Device and method for coordinating and controlling power closed loop of hydroelectric generating set monitoring system and primary frequency modulation of speed regulation system

Abstract

The invention provides a device and method for coordinately controlling power closed loop of a monitoring system of a hydroelectric generating set and primary frequency modulation of a speed regulation system, and the device comprises a signal collection module which is used for collecting various data of the generating set, and obtaining a control input signal; the coordination control module is used for calculating a control signal output value through a coordination control function according to the control input signal; the control mode selection module is used for automatically matching large / small / isolated network control modes of the hydroelectric generating set speed regulation system according to a speed regulator operation mode acquired by input signal acquisition; and the control signal output module is used for outputting the control signal output value calculated by the coordination control module to an active signal superposition point of the monitoring system. The method has the advantages that the output capacity of the PFR of the hydroelectric generating set is not limited while the hydroelectric generating set correctly responds to the AGC instruction, the stability of the hydroelectric generating set is guaranteed, and the primary frequency modulation power and the secondary frequency modulation power are sufficiently contributed.

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 guarantee the regulation effect of the priority function. When the power grid experiences large frequency fluctuations and PFR and AGC operate simultaneously, mutual interlocking or non-interlocking will lead to a decrease in the frequency regulation capability 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 defects of the prior art that when a large frequency fluctuation occurs in the power grid, when PFR and AGC operate simultaneously, they are locked or not locked with each other, which will lead to a decrease in the frequency regulation capability of the unit and the inability to fully ensure the stability of the system frequency.

[0013] In order to achieve the above-mentioned purpose, the present application proposes a coordinated control device for the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation of the speed regulation system, the device comprising: a signal acquisition module, a coordinated control module, a control mode selection module and a control signal output module; wherein,

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

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

[0016] The control mode selection module is used to automatically match 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;

[0017] 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.

[0018] As an improvement of the above device, the data collected by the signal acquisition module include: three-phase voltage and current at the generator end, 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 three groups of different frequency signals, namely, the frequency measurement signal from the voltage transformer and two groups of AO signals from different sources of external system input, and filters the collected frequencies respectively, and finally obtains the control input signal by a "three-in-one" method.

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

[0021] A filtering unit, 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] A frequency dead zone and amplitude limiting unit, which is used to perform dead zone removal and amplitude limiting processing on the frequency deviation signal calculated from the collected control input signal and the rated frequency of the unit to obtain an effective frequency deviation calculation signal;

[0023] An 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] 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 signal;

[0025] 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 the active power adjustment amount limiting rate value;

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

[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] The 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 amount of the output active power adjustment amount y; dt represents the change amount of time t; y1 represents the actual output value after the active power adjustment amount limiting rate of this output; y0 represents the actual output value after the active power adjustment amount limiting rate of the previous output.

[0033] As an improvement of the above-mentioned device, the device supports three control modes: large network, small network and isolated network, and each control mode has different parameter settings; the coordination control module simultaneously calculates the control signal output values ​​of the three control modes, and the control mode selection module selects the control signal output value actually used.

[0034] As an improvement of the above device, the device further comprises:

[0035] 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.

[0036] As an improvement of the above device, the device further comprises:

[0037] 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;

[0038] 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;

[0039] 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;

[0040] 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;

[0041] 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

[0042] 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.

[0043] The present application also provides a method for coordinating and controlling the power closed loop of a hydropower unit monitoring system and the primary frequency regulation of a speed regulation system, which is implemented based on the above-mentioned device, and the method includes:

[0044] The signal acquisition module collects various data of the generator set and obtains the control input signal;

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

[0046] 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;

[0047] 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.

