow deviation and the preset flow hysteresis control mode; Step 6: If the current scheduling instruction is a preset power scheduling instruction, obtain the current power, the given power, and the power steady-state threshold; Step 7: Calculate the power deviation value based on the current power and the given power; Step 8: When the power deviation is less than the power steady-state threshold, adjust the valve according to the power deviation and the preset power PID control mode; Step 9: When the power deviation value is not less than the power steady-state threshold, adjust the valve according to the power deviation value and the preset power hysteresis control mode.

[0007] By adopting the above technical solutions, the system can achieve closed-loop autonomous switching between flow and power modes, automatically select the control target according to the dispatching instructions, and adaptively adopt PID or hysteresis control based on the magnitude of the deviation, thus balancing steady-state control accuracy and dynamic response speed, and improving the operational stability of the unit under complex hydrological and power grid conditions.

[0008] Optionally, it also includes an optimization method in which the control valve adjusts according to a preset power hysteresis control mode when the power deviation value is not less than the power steady-state threshold. This method includes: Step 500: When the power deviation is not less than the power steady-state threshold, the control valve is adjusted according to the power hysteresis control mode and the real-time hysteresis power is obtained; Step 501: Calculate the hysteresis power deviation value based on the real-time hysteresis power and the given power; Step 502: When the hysteresis power deviation is less than the power steady-state threshold, the control valve is adjusted according to the power PID control mode and the real-time PID power is obtained; Step 503: Calculate the PID power deviation value based on the PID real-time power and the given power; Step 504: When the PID power deviation value is less than the preset power accuracy threshold, the control valve stops opening and closing.

[0009] By adopting the above technical solution, a smooth transition from rapid response to precise and stable power regulation is achieved. First, hysteresis control is used to quickly bring the power closer, then PID control is used to finely stabilize the amplitude, and finally the valve action is stopped when the accuracy threshold is reached, thereby improving the quality of power generation output.

[0010] Optional, also includes: Step 10: When both flow scheduling command and power scheduling command exist, execute steps 6 to 9 and obtain the regulated flow. Step 11: Calculate the deviation value of the adjusted flow rate based on the adjusted flow rate and the given flow rate; Step 12: When the adjusted flow deviation value is less than zero and the absolute value of the adjusted flow deviation value is not less than the preset flow accuracy threshold, execute steps 4 to 5 until the adjusted flow deviation value is less than the flow accuracy threshold. Step 13: Obtain the regulated power and rated energy dissipation power; Step 14: Calculate the excess power based on the adjusted power and the given power; Step 15: When the excess power is less than the rated power of energy dissipation, control the energy dissipation resistor to dissipate energy according to the preset energy dissipation mode.

[0011] By adopting the above technical solution, power demand is prioritized when dual dispatch commands coexist, while the flow rate is accurately corrected. Excess power exceeding the demand is safely discharged through energy dissipation resistors, reducing unit overload and voltage abnormality problems caused by low flow rate and high power or power excess.

[0012] Optional, also includes: Step 16: When the excess power is not less than the rated energy dissipation power, calculate the maximum working power based on the given power and the rated energy dissipation power; Step 17: Define the maximum operating power as the currently given power; Step 18: Execute steps 6 to 8 according to the current given power, and control the energy dissipation resistor to dissipate energy according to the energy dissipation mode.

[0013] By adopting the above technical solution, when the excess power exceeds the rated capacity of the energy dissipation resistor, the maximum output power of the unit is automatically limited, thereby reducing the risk of overload damage to the energy dissipation resistor and meeting the given power output requirements as much as possible while ensuring equipment safety.

[0014] Optional, also includes: Step 19: When the adjusted flow deviation value is not less than zero and the adjusted flow deviation value is not less than the flow accuracy threshold, calculate the surplus flow based on the adjusted flow and the given flow. Step 20: Obtain the overload flow threshold; Step 21: When the surplus flow is not less than the overload flow threshold, accumulate the overload time; Step 22: When the cumulative overload time is not less than the preset damage time, generate the current overload signal based on the current motor number and overload time, and output the current overload signal.

[0015] By adopting the above technical solution, surplus flow can be monitored and overload accumulated in real time. When the flow overload exceeds the safe time limit, an overload signal will be output in a timely manner to remind operation and maintenance personnel to intervene, thereby reducing problems such as cavitation, vibration and structural damage caused by long-term overflow of the hydro turbine generator.

[0016] Optional, also includes: Step 23: When the cumulative overload time is less than the damage time, search for the continuous overload time in the preset overload time database according to the current motor number; Step 24: When the continuous overload time is not less than the preset continuous overload threshold, generate a continuous overload signal based on the current motor number and the continuous overload time, and output the continuous overload signal.

[0017] By adopting the above technical solution, short-term but continuous overloads can be continuously monitored. Even if the cumulative overload time does not exceed the damage time, continuous single overloads can still trigger an early warning, realizing the prediction of overload risk throughout the entire cycle of the unit and strengthening equipment safety protection.

