CN211287799U - Device for preventing oscillation of low-frequency power of steam turbine generator unit - Google Patents
Device for preventing oscillation of low-frequency power of steam turbine generator unit Download PDFInfo
- Publication number
- CN211287799U CN211287799U CN201922277541.XU CN201922277541U CN211287799U CN 211287799 U CN211287799 U CN 211287799U CN 201922277541 U CN201922277541 U CN 201922277541U CN 211287799 U CN211287799 U CN 211287799U
- Authority
- CN
- China
- Prior art keywords
- power
- steam turbine
- generator
- transmitter
- oscillation
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Landscapes
- Control Of Eletrric Generators (AREA)
Abstract
The utility model relates to a prevent device of turbo generator set low frequency power oscillation, include: the system comprises a steam turbine valve, a steam turbine, a generator, a power grid, a power transmitter, a frequency transmitter and an industrial control computer; a steam turbine regulating valve is arranged at a steam inlet of the steam turbine, and the steam turbine is connected with the generator; the generator is connected into a power grid and is connected with the power transmitter; a frequency transmitter is connected in the power grid; the industrial control computer is connected with the steam turbine regulating valve, the power transmitter and the frequency transmitter. The utility model has the advantages that: the method can be applied to a steam turbine generator unit and a generator unit with power closed-loop control. The utility model discloses can be when grid system takes place the low frequency power oscillation, the emergence of unusual operating mode is judged to the accuracy, utilizes the running state that this device changed the unit rapidly, cuts generator power closed-loop control, prevents the unit power fluctuation aggravation, is favorable to the dissipation of low frequency power oscillation, guarantees the security of generating set and electric wire netting operation.
Description
Technical Field
The utility model relates to a unit low frequency power oscillation field especially includes the device that prevents turbo generator set low frequency power oscillation.
Background
When the line power of the generator oscillates with approximately constant or increased amplitude and the oscillation frequency is low, it is called low frequency power oscillation. The low-frequency power oscillation has a great influence on the stability of a power grid system, and even the power grid system can be disconnected in extreme cases, so that how to prevent and reduce the influence of the low-frequency power oscillation on the operation safety of the system and a unit is always a hot problem of research. When low-frequency power oscillation occurs, the output power of the unit fluctuates greatly in a short time, if the control system cannot judge the occurrence of the abnormal condition, the output of the unit is continuously controlled in a power closed-loop mode, so that frequent switching of a steam turbine valve is caused, further aggravation of power fluctuation is caused, and the operation safety of the unit and a power grid system is possibly threatened. Therefore, the power oscillation working condition must be judged quickly and accurately, and the operation mode of the steam turbine generator unit is switched in time, so that the operation safety of equipment and the unit is ensured.
The steam turbine generator unit is a device which converts steam heat energy into rotary mechanical energy and drives a generator to output electric energy. The output of the steam turbine and the generator is further changed by mainly controlling the opening of the regulating valve to change the flow of steam entering the steam turbine to do work, so that the control on the output power of the unit is realized. The related devices mainly comprise a steam turbine which utilizes steam to do work, a generator which is driven by the steam turbine to convert mechanical energy into electric energy, a regulating valve for regulating the output of the steam turbine, a power transmitter for measuring the power of the generator, a frequency measuring device for measuring the frequency of a power grid, an industrial control computer for performing logic calculation and control and the like. Under normal conditions, the power transmitter measures the output power of the generator and transmits the power signal to the industrial computer; the industrial computer generates a steam turbine valve opening instruction and controls a steam turbine valve according to the real-time power of the generator and the received power instruction; the change of the opening of the steam turbine throttle changes the flow of steam entering the steam turbine to do work, further adjusts the power of the generator and achieves the aim of accurately controlling the power.
The output control strategy of the existing steam turbine set is mainly to regulate the output of the steam turbine according to the power of the generator obtained by real-time measurement so as to realize the closed-loop control of the power. When low-frequency power oscillation occurs, the existing control system has no effective means to judge the abnormal state, and the unit continues to perform closed-loop power control under the condition of power oscillation, so that the output of the unit repeatedly and rapidly rises and falls along with the power oscillation, and the oscillation in the system can be further aggravated. This not only will lead to the quick, big switching action of steam turbine valve, influences the operational safety of unit, still can threaten the operational safety of whole electric wire netting system.