[0048] As an improvement of the above method, the coordination control module calculates the 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 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;

[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 water 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, and calculates the active power adjustment amount rate limit value;

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

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

[0056] 1. The coordinated control device has multi-mode adaptability and is equipped with 3 sets of independent control logics to set parameters separately. It can automatically match the large / small / isolated grid control mode of the unit according to the operation mode of the speed regulation system, meet the differentiated primary frequency regulation requirements under multiple power grid forms, and realize multi-mode primary frequency regulation adaptive control;

[0057] 2. The coordinated control device can achieve the hydropower unit to correctly respond to the AGC command without limiting its PFR output capacity, without changing the existing monitoring system, speed control system control logic and parameters of the unit, and ensure that the hydropower unit can contribute to the primary and secondary frequency regulation power stably and in sufficient quantity, which is of great significance to maintaining the stability of the system frequency;

[0058] 3. The coordinated control system has the ability to accurately calculate the power frequency regulation increment that meets the system requirements according to the unit's operating status and control mode, and realize "more retreat and less supplement" for the primary frequency regulation of the speed control system, and automatically calculate and adjust the speed according to the unit's head size, real-time power and current opening, thereby achieving primary frequency regulation power overshoot suppression. It can improve the existing speed control system's primary frequency regulation function of insufficient primary frequency regulation power or excessive primary frequency regulation power under different heads, and can achieve "power overshoot" suppression during regulation. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0060] Figure 2 The figure shows the deployment diagram of the power closed loop of the monitoring system for the coordinated control of the hydropower units and the primary frequency regulation device of the speed regulation system;

[0061] Figure 3 The figure shows the operation process of the power closed loop of the monitoring system of the hydropower unit and the primary frequency regulation method of the speed regulation system for coordinated control;

[0062] Figure 4 The figure shows the control effect of adjusting the operation of the hydropower unit by using the power closed loop of the coordinated control hydropower unit monitoring system and the primary frequency regulation device of the speed regulation system. Figure 1 ;

[0063] Figure 5 The figure shows the control effect of adjusting the operation of the hydropower unit by using the power closed loop of the coordinated control hydropower unit monitoring system and the primary frequency regulation device of the speed regulation system. Figure 2 ;

[0064] Figure 6 The figure shows the control effect of adjusting the operation of the hydropower unit by using the power closed loop of the coordinated control hydropower unit monitoring system and the primary frequency regulation device of the speed regulation system. Figure 3 ;

[0065] Figure 7 The figure shows the control effect of adjusting the operation of the hydropower unit by using the power closed loop of the coordinated control hydropower unit monitoring system and the primary frequency regulation device of the speed regulation system. Figure 4 ;

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

[0067] Fig. 9 The following is a comparison curve of unit output changes;

[0068] Fig.10 Shown is a comparison curve of power grid frequency changes;

[0069] Fig.11 The figure shows the primary frequency modulation recording curve (same direction adjustment) of the unit after the auxiliary control device is put into use;

[0070] Fig.12 The figure shows the primary frequency modulation recording curve (reverse adjustment) of the unit after the auxiliary control device is put into use;

[0071] Fig.13 The graph shows the relationship between turbine head, guide vane opening, and power. DETAILED DESCRIPTION

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

[0073] The present application provides a device and method for coordinated control of the power closed loop of the monitoring system of a hydropower unit and the primary frequency regulation of the speed regulation system. Through the coordinated control strategy, the expected set active power given correction value is calculated in real time according to the frequency change, and algebraic superposition is achieved with the original set active power given value (the given value includes the AGC power given value), which improves the existing strategy of locking the AGC instruction or locking the primary frequency regulation instruction when the AGC is in action, thereby achieving the correct action of the PFR of the speed regulation system of the unit and the active power closed loop of the monitoring system. It can respond normally to the primary frequency regulation and AGC instructions under the frequency change of the power grid at the same time, solve the coordination problem of the active power / frequency regulation of the hydropower unit from the root, and give full play to the frequency / active power support capacity of the hydropower unit for the power grid. At the same time, in order to improve the adaptability of the coordinated control of the active power and primary frequency regulation of the generator set, the coordinated control module in the system can set 3 sets of independent parameters to match the three control modes of large / small / isolated grid of the speed regulation system of the hydropower unit. The coordinated control of the power closed loop of the hydropower unit monitoring system and the primary frequency regulation device and method of the speed regulation system provided in this application support all hydropower units connected to the power grid, including large-scale supporting hydropower units with ultra-high voltage AC and DC (including those above 750 kV).