[0018] Optionally, an optimization method is also included when the cumulative overload time is not less than a preset failure time, the method comprising: Step 2200: Obtain the serial numbers of other motors; Step 2201: Search for other cumulative overload times in the overload time database based on other motor numbers; Step 2202: When the other cumulative overload time is less than the damage time, define the motor number corresponding to the other cumulative overload time as the overloadable motor number; Step 2203: Calculate the maximum operating flow rate based on the given flow rate and the overload flow rate threshold; Step 2204: Calculate the overload flow difference based on the maximum operating flow rate and the adjusted flow rate; Step 2205: Calculate the overload operating flow rate based on the overload flow rate difference and the adjusted flow rate; Step 2206: Control the turbine generator corresponding to the current motor number to adjust to the maximum working flow according to the flow PID control mode, and control the turbine generator corresponding to the overloadable motor number to adjust to the overload working flow according to the flow PID control mode.

[0019] By adopting the above technical solutions, when a single unit is about to be overloaded and damaged, other healthy units are automatically dispatched to share the overload flow, realizing multi-unit coordinated current limiting and load transfer, reducing the occurrence of single equipment overload shutdowns, and ensuring continuous power generation of the power station as a whole.

[0020] Optionally, a control method is also included when there are multiple overloadable motor numbers, the method comprising: Step 22020: When there are multiple overloadable motor numbers, obtain the number of overloadable motors based on the overloadable motor numbers; Step 22021: Calculate the average overload flow difference based on the overload flow difference and the number of motors that can be overloaded; Step 22022: Calculate the average overload operating flow rate based on the average overload flow rate difference and the adjusted flow rate; Step 22023: Control the turbine generator corresponding to the current motor number to adjust to the maximum working flow according to the flow PID control mode, and control the turbine generator corresponding to each overloadable motor number to adjust to the average overload working flow according to the flow PID control mode.

[0021] By adopting the above technical solutions, multiple overload-capable units share the overload flow evenly, avoiding individual units from bearing excessive loads, making the load distribution of all units in the station more balanced, extending the overall service life of the units, and improving the operating efficiency of the distributed power station.

[0022] Optionally, methods for obtaining current traffic include: Step 200: Obtain the current detection traffic; Step 201: If the current detected traffic falls within the preset normal detected traffic range, then define the current detected traffic as the current traffic. Step 202: If the current detected flow rate does not fall within the preset normal detected flow rate range, generate a flow abnormality signal based on the current detected flow rate and output the flow abnormality signal.

[0023] By adopting the above technical solution, the validity of the collected flow values ​​is verified, the interference of abnormal data on the control logic is eliminated, the adjustment errors caused by sensor failure or signal interference are reduced, and the accuracy and anti-interference capability of the entire control system are improved.

[0024] Secondly, the present invention provides a permanent magnet hydropower generation system with a dual closed-loop control strategy, employing the following technical solution: A permanent magnet hydroelectric power generation system with a dual closed-loop control strategy includes: The acquisition module is used to acquire the current scheduling instruction and the current motor number; The memory is used to store the program of the permanent magnet hydropower generation method with a dual closed-loop control strategy as described above. The processor loads and executes programs from memory.

[0025] By adopting the above technical solution, the dual closed-loop control method is programmed and modularized, and automated operation is achieved through memory and processor. It can be directly installed on existing hydropower converters and local controllers, with strong adaptability and easy engineering deployment.

[0026] In summary, the present invention has at least one of the following beneficial technical effects: It achieves independent closed-loop control of flow and power and automatic mode switching, which can adapt to complex operating conditions such as flood season, dry season, and power grid peak shaving, and significantly improves the operating condition adaptability and operational stability of permanent magnet hydro turbine generator units. Built-in excess power discharge, overload protection, multi-unit collaborative current limiting and other multi-layer safety mechanisms effectively avoid risks such as overcurrent, overvoltage, cavitation and equipment burnout, significantly improving the safety and service life of the unit. Attached Figure Description

[0027] Figure 1 This is a flowchart of a permanent magnet hydropower generation method with a dual closed-loop control strategy according to an embodiment of this application. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0029] This invention discloses a permanent magnet hydropower generation method with a dual closed-loop control strategy. (Refer to...) Figure 1 A permanent magnet hydropower generation method with a dual closed-loop control strategy includes: Step 1: In response to the scheduling signal, obtain the current scheduling instruction and the current motor number.

[0030] Dispatch signals are instruction signals issued by the power grid or hydropower station dispatch center to adjust the current operating status of generator units. Dispatch signals are obtained by transmitting data to the local control unit of the generator unit via wired or wireless communication.

[0031] The current dispatch instruction refers to the operational target requirements of the current generator set for this dispatch. It is divided into two types: flow dispatch instructions and power dispatch instructions. Flow dispatch instructions require the generator set to stabilize the flow rate through the generator at a specified value, while power dispatch instructions require the generator set to stabilize the output power at a specified value. The current dispatch instruction is obtained by parsing the dispatch signal.

[0032] The current generator number refers to the unique identifier of the current permanent magnet hydroelectric generator, used to distinguish different units when multiple generators are operating in parallel. The current generator number is obtained by: staff pre-assigning a number to each hydroelectric generator and storing it in the system; the system can then retrieve the current generator number by reading the corresponding generator number.

[0033] Step 2: If the current scheduling instruction is a preset flow scheduling instruction, obtain the current flow, the given flow, and the steady-state flow threshold based on the current motor number.

[0034] Flow dispatch instructions refer to a type of dispatch instruction pre-set by the system, used to stabilize the inlet flow of hydroelectric generators as a control objective. Flow dispatch instructions are issued by staff during flood season flow control, ecological flow assurance, and other situations.