SUMMERY OF THE UTILITY MODEL
The utility model aims at overcoming not enough among the prior art, providing the device that prevents turbo generator set low frequency power oscillation.
The device for preventing the oscillation of the low-frequency power of the steam turbine generator unit comprises: the system comprises a steam turbine valve, a steam turbine, a generator, a power grid, a power transmitter, a frequency transmitter and an industrial control computer; a steam turbine regulating valve is arranged at a steam inlet of the steam turbine, and the steam turbine is connected with a generator; the generator is connected into a power grid and is connected with a power transmitter; a frequency transmitter is connected in the power grid; the industrial control computer is connected with the steam turbine regulating valve, the power transmitter and the frequency transmitter.
The utility model has the advantages that:
(1) the utility model discloses can be applied to turbo generator set and possess on power closed-loop control's the generating set. The utility model discloses can be when grid system takes place the low frequency power oscillation, the emergence of unusual operating mode is judged to the accuracy, utilizes the running state that this device changed the unit rapidly, cuts generator power closed-loop control, prevents the unit power fluctuation aggravation, is favorable to the dissipation of low frequency power oscillation, guarantees the security of generating set and electric wire netting operation.
(2) The utility model discloses the signal and the logic criterion that utilize the collection are accurate to be judged the condition of low frequency power oscillation to make power closed loop control mode amputated, the unit is exerted oneself stably, obtain alleviating or eliminating with the help low frequency power oscillation. The reliability of the operation of the generator set is improved, and the safety of the grid-connected operation of the generator set is improved. When the power oscillation occurs in the turbo generator set, the occurrence of the low-frequency power oscillation is accurately judged by monitoring corresponding technical indexes, the power oscillation is reduced or eliminated by adjusting the control mode of the set, and the operation reliability of the set and a power grid system is improved.
Drawings
FIG. 1 is a schematic view of an apparatus for preventing low frequency power oscillations of a turbo unit;
fig. 2 is a logic structure diagram for judging low-frequency power oscillation of the unit.
Description of reference numerals: the system comprises a steam turbine adjusting valve 1, a steam turbine 2, a generator 3, a power grid 4, a power transmitter 5, a frequency transmitter 6 and an industrial control computer 7.
Detailed Description
The present invention will be further described with reference to the following examples. The following description of the embodiments is merely provided to aid in understanding the invention. It should be noted that, for those skilled in the art, the present invention can be modified in several ways without departing from the principle of the present invention, and these modifications and modifications also fall into the protection scope of the claims of the present invention.
The main structure of the utility model is as shown in figure 1, and the system mainly comprises a steam turbine 2, a generator 3, a steam turbine throttle 1, a power transmitter 5, a frequency transmitter 6 and an industrial control computer 7. A steam turbine adjusting valve 1 is arranged at a steam inlet of a steam turbine 2, and the steam turbine 2 is connected with a generator 3; the generator 3 is connected into the power grid 4, and the generator 3 is connected with the power transmitter 5; a frequency transmitter 6 is connected in the power grid 4; the industrial control computer 7 is connected with the steam turbine regulating valve 1, the power transmitter 5 and the frequency transmitter 6.
In a normal state, the industrial control computer 7 compares the real-time output power of the unit sent by the power transmitter 5 with the received power instruction of the unit, calculates to generate an opening instruction of the steam turbine throttle 1, controls the steam flow entering the steam turbine by using the steam turbine throttle 1, and changes the output of the generator unit, thereby realizing accurate closed-loop power control.
Because generating set low frequency power oscillation influences the safety of generating set and 4 operations of electric wire netting, and also appear very seldom, the difficult completion of actual operation, consequently the utility model discloses the method configuration and analogue test are carried out on the emerson OVATION decentralized control system, and this control system wide application realizes the analog process in each big generating set, and the power measurement signal and the 4 frequency measurement signals of electric wire netting of main compulsory unit rely on manual quick forcing signal value to come the realization simulation process during, judge the abnormal conditions of low frequency power oscillation according to comprehensive logic criterion.