[0074] like Figure 1 As shown, the present application provides a coordinated control device for the power closed loop of the hydropower unit monitoring system and the primary frequency regulation device of the speed regulation system, referred to as the coordinated control device, which 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. Signal acquisition module, used to collect various data of the generator set, including: three-phase voltage and current at the generator end, unit frequency signal, AGC power command signal, guide vane opening command signal, governor control mode signal, and head signal. The unit frequency signal is the input signal of the coordination control module. The signal acquisition module can simultaneously collect three groups of different frequency signals, including the frequency measurement signal from the device PT (Potential Transformer) voltage, and AO signals (Analog Output analog output; AO signal refers to the analog signal output by the device, which is usually a continuously changing current or voltage. Here, it refers to the frequency signal calculated based on the collected voltage signal), and filter the collected frequencies respectively. Finally, the control input signal is obtained redundantly by the "three-in-one" method. The "three-in-one" method is to take the number in the middle position after arranging 3 numbers in order of size.

[0076] 2. The coordination control module is used to calculate the control signal output value through the coordination control function according to the control input signal. The coordination control 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 at the same time, and the control mode selection module selects the control signal output value actually used.

[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 calculation signals that can be used for frequency and power control.

[0079] The frequency dead zone and limiting unit is used to remove the dead zone and limit the frequency deviation signal obtained by calculating the rated frequency of the unit by the collected real-time frequency signal (a frequency signal obtained by the signal acquisition module using the "three-way middle" method for three signals) and obtain an effective frequency deviation calculation signal;

[0080] The frequency deviation signal is calculated as:

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

[0082] The frequency deviation calculation signal is processed through dead zone and amplitude 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 perform calculation and conversion 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 = effective frequency deviation calculation signal ÷ 50Hz ÷ 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 conditions of rated speed and normal operation and the turbine power generation condition t and the control curve of the guide vane opening α and the head H, as Fig.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 the active power adjustment amount limiting rate value;

[0090] The calculation method is as follows:

[0091] When dp1p is the forward 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, and when dy / dt<=dp1n, the output is y1=y0+dp1n, and y0 is the previous output value.

[0093] Wherein, dy represents the change of the output active power adjustment y; dt represents the change of time t; y1 is the actual output value of the active power adjustment after rate limiting.

[0094] Output signal limiting unit: used to limit the active adjustment rate limit value (the control system has an output limit value to prevent excessive output from affecting normal operation) to obtain the output signal of the cooperative control device.

[0095] 3. A control signal output module is used to output the active power adjustment limit rate value calculated by the coordination control module to the active power signal superposition point of the monitoring system.

[0096] 4. The control mode selection module is used to automatically match 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.

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

[0098] The large network cooperative control mode automatically switches to the isolated network cooperative control mode by the method of "frequency deviation exceeding the limit" + "delay";

[0099] The small network cooperative control mode automatically switches to the isolated network cooperative control mode by the method of "frequency deviation exceeding the limit" + "delay";

[0100] The isolated network cooperative control mode does not automatically switch back to the large network cooperative control mode;

[0101] The isolated network cooperative control mode does not automatically switch back to the small network cooperative control mode;

[0102] 5. Control parameter setting module, used to coordinate the setting of all parameters in the control module, including unit parameters, system parameters and control logic parameters.

[0103] These parameters include:

[0104] Power limit enable pelmtactive

[0105] Co-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] Forward dead zone db1p = 0.001

[0114] Positive dead zone db1n = -0.001

[0115] Forward limit max1=0.01

[0116] Negative limit min1 = -0.01

[0117] Adjustment coefficient ep1 = 0.03

[0118] Forward rate limit dp1p = 0.005

[0119] Negative rate limit dp1n = -0.004

[0120] Forward output limit pfrmax1=70

[0121] Negative output limit pfrmin1 = -70

[0122] Power grid dynamic characteristics matching logic function

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

[0124] 7. Data recording and storage module is used for automatic data recording and storage. Waveform recording is automatically started through real-time monitoring of frequency deviation signals, and can also be started manually.