[0035] The current flow rate refers to the real-time flow rate through the inlet of the hydro-generator corresponding to the current motor number. The method for obtaining the current flow rate is described in detail in steps 200 to 202.

[0036] The given flow rate refers to the target value to which the flow rate is to be stabilized in this flow scheduling command. The given flow rate is obtained by parsing the scheduling signal.

[0037] The steady-state flow threshold is a threshold used to determine whether the current flow rate is close to a given flow rate. This threshold is pre-set by operators based on the actual operating parameters and adjustment accuracy requirements of the generator set and stored in the system.

[0038] Step 3: Calculate the flow deviation value based on the current flow rate and the given flow rate.

[0039] Flow deviation value refers to the degree of deviation between the current flow and the given flow. The flow deviation value is calculated as follows: Flow deviation value = |(current flow - given flow) / given flow|. The larger the flow deviation value, the greater the degree of deviation between the current flow and the given flow.

[0040] Step 4: When the flow deviation value is less than the steady-state flow threshold, adjust the valve according to the flow deviation value and the preset flow PID control mode.

[0041] Flow PID control mode refers to a pre-set flow closed-loop control mode that prioritizes steady-state accuracy and is suitable for stable operating conditions with small flow deviations. The flow PID control mode is achieved by operators pre-writing the corresponding control algorithm based on the unit's control requirements and storing it in the control unit.

[0042] When the flow deviation is less than the steady-state threshold, it means that the deviation between the current flow and the given flow is not particularly large. The current flow can be stabilized to the target flow through more refined adjustment. At this time, the use of flow PID control can ensure the smoothness of the adjustment and stabilize the flow within the required accuracy range.

[0043] Step 5: When the flow deviation value is not less than the steady-state flow threshold, adjust the valve according to the flow deviation value and the preset flow hysteresis control mode.

[0044] Flow hysteresis control mode refers to a pre-set flow closed-loop control mode that prioritizes response speed and is suitable for rapid adjustment conditions with large flow deviations. In flow hysteresis control mode, the control algorithm is written by the operators based on the unit's control requirements and stored in the control unit.

[0045] When the flow deviation is not less than the steady-state threshold, it indicates that the current flow deviates significantly from the given flow and needs to be reduced quickly. In this case, flow hysteresis control can speed up the adjustment and quickly bring the flow closer to the given flow, thus avoiding long-term operation with large deviations that could affect power generation stability.

[0046] Step 6: If the current scheduling instruction is a preset power scheduling instruction, obtain the current power, the given power, and the power steady-state threshold.

[0047] Power dispatch instructions refer to a type of dispatch instruction that is pre-set by the system and aims to stabilize the output power of permanent magnet hydroelectric generators. They are generally issued when the power grid needs to regulate peak and frequency and meet the power supply requirements of the load.

[0048] Current power refers to the current output power of the permanent magnet hydroelectric generator corresponding to the current motor number. The current power is obtained by collecting the current voltage and current through the voltmeter and ammeter installed at the generator set output terminal, and multiplying the current voltage and current to obtain the current power.

[0049] The given power refers to the target value to which the power generation output power is required to be stabilized in this power dispatch instruction, which is obtained by parsing the dispatch signal issued by the dispatch center.

[0050] The power steady-state threshold is a threshold used to determine whether the current output power is close to a given power. It is preset by the staff based on the actual operating parameters of the generator set and the accuracy requirements of the power grid dispatch and stored in the system.

[0051] Step 7: Calculate the power deviation value based on the current power and the given power.

[0052] The power deviation value is the absolute value of the difference between the current power and the given power, used to determine the degree of deviation between the actual output power and the given power. The power deviation value is calculated as follows: Power Deviation Value = |(Current Power - Given Power) / Given Power|. The larger the power deviation value, the greater the deviation of the current output power from the given power.

[0053] Step 8: When the power deviation value is less than the power steady-state threshold, adjust the valve according to the power deviation value and the preset power PID control mode.

[0054] Power PID control mode refers to a pre-set power closed-loop control mode that prioritizes steady-state accuracy and is suitable for stable operating conditions with small power deviations. The power PID control mode is also derived by operators who write control algorithms based on the unit's control requirements and store them in the control unit.

[0055] When the power deviation is less than the power steady-state threshold, it means that the deviation between the current power generation and the given power is small. Only fine-tuning is needed to meet the dispatch requirements. At this time, power PID control can ensure a smooth adjustment process and stabilize the output power within the required accuracy range to meet the power supply quality requirements of the power grid.

[0056] Step 9: When the power deviation value is not less than the power steady-state threshold, adjust the valve according to the power deviation value and the preset power hysteresis control mode.

[0057] Power hysteresis control mode refers to a pre-set power closed-loop control mode that prioritizes response speed and is suitable for rapid adjustment conditions with large power deviations. Similarly, the control algorithm for power hysteresis control mode is pre-programmed according to the unit's control requirements and stored in the control unit.

[0058] When the power deviation is not less than the power steady-state threshold, it indicates that the current power generation is significantly different from the given power, and the deviation needs to be reduced quickly. At this time, power hysteresis control can speed up the adjustment and quickly bring the output power closer to the given power, avoiding long-term operation with large deviations that could affect power supply stability and better meet the response requirements of grid peak regulation and frequency regulation.

