A device and method for coordinately controlling the power closed-loop of a hydropower unit monitoring system and the primary frequency modulation device of a speed regulation system

Abstract

The present application provides a coordinated control device and method for a power closed-loop of a hydro-generator unit monitoring system and a primary frequency modulation device of a speed regulation system. The device includes: a signal acquisition module, configured to acquire various data of a generating set to obtain a control input signal; a coordinated control module, configured to calculate a control signal output value through a coordinated control function according to the control input signal; a control mode selection module, configured to automatically match three control modes of large / small / islanded network of the hydro-generator unit speed regulation system according to the speed governor operation mode acquired from the input signal; and a control signal output module, configured to output the control signal output value calculated by the coordinated control module to the active power signal superposition point of the monitoring system. The advantages of the present application are as follows: while the hydro-generator unit correctly responds to the AGC instruction, its PFR output capacity is not restricted, ensuring that the hydro-generator unit stably and sufficiently contributes primary frequency modulation and secondary frequency modulation power.

Description

Technical Field

[0001] The present application belongs to the technical field of hydropower unit control in an electric power system, and specifically relates to a device and method for coordinating and controlling a power closed loop of a monitoring system for a hydropower unit and a primary frequency regulation system of a speed regulation system. Background Art

[0002] With the ultra-large-scale AC and DC transmission and the access of a large number of new energy power electronic devices to the system, my country's power grid structure and power supply structure are undergoing major changes. The system inertia level is low, the ability to tolerate unbalanced power is limited, the number of grid frequency violations has increased, and the primary frequency control (PFR) and automatic generation control (AGC) of the units are more frequent during grid operation. AGC and PFR are the main means of system frequency regulation, and the coordinated action of the two is crucial to frequency stability.

[0003] The lack of coordination between PFR and AGC of a large number of hydropower units in my country's power grid is an important factor limiting the primary frequency regulation capability of the units. Therefore, the coordination between the two needs to be solved urgently to release the frequency regulation capability of the units and ensure sufficient PFR reserve in the power grid. The active power / frequency regulation of the hydropower units is jointly achieved by the active power control of the local control unit (LCU) and the speed governing system (GOV) after the monitoring system receives the AGC command. Regarding the coordination problem between AGC and PFR, the research directions of the existing technologies include:

[0004] 1. By taking measures such as unit power limitation, short-term AGC lockout, and optimization of primary frequency regulation and monitoring system coordination strategy;

[0005] 2. Improved method of using two sets of PID parameters in power regulation mode;

[0006] 3. Use the AGC delay control method to improve the coordination principle between AGC and PFR.

[0007] In actual operation, the improvement measures taken by hydropower units mainly include:

[0008] 1. After PFR is activated, the monitoring system will automatically lock and adjust the output;

[0009] 2. PFR blocks the reverse AGC command, and maintains the status quo when the AGC command is in the same direction (primary frequency modulation is weakened);

[0010] 3. AGC locks the primary frequency modulation.

[0011] These improvement measures all have obvious defects and can only ensure the adjustment effect of the priority function. When there are large frequency fluctuations in the power grid and PFR and AGC act simultaneously, whether they are mutually blocked or not, it will lead to a decline in the frequency regulation ability of the unit, and the system frequency stability cannot be fully guaranteed. Summary of the Invention

[0012] The purpose of this application is to overcome the defect that in the prior art, when there are large frequency fluctuations in the power grid and PFR and AGC act simultaneously, whether they are mutually blocked or not, it will lead to a decline in the frequency regulation ability of the unit, and the system frequency stability cannot be fully guaranteed.

[0013] To achieve the above purpose, this application proposes a coordinated control device for the power closed-loop of a hydro-generator unit monitoring system and the primary frequency regulation device of the speed control system. The device includes: a signal acquisition module, a coordinated control module, a control mode selection module, and a control signal output module; where

[0014] The signal acquisition module is used to collect various data of the generator set to obtain a control input signal;

[0015] The coordinated control module is used to calculate a control signal output value through a coordinated control function according to the control input signal;

[0016] The control mode selection module is used to automatically match the large / small / islanded grid three control modes of the hydro-generator unit speed control system according to the governor operation mode collected from the input signal;

[0017] The control signal output module is used to output the control signal output value calculated by the coordinated control module to the active power signal superposition point of the monitoring system.

[0018] As an improvement of the above device, the data collected by the signal acquisition module includes: three-phase voltage and current at the generator terminal, unit frequency signal, AGC power command signal, guide vane opening command signal, governor control mode signal, and water head signal;

[0019] The signal acquisition module also collects frequency measurement signals from a voltage transformer and three different frequency signals of AO signals input from two external systems with different sources, and filters the collected frequencies respectively, and finally adopts the "middle value of three" method to obtain a control input signal.

[0020] As an improvement of the above device, the coordinated control module includes:

[0021] A filtering unit, which is used to perform hardware filtering and software low-pass filtering on the collected frequency and power signals to obtain calculation signals that can be used for frequency and power control;

[0022] Frequency dead zone and amplitude limiting unit, which is used to perform dead zone removal and amplitude limiting processing on the frequency deviation signal obtained by calculating the collected control input signal and the rated frequency of the unit to obtain an effective frequency deviation calculation signal;

[0023] Active power adjustment amount calculation unit, which is used to calculate the expected coordinated control active power adjustment amount according to the effective frequency deviation calculation signal;

[0024] Operating condition correction calculation unit, which is used to correct the adjustment speed of the expected coordinated control active power adjustment amount according to the unit head and guide vane opening signal;

[0025] Active power adjustment rate limiting unit: which is used to process the expected coordinated control active power adjustment amount according to the set limiting rate to calculate the active power adjustment amount limiting rate value;

[0026] Output signal amplitude limiting unit: which is used to obtain the coordinated control device output signal after amplitude limiting the active power adjustment amount limiting rate value.