[0125] 8. Automatic locking control module, used for automatic locking control of the auxiliary control device, shuts down the output of the auxiliary control device when multiple abnormalities are detected. The automatic locking control module includes: power over-limit locking unit, oscillation locking unit, hardware abnormality locking unit, and fault signal locking unit.

[0126] Power over-limit locking unit: used to automatically lock the control signal output of the auxiliary control device when the auxiliary control device detects that the active power of the unit exceeds the maximum or minimum allowable value.

[0127] Oscillation locking unit: used to automatically lock the control signal output of the auxiliary control device when the auxiliary control device detects that the unit frequency or active power continues to oscillate.

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

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

[0130] like Figure 2 As shown in the figure, the cooperative control device works independently of the unit monitoring system and speed control system, and collects signals such as the unit guide vane opening, active power and machine-end frequency, speed control system control mode, and AGC power command signal. Logical operations are performed in the cooperative control device, and the control output of the cooperative control device is sent to the local control unit (LCU) of the lower computer of the external monitoring system. The LCU receives the control command of the cooperative control device and superimposes it on its power given point to realize the joint coordinated control of the unit's primary frequency regulation and AGC. When the machine-end frequency difference exceeds the primary frequency regulation dead zone, the cooperative control device accurately calculates the power frequency regulation increment that meets the system requirements based on the frequency difference and the unit's operating status and control mode, and calculates the output active adjustment amount rate limit value monitoring system LCU active input superposition point. Without changing the control logic and parameters of the unit's existing monitoring system and speed control system, the coordinated control device can achieve the output capacity of the hydropower unit while correctly responding to the AGC command without limiting its PFR.

[0131] Example 2

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

[0133] The signal acquisition module collects various data of the generator set and obtains the control input signal;

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

[0135] 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;

[0136] 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.

[0137] During the operation of the method of the present application, the control parameter setting module can be used to set all the parameters in the coordinated control module, including unit parameters, system parameters and control logic parameters; the interface module uses the display screen to display data in real time during the operation of the cooperative control device; the data recording and storage module automatically records and stores data, and automatically starts waveform recording through the real-time monitoring frequency deviation signal, and can also start recording manually; the automatic locking control module automatically shuts down the output of the cooperative control device when various abnormalities are detected.

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

[0139] The filter module 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;

[0140] 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;

[0141] The active power adjustment amount calculation unit divides the effective frequency deviation calculation signal by the adjustment 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 the unit water head, guide vane opening and other signals;

[0143] 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;

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

[0145] like Figure 4-Figure 7 The figure shows the control effect achieved by using the cooperative control device to control the unit operation.

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

[0147] (1) AGC and primary frequency regulation do not affect each other, and the unit power is stable until the last effective AGC instruction;

[0148] (2) The primary frequency modulation operates during the AGC operation and does not affect the steady-state power value.

[0149] like Figure 5 As shown: The action sequence is △P AGC1 Power increase-PFR Power increase-PFR reset-△P AGC2 Power reduction

[0150] (1) AGC and primary frequency regulation do not affect each other, and the unit power is stable until the last AGC effective command is △P AGC1 -△P AGC2 ;

[0151] (2) The primary frequency modulation operates during the AGC operation and does not affect the steady-state power value.

[0152] like Figure 6 As shown: The action sequence is PFR power increase-△P AGC1 Increased power - △P AGC2 Power increase-PFR reset

[0153] (1) AGC and primary frequency regulation do not affect each other, and the unit power is stable until the last AGC effective command is △P AGC2 +△P AGC2 ;

[0154] (2) AGC operates during a frequency modulation operation. AGC does not limit PFR, and PFR does not lock AGC.