As shown in fig. 2, in the low-frequency power oscillation judgment logic of the unit: in the power measured value holding loop, the power measured value holding loop (holds for 1s), the output of the RS trigger is TRUE, 1s pulse is sent, 0.75s is delayed, and then 0.75s pulse is sent to reset the RS trigger. At the input position of a unit power measurement signal, a dotted line is input switching value, when the switching value is TURE, the analog quantity signal input of the functional block is Y end, the switching value is FALSE, and the analog quantity input is N end. The value of H is obtained by calculating the uplink frequency-power conversion function and amplifying the gain, and is a variable value, and when the uplink input analog quantity is larger than the value, the output of the function block is TRUE. The logic and function block judges the abnormal power signal of the unit, the counting module calculates the times of switching the logic and function block from FALSE (0) to TRUE (1) in a period of 15s, and each large main flow control system has the function block for realizing the function.
The judgment conditions for judging the low-frequency power oscillation condition are as follows:
a) periodically scanning the real-time power measured value of the generator 3, receiving the real-time power of the generator 3 by the industrial control computer 7, keeping the value for 1 second, comparing the value with the current real-time power value within the 1 second, and if the power variation amplitude of the generator 3 exceeds 5% of the rated power of the generator 3 within the 1 second, judging that the logic is established; after 1 second comparison, the held power value is released, the current power value is held again after tracking the current actual power value for 0.5 second, and a next judgment period is entered;
b) in order to eliminate the interference of the primary frequency modulation response power of the generator set on the logic judgment, the logic algorithm synchronously compares the amplitude of the power change of the generator 3 within 1 second with the primary frequency modulation theoretical action power required by the current frequency fluctuation of the power grid 4, and if the actual power change amplitude exceeds the limit value of the primary frequency modulation theoretical action power requirement, the logic judgment is established; the calculation formula of the primary frequency modulation power required by the current power grid 4 frequency fluctuation is as follows:
primary frequency modulation theoretical action power ═ rated generating power x (rotating speed difference-dead zone) ]/(turbine theoretical rotating speed x rotating speed unequal rate)
In the above formula, the rotation speed difference is the difference between the actual steam turbine rotation speed and the theoretical value of 3000 r/min; the dead zone is 2 r/min; the rotation speed difference does not respond to primary frequency modulation action within +/-2 r/min; the theoretical rotating speed of the steam turbine is 3000 r/min; the rate of rotation inequality is 5%. The method can refer to the standard 'Primary frequency modulation test and Performance acceptance guide rule' of thermal generator sets (GB/T30370-2013); for example, when the rated power generation amount of the unit is 660MW and the rotating speed is 3002r/min, the calculated value of the primary frequency modulation motion amount is 0MW, when the rotating speed is 3011r/min, the theoretical value of the primary frequency modulation motion amount is-39.6 MW, and similarly, when the rated power generation amount of the unit is 1000MW and the rotating speed is 3011r/min, the theoretical value of the primary frequency modulation motion amount is-60 MW.
c) Multiplying the variation of the power measurement signal of the generator 3 in 1 second by the theoretical action power of primary frequency modulation corresponding to the frequency variation; if the frequency modulation is negative, the power change direction of the motor 3 is opposite to the change direction of the primary frequency modulation theoretical action power, and the logic judgment is true;
in a judging period, when the judging condition a) is met and the condition b) or the condition c) is met, judging that the power abnormity of the generator 3 occurs for 1 time; if the logic judgment is established for 3 times within 15 seconds, the generator 3 is considered to be in the low-frequency power oscillation working condition; in a logic or mode, a low-frequency power oscillation signal is added in a judgment loop of cutting off automatic control in the power closed-loop control of the generator; when the generator 3 is judged to be in low-frequency power oscillation, if the closed-loop control of the generator power is in an input state, the control system cuts off the power closed-loop control, and the output of the generator 3 is manually controlled by an operator; and when the low-frequency power oscillation phenomenon of the generator 3 disappears, the power closed-loop control is put into operation again manually by an operator.
The limit value of the primary frequency modulation theoretical action power requirement under the judgment condition b) is as follows: and amplifying the theoretical action power of the primary frequency modulation by a gain coefficient by 2-3 times.
The determination condition c) is that the absolute value of the amount of change in the power measurement signal of the generator 3 in 1 second is not obtained.
Example (b):
1) firstly, determining a set value in the method, setting the rated load of a generator set as 660MW, setting the 5% rated load as 33MW, setting parameters in a frequency-power conversion function according to the rotating speed unequal rate of 5% of an actual steam turbine, setting the rotating speed of the steam turbine as 3000r/min, setting the frequency of a power grid 4 as 50Hz, and referring to GB/T30370 plus 2013 'Primary frequency modulation test and Performance acceptance guide rule of a thermal generator set'.