[0027] As an improvement of the above device, the calculation of the expected coordinated control active power adjustment amount according to the effective frequency deviation calculation signal is specifically:

[0028] Expected coordinated control active power adjustment amount = (effective frequency deviation calculation signal ÷ 50Hz ÷ regulation rate) × per-unit reference value of active power.

[0029] As an improvement of the above device, the method of processing the expected coordinated control active power adjustment amount according to the set limiting rate to calculate the active power adjustment amount limiting rate value is:

[0030] When dp1p > 0 and dy / dt > 0, if dy / dt < dp1p, then output y1 = y; if dy / dt >= dp1p, then the output is y1 = y0 + dp1p;

[0031] When dp1n < 0 and dy / dt < 0, if dy / dt > dp1n, then output y1 = y; if dy / dt <= dp1n, then the output is y1 = y0 + dp1n;

[0032] Among them, dp1p represents the positive rate limit; dp1n represents the negative rate limit; dy represents the change in the output active power adjustment amount y; dt represents the change in time t; y1 represents the actual output value after amplitude limiting the active power adjustment amount this time; y0 represents the actual output value after amplitude limiting the active power adjustment amount last time.

[0033] As an improvement to the above device, the device supports three control modes: large network, small network, and isolated network, each with different parameter settings; the coordinated control module calculates the control signal output values of the three control modes simultaneously, and the control mode selection module selects the actual control signal output value to be used.

[0034] As an improvement to the above device, the device further includes:

[0035] A control parameter tuning module for tuning all parameters in the coordinated control module, including unit parameters, system parameters, and control logic parameters.

[0036] As an improvement to the above device, the device further includes:

[0037] An automatic locking control module for the automatic locking control of the device. When multiple abnormalities are detected, the output of the device is turned off;

[0038] The automatic locking control module includes: a power limit locking unit, an oscillation locking unit, a hardware abnormality locking unit, and a fault signal locking unit;

[0039] The power limit locking unit: is used to automatically lock the control signal output of the device when the device detects that the active power of the unit exceeds the maximum or minimum allowable value;

[0040] The oscillation locking unit: is used to automatically lock the control signal output of the device when the device detects continuous oscillation of the unit frequency or active power;

[0041] The hardware abnormality locking unit: is used to automatically lock the control signal output of the device when the device detects abnormalities in the internal controller and cards of the hydropower unit; and

[0042] The fault signal locking unit: is used to automatically lock the control signal output of the device when the device receives frequency measurement faults, power measurement faults, or governor system fault signals.

[0043] This application also provides a method for coordinating the power closed-loop control and the primary frequency regulation of the governor system of a hydropower unit, which is implemented based on the above device. The method includes:

[0044] The signal acquisition module acquires various data of the generator set to obtain a control input signal;

[0045] The coordinated control module calculates the control signal output value according to the control input signal;

[0046] The control mode selection module automatically matches the large / small / isolated network control modes of the hydropower unit governor system according to the governor operation mode acquired from the input signal acquisition;

[0047] The control signal output module outputs the active power adjustment rate limit value calculated by the coordinated control module to the active power signal superposition point of the monitoring system.

[0048] As an improvement to the above method, the coordinated control module calculates a control signal output value according to the control input signal, including:

[0049] The filtering unit performs hardware filtering and software low-pass filtering on the collected frequency and power signals to obtain calculation signals that can be used for frequency and power control;

[0050] The frequency dead zone and limiting unit performs dead zone removal and limiting processing on the frequency deviation signal calculated from the collected real-time frequency signal and the rated frequency of the unit to obtain an effective frequency deviation calculation signal;

[0051] The active power adjustment amount calculation unit calculates the expected coordinated control active power adjustment amount according to the effective frequency deviation calculation signal;

[0052] The operating condition correction calculation unit corrects the adjustment speed of the expected coordinated control active power adjustment amount according to the unit head and guide vane opening signals;

[0053] The active power adjustment rate limiting unit processes the expected coordinated control active power adjustment amount according to the set rate limit to calculate the active power adjustment rate limit value;

[0054] The output signal limiting unit limits the active power adjustment rate limit value to obtain the output signal of the coordinated control device.