[0155] like Figure 7 As shown: The action sequence is PFR power increase-△P AGC1 Increased power - △P AGC2 Power reduction (invalid instruction)-PFR reset

[0156] (1) AGC and primary frequency regulation do not affect each other, and the unit power is stable until the last AGC effective command △P AGC1 ;

[0157] (2) AGC operates during a frequency modulation action. AGC does not limit PFR. During PFR action, the monitor automatically blocks the AGC reverse command. △P AGC2 This is an invalid instruction.

[0158] like Figure 8 As shown in the figure, the simulation effect diagram of a single machine infinite system using this cooperative control device is as follows:

[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 power of 250MW. The blocking AGC command (the monitoring LCU does not work), the normal regulation of the monitoring system and the speed control system (incoordination), and the addition of a cooperative control device are simulated and analyzed. The simulation results are as follows: Figure 4 shown.

[0160] Case 1: Simulating the AGC lockout command, the monitoring system does not work. The unit power increases from the initial 250MW under disturbance and is adjusted to 311MW after 100 seconds. The unit has an ideal primary frequency regulation capability.

[0161] Scenario 2: The simulation monitoring system uses normal power closed-loop regulation and the speed control system to work together. The unit active power increases from the initial 250MW to 286MW and then gradually adjusts back to 250MW (the power given by the monitoring system). The primary frequency regulation power contribution is completely offset by the reverse regulation of the active control of the monitoring system.

[0162] Case 3: When the coordination monitoring system and the speed control system are working together, the auxiliary control device is added, and the unit power increases from the initial 250MW and is adjusted to 311.5MW after 100 seconds. It can be seen that the PFR adjustment amount is not limited under the same frequency disturbance, and the monitoring system and the speed control system can be coordinated and controlled.

[0163] like Fig. 9 and Fig.10 As shown, this is a diagram of the simulation effect of a large power grid using the cooperative control device.

[0164] Based on the typical operation mode of the power grid, three large hydropower station units (a total of 27 units) were added with a joint control system in the simulation calculation. The disturbance fault is a fault-free removal unit (2*600MW), the simulation time is 160 seconds, and the output change comparison curve of a 1000MW unit is as follows Fig. 9 As shown in the figure, the comparison curve of grid frequency change is as follows Fig.10 shown. Figure 2 In the simulation, the unit adopts the joint control mode of the original monitoring system and the auxiliary control device. Under the frequency difference disturbance, the unit's active output increases from 1002MW to 1030MW. Due to the reverse adjustment of the primary frequency modulation power by the monitoring system, the active power is reduced back and forth to the initial value of 1002MW. After 160s, the grid frequency stabilizes at 49.891Hz. After adding the auxiliary control device, the unit's active output increases from 1002MW to 1034MW, and the grid frequency recovers and stabilizes to 49.915Hz. In this simulation case, after the 27 units added active power auxiliary control devices, the grid frequency recovery level increased by 0.024Hz.

[0165] like Fig.11 and Fig.12 The figure shows the waveform diagram of the cooperative control device in actual engineering application.

[0166] Set the assistant control device according to Figure 2 Deployed in the LCU screen of a hydropower unit monitoring system, according to Figure 1The input signal is connected and the output signal is sent to the monitoring system LCU respectively, and the field test is carried out for verification. After the cooperative control device is put into use, the test is carried out for frequency modulation and AGC instruction co-directional test (see the test recording diagram Fig.11 ), and the reverse test of primary frequency modulation and AGC command (see the test waveform diagram Fig.12 The test verified that after the cooperative control device was put into use, the AGC and the primary frequency regulation did not affect each other, which solved the problem of limited action of the AGC or the primary frequency regulation and strengthened the primary frequency regulation capability of the speed regulation system.

[0167] Fig.11 Stage 1: The grid frequency has a negative step of 0.15Hz, and the speed control system has a correct frequency regulation action to increase the active power, and the unit active power is adjusted upward by about 60MW; Stage 2: After the power adjustment is stable, the AGC issues a command to increase the active power by 50MW, and the active power responds by increasing the active power by 50MW; Stage 3: After the power adjustment is stable, the grid frequency has a positive step of 0.15Hz, and the speed control system has a correct frequency regulation action to decrease the active power, and the unit active power is adjusted downward by about 60MW.