[0059] This includes an optimized method for adjusting the control valve according to a preset power hysteresis control mode when the power deviation is not less than the power steady-state threshold. This method includes: Step 500: When the power deviation value is not less than the power steady-state threshold, the control valve is adjusted according to the power hysteresis control mode and the real-time hysteresis power is obtained.

[0060] Hysteresis real-time power refers to the real-time output power of the permanent magnet hydroelectric generator corresponding to the current motor number during the real-time adjustment of the valve according to the power hysteresis control mode. The hysteresis real-time power is obtained by collecting the real-time voltage and current during the adjustment process using voltmeters and ammeters installed at the generator set's output terminals, and then multiplying the real-time voltage and current to obtain the hysteresis real-time power.

[0061] Step 501: Calculate the hysteresis power deviation value based on the real-time hysteresis power and the given power.

[0062] Hysteresis power deviation refers to the degree of deviation between the real-time hysteresis power and the given power. It is calculated as follows: Hysteresis power deviation = |(real-time hysteresis power - given power) / given power|.

[0063] Step 502: When the hysteresis power deviation is less than the power steady-state threshold, the control valve is adjusted according to the power PID control mode and the real-time PID power is obtained.

[0064] PID real-time power refers to the real-time output power of the permanent magnet hydroelectric generator corresponding to the current motor number during the real-time adjustment of the valve in the power PID control mode. The PID real-time power is obtained by real-time collecting the voltage and current during the adjustment process using voltmeters and ammeters installed at the generator set's output terminals, and then multiplying the collected voltage and current to obtain the PID real-time power.

[0065] When the hysteresis power deviation is less than the power steady-state threshold, it means that the power generation has been brought close to the given power after the rapid adjustment by hysteresis control. At this time, switching to the more precise power PID control mode can further reduce the power deviation and stabilize the output power within the accuracy requirement range, taking into account both the adjustment speed and the adjustment accuracy, and improving the overall effect of power control.

[0066] The difference between this step and steps 8 to 9 is that steps 8 to 9 use either the power PID control mode or the power hysteresis control mode for regulation, while here the power hysteresis control mode is used first to quickly reduce the deviation between the power generation of the hydro generator and the given power. When the deviation is less than the power steady-state threshold, the power PID control mode is switched to perform more precise control to reduce the deviation, thereby improving the speed of regulation while ensuring accuracy.

[0067] Step 503: Calculate the PID power deviation value based on the PID real-time power and the given power.

[0068] The PID power deviation value refers to the degree of deviation between the real-time power of the PID controller and the setpoint power during the regulation process using the power PID control mode. The PID power deviation value is calculated as follows: PID power deviation value = |(PID real-time power - setpoint power) / setpoint power|.

[0069] Step 504: When the PID power deviation value is less than the preset power accuracy threshold, the control valve stops opening and closing.

[0070] The power accuracy threshold is a threshold used to determine whether the output power meets the final dispatch accuracy requirements. The power accuracy threshold is preset and stored in the system by staff based on the power grid's requirements for power quality and the generator set's regulation capabilities.

[0071] When the PID power deviation value is less than the power accuracy threshold, it means that the current output power has met the accuracy requirements of the scheduling and no further adjustment is needed.

[0072] This also includes: Step 10: When both flow scheduling command and power scheduling command are present, execute steps 6 to 9 and obtain the regulated flow.

[0073] The adjusted flow rate refers to the actual flow rate through the inlet of the turbine generator corresponding to the current motor number after adjusting the valve according to steps 6 to 9. The adjusted flow rate is also obtained in real time by a flow sensor installed on the turbine generator's inlet pipe.

[0074] Step 11: Calculate the deviation value of the adjusted flow rate based on the adjusted flow rate and the given flow rate.

[0075] The adjusted flow deviation value refers to the degree of deviation between the adjusted flow rate and the given flow rate. The adjusted flow deviation value is calculated as follows: Adjusted flow deviation value = (Adjusted flow rate - Given flow rate) / Given flow rate. The calculation of the adjusted flow deviation value does not use an absolute value because it is necessary to determine whether the adjusted flow rate is greater than the given flow rate based on the result. If the result is positive, it means that the adjusted flow rate is greater than the given flow rate, and the larger the result, the greater the excess. If the result is negative, it means that the adjusted flow rate is less than the given flow rate.

[0076] Step 12: When the adjusted flow deviation value is less than zero and the absolute value of the adjusted flow deviation value is not less than the preset flow accuracy threshold, execute steps 4 to 5 until the adjusted flow deviation value is less than the flow accuracy threshold.

[0077] The flow accuracy threshold is a threshold used to determine whether the regulated flow rate meets the accuracy requirements of flow dispatching. This threshold is also preset and stored in the system by staff based on the actual regulation accuracy requirements of the generator units and the dispatching needs of the hydropower station.

[0078] When the adjusted flow deviation value is less than zero and not less than the preset flow accuracy threshold, it indicates that the water flow at the inlet of the hydro-generator is much lower than the normal operating flow under the condition of meeting the power supply requirements. If the hydro-generator operates for a long time under such circumstances, the working efficiency of the hydro-generator may be greatly reduced and the vibration of the unit may be aggravated. At this time, steps 4 to 5 are executed until the adjusted flow deviation value is less than the flow accuracy threshold, thereby reducing the occurrence of the above consequences.