[0055] Compared with the prior art, the advantages of this application are:

[0056] 1. The coordinated control device has multi-mode adaptability, with 3 sets of independent control logics that can be set with parameters respectively, and automatically matches the unit's large / small / islanded grid control mode according to the operation mode of the speed regulation system, meeting the differentiated primary frequency modulation requirements under multiple grid forms and realizing multi-mode primary frequency modulation adaptive control;

[0057] 2. Without changing the control logic and parameters of the existing monitoring system and speed regulation control system of the unit, the coordinated control device can enable the hydropower unit to correctly respond to the AGC command without restricting its PFR output ability, ensuring that the hydropower unit stably and sufficiently contributes to primary frequency modulation and secondary frequency modulation power, which is of great significance for maintaining system frequency stability;

[0058] 3. The coordinated control system can accurately calculate the power frequency modulation increment that meets the system requirements according to the unit operation status and control mode, "compensate more and make up less" for the primary frequency modulation amount of the speed regulation system, and automatically calculate and adjust the speed according to the unit head size, real-time power and current opening, so as to achieve the suppression of primary frequency modulation power overshoot. It can improve the functions of insufficient primary frequency modulation power or excessive primary frequency modulation power of the existing speed regulation system under different heads, and can achieve the suppression of "power overshoot" during regulation. Description of the Drawings

[0059] Figure 1 The figure shows the block diagram of the power closed-loop of the coordinated control hydro-generator unit monitoring system and the primary frequency modulation device of the speed regulation system;

[0060] Figure 2 The figure shows the deployment diagram of the power closed-loop of the coordinated control hydro-generator unit monitoring system and the primary frequency modulation device of the speed regulation system;

[0061] Figure 3 The figure shows the schematic diagram of the operation process of the coordinated control hydro-generator unit monitoring system power closed-loop and the primary frequency modulation method of the speed regulation system;

[0062] Figure 4 The figure shows the control effect of using the coordinated control hydro-generator unit monitoring system power closed-loop and the primary frequency modulation device of the speed regulation system to adjust the operation of the hydro-generator unit Figure 1 ;

[0063] Figure 5 The figure shows the control effect of using the coordinated control hydro-generator unit monitoring system power closed-loop and the primary frequency modulation device of the speed regulation system to adjust the operation of the hydro-generator unit Figure 2 ;

[0064] Figure 6 The figure shows the control effect of using the coordinated control hydro-generator unit monitoring system power closed-loop and the primary frequency modulation device of the speed regulation system to adjust the operation of the hydro-generator unit Figure 3 ;

[0065] Figure 7 The figure shows the control effect of using the coordinated control hydro-generator unit monitoring system power closed-loop and the primary frequency modulation device of the speed regulation system to adjust the operation of the hydro-generator unit Figure 4 ;

[0066] Figure 8 The figure shows the primary frequency modulation simulation result diagram of the single-machine infinite system;

[0067] Figure 9 The figure shows the comparison curve of the unit output change;

[0068] Figure 10 The figure shows the comparison curve of the grid frequency change;

[0069] Figure 11 The figure shows the first frequency modulation recording curve (co-directional adjustment) diagram of the unit after the input of the coordinated control device;

[0070] Figure 12 The figure shows the first frequency modulation recording curve (reverse adjustment) diagram of the unit after the input of the coordinated control device;

[0071] Figure 13 The figure shows the relationship curve diagram of the water turbine head, guide vane opening, and power. Specific implementation manners

[0072] The technical solution of the present application will be described in detail below with reference to the accompanying drawings.

[0073] The present application provides a coordinated control device and method for the power closed-loop of a hydro-generator unit monitoring system and the first frequency modulation device of the speed regulation system. Through a coordinated control strategy, the expected correction value of the unit active power setpoint is calculated in real time according to the frequency change, and is algebraically superimposed with the original unit active power setpoint (this setpoint includes the AGC power setpoint), improving the existing strategy that the first frequency modulation action locks the AGC command or the AGC action locks the first frequency modulation command, so as to realize the correct action of the unit speed regulation system PFR and the active power closed-loop of the monitoring system. It can simultaneously and normally respond to the first frequency modulation and AGC commands under the change of the power grid frequency, fundamentally solve the coordination problem of the active power / frequency regulation of the hydro-generator unit, and give full play to the frequency / active power support ability of the hydro-generator unit for the power grid. At the same time, to improve the adaptability of the coordinated control of the active power of the generator set and the first frequency modulation, three sets of independent parameters can be set in the coordinated control module of the system to match the three control modes of the large / small / islanded network of the hydro-generator unit speed regulation system. The coordinated control device and method for the power closed-loop of the hydro-generator unit monitoring system and the first frequency modulation device of the speed regulation system provided by the present application support all hydro-generator units connected to the power grid, including large-scale supporting hydro-generator units for UHV AC / DC (including those above 750 kV).

[0074] As Figure 1 shown, a coordinated control device for the power closed-loop of a hydro-generator unit monitoring system and the first frequency modulation device of the speed regulation system provided by the present application, abbreviated as the coordinated control device, includes: a signal acquisition module, a coordinated control module, a control signal output module, a control mode selection module, a control parameter setting module, a real-time display interface module, a data recording and storage module, and an automatic locking control module.

[0075] 1. The signal acquisition module is used to collect various data of the generator set, including: three-phase voltage and current at the generator terminal, unit frequency signal, AGC power command signal, guide vane opening command signal, governor control mode signal, and water head signal. Among them, the unit frequency signal is the input signal of the coordinated control module. The signal acquisition module can simultaneously collect three different frequency signals, namely, the frequency measurement signal of the voltage from the device PT (Potential Transformer), and two groups of AO signals (Analog Output; the AO signal refers to the analog signal output by the device, and these signals are usually continuously varying current or voltage. Here, it refers to the frequency signal calculated based on the collected voltage signal) from two external systems (governor system) with different sources, and respectively filter the collected frequencies, and finally obtain the control input signal by adopting the "middle value selection from three" redundancy method. The "middle value selection from three" method means taking the number in the middle position after arranging 3 numbers in ascending order.