The input x of the broken line function is the rotating speed of the steam engine (which can also be set as the frequency, the rotating speed is selected in the simulation process), the output y of the function is the theoretical calculated value of the primary frequency modulation power, and the function value is (x 3002, y 0, x 3011, y 39.6, x 2998, y 0, x 2989, y 39.6) according to the theoretical calculated value of the primary frequency modulation power, namely, the primary frequency modulation does not act when the rotating speed difference is +/-2 r/min (+/-0.033 Hz); the polyline function is a linear function of an equation of Y ═ aX + b, which is realized by an f (X) function block, and an interval function equation is independently calculated by two end points arranged, such as the intervals of points (3002,0) to (3011, -39.6) arranged as described above, the function equation is Y ═ 4.4X +13208.8, and the intervals of points (2998,0) to (2989,39.6) are such that the function equation is Y ═ 4.4X + 13191.2; when the rotating speed difference is +/-11 r/min, the value is the maximum rotating speed deviation of the primary frequency modulation action, and the corresponding maximum power response is 39.6 MW; the gain amplification factor K is set according to the situation, and the simulation process is temporarily set to be 2; before the simulation test, the functional blocks are confirmed to work normally, the power signal and the rotating speed value are provided with an operation panel, and an add-subtract load button is arranged in the power signal panel, so that the rapid operation can be realized.
2) The simulation process is started, the rotating speed is set to be 2993r/min, the f (x) function is automatically calculated and output to be 22MW, after amplification and absolute value calculation, the primary frequency modulation action limit value is output to be 44MW, at the moment, the simulation power measurement signal is 500MW, timing is started, the simulation test needs to be completed within a period of 15s, and the current time sequence is 0 second.
And directly simulating an input power signal to be 450MW at the 1 st second, calculating that the absolute value of the variation within 1 second is 50MW greater than 44MW, and judging that the power of the unit is abnormal for 1 time if the condition a) and the condition b) are simultaneously met. And setting the power signal to be 480MW in the 3 rd second, wherein the power change direction in the 1 second time sequence is opposite to the power change direction of the primary frequency modulation action, the power change amount is 30MW and does not reach the limit value, the condition a and the condition b are not met, the condition c is met, and the power abnormal signal disappears. And setting the power signal to 520MW at the 4 th second, wherein the power variation of 40MW within the 1 second time sequence is greater than the 5% rated load limit value and smaller than the primary frequency modulation limit value, the power variation direction is opposite to the primary frequency modulation action power variation direction, the condition a and the condition c are simultaneously satisfied, and judging that the unit power is abnormal for 1 time. And setting the power signal back to 500MW again in the 5 th second, and similarly, the condition a, the condition b and the condition c are not met, so that the power abnormal signal disappears. And repeatedly setting the power signal to 450MW again in the 6 th second, judging that the power of the unit is abnormal for 1 time, and triggering the power abnormal signal for 3 times in total and then triggering the low-frequency power oscillation signal.
3) And after the low-frequency power oscillation signal is sent to the power closed-loop control of the generator set, a manual signal is sent out.
4) And repeating the step of judging the power abnormality of the unit, triggering for 2 times in 15 seconds in total, and not triggering the low-frequency power oscillation signal.
By utilizing the control judgment logic, the low-frequency power oscillation can be accurately generated in time. If the power closed-loop control circuit of the generator set is put into operation at the moment, the signal can directly cut off the control circuit, the instruction of the turbine governor 1 can be manually given by an operator through the industrial control computer 7, and the output of the generator set does not fluctuate along with the change of the power measurement value. The measure is beneficial to the dissipation of the low-frequency power oscillation, and the operation safety of the generator set and the power grid 4 is ensured.
When the oscillation phenomenon of the low-frequency power of the unit disappears, the operator needs to confirm that the abnormal condition disappears, and then the signal can be manually reset, and the closed-loop control of the power of the unit is manually put into operation again.