[0079] Step 13: Obtain the adjusted power and rated energy dissipation power.

[0080] Adjusted power refers to the actual power output of the hydro-generator corresponding to the current motor number after flow regulation is completed. Adjusted power is also calculated by collecting voltage and current data from voltmeters and ammeters at the generator set's output terminals.

[0081] Rated energy dissipation power refers to the maximum power that the energy dissipation device configured on a permanent magnet hydroelectric generator can withstand. This rated power is determined and recorded by staff through numerous tests. The energy dissipation device includes an energy dissipation resistor, which protects the current circuit. Excess energy stored in the turbine generator rotor is transferred to the energy dissipation resistor, thereby dissipating excess hydroelectric conversion energy. The system also includes an energy dissipation liquid resistance cabinet, which can disconnect the generator set from the grid in case of an accident. After disconnection, the turbine generator continues to output power due to reservoir water release, which can also be dissipated through the energy dissipation resistor.

[0082] Step 14: Calculate the excess power based on the adjusted power and the given power.

[0083] Excess power refers to the portion of the power generated after adjustment that exceeds the given power. It represents the portion of the generated power exceeding the demand when the minimum water flow rate is met under normal operating conditions of the hydroelectric generator. Excess power is calculated as follows: Excess Power = Adjusted Power - Given Power.

[0084] Step 15: When the excess power is less than the rated power of energy dissipation, control the energy dissipation resistor to dissipate energy according to the preset energy dissipation mode.

[0085] A power dissipation resistor is an energy-consuming component installed in a hydro generator to dissipate excess power generated, converting excess electrical energy into heat energy.

[0086] The energy dissipation mode refers to a control mode in which the system consumes excess generated power by connecting the circuit of the energy dissipation resistor in parallel with the circuit of the hydro-generator during normal power generation. The control logic for the energy dissipation mode is programmed based on the parameters of the energy dissipation device and stored in the control unit. Controlling the energy dissipation resistor to dissipate energy according to the energy dissipation mode involves connecting the circuit of the energy dissipation resistor in parallel with the circuit of the hydro-generator during normal power generation, thereby enabling the energy dissipation resistor to consume excess generated power.

[0087] When the excess power is less than the rated power for energy dissipation, it means that the excess power generated under the normal operating conditions of the hydro-generator can be absorbed by the energy dissipation resistor. Therefore, the energy dissipation resistor is controlled to dissipate energy according to the preset energy dissipation mode. This not only meets the power dispatching requirements, but also ensures that the hydro-generator reduces the probability of potential malfunctions due to low water flow.

[0088] This also includes: Step 16: When the excess power is not less than the rated power of energy dissipation, calculate the maximum working power based on the given power and the rated power of energy dissipation.

[0089] Maximum operating power refers to the sum of the given power and the rated power that the energy dissipation resistor can withstand. It represents the upper limit of the maximum power that the hydro-generator can stably output under the current energy dissipation conditions. The maximum operating power is calculated as follows: Maximum operating power = Given power + Rated energy dissipation power.

[0090] Step 17: Define the maximum operating power as the current given power.

[0091] The current given power refers to the maximum operating power defined as the target power that the hydro-generator needs to generate, which is similar in meaning to the given power.

[0092] Step 18: Execute steps 6 to 8 according to the current given power, and control the energy dissipation resistor to dissipate energy according to the energy dissipation mode.

[0093] Based on the current given power, execute steps 6 to 8. If the power requirement is met but the water flow cannot reach the minimum water flow when the turbine generator is operating normally, increase the water flow to the maximum extent to reduce the potential risks of unit vibration and inefficient operation.

[0094] This also includes: Step 19: When the adjusted flow deviation value is not less than zero and the adjusted flow deviation value is not less than the flow accuracy threshold, calculate the surplus flow based on the adjusted flow and the given flow.

[0095] When the adjusted flow deviation value is not less than zero and the adjusted flow deviation value is not less than the flow accuracy threshold, it means that after power regulation, the actual flow rate through the turbine generator inlet is higher than the target flow rate required by the flow scheduling. Long-term high flow rate through the turbine generator will not only exceed the design capacity of the turbine generator, but also cause problems such as accelerated blade wear and unit overload.

[0096] Surplus flow refers to the portion of the flow rate after adjustment that exceeds the given flow rate. It represents the excess water volume that exceeds the dispatch requirement after meeting the power generation demand. The surplus flow rate is calculated as follows: Surplus flow rate = Adjusted flow rate - Given flow rate.

[0097] Step 20: Obtain the overload flow threshold.

[0098] The overload flow threshold refers to the maximum allowable flow rate through the turbine generator as designed. This threshold is provided by the equipment manufacturer and verified through on-site testing before being stored in the system. It is used to determine whether the current flow rate exceeds the safe operating range of the turbine generator.

[0099] Step 21: When the surplus flow is not less than the overload flow threshold, accumulate the overload time.

[0100] Overload time refers to the cumulative duration during which the current flow rate exceeds the safe overload threshold. The overload time is automatically calculated by the system control unit starting from the moment the overload condition is met. The length of the cumulative overload time directly reflects the risk level of the hydro-generator operating beyond the safe flow range for an extended period; the longer the cumulative time, the higher the probability of equipment damage or failure.