[0076] 2. The coordinated control module is used to calculate the control signal output value through the coordinated control function according to the control input signal. The coordinated control device supports three control modes: large grid, small grid, and isolated grid. Each control mode has different parameter settings. The coordinated control module calculates the control signal output values of the three control modes simultaneously, and the control mode selection module selects the actually used control signal output value.

[0077] The coordinated control module includes: a filtering unit, a frequency dead zone and limiting unit, an active power adjustment amount calculation unit, a working condition correction calculation unit, an active power adjustment rate limiting unit, and an output signal limiting unit.

[0078] The filtering unit is used to perform hardware filtering and software low-pass filtering on the collected frequency and power signals to obtain the calculation signals that can be used for frequency and power control.

[0079] The frequency dead zone and limiting unit is used to perform dead zone removal and limiting processing on the frequency deviation signal obtained by calculating the real-time frequency signal (a frequency signal obtained by the signal acquisition module using the "middle value selection from three" method for three signals) and the unit rated frequency to obtain an effective frequency deviation calculation signal;

[0080] The calculation method of the frequency deviation signal is:

[0081] Frequency deviation signal = rated frequency - real-time frequency

[0082] The frequency deviation calculation signal undergoes dead zone and limiting operations to obtain an effective frequency deviation calculation signal.

[0083] The active power adjustment amount calculation unit is used to divide the effective frequency deviation calculation signal by the droop rate to obtain the coordinated control active power adjustment amount, and calculate and convert it with the set per-unit reference value of the active power to obtain the expected coordinated control active power adjustment amount;

[0084] The calculation method of the coordinated control active power adjustment amount is as follows:

[0085] The per-unit value of the expected coordinated control active power adjustment amount = the effective frequency deviation calculation signal ÷ 50Hz ÷ the droop rate

[0086] The expected coordinated control active power adjustment amount = the per-unit value of the expected coordinated control active power adjustment amount × the per-unit reference value of the active power

[0087] The operating condition correction calculation unit is used to correct the adjustment speed of the expected coordinated control active power adjustment amount according to signals such as the unit head and guide vane opening;

[0088] The specific method of operating condition correction is as follows: Using the turbine characteristic curve, obtain the relative value p of the unit shaft power under the normal operating condition of the rated speed and the turbine power generation condition t and the control curve of the guide vane opening α and the head H, as Figure 13 shown. That is, when p t >0, for a given H, p t increases with the increase of α; for a given guide vane opening, p t increases with the increase of H. There is a fixed correlation relationship among the head value, the guide vane opening value, and the power value. Through any two of the three values, the third value can be obtained by looking up the table. There is also a fixed correlation relationship among the head value change amount, the guide vane opening value change amount, and the power value change amount. Knowing any two value changes, the change amount of the third value can be obtained by looking up the table. This link realizes the dynamic correction of the adjustment speed of the current head, guide vane opening, and the expected coordinated control active power adjustment amount through the look-up table calculation of the change amount.

[0089] The active power adjustment rate limiting unit: is used to process the expected coordinated control active power adjustment amount according to the set limiting rate, and calculate and obtain the active power adjustment amount limiting rate value;

[0090] The calculation method is as follows:

[0091] When dp1p is the positive rate limit, dp1p>0, if dy / dt>0, when dy / dt<dp1p, then output y1 = y, when dy / dt>=dp1p, then the output is y1 = y0 + dp1p, where y0 is the previous output value.

[0092] When dp1n is the negative rate limit, dp1n < 0. If dy / dt < 0, when dy / dt > dp1n, the output is y1 = y; when dy / dt <= dp1n, the output is y1 = y0 + dp1n, where y0 is the previous output value.

[0093] Among them, dy represents the change in the output active power adjustment amount y; dt represents the change in time t; y1 is the actual output value after the active power adjustment amount is limited by the rate.

[0094] Output signal limiting unit: used to limit the active power adjustment amount limited by the rate value (the control system has an output limit value to prevent the output amount from being too large and affecting normal operation) to obtain the output signal of the coordinated control device.

[0095] 3. Control signal output module, used to output the active power adjustment amount limited by the rate value calculated by the coordinated control module to the active power signal superposition point of the monitoring system.

[0096] 4. Control mode selection module, used to automatically match the large / small / island grid three control modes of the hydro-generator unit speed control system according to the governor operation mode collected from the input signal.

[0097] Among them, the large grid coordinated control mode and the small grid coordinated control mode are manually selected and switched;

[0098] The large grid coordinated control mode automatically switches to the island grid coordinated control mode in the way of "frequency deviation exceeding the limit" + "delay";

[0099] The small grid coordinated control mode automatically switches to the island grid coordinated control mode in the way of "frequency deviation exceeding the limit" + "delay";

[0100] The island grid coordinated control mode does not automatically switch back to the large grid coordinated control mode;

[0101] The island grid coordinated control mode does not automatically switch back to the small grid coordinated control mode;

[0102] 5. Control parameter tuning module, used to tune all parameters in the coordinated control module, including unit parameters, system parameters, and control logic parameters.

[0103] These parameters include:

[0104] Power limit enable pelmtactive

[0105] Coordinated control output enable xkactive

[0106] Rated power pe0 = 1

[0107] Delay time tdy1 = 0.01

[0108] Frequency measurement time tr1 = 0.01

[0109] Filter parameter gl1 = 0.01

[0110] Filter parameter gl2 = 0.01

[0111] Filter parameter fl1 = 0.01

[0112] Filter parameter fl2 = 0.01

[0113] Positive dead zone db1p = 0.001

[0114] Negative dead zone db1n = -0.001

[0115] Positive limit max1 = 0.01

[0116] Negative limit min1 = -0.01

[0117] Differential coefficient ep1 = 0.03

[0118] Positive rate limit dp1p = 0.005

[0119] Negative rate limit dp1n = -0.004

[0120] Positive output limit pfrmax1 = 70

[0121] Negative output limit pfrmin1 = -70

[0122] Grid dynamic characteristic matching logic function

[0123] 6. Interface module, used to display data in real time on the display screen, including: controlling the input unit frequency, grid frequency, output unit active power adjustment amount, unit real-time active power, AGC command value, guide vane opening value, coordinated control action signal.

[0124] 7. Data recording and storage module, used to automatically record and store data, automatically start waveform recording through the real-time monitored frequency deviation signal, and can also start wave recording manually.

[0125] 8. Automatic locking control module, used for the automatic locking control of the coordinated control device. When multiple abnormalities are detected, the output of the coordinated control device is turned off. The automatic locking control module includes: power overlimit locking unit, oscillation locking unit, hardware abnormality locking unit, fault signal locking unit.

[0126] Power overlimit locking unit: used to realize that when the coordinated control device detects that the unit active power exceeds the maximum or minimum allowable value, the control signal output of the coordinated control device is automatically locked.

[0127] Oscillation locking unit: used to automatically lock the output of the control signal of the coordinated control device when the coordinated control device detects continuous oscillation of the unit frequency or active power.

[0128] Hardware abnormality locking unit: used to automatically lock the output of the control signal of the coordinated control device when the coordinated control device detects abnormalities in the internal controller and cards of the hydropower unit.

[0129] Fault signal locking unit: used to automatically lock the output of the control signal of the coordinated control device when the coordinated control device receives fault signals such as frequency measurement fault, power measurement fault, and speed control system fault.

[0130] As Figure 2 shown, the coordinated control device works independently of the unit monitoring system and the speed control system, collects signals such as the guide vane opening of the unit, active power, terminal frequency of the unit, speed control system control mode, and AGC power command signal. The coordinated control device performs logical operations and outputs the control of the coordinated control device to the local control unit (LCU) of the lower computer of the external monitoring system. The LCU receives the control command of the coordinated control device and superimposes it on its power set point to achieve the combined coordinated control of the primary frequency regulation and AGC of the unit. When the terminal frequency difference exceeds the primary frequency regulation dead zone, the coordinated control device accurately calculates the power frequency modulation increment that meets the system requirements according to the frequency difference, unit operating state, and control mode, calculates and outputs the active power adjustment limit rate value to the active power input superimposition point of the monitoring system LCU. Without changing the control logic and parameters of the existing unit monitoring system and speed control system, the coordinated control device can enable the hydropower unit to correctly respond to the AGC command without restricting its PFR output ability.

[0131] Embodiment 2

[0132] This application also provides a method for coordinating the power closed-loop of the hydropower unit monitoring system and the primary frequency regulation of the speed control system, which is implemented based on the above-mentioned coordinated control device. The method includes:

[0133] The signal acquisition module acquires various data of the generator set to obtain the control input signal;

[0134] The coordinated control module calculates the control signal output value through the coordinated control function according to the control input signal;

[0135] The control mode selection module automatically matches the large / small / islanded network three control modes of the hydropower unit speed control system according to the governor operation mode acquired from the input signal;

[0136] The control signal output module outputs the active power adjustment limit rate value calculated by the coordinated control module to the active power signal superimposition point of the monitoring system.

[0137] During the operation of the method of this application, all parameters in the coordinated control module can be tuned by using the control parameter tuning module, including unit parameters, system parameters, control logic parameters, etc.; the interface module uses the display screen to display data in real time during the operation of the coordinated control device; the data recording and storage module automatically records and stores data, automatically starts waveform recording through the frequency deviation signal monitored in real time, and can also start wave recording manually; the automatic locking control module automatically shuts down the output of the coordinated control device when detecting multiple abnormalities.

[0138] As Figure 3 shown, the process of the coordinated control module calculating the output value of the control signal includes:

[0139] The filtering module filters the collected frequency and power signals through hardware filtering and software low-pass filtering to obtain calculation signals that can be used for frequency and power control;

[0140] The frequency dead zone and limiting unit processes the collected real-time frequency signal and the frequency deviation signal calculated from the rated frequency of the unit to remove the dead zone and limit, and obtains an effective frequency deviation calculation signal;

[0141] The active power adjustment amount calculation unit divides the effective frequency deviation calculation signal by the regulation rate to obtain the coordinated control active power adjustment amount, and calculates and converts it with the set per-unit reference value to obtain the expected coordinated control active power adjustment amount;

[0142] The operating condition correction calculation unit corrects the adjustment speed of the expected coordinated control active power adjustment amount according to signals such as unit head and guide vane opening;

[0143] The active power adjustment rate limiting unit processes the expected coordinated control active power adjustment amount according to the set limiting rate, and calculates the active power adjustment amount limiting rate value;

[0144] The output signal limiting unit limits the active power adjustment amount limiting rate value to obtain the output signal of the coordinated control device.