Claims (1)
1. The utility model provides a prevent the device of turbo generator set low frequency power oscillation which characterized in that includes: the system comprises a steam turbine regulating valve (1), a steam turbine (2), a generator (3), a power grid (4), a power transmitter (5), a frequency transmitter (6) and an industrial control computer (7); a steam turbine regulating valve (1) is arranged at a steam inlet of the steam turbine (2), and the steam turbine (2) is connected with a generator (3); the generator (3) is connected into the power grid (4), and the generator (3) is connected with the power transmitter (5); a frequency transmitter (6) is connected in the power grid (4); and the industrial control computer (7) is connected with the steam turbine regulating valve (1), the power transmitter (5) and the frequency transmitter (6).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922277541.XU CN211287799U (en) | 2019-12-17 | 2019-12-17 | Device for preventing oscillation of low-frequency power of steam turbine generator unit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922277541.XU CN211287799U (en) | 2019-12-17 | 2019-12-17 | Device for preventing oscillation of low-frequency power of steam turbine generator unit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211287799U true CN211287799U (en) | 2020-08-18 |
Family
ID=72019256
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922277541.XU Active CN211287799U (en) | 2019-12-17 | 2019-12-17 | Device for preventing oscillation of low-frequency power of steam turbine generator unit |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211287799U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111042874A (en) * | 2019-12-17 | 2020-04-21 | 浙江浙能技术研究院有限公司 | Device and method for preventing low-frequency power oscillation of steam turbine generator unit |
| CN112832876A (en) * | 2020-12-31 | 2021-05-25 | 威立雅（哈尔滨）热电有限公司 | Method for carrying out isolated network starting operation of steam turbine generator through automatic control system |
-
2019
- 2019-12-17 CN CN201922277541.XU patent/CN211287799U/en active Active
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111042874A (en) * | 2019-12-17 | 2020-04-21 | 浙江浙能技术研究院有限公司 | Device and method for preventing low-frequency power oscillation of steam turbine generator unit |
| CN111042874B (en) * | 2019-12-17 | 2023-08-22 | 浙江浙能技术研究院有限公司 | Device and method for preventing low-frequency power oscillation of steam turbine generator unit |
| CN112832876A (en) * | 2020-12-31 | 2021-05-25 | 威立雅（哈尔滨）热电有限公司 | Method for carrying out isolated network starting operation of steam turbine generator through automatic control system |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN211287799U (en) | Device for preventing oscillation of low-frequency power of steam turbine generator unit | |
| RU2011122613A (en) | DEVICE FOR MANAGING ENERGY GENERATION AND METHOD FOR MANAGING ENERGY GENERATION FOR A FUEL ELEMENT | |
| US4467216A (en) | Multiple fixed hydraulic geometry turbine control system | |
| GB1462476A (en) | Electrical power generation unit load control | |
| CN108597632B (en) | Grid-connected load regulation control method and system for nuclear power unit | |
| US4746807A (en) | Automatic control system for controlling the output power of a power plant | |
| CN112628793B (en) | Boiler stable combustion control method under deep peak regulation working condition of coal-fired unit | |
| CN112531769A (en) | Primary frequency modulation control method for thermal power plant | |
| CN111042874A (en) | Device and method for preventing low-frequency power oscillation of steam turbine generator unit | |
| CN114609902A (en) | Variable-rate load control method and device of coal-fired unit based on AGC instruction state change judgment | |
| CN114465284A (en) | Unit load control method adaptive to fast-change AGC (automatic gain control) instruction | |
| CN111379597A (en) | Method and system for detecting and controlling forced oscillation of steam turbine generator unit | |
| CN107939590A (en) | A kind of control method by water level power generation | |
| CN104989464A (en) | Cement kiln waste heat generation constant-voltage automatic generation control module and control method | |
| WO2020098887A1 (en) | Method for stabilising a rotor of a wind turbine | |
| GB1374871A (en) | Digital computer control system for monitoring and controlling operation of industrial gas turbine apparatus | |
| CN112104010B (en) | Power control method for generator | |
| CN115614112A (en) | Electric power control method and system for steam turbine generator of nuclear power plant | |
| CN109340038B (en) | Power gradual change fault judgment method based on continuous slope change threshold judgment | |
| CN110492823B (en) | Overvoltage stall suppression parameter self-adaption and stall loss time self-compensation method | |
| CN210919166U (en) | Steam turbine speed governing optimization system under FCB operating mode | |
| SU1467731A1 (en) | Self-sufficient power unit | |
| CN209557046U (en) | A kind of cogeneration unit off-grid speed limit half-wave control device | |
| CN216310623U (en) | Static deviation eliminating device for steam pressure of power plant | |
| CN210087535U (en) | PCC control device of variable speed water turbine |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |