A test method for regulating performance of an isolated grid of impulse hydroelectric generating set

Abstract

The present application relates to a kind of impulse hydroelectric generating set isolated network regulation performance test method, belong to hydroelectric generating set isolated network control technical field.The present application is test method:1, static test, when unit shutdown state, simulate unit grid connection, by applying sinusoidal wave frequency signal to speed regulator unit frequency side, isolated network threshold, isolated network dead zone, the action threshold of deflector is verified;2, no-load simulation isolated network test, when unit no-load state, in speed regulator side forced grid connection signal, by manually operating spray needle opening degree to make unit enter isolated network mode, verify the rationality of speed regulation system isolated network parameter;3, load rejection simulation isolated network test, unit grid connection with more than 30% rated load, in speed regulator side forced grid connection signal, grid connection state is implemented load rejection, realize the dynamic verification of impulse unit isolated network parameter.Both ensure the authenticity of impulse unit isolated network regulation ability verification, and reduce the difficulty and risk of test.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of isolated network control of hydroelectric generating units, and particularly relates to a method for testing the regulation performance of an impulse hydroelectric generating unit in an isolated network. BACKGROUND

[0002] The impulse unit operates at a high water head, and is the main power source at the end of the power grid in some remote mountainous areas. The grid structure of the regional power grid mainly connected by long chains is weak, and the installed capacity of the hydroelectric generating units in the region is much higher than the total load of the regional power grid. If the regional power grid is fault-decoupled from the main grid to form a regional isolated network, the high-frequency problem of the isolated network is prominent.

[0003] It is crucial to set reasonable isolated network PID parameters, isolated network dead zone, isolated network threshold and other parameters for the stable frequency of the isolated network and the improvement of the regulation ability of the isolated network of the unit. At present, how to verify the regulation effect of the isolated network parameters of the impulse unit has been a problem to be solved. If starting from the engineering practice, the power grid dispatching artificially adjusts the power station transmission line to create the conditions of the regional isolated network, but the test cost is too high and the test risk is too large, so this method is generally not adopted. The test of the online isolated network simulator cannot realize the scene that the unit actually operates in the isolated network mode to participate in the frequency regulation by sending a frequency signal instead of the actual frequency of the unit to simulate the regulation of the isolated network parameters of the unit. SUMMARY

[0004] The purpose of the application is to solve the problems of the high test cost and the large risk of the actual measurement of the impulse unit in the regional isolated network and the test of the online isolated network simulator which cannot realize the scene that the unit actually operates in the isolated network mode to participate in the frequency regulation. The application provides a method for testing the regulation performance of an impulse hydroelectric generating unit in an isolated network, which not only ensures the authenticity of the verification of the isolated network regulation ability of the impulse unit, but also reduces the difficulty and risk of the test.

[0005] The test method of the application comprises the following steps: 1. Static test: simulate the grid connection of the unit when the unit is in a shutdown state, verify the isolated network threshold, isolated network dead zone, action threshold of the diverter, etc. by applying a sinusoidal frequency signal to the frequency side of the governor; 2. No-load simulated isolated network test: forcibly connect the grid signal to the side of the governor when the unit is in a no-load state, make the unit enter the isolated network mode by manually operating the injection needle opening degree, and verify the rationality of the isolated network parameters of the speed regulation system; 3. Load shedding simulated isolated network test: connect the grid signal to the side of the governor when the unit is in a grid-connected state with more than 30% of the rated load, and implement load shedding to dynamically verify the isolated network parameters of the impulse unit.

[0006] The specific technical scheme of the application is as follows:

[0007] A method for testing the regulation performance of an impulse hydroelectric generating unit in an isolated network, comprising the following steps:

[0008] Step 1, the impulse water turbine needle opening degree signal, active power signal, deflector action and reset signal, unit frequency signal is connected to the speed regulating system tester, which is used for analog signal measurement (needle opening degree signal, active power signal), switch signal measurement (deflector action and reset signal), unit frequency signal measurement and output;

[0009] Step 2, static test of unit: the threshold of isolated network, the dead zone of isolated network frequency, and the control parameters of isolated network are respectively rechecked. The threshold of isolated network and the dead zone of isolated network meet the requirements of the regulation, and the control parameters of isolated network meet the requirements of isolated network regulation.