[0145] As Figures 4 - 7 shown, it is the control effect diagram achieved by using this coordinated control device for unit operation control.

[0146] As Figure 4 shown: The action sequence is △P AGC1 Increase power - PFR increase power - PFR return - △P AGC2 Increase power

[0147] (1) AGC and primary frequency modulation do not affect each other, and the unit power is stabilized to the last effective AGC command;

[0148] (2) Primary frequency modulation acts during the AGC action, and primary frequency modulation does not affect the power steady-state value.

[0149] As Figure 5 shown: The action sequence is △P AGC1 Increasing power - PFR increasing power - PFR restoration - △P AGC2 Decreasing power

[0150] (1) AGC and primary frequency regulation do not affect each other, and the unit power stabilizes to the last valid AGC command of △P AGC1 -△P AGC2 ;

[0151] (2) Primary frequency regulation acts during AGC operation, and primary frequency regulation does not affect the steady-state power value.

[0152] As Figure 6 shown: The action sequence is PFR increasing power - △P AGC1 Increasing power - △P AGC2 Increasing power - PFR restoration

[0153] (1) AGC and primary frequency regulation do not affect each other, and the unit power stabilizes to the last valid AGC command of △P AGC2 +△P AGC2 ;

[0154] (2) AGC acts during primary frequency regulation operation. AGC does not limit PFR, and PFR does not block AGC.

[0155] As Figure 7 shown: The action sequence is PFR increasing power - △P AGC1 Increasing power - △P AGC2 Decreasing power (invalid command) - PFR restoration

[0156] (1) AGC and primary frequency regulation do not affect each other, and the unit power stabilizes to the last valid AGC command △P AGC1 ;

[0157] (2) AGC acts during primary frequency regulation operation. AGC does not limit PFR, and PFR monitors and automatically blocks reverse AGC commands during operation. △P AGC2 is an invalid command.

[0158] As Figure 8 shown, it is the simulation effect diagram of the single-machine infinite system using this coordinated control device:

[0159] In the power system simulation software PSASP, a single-machine infinite system with a monitoring system simulation model is established. A 0.1Hz frequency step disturbance is applied at the initial unit power of 250MW, and the cases of blocking AGC commands (the monitoring LCU does not work), normal regulation of the monitoring system and speed regulation system (uncoordinated), and the addition of a coordinated control device are respectively simulated and analyzed. The simulation results are as Figure 4 shown.

[0160] Case 1: Simulate the blocking of the AGC command. The monitoring system does not work. The power of the unit starts to increase upward from the initial 250 MW under the disturbance. After 100 seconds, it is adjusted to 311 MW. The unit has ideal primary frequency regulation ability.

[0161] Case 2: Simulate the combined action of the normal power closed-loop regulation of the monitoring system and the speed regulation system. The active power of the unit rises from the initial 250 MW to 286 MW and then gradually returns to 250 MW (the power setting of the monitoring system). The contribution of the primary frequency regulation power is completely offset by the reverse regulation of the active power control of the monitoring system.

[0162] Case 3: Simulate the condition of adding a coordinated control device under the combined action of the coordinated monitoring system and the speed regulation system. The power of the unit starts to increase upward from the initial 250 MW. After 100 seconds, it is adjusted to 311.5 MW. It can be seen that under the same frequency disturbance, the PFR adjustment amount is not restricted, and the monitoring system and the speed regulation system can be coordinated and controlled.

[0163] As Figure 9 and Figure 10 shown, it is the simulation effect diagram of the large power grid using this coordinated control device.

[0164] Based on the typical operation mode of the power grid, in the simulation calculation, a combined control system is added to the units of three large hydropower stations (a total of 27 units). The disturbance fault is the removal of a non-faulty machine (2*600 MW), the simulation time is 160 seconds, and the comparison curve of the output power change of a certain 1000 MW-class unit is as Figure 9 shown, and the comparison curve of the power grid frequency change is as Figure 10 shown. Figure 2 In, the unit adopts the combined control mode of the original monitoring system and the coordinated control device. Under the frequency difference disturbance, the active power output of the unit increases from 1002 MW to 1030 MW. Then, due to the reverse regulation of the primary frequency regulation power by the monitoring system, the active power returns to the initial value of 1002 MW. After 160 s, the power grid frequency stabilizes at 49.891 Hz. After adding the coordinated control device, the active power output of the unit increases from 1002 MW to 1034 MW, and the power grid frequency resumes stability at 49.915 Hz. In this simulation case, after adding the active power coordinated control device to 27 units, the power grid frequency recovery level is increased by 0.024 Hz.

[0165] As Figure 11 and Figure 12 shown, it is the oscillogram of the actual engineering application using this coordinated control device.

[0166] Deploy the coordinated control device into the LCU screen of the monitoring system of a certain hydropower unit according to Figure 2 and deploy it according to Figure 1Connect the input signals respectively, output the output signals to the monitoring system LCU, and conduct on-site test verification. After the coordinated control device is put into operation, the tests include a test with the same direction of the primary frequency regulation and AGC commands (see the test oscillogram in Figure 11 ), and a test with the opposite direction of the primary frequency regulation and AGC commands (see the test oscillogram in Figure 12 ). The tests verify that after the coordinated control device is put into operation, AGC and primary frequency regulation do not affect each other, solve the problem of limited operation of AGC or primary frequency regulation, and strengthen the primary frequency regulation ability of the speed control system.