[0168] Fig.12 In stage 1, the grid frequency steps forward by 0.2Hz, and the speed control system performs the first frequency regulation correctly to adjust the active power downward, and the active power of the unit is adjusted downward by about 90MW; stage 2: after the power adjustment is stable, the AGC issues a command to increase by 50MW, and the active power responds by increasing by 50MW; stage 3: after the power adjustment is stable, the AGC issues a command to decrease by 50MW, and the active power responds by decreasing by 50MW; stage 4: after the power adjustment is stable, the grid frequency steps negatively by 0.2Hz, and the speed control system performs the first frequency regulation correctly to adjust the active power upward, and the active power of the unit is adjusted upward by about 90MW.

[0169] The present application may also provide a computer device, comprising: at least one processor, a memory, at least one network interface and a user interface. The various components in the device are coupled together through a bus system. It is understood that the bus system is used to achieve 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] The user interface may include a display, a keyboard or a pointing device, such as a mouse, a trackball, a touch pad or a touch screen.

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

[0172] In some embodiments, the memory stores the following elements, executable modules or data structures, or a subset thereof, or an extended set thereof: an operating system and applications.

[0173] The operating system includes various system programs, such as a framework layer, a core library layer, a driver layer, etc., which are used to implement various basic services and process hardware-based tasks. The application includes various application programs, such as a media player (Media Player), a browser (Browser), etc., which are used to implement various application services. The program for implementing the method of the embodiment of the present disclosure can be included in the application.

[0174] In the above embodiment, the processor may also call a program or instruction stored in the memory, specifically, a program or instruction stored in an application program, and is used to:

[0175] Execute the steps of the above method.

[0176] The above method can be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the above method can be completed by an integrated logic circuit of hardware in the processor or an instruction in the form of software. The above processor may be a general processor, a digital signal processor (Digital Signal Processor, DSP), an application specific integrated circuit (Application Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA) or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The above-disclosed methods, steps and logic block diagrams can be implemented or executed. The general processor may be a microprocessor or the processor may also be any conventional processor, etc. The steps of the above-disclosed method can be directly embodied as a hardware decoding processor to execute, or the hardware and software modules in the decoding processor are combined to execute. The software module can be located in a mature storage medium in the field such as a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, etc. The storage medium is located in the memory, and the processor reads the information in the memory and completes the steps of the above method in combination with its hardware.

[0177] It is understood that the embodiments described in the present application can be implemented by 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 (ASIC), digital signal processors (DSP), digital signal processing devices (DSPD), programmable logic devices (PLD), field programmable gate arrays (FPGA), general-purpose processors, controllers, microcontrollers, microprocessors, other electronic units for performing the functions described in the present application or a combination thereof.

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

[0179] The present application may 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 embodiment can be implemented.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present application and are not intended to limit it. Although the present application is described in detail with reference to the embodiments, a person skilled in the art should understand that any modification or equivalent replacement of the technical solution of the present application does not depart from the spirit and scope of the technical solution of the present application and should be included in 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 collect 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 obtained by collecting 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.

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 data collected 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 collects three different frequency signals, namely, the frequency measurement signal from the voltage transformer and the AO signals from two groups of external systems with different sources, filters the collected frequencies respectively, and finally obtains the control input signal by adopting the "middle value selection from three" method.

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 coordination control module includes: 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; a frequency dead zone and limiting unit, which is used to perform dead zone removal and 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; an 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; 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 the 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 the output signal of the coordinated control device.

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 3 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.

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 3 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.

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 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.

7. 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.

8. 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.

9. A method for coordinated control of power closed loop of hydropower unit monitoring system and primary frequency regulation of speed regulation system, implemented based on the device of any one of claims 1 to 7, 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.

10. 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 9 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 that can be used 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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