[0101] Step 22: When the cumulative overload time is not less than the preset damage time, generate the current overload signal based on the current motor number and overload time, and output the current overload signal.

[0102] Damage time refers to the maximum allowable cumulative overload operation duration. When the cumulative overload time exceeds this duration, the probability of structural damage to the hydro-generator increases significantly. The damage time is determined by personnel after conducting multiple tests based on the hydro-generator's material strength and design tolerance.

[0103] The current overload signal is an alarm signal used to notify staff that the turbine generator corresponding to the current motor number has been operating in an overload state for an extended period. The current overload signal is generated based on the current motor number and the cumulative overload duration, and is output to staff through the system's human-machine interface via text prompts and audible / visual alarms.

[0104] This also includes: Step 23: When the cumulative overload time is less than the damage time, search for the continuous overload time in the preset overload time database according to the current motor number.

[0105] The overload time database is a database that stores historical overload operating time records for each hydro-generator. The overload time database is automatically recorded by the system based on historical operating data of the hydro-generators, storing information such as the cumulative duration and time of each overload operation.

[0106] The continuous overload time refers to the duration of continuous overload operation of the hydro-generator corresponding to the current generator number during its current operation. The continuous overload time is obtained by querying the overload time database for the current generator number.

[0107] Step 24: When the continuous overload time is not less than the preset continuous overload threshold, generate a continuous overload signal based on the current motor number and the continuous overload time, and output the continuous overload signal.

[0108] The continuous overload threshold refers to the maximum duration during which a hydro-generator is allowed to operate under continuous overload for a single period. The continuous overload threshold is set by personnel based on the hydro-generator's design tolerance standards and on-site operating experience.

[0109] A continuous overload signal is an alarm signal used to notify staff that the turbine generator corresponding to the current motor number has been operating under continuous overload for the warning duration, requiring timely intervention and adjustment. The continuous overload signal is also output through the system's human-machine interface via text prompts and audible / visual alarms.

[0110] When the continuous overload time is not less than the continuous overload threshold, it indicates that the hydro generator has been running at overflow for a period of time. At this time, a continuous overload alarm signal is generated and output to remind the staff to adjust the operating conditions in time and reduce the occurrence of irreversible damage to the equipment caused by long-term overload.

[0111] This includes an optimization method when the cumulative overload time is not less than a preset damage time, the method comprising: Step 2200: Obtain the other motor numbers.

[0112] Other generator numbers refer to the numbers of the permanent magnet hydroelectric generators in normal operation within the hydroelectric power station, excluding those currently operating under overload conditions. These other generator numbers are obtained by removing the numbers of the target generators currently under overload from the list of generator unit numbers stored in the hydroelectric power station's central control system, thus obtaining the set of numbers for the remaining operating units.

[0113] Step 2201: Search for other cumulative overload times in the overload time database based on other motor numbers.

[0114] Other cumulative overload time refers to the total historical cumulative overload operation time of all permanent magnet hydroelectric generators currently in operation within the hydropower station, excluding the currently overloaded turbine generator. The method for finding other cumulative overload time is as follows: match each generator number against historical records in the overload time database, extract the cumulative overload operation time data for the corresponding generator set, and complete the query and statistics for other cumulative overload time.

[0115] Step 2202: When the other cumulative overload time is less than the damage time, define the motor number corresponding to the other cumulative overload time as the overloadable motor number.

[0116] The overloadable motor number refers to the number of a hydro-generator whose total historical cumulative overload time is still less than the maximum allowable damage time and has a certain overload operating redundancy.

[0117] Step 2203: Calculate the maximum operating flow rate based on the given flow rate and the overload flow rate threshold.

[0118] Maximum operating flow rate refers to the maximum allowable flow rate through the overloaded hydro-generator. It represents the upper limit of the maximum flow rate that the overloaded hydro-generator can withstand without damaging the equipment. The maximum operating flow rate is calculated as follows: Maximum operating flow rate = Overload flow rate threshold + Given flow rate.

[0119] Step 2204: Calculate the overload flow difference based on the maximum working flow and the adjusted flow.

[0120] Overload flow difference refers to the portion of the adjusted flow rate that exceeds the maximum operating flow rate. The overload flow difference is calculated as follows: Overload flow difference = Adjusted flow rate - Maximum operating flow rate.

[0121] Step 2205: Calculate the overload working flow rate based on the overload flow rate difference and the adjusted flow rate.

[0122] Overload operating flow rate refers to the flow rate through the turbine generator corresponding to the overloadable motor number when it shares some of the generating power with the current motor number. The overload operating flow rate is calculated as follows: Overload operating flow rate = Overload flow rate difference + Adjusted flow rate.

[0123] Step 2206: Control the turbine generator corresponding to the current motor number to adjust to the maximum working flow according to the flow PID control mode, and control the turbine generator corresponding to the overloadable motor number to adjust to the overload working flow according to the flow PID control mode.

[0124] The turbine generator corresponding to the current motor number is controlled to adjust to the maximum working flow rate according to the flow PID control mode, reducing the flow rate of the currently overloaded turbine generator to the maximum safe allowable value range, reducing its cumulative overload duration, and avoiding structural damage to the equipment. At the same time, the excess flow rate exceeding the safe bearing range of the turbine generator corresponding to the current motor number is allocated to the turbine generator corresponding to the overloadable motor number that still has overload redundancy space.