[0010] Step 3, static deflector test of unit: disconnect the unit frequency terminal of the speed regulator, and apply a sinusoidal frequency signal with an amplitude of ±0.1-±3.0 Hz and a period of 10-100 s to the unit frequency side of the impulse water turbine speed regulator through the speed regulating system tester, and monitor the deflector action, including the deflector action threshold and the deflector reset delay lock time.

[0011] Step 4, unit no-load simulation isolated network test: the unit is in no-load operation state, the speed regulating system grid signal line is short-circuited, the needle opening degree is manually increased or decreased, the unit frequency exceeds the isolated network threshold, and the unit enters the isolated network mode; then continue to manually increase or decrease the needle opening degree, when the unit frequency rises to 52 Hz or falls to 48 Hz, immediately cut the automatic, monitor the speed regulating system to adjust the unit frequency to 50 Hz, and verify the rationality of the isolated network parameter setting of the speed regulating system;

[0012] Step 5, unit load rejection simulation isolated network test: the unit is in grid operation state with 30% rated load, the speed regulating system grid signal line is short-circuited, then the generator outlet circuit breaker is disconnected, the frequency maximum amplitude reaches the isolated network threshold condition after the unit rejects 30% rated load, the speed regulating system enters the isolated network mode for frequency regulation, and the speed and stability meet the requirements of the regulation.

[0013] The static test of step 2 refers to the unit shutdown state, the water inlet valve is closed, the unit frequency terminal of the speed regulator is disconnected, the speed regulating system grid signal line is short-circuited, and the speed regulating system tester provides a frequency output signal with an amplitude of ±0.1-±3.0 Hz and a period of 10-100 s to the unit speed regulator, and monitors whether the speed regulator action logic and actual action signal output are correct.

[0014] The isolated network threshold of step 2 refers to the frequency threshold of other control modes (such as primary frequency modulation mode, large network mode, etc.) entering isolated network mode. If the frequency threshold is set to ±0.5 Hz, when the frequency exceeds the range of 50±0.5 Hz, the speed regulating system automatically enters the isolated network mode, calls the isolated network regulation parameters, and generally the isolated network threshold is set to ±0.5 Hz.

[0015] The isolated network frequency dead zone described in step 2 refers to the manually set frequency dead zone. If the isolated network frequency dead zone is set to ±0.1Hz, after the unit enters the isolated network mode, the speed control system will not adjust when the unit frequency changes within 49.9Hz-50.1Hz.

[0016] The deflector reset delay lockout time described in step 3 means that after the unit's deflector is actuated, when the frequency drops to the deflector reset value, the deflector will not reset immediately but will reset after a certain delay. This lockout time is to protect the impulse unit from frequency oscillation caused by frequent deflector actuation, but too long a lockout time will affect the speed of the impulse unit's isolated grid adjustment.

[0017] Furthermore, a sinusoidal frequency signal with an amplitude of ±0.1-±3.0 Hz and a period of 10-100 s is applied to the frequency side of the speed regulator of the impulse hydropower unit through the speed regulation system tester, as shown in the following figure: Figure 2 As shown, the deflector will perform logical judgment based on the frequency change. If the frequency exceeds the deflector action threshold of ±2Hz and the frequency rises above 52Hz, the deflector will operate, deflecting the water flow from the nozzle to the runner and rapidly reducing the unit frequency. When the frequency drops below 48Hz, the deflector will reset, restoring the water flow from the nozzle to the runner and rapidly increasing the unit frequency. The periodic sinusoidal frequency signal is closer to the frequency oscillation of the unit in the actual isolated state than the traditional step frequency signal. It can accurately detect the rationality of the deflector action threshold and reset delay lockout time settings, and verify the deflector action logic.