[0167] Figure 11 In stage 1: the grid frequency steps negatively by 0.15 Hz, and the primary frequency regulation of the speed control system correctly operates to increase the active power, and the active power of the unit increases by about 60 MW; in stage 2: after the power adjustment is stable, the AGC issues an instruction to increase by 50 MW, and the active power responds and increases by 50 MW; in stage 3: after the power adjustment is stable, the grid frequency steps positively by 0.15 Hz, and the primary frequency regulation of the speed control system correctly operates to decrease the active power, and the active power of the unit decreases by about 60 MW.

[0168] Figure 12 In stage 1: the grid frequency steps positively by 0.2 Hz, and the primary frequency regulation of the speed control system correctly operates to decrease the active power, and the active power of the unit decreases by about 90 MW; in stage 2: after the power adjustment is stable, the AGC issues an instruction to increase by 50 MW, and the active power responds and increases by 50 MW; in stage 3: after the power adjustment is stable, the AGC issues an instruction to decrease by 50 MW, and the active power responds and decreases by 50 MW; in stage 4: after the power adjustment is stable, the grid frequency steps negatively by 0.2 Hz, and the primary frequency regulation of the speed control system correctly operates to increase the active power, and the active power of the unit increases by about 90 MW.

[0169] This application can also provide a computer device, including: at least one processor, a memory, at least one network interface, and a user interface. Each component in the device is coupled together through a bus system. It can be understood that the bus system is used to realize the connection and communication between these components. In addition to the data bus, the bus system also includes a power bus, a control bus, and a status signal bus.

[0170] Among them, the user interface can include a display, a keyboard, or a pointing device. For example, a mouse, a trackball, a touchpad, or a touch screen, etc.

[0171] It can be understood that the memory in the disclosed embodiments of the present application can be a volatile memory or a non-volatile memory, or can include both volatile and non-volatile memories. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), or a flash memory. The volatile memory can be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DRRAM). The memory described herein is intended to include but not be limited to these and any other suitable types of memory.

[0172] In some embodiments, the memory stores the following elements, executable modules, or data structures, or subsets or supersets thereof: an operating system and application programs.

[0173] Among them, the operating system includes various system programs, such as the framework layer, the core library layer, the driver layer, etc., and is used to implement various basic services and handle hardware-based tasks. The application programs include various application programs, such as a media player and a browser, etc., and are used to implement various application services. The program for implementing the method of the disclosed embodiments of the present application can be included in the application programs.

[0174] In the above-mentioned embodiments, the processor is further configured to call the program or instruction stored in the memory, specifically, the program or instruction stored in the application program, to:

[0175] Execute the steps of the above method.

[0176] The above method can be applied to or implemented by a processor. The processor may be an integrated circuit chip with the ability to process signals. During implementation, the steps of the above method can be completed by the integrated logic circuit of the hardware in the processor or instructions in the form of software. The above-mentioned processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components. It can implement or execute the various methods, steps, and logic block diagrams disclosed above. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc. Combining the steps of the above-disclosed method can be directly embodied as being executed and completed by a hardware decoding processor, or by a combination of the hardware and software modules in the decoding processor. The software module may be located in a mature storage medium in the art such as random access memory, flash memory, read-only memory, programmable read-only memory, or electrically erasable programmable memory, registers, etc. This storage medium is located in the memory, and the processor reads the information in the memory and combines its hardware to complete the steps of the above method.

[0177] It can be understood that the embodiments described in this application can be implemented using hardware, software, firmware, middleware, microcode, or a combination thereof. For hardware implementation, the processing unit can be implemented in one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in this application, or a combination thereof.

[0178] For software implementation, the technology of this application can be implemented by executing the functional modules of this application (such as procedures, functions, etc.). The software code can be stored in the memory and executed by the processor. The memory can be implemented inside or outside the processor.

[0179] The present application can also provide a non-volatile storage medium for storing a computer program. When the computer program is executed by a processor, each step in the above method embodiments can be implemented.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit them. Although the present application has been described in detail with reference to the embodiments, those of ordinary skill in the art should understand that any modification or equivalent replacement of the technical solutions of the present application does not depart from the spirit and scope of the technical solutions of the present application, and they should all be covered within the scope of the claims of the present application.

Claims

1. A coordinated control of the power closed loop of the monitoring system of a hydropower unit and the primary frequency regulation device of the speed regulation system, characterized in that: The device includes: a signal acquisition module, a coordination control module, a control mode selection module, and a control signal output module; where the signal acquisition module is used to acquire various data of the generator set to obtain a control input signal; the coordination control module is used to calculate a control signal output value through a coordination control function according to the control input signal; the control mode selection module is used to automatically match the large / small / island control modes of the hydro-generator set governor system according to the governor operation mode acquired from the input signal; and the control signal output module is used to output the control signal output value calculated by the coordination control module to the active signal superposition point of the monitoring system; the data acquired by the signal acquisition module includes: generator terminal three-phase voltage, current, unit frequency signal, AGC power command signal, guide vane opening command signal, governor control mode signal, and head signal; the signal acquisition module also acquires three different frequency signals including a frequency measurement signal from a voltage transformer and AO signals from two groups of external systems with different sources, filters the acquired frequencies respectively, and finally obtains a control input signal by adopting the "middle value selection from three" method; the coordination control module includes: a filtering unit, which is used to perform hardware filtering and software low-pass filtering on the acquired frequency and power signals to obtain calculation signals for frequency and power control; a frequency dead zone and limiting unit, which is used to perform dead zone removal and limiting processing on the frequency deviation signal calculated from the acquired control input signal and the rated frequency of the unit to obtain an effective frequency deviation calculation signal; an active power adjustment amount calculation unit, which is used to calculate an expected coordinated control active power adjustment amount according to the effective frequency deviation calculation signal; a working condition correction calculation unit, which is used to correct the adjustment speed of the expected coordinated control active power adjustment amount according to the unit head and guide vane opening signals; an active power adjustment rate limiting unit: which is used to process the expected coordinated control active power adjustment amount according to the set limiting rate to calculate an active power adjustment amount limiting rate value; and an output signal limiting unit: which is used to limit the active power adjustment amount limiting rate value to obtain a coordinated control device output signal.

2. The coordinated control of the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation device of the speed regulation system according to claim 1 is characterized in that: The calculation of the expected coordinated control active power adjustment amount according to the effective frequency deviation calculation signal is specifically: Expected coordinated control active power adjustment amount = (effective frequency deviation calculation signal ÷ 50Hz ÷ regulation rate) × per-unit reference value of active power.

3. The coordinated control of the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation device of the speed regulation system according to claim 1 is characterized in that: The method for processing the expected coordinated control active power adjustment amount according to the set limiting rate to calculate the active power adjustment amount limiting rate value is: When dp1p>0 and dy / dt>0, if dy / dt<dp1p, then output y1 = y; if dy / dt>=dp1p, then the output is y1 = y0 + dp1p; When dp1n<0 and dy / dt<0, if dy / dt>dp1n, then output y1 = y; if dy / dt<=dp1n, then the output is y1 = y0 + dp1n; Among them, dp1p represents the positive rate limit; dp1n represents the negative rate limit; dy represents the change in the output active power adjustment amount y; dt represents the change in time t; y1 represents the actual output value of the active power adjustment amount after the current output rate limit; y0 represents the actual output value of the active power adjustment amount after the last output rate limit.

4. The coordinated control of the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation device of the speed regulation system according to claim 1 is characterized in that: The device supports three control modes: large network, small network and isolated network, each control mode has different parameter settings; the coordination control module calculates the control signal output values ​​of the three control modes simultaneously, and the control mode selection module selects the control signal output value actually used.

5. The coordinated control of the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation device of the speed regulation system according to claim 1 is characterized in that: The device also includes: The control parameter setting module is used to coordinate the setting of all parameters in the control module, including unit parameters, system parameters and control logic parameters.

6. The coordinated control of the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation device of the speed regulation system according to claim 1 is characterized in that: The device also includes: An automatic locking control module, used for automatic locking control of the device, shutting down the output of the device when multiple abnormalities are detected; The automatic locking control module includes: a power over-limit locking unit, an oscillation locking unit, a hardware abnormality locking unit and a fault signal locking unit; The power over-limit locking unit is used to automatically lock the control signal output of the device when the device detects that the active power of the unit exceeds the maximum or minimum allowable value; Oscillation locking unit: used to automatically lock the control signal output of the device when the device detects that the frequency or active power of the unit continues to oscillate; Hardware abnormality locking unit: used to automatically lock the control signal output of the device when the device detects abnormalities in the internal controller and card of the hydropower unit; and Fault signal locking unit: used to automatically lock the control signal output of the device when the device receives a frequency measurement fault, a power measurement fault or a speed control system fault signal.

7. A method for coordinating and controlling the power closed loop of a monitoring system for a hydropower unit and the primary frequency regulation of a speed regulation system, implemented based on the device described in any one of claims 1 to 6, the method comprising: The signal acquisition module collects various data of the generator set and obtains the control input signal; The coordination control module calculates the control signal output value according to the control input signal; The control mode selection module automatically matches the three control modes of large / small / isolated grid of the hydropower unit speed control system according to the speed regulator operation mode obtained by input signal acquisition; The control signal output module outputs the active power adjustment limit rate value calculated by the coordination control module to the active power signal superposition point of the monitoring system.

8. The method for coordinating and controlling the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation of the speed regulation system according to claim 7 is characterized in that: The coordination control module calculates the control signal output value according to the control input signal, including: The filtering unit performs hardware filtering and software low-pass filtering on the collected frequency and power signals to obtain calculation signals for frequency and power control; The frequency dead zone and amplitude limiting unit removes the dead zone and amplitude limits the frequency deviation signal obtained by calculating the collected real-time frequency signal and the rated frequency of the unit to obtain an effective frequency deviation calculation signal; The active power adjustment amount calculation unit calculates the expected coordinated control active power adjustment amount according to the effective frequency deviation calculation signal; The operating condition correction calculation unit corrects the adjustment speed of the expected coordinated control active power adjustment amount according to the unit water head and guide vane opening signals; The active power adjustment rate limiting unit processes the expected coordinated control active power adjustment amount according to the set rate limit, and calculates the active power adjustment amount rate limit value; The output signal limiting unit limits the active adjustment amount rate limit value to obtain the output signal of the cooperative control device.

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