[0125] This also includes a control method when there are multiple overloadable motor numbers, the method comprising: Step 22020: When there are multiple overloadable motor numbers, obtain the number of overloadable motors based on the overloadable motor numbers.

[0126] The number of overloadable motors refers to the total number of generator units in the current hydropower station that meet the overload redundancy conditions. It is obtained by counting and statistically analyzing the selected overloadable motor numbers.

[0127] Step 22021: Calculate the average overload flow difference based on the overload flow difference and the number of motors that can be overloaded.

[0128] The average overload flow difference refers to the additional overload flow that a single overloadable generator set needs to bear after the overload flow difference that needs to be shared is evenly distributed to each overloadable generator set. The average overload flow difference is calculated as follows: Average overload flow difference = Overload flow difference / Number of overloadable generators.

[0129] Step 22022: Calculate the average overload operating flow rate based on the average overload flow rate difference and the adjusted flow rate.

[0130] Average overload operating flow rate refers to the flow rate that each hydro-generator corresponding to its overloadable motor number needs to maintain after fulfilling its original power generation task and being allocated additional overload flow rate. The average overload operating flow rate is calculated as follows: Average overload operating flow rate = Regulated flow rate + Average overload flow rate difference.

[0131] Step 22023: Control the turbine generator corresponding to the current motor number to adjust to the maximum working flow according to the flow PID control mode, and control the turbine generator corresponding to each overloadable motor number to adjust to the average overload working flow according to the flow PID control mode.

[0132] By distributing the excess flow from the overloaded turbine generators, the excess flow can be distributed and kept within a safe operating range. This also helps to evenly distribute the excess flow, preventing any single overloadable generator unit from bearing too much extra flow. This further reduces the risk of overload damage during multi-unit coordinated operation, ensuring that the entire power station's hydropower generation process meets power dispatch requirements while improving the overall safety of equipment operation.

[0133] The methods for obtaining current traffic include: Step 200: Obtain the current detection traffic.

[0134] The current detected flow rate refers to the flow rate through the turbine generator corresponding to the current motor number during its current operation. The current detected flow rate is obtained directly from a flow meter installed on the turbine generator's inlet pressure pipeline.

[0135] Step 201: If the current detected traffic falls within the preset normal detected traffic range, then the current detected traffic is defined as the current traffic.

[0136] The normal detection flow range refers to the flow detection interval set after the flow meter is calibrated at the factory, which ensures that the accuracy of the flow detection value meets the requirements. Only when the current detected flow is within this range can it be directly used as the current flow rate. The normal detection flow range is obtained by the flow meter manufacturer based on the sensor's detection accuracy parameters and is stored in the system's parameter configuration unit.

[0137] Step 202: If the current detected flow rate does not fall within the preset normal detected flow rate range, generate a flow abnormality signal based on the current detected flow rate and output the flow abnormality signal.

[0138] If the current detected flow rate does not fall within the preset normal detected flow rate range, it means that the current flow meter's detection result has exceeded the accuracy guarantee range, and the reliability of the detection data is insufficient. Continuing to use this value for subsequent flow rate adjustment may lead to excessive control deviation.

[0139] The abnormal flow signal is an alarm signal that indicates to the staff that the current flow meter at the inlet of the corresponding turbine generator is abnormal and that the flow meter needs to be calibrated or repaired in time. It is also output to the staff through the system's human-machine interface in the form of text prompts and audible and visual alarms.

[0140] Based on the same inventive concept, embodiments of the present invention provide a permanent magnet hydropower generation system with a dual closed-loop control strategy.

[0141] A permanent magnet hydroelectric power generation system with a dual closed-loop control strategy includes: The acquisition module is used to acquire the current scheduling instruction and the current motor number; A memory for storing a program for a permanent magnet hydropower generation method with a dual closed-loop control strategy; The processor loads and executes programs from memory.

[0142] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional modules is used as an example. In practical applications, the above functions can be assigned to different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0143] The above description is merely a preferred embodiment of the present invention. The scope of protection of the present invention is not limited to the above embodiments. All technical solutions falling within the scope of the present invention's concept are within the scope of protection of the present invention. It should be noted that for those skilled in the art, any improvements and modifications made without departing from the principles of the present invention should also be considered within the scope of protection of the present invention.

Claims

1. A permanent magnet hydropower generation method with a dual closed-loop control strategy, characterized in that, include: Step 1: In response to the scheduling signal, obtain the current scheduling instruction and the current motor number; Step 2: If the current scheduling instruction is a preset flow scheduling instruction, obtain the current flow, the given flow, and the steady-state flow threshold based on the current motor number; Step 3: Calculate the flow deviation value based on the current flow rate and the given flow rate; Step 4: When the flow deviation is less than the steady-state flow threshold, adjust the valve according to the flow deviation and the preset flow PID control mode; Step 5: When the flow deviation is not less than the steady-state flow threshold, adjust the valve according to the flow deviation and the preset flow hysteresis control mode; Step 6: If the current scheduling instruction is a preset power scheduling instruction, obtain the current power, the given power, and the power steady-state threshold; Step 7: Calculate the power deviation value based on the current power and the given power; Step 8: When the power deviation is less than the power steady-state threshold, adjust the valve according to the power deviation and the preset power PID control mode; Step 9: When the power deviation value is not less than the power steady-state threshold, adjust the valve according to the power deviation value and the preset power hysteresis control mode.

2. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 1, characterized in that, It also includes an optimized method for adjusting the control valve according to a preset power hysteresis control mode when the power deviation value is not less than the power steady-state threshold. This method includes: Step 500: When the power deviation is not less than the power steady-state threshold, the control valve is adjusted according to the power hysteresis control mode and the real-time hysteresis power is obtained; Step 501: Calculate the hysteresis power deviation value based on the real-time hysteresis power and the given power; Step 502: When the hysteresis power deviation is less than the power steady-state threshold, the control valve is adjusted according to the power PID control mode and the real-time PID power is obtained; Step 503: Calculate the PID power deviation value based on the PID real-time power and the given power; Step 504: When the PID power deviation value is less than the preset power accuracy threshold, the control valve stops opening and closing.

3. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 1, characterized in that, Also includes: Step 10: When both flow scheduling command and power scheduling command exist, execute steps 6 to 9 and obtain the regulated flow. Step 11: Calculate the deviation value of the adjusted flow rate based on the adjusted flow rate and the given flow rate; Step 12: When the adjusted flow deviation value is less than zero and the absolute value of the adjusted flow deviation value is not less than the preset flow accuracy threshold, execute steps 4 to 5 until the adjusted flow deviation value is less than the flow accuracy threshold. Step 13: Obtain the regulated power and rated energy dissipation power; Step 14: Calculate the excess power based on the adjusted power and the given power; Step 15: When the excess power is less than the rated power of energy dissipation, control the energy dissipation resistor to dissipate energy according to the preset energy dissipation mode.

4. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 3, characterized in that, Also includes: Step 16: When the excess power is not less than the rated energy dissipation power, calculate the maximum working power based on the given power and the rated energy dissipation power; Step 17: Define the maximum operating power as the currently given power; Step 18: Execute steps 6 to 8 according to the current given power, and control the energy dissipation resistor to dissipate energy according to the energy dissipation mode.

5. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 4, characterized in that, Also includes: Step 19: When the adjusted flow deviation value is not less than zero and the adjusted flow deviation value is not less than the flow accuracy threshold, calculate the surplus flow based on the adjusted flow and the given flow. Step 20: Obtain the overload flow threshold; Step 21: When the surplus flow is not less than the overload flow threshold, accumulate the overload time; Step 22: When the cumulative overload time is not less than the preset damage time, generate the current overload signal based on the current motor number and overload time, and output the current overload signal.

6. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 5, characterized in that, Also includes: Step 23: When the cumulative overload time is less than the damage time, search for the continuous overload time in the preset overload time database according to the current motor number; Step 24: When the continuous overload time is not less than the preset continuous overload threshold, generate a continuous overload signal based on the current motor number and the continuous overload time, and output the continuous overload signal.

7. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 6, characterized in that, It also includes an optimization method when the cumulative overload time is not less than a preset failure time, the method comprising: Step 2200: Obtain the serial numbers of other motors; Step 2201: Search for other cumulative overload times in the overload time database based on other motor numbers; Step 2202: When the other cumulative overload time is less than the damage time, define the motor number corresponding to the other cumulative overload time as the overloadable motor number; Step 2203: Calculate the maximum operating flow rate based on the given flow rate and the overload flow rate threshold; Step 2204: Calculate the overload flow difference based on the maximum operating flow rate and the adjusted flow rate; Step 2205: Calculate the overload operating flow rate based on the overload flow rate difference and the adjusted flow rate; Step 2206: Control the turbine generator corresponding to the current motor number to adjust to the maximum working flow according to the flow PID control mode, and control the turbine generator corresponding to the overloadable motor number to adjust to the overload working flow according to the flow PID control mode.

8. The permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 7, characterized in that, It also includes a control method when there are multiple overloadable motor numbers, the method comprising: Step 22020: When there are multiple overloadable motor numbers, obtain the number of overloadable motors based on the overloadable motor numbers; Step 22021: Calculate the average overload flow difference based on the overload flow difference and the number of motors that can be overloaded; Step 22022: Calculate the average overload operating flow rate based on the average overload flow rate difference and the adjusted flow rate; Step 22023: Control the turbine generator corresponding to the current motor number to adjust to the maximum working flow according to the flow PID control mode, and control the turbine generator corresponding to each overloadable motor number to adjust to the average overload working flow according to the flow PID control mode.

9. A permanent magnet hydropower generation method with a dual closed-loop control strategy according to claim 1, characterized in that, Methods for obtaining current traffic include: Step 200: Obtain the current detection traffic; Step 201: If the current detected traffic falls within the preset normal detected traffic range, then define the current detected traffic as the current traffic. Step 202: If the current detected flow rate does not fall within the preset normal detected flow rate range, generate a flow abnormality signal based on the current detected flow rate and output the flow abnormality signal.

10. A permanent magnet hydropower generation system with a dual closed-loop control strategy, characterized in that, include: The acquisition module is used to acquire the current scheduling instruction and the current motor number; A memory for storing a program of a permanent magnet hydropower generation method with a dual closed-loop control strategy as described in any one of claims 1 to 9; The processor loads and executes programs from memory.

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