[0018] The unit no-load simulated isolated grid test in step 4 means that the unit is in a no-load frequency mode and is adjusted using no-load parameters.

[0019] Furthermore, by short-circuiting the grid-connected signal in the speed governor, the speed governor is forced to enter the grid-connected operation state, simulating the unit entering the primary frequency regulation or large grid control mode. The actual generator outlet circuit breaker is not closed, and the speed governor is switched to manual operation. The manual increase or decrease of the nozzle opening causes the flow rate through the unit to change, and the unit frequency gradually deviates from 50Hz. When the unit frequency exceeds the isolated grid threshold of ±0.5Hz, the speed governor enters the isolated grid mode, and the isolated grid parameters are used for adjustment. The nozzle opening is then greatly increased or decreased to cause the unit frequency to deviate by more than ±2Hz. Finally, the speed governor is switched to automatic operation to simulate the large fluctuation of the grid frequency in the isolated grid environment, and verify the rationality of the isolated grid parameters and the deflector action threshold settings of the speed governor during the process of adjusting the unit frequency to 50Hz.

[0020] The step 5 described unit load shedding simulation island test refers to that the unit enters primary frequency modulation or a large network control mode, the actual generator outlet breaker is closed, the speed regulation system is short-circuited, the island signal is disconnected, the generator outlet breaker is opened, 30% rated load of the unit is thrown off, at this time, the speed regulation system is short-circuited, the governor is still in the grid-connected operation state, and the rationality of the island parameter of the governor in the process of frequency regulation of the unit to 50 Hz and the threshold setting of the folding device is verified again.

[0021] The procedure described in step 5 requires that the speed of the island regulation frequency change attenuation degree be ≤30% (the ratio of the second speed deviation peak value to the starting deviation peak value with the same sign as the starting deviation), and the stability of the island regulation frequency stability time ≤60 s.

[0022] The impact type hydroelectric generating unit island regulation performance test method provided by the application fills the gap that the impact type unit island parameter cannot be dynamically verified by a real machine; by applying a sinusoidal frequency signal to the speed regulator of the impact type hydroelectric generating unit on the unit frequency side, the frequency oscillation of the unit in the actual island state is simulated, the rationality of the setting of the folding device action threshold and the reset delay lockout time can be accurately detected, and the folding device action logic is verified; by forcibly connecting the grid signal on the speed regulator side, the needle opening degree is manually operated under the no-load state of the impact type unit, and load shedding is implemented under the grid-connected state, the dynamic verification of the impact type unit island parameter is realized, the authenticity of the impact type unit island regulation capability verification is ensured, and the difficulty and risk of the test are reduced. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The flowchart of the impact type hydroelectric generating unit island regulation performance test method of the application is shown.

[0024] Figure 2 The model block diagram of the impact type unit of the application is shown, where f ref is a frequency given; f g is a unit frequency.

[0025] Figure 3 The island threshold test curve in the example of the application is shown.

[0026] Figure 4 The folding device action threshold and reset delay lockout time test curve in the example of the application is shown.

[0027] Figure 5 The no-load simulation island test curve of the unit in the example of the application is shown.

[0028] Figure 6 The load shedding simulation island test curve of the unit in the example of the application is shown. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the present application more clear, the present application will be further described in detail below with examples. Those skilled in the art will understand that the following examples are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. If the specific technology or condition is not specified in the examples, it is carried out according to the technology or condition described in the literature in the art or according to the product instruction. If the manufacturer of the instrument is not specified, it is a conventional product that can be obtained by purchase. Examples

[0030] As Figure 1 shown, a test method for regulating performance of an impulse hydroelectric generating unit in an isolated network, comprising the following steps:

[0031] Step 1, connect the impulse hydroelectric generating unit injection needle opening degree signal, active power signal, deflector action and reset signal, and unit frequency signal to the speed regulation system tester (the tester is a device for realizing field test, prior art). The speed regulation system tester is used for measuring analog signals (injection needle opening degree signal, active power signal), switching value signal measurement (deflector action and reset signal), and measurement and output of unit frequency signal. The tester is a device for realizing field test.

[0032] Step 2, static test of the unit: respectively perform review test on the isolated network threshold, isolated network frequency dead zone, and isolated network control parameters of the impulse hydroelectric generating unit. The isolated network threshold and isolated network dead zone meet the requirements of the regulations, and the isolated network control parameters meet the requirements of isolated network regulation.

[0033] Step 3, static deflector test of the unit: disconnect the speed regulator unit frequency terminal, and respectively apply a sinusoidal frequency signal with an amplitude of ±0.1-±3.0 Hz and a period of 10-100 s to the speed regulation system tester on the frequency side of the speed regulator of the impulse hydroelectric generating unit, and monitor the deflector action, including deflector action threshold and deflector reset delay lockout time.

[0034] Step 4, no-load simulated isolated network test of the unit: when the unit is in no-load operation state, short-circuit the grid signal line of the speed regulation system, manually increase or decrease the injection needle opening degree, so that the unit frequency exceeds the isolated network threshold, and the unit enters the isolated network mode; then continue to manually increase or decrease the injection needle opening degree, and immediately cut off the automatic when the unit frequency rises to 52 Hz or falls to 48 Hz, monitor the process of adjusting the unit frequency to 50 Hz by the speed regulation system, and verify the rationality of the isolated network parameter setting of the speed regulation system.

[0035] Step 5, simulated isolated network test of the unit with load rejection: the unit is in grid-connected operation with 30% rated load, the grid signal line of the speed regulation system is short-circuited, then the generator outlet circuit breaker is disconnected, the maximum amplitude of the unit frequency reaches the isolated network threshold condition after the unit rejects 30% rated load, the speed regulation system enters the isolated network mode for frequency regulation, and the speed and stability meet the requirements of the regulations.

[0036] The static test described in step 2 refers to the unit shutdown state, the water inlet valve is closed, the speed regulator unit frequency terminal is disconnected, the speed regulation system grid-connected signal line is short-circuited, and a sinusoidal frequency signal with an amplitude of ±0.1-±3.0Hz and a period of 10-100s is provided to the unit speed regulator through the speed regulation system tester to monitor whether the speed regulator action logic and actual action signal output are correct.

[0037] The isolated network threshold in step 2 refers to the frequency threshold at which other control modes (such as primary frequency modulation mode and large network mode) enter the isolated network mode. If the frequency threshold is set to ±0.5Hz, when the frequency exceeds the range of 50±0.5Hz, the speed regulation system automatically enters the isolated network mode and calls the isolated network adjustment parameters. Generally, the isolated network threshold is set to ±0.5Hz.

[0038] The isolated network frequency dead zone described in step 2 refers to the manually set frequency dead zone. If the isolated network frequency dead zone is set to ±0.1Hz, after the unit enters the isolated network mode, the speed control system will not adjust when the unit frequency changes within 49.9Hz-50.1Hz.

[0039] The deflector reset delay lockout time described in step 3 means that after the unit's deflector is actuated, when the frequency drops to the deflector reset value, the deflector will not reset immediately but will reset after a certain delay. This lockout time is to protect the impulse unit from frequency oscillation caused by frequent deflector actuation, but too long a lockout time will affect the speed of the impulse unit's isolated grid adjustment.

[0040] A sine wave frequency signal with an amplitude of ±0.1-±3.0Hz and a period of 10-100s is applied to the frequency side of the speed regulator of the impulse hydropower unit through the speed regulation system tester. Figure 2 As shown, the deflector will perform logical judgment based on the frequency change. If the frequency exceeds the deflector action threshold of ±2Hz and the frequency rises above 52Hz, the deflector will operate, deflecting the water flow from the nozzle to the runner and rapidly reducing the unit frequency. When the frequency drops below 48Hz, the deflector will reset, restoring the water flow from the nozzle to the runner and rapidly increasing the unit frequency. The periodic sinusoidal frequency signal is closer to the frequency oscillation of the unit in the actual isolated state than the traditional step frequency signal. It can accurately detect the rationality of the deflector action threshold and reset delay lockout time settings, and verify the deflector action logic.

[0041] The unit no-load simulated isolated grid test in step 4 means that the unit is in a no-load frequency mode and is adjusted using no-load parameters.

[0042] By short-circuiting the governor grid-connected signal, forcing the governor to enter the grid-connected operation state, simulating the unit entering primary frequency modulation or large grid control mode, the actual generator outlet breaker is not closed, the governor is cut to manual operation, and the needle opening degree is manually increased or decreased to make the unit flow change, the unit frequency gradually deviates from 50Hz, when the unit frequency exceeds the threshold of ±0.5Hz of the isolated grid, the governor enters the isolated grid mode, and the isolated grid parameters are adjusted, and then the needle opening degree is greatly increased or decreased to make the unit frequency deviate by ±2Hz or more, and finally the governor is cut to automatic operation, simulating the large fluctuation state of the grid frequency in the isolated grid environment, verifying the rationality of the isolated grid parameters and the action threshold setting of the speed changer during the process of adjusting the unit frequency to 50Hz.

[0043] The unit load rejection simulation isolated grid test of step 5 refers to that the unit enters primary frequency modulation or large grid control mode, the actual generator outlet breaker is closed, the governor grid-connected signal is short-circuited, the generator outlet breaker is opened, and the unit is rejected by 30% of the rated load. At this time, the governor grid-connected signal is short-circuited, the governor is still in the grid-connected operation state, and the rationality of the isolated grid parameters and the action threshold setting of the speed changer during the process of adjusting the unit frequency to 50Hz is verified again.

[0044] According to the procedure of step 5, the speed of the isolated grid regulation frequency change is required to be ≤30% (the ratio of the second speed deviation peak value to the starting deviation peak value with the same sign as the starting deviation), and the stability of the isolated grid regulation frequency is required to be ≤60s.

[0045] Application example:

[0046] A certain power station No. 1 unit, the unit type is impact type, the water delivery system adopts one pipe and two machine water diversion mode, the rated active power is 6300kW, the rated water head is 435.5m, the rated speed is 600r / min, and the rated flow is 1.9m 3 / s; the primary frequency modulation parameters of the unit are: bt=20%, Td=1s, Tn=0s, primary frequency modulation dead zone ±0.05Hz, bp=4%; the isolated grid parameter setting of the unit is: bt=55%, Td=10s, Tn=0.2s, isolated grid threshold ±0.5Hz, isolated grid dead zone ±0.2Hz, bp=1%; the action logic of the speed changer is: the speed changer is closed at 52Hz, and the speed changer is opened at 50.1Hz.

[0047] Step 1: Connect the needle opening degree signal, active power signal, speed changer action and reset signal, and unit frequency signal to the governor test instrument.

[0048] Step 2: The unit is in shutdown state, the water inlet valve is closed, the governor unit frequency feedback f g is disconnected, and the governor grid-connected signal line is short-circuited, such as Figure 2The frequency signal with amplitude of ±0.6 Hz and period of 100 s is provided to the unit governor through the governor testing instrument, as shown in Figure 3 When the frequency difference exceeds 0.5 Hz, the unit governor enters the isolated grid mode and switches to the isolated grid parameters, and the isolated grid threshold is actually measured as ±0.5 Hz. The governor exits the isolated grid mode and enters the primary frequency modulation mode 30 s after the frequency is adjusted to 50 Hz. When the frequency is recovered, the needle appears a rapid action phenomenon.

[0049] Figure 2 f ref is the frequency given; f g is the unit frequency.

[0050] Step 3: As shown in Figure 2 , the frequency signal with amplitude of ±2.6 Hz and period of 100 s is applied to the unit governor of the impulse water turbine generator through the governor testing instrument, and the governor makes logical judgment according to the frequency change, as shown in Figure 4 The periodic sinusoidal frequency signal is closer to the frequency oscillation in the actual isolated grid state of the unit than the traditional step frequency signal, and can accurately detect that the deflector closes when the frequency rises to 52 Hz and opens when the frequency drops to 50.1 Hz. The deflector action and return logic under the current needle action is too frequent, and the deflector action logic is modified as follows: the deflector is closed at 53 Hz and opened at 52.6 Hz.

[0051] Step 4: The unit is in an idle running state, and the governor is forced to enter the grid-connected running state by short-circuiting the grid-connected signal of the governor, simulating the unit entering the primary frequency modulation mode. The actual generator outlet breaker is not closed, the governor is switched to manual operation, the needle opening degree is manually reduced to change the flow of the unit, and the unit frequency gradually deviates from 50 Hz. When the unit frequency exceeds the isolated grid threshold ±0.5 Hz, the governor enters the isolated grid mode and adjusts using the isolated grid parameters. The needle opening degree is further reduced to make the unit frequency deviate by ±2 Hz or more. Finally, the governor is switched to automatic operation to simulate the state of large fluctuations of the grid frequency in the isolated grid environment, verify the rationality of the isolated grid parameters and the deflector action threshold setting of the governor in the process of adjusting the unit frequency to 50 Hz, and the test curve is shown in Figure 5 It can be seen from Figure 5 that the unit can be adjusted to 50 Hz relatively quickly when the current isolated grid parameters and the modified deflector action threshold are used.

[0052] Step 5: the unit is in the primary frequency control mode, the speed regulating system is short-circuited, the on-grid signal line is short-circuited, and then the outlet circuit breaker of the motor is disconnected, the unit actually experiences load shedding, but because the on-grid signal line of the speed regulating system is short-circuited, the speed regulator is still in the on-grid operation state, and the recording curve of the whole test process is as shown in Figure 6 After the unit sheds 30% rated load, the frequency is as high as 56.1 Hz, reaching the threshold condition of entering the isolated network, and in the process of frequency rising after the unit sheds load, the unit has entered the isolated network mode, when the frequency rises to 53 Hz, the frequency converter is closed, and when the frequency drops to 52.6 Hz, the frequency converter is opened. The isolated network regulation frequency variation attenuation degree is 3% (the ratio of the second speed deviation peak value to the starting deviation peak value with the same sign), and the isolated network regulation frequency stable time is about 55 s.

[0053] The above shows and describes the basic principles, main features and advantages of the present application. It should be understood by those skilled in the art that the present application is not limited by the above examples, and the above examples and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A test method for regulating performance of an isolated grid of a pelton water turbine generator set, characterized in that: Comprise the following steps: Step 1, the impulse water turbine needle opening signal, active power signal, deflector action and reset signal, unit frequency signal is connected to the speed regulating system tester, the speed regulating system tester is used for analog quantity signal measurement, switch quantity signal measurement, unit frequency signal measurement and output;Analog quantity signal includes needle opening signal, active power signal, switch quantity signal includes deflector action and reset signal; Step 2, static test of unit: the threshold of isolated network, the dead zone of isolated network frequency and the control parameters of isolated network are respectively rechecked, the threshold of isolated network and the dead zone of isolated network frequency meet the requirements of the regulation, and the control parameters of isolated network meet the requirements of isolated network regulation; Step 3, static deflector test of unit: disconnect the unit frequency terminal of speed regulator, apply a sinusoidal frequency signal with amplitude of ± 0.1-± 3.0 Hz and period of 10-100 s to the unit frequency side of the speed regulator of the impulse water turbine through the speed regulating system tester, and monitor the deflector action, including deflector action threshold and deflector reset delay lock time; Step 4, unit no-load simulated isolated network test: the unit is in no-load operation state, the speed regulating system grid signal line is short-circuited, the needle opening is manually increased or decreased, the unit frequency exceeds the threshold of isolated network, and the unit enters the isolated network mode;Then continue to manually increase or decrease the needle opening, when the unit frequency rises to 52 Hz or falls to 48 Hz, immediately cut the automatic, monitor the speed regulating system to adjust the unit frequency to 50 Hz, and verify the rationality of the isolated network parameter setting of the speed regulating system; Step 5, unit load rejection simulated isolated network test: the unit is in grid operation state with 30% rated load, the speed regulating system grid signal line is short-circuited, then the generator outlet circuit breaker is disconnected, the frequency maximum amplitude reaches the threshold of isolated network after the unit rejects 30% rated load, the speed regulating system enters the isolated network mode for frequency regulation, and the speed and stability meet the requirements of the regulation.

2. The test method for regulating performance of an isolated grid of a Pelton turbine unit according to claim 1, characterized in that: The static test of step 2 refers to the unit shutdown state, the water inlet valve is closed, the unit frequency terminal of speed regulator is disconnected, the speed regulating system grid signal line is short-circuited, the frequency output signal with amplitude of ± 0.1-± 3.0 Hz and period of 10-100 s is provided to the unit speed regulator through the speed regulating system tester, and the correctness of the action logic and actual action signal output of the speed regulator is monitored.

3. The test method for regulating performance of an isolated grid of a Pelton turbine unit according to claim 1, characterized in that: The isolated network threshold of step 2 refers to the frequency threshold of other control modes entering the isolated network mode, if the frequency threshold is set to ± 0.5 Hz, when the frequency exceeds the range of 50± 0.5 Hz, the speed regulating system automatically enters the isolated network mode, calls the isolated network regulation parameters, and the isolated network threshold is set to ± 0.5 Hz.

4. The isolated network regulation performance test method for the Pelton water turbine generator set according to claim 1, characterized in that: The isolated network frequency dead zone of step 2 refers to the artificially set frequency dead zone, if the isolated network frequency dead zone is set to ± 0.1 Hz, when the unit frequency changes in the range of 49.9 Hz-50.1 Hz after the unit enters the isolated network mode, the speed regulating system does not regulate.

5. The isolated network regulation performance test method for the Pelton water turbine generator set according to claim 1, characterized in that: The deflector reset delay lockout time in step 3 refers to the time when the frequency of the unit deflector action decreases to the deflector reset value, the deflector does not reset immediately but delays for a certain time before resetting. The lockout time is to protect the impulse unit from frequent action of the deflector leading to frequency oscillation, but the lockout time is too long, which will affect the quickness of the impulse unit in isolated network regulation.

6. The isolated network regulation performance test method for the Pelton water turbine generator set according to claim 1, characterized in that: The unit no-load simulation isolated network test in step 4 refers to the unit in no-load frequency mode, using no-load parameters for regulation.

7. The isolated network regulation performance test method for the Pelton water turbine generator set according to claim 1, characterized in that: The unit load shedding simulation isolated network test in step 5 refers to the unit entering primary frequency regulation or large network control mode, the actual generator outlet circuit breaker is closed, the speed regulation system is short-circuited, the generator outlet circuit breaker is opened, and the unit sheds 30% of the rated load. At this time, the speed regulation system is short-circuited, the governor is still in parallel operation state, and the rationality of the isolated network parameters and the deflector action threshold setting in the process of frequency regulation of the unit to 50Hz is verified again.

8. The isolated network regulation performance test method for the Pelton water turbine generator set according to claim 1, characterized in that: The procedure in step 5 requires that the quickness of the isolated network regulation frequency change attenuation degree is ≤30%, and the stability of the isolated network regulation frequency stability time is ≤60s.

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