CN117081104A - Primary frequency modulation control method for energy storage of combined battery of gas steam cycle unit - Google Patents
Primary frequency modulation control method for energy storage of combined battery of gas steam cycle unit Download PDFInfo
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- CN117081104A CN117081104A CN202311030489.2A CN202311030489A CN117081104A CN 117081104 A CN117081104 A CN 117081104A CN 202311030489 A CN202311030489 A CN 202311030489A CN 117081104 A CN117081104 A CN 117081104A
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- 238000004146 energy storage Methods 0.000 title claims abstract description 65
- 238000000034 method Methods 0.000 title claims abstract description 18
- 230000009471 action Effects 0.000 claims abstract description 18
- 230000008859 change Effects 0.000 claims description 15
- 239000000446 fuel Substances 0.000 claims description 12
- 230000007423 decrease Effects 0.000 claims description 8
- 238000002485 combustion reaction Methods 0.000 claims description 5
- 230000033228 biological regulation Effects 0.000 claims description 4
- 238000010248 power generation Methods 0.000 claims description 4
- 230000003247 decreasing effect Effects 0.000 claims description 3
- 230000001105 regulatory effect Effects 0.000 claims description 2
- 238000011217 control strategy Methods 0.000 abstract description 3
- 239000007789 gas Substances 0.000 description 26
- 230000004044 response Effects 0.000 description 5
- 238000012797 qualification Methods 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 239000002918 waste heat Substances 0.000 description 3
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 2
- 239000013589 supplement Substances 0.000 description 2
- 238000010276 construction Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000003912 environmental pollution Methods 0.000 description 1
- 239000002737 fuel gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 230000036632 reaction speed Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 239000000779 smoke Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/24—Arrangements for preventing or reducing oscillations of power in networks
- H02J3/241—The oscillation concerning frequency
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/007—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources
- H02J3/0075—Arrangements for selectively connecting the load or loads to one or several among a plurality of power lines or power sources for providing alternative feeding paths between load and source according to economic or energy efficiency considerations, e.g. economic dispatch
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/12—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load
- H02J3/14—Circuit arrangements for ac mains or ac distribution networks for adjusting voltage in ac networks by changing a characteristic of the network load by switching loads on to, or off from, network, e.g. progressively balanced loading
- H02J3/144—Demand-response operation of the power transmission or distribution network
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
- H02J3/46—Controlling of the sharing of output between the generators, converters, or transformers
- H02J3/466—Scheduling the operation of the generators, e.g. connecting or disconnecting generators to meet a given demand
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Supply And Distribution Of Alternating Current (AREA)
Abstract
The application relates to a primary frequency modulation control method for energy storage of a combined battery of a gas steam cycle unit, belonging to the technical field of frequency modulation of an electric power system; the method comprises the steps of dividing the size of the fluctuation of the network frequency into intervals, and providing different control strategies according to the SOC of the energy storage system on the premise of guaranteeing the economical efficiency and the service life of the energy storage system according to the primary frequency modulation action characteristics of the gas-steam combined cycle unit. The application can utilize the rapid charge and discharge performance of the energy storage system to balance the load fluctuation of the gas-steam combined cycle unit caused by the hysteresis of the steam turbine when responding to primary frequency modulation, and simultaneously solve the problem of insufficient integral electric quantity caused by the fact that the load-reducing speed of the unit is greater than the load-increasing speed.
Description
Technical Field
The application belongs to the technical field of frequency modulation of power systems, and particularly relates to a primary frequency modulation control method for energy storage of a combined battery of a gas steam cycle unit.
Background
The gas-steam combined cycle unit has the advantages of high efficiency, low consumption, quick start, flexible adjustment, high availability, investment saving, short construction period, small environmental pollution and the like, and is increasingly valued and developed in the foreign power industry. The natural gas is directly combusted in the gas turbine to do work, so that the gas turbine drives the generator to generate power, high-temperature tail gas generated by combustion passes through the waste heat boiler to heat boiler water supply, high-temperature and high-pressure steam is generated and then drives the steam turbine to drive the generator to generate power. In general, the turbine inlet is fully opened, and the turbine power generation load increases with the increase of the turbine load and decreases with the decrease of the turbine load. The test shows that the response load change rate of the gas-steam combined cycle unit is also related to the load instruction adding and subtracting direction, and the load adding is slightly slow, mainly because the load adding and subtracting rate of the gas engine is different, the load rising rate is slow, and the load subtracting rate is fast. When the gas turbine acts, only the inertia time value of the guide vane angle switch is larger, and the inertia time constant of the fuel volume, the inertia time constant of the air volume, the combustion reaction delay and the turbine exhaust delay value are smaller, so that the output power of the gas turbine part after the frequency disturbance is fast and stable, and the power of the turbine is gradually increased. Because of the hysteresis of the steam turbine, the overshoot phenomenon is always caused no matter the load is increased or decreased in the primary frequency modulation process, and the primary frequency modulation process of the unit is difficult to control.
At present, most common in the known control strategy is that a fuel engine bears most primary frequency modulation load, the speed is high, certain advantages are occupied, but the load change of the fuel engine influences the load of a steam turbine, so that certain deviation is generated between the integral output of a unit and the actual due output, and the qualification rate of primary frequency modulation is reduced.
Disclosure of Invention
The application aims to provide a primary frequency modulation control method for energy storage of a combined battery of a gas-steam cycle unit, which aims to solve the problems that a gas turbine of the gas-steam combined cycle unit usually actively responds to a unit load instruction, a steam turbine follows, and the load change is rapid when the gas turbine responds rapidly. The load change of the gas turbine can cause the change of the steam heat load of the waste heat boiler, and under the condition that the opening degree of a valve at the inlet of the gas turbine is unchanged, the load of the gas turbine can change along with the change of the steam heat load of the waste heat boiler, but a delay phenomenon exists. Therefore, the technical problem that the gas turbine and the steam turbine are mutually coupled and finally the overshoot phenomenon occurs in the primary frequency modulation process is caused.
In order to achieve the purpose, the specific technical scheme of the combined battery energy storage primary frequency modulation control method of the gas steam cycle unit is as follows:
the primary frequency modulation control method for the combined battery energy storage of the gas steam cycle unit comprises the following steps of:
the battery energy storage system is provided for the gas-steam combined cycle unit. And selecting the rated power of the energy storage battery to be 2% of the rated power of the combined unit, and releasing the capacity within 0.5-1 hour. And besides fully guaranteeing the realization of the functions, the economy and the environmental protection are ensured. Determining the action condition of each device according to the change range of the network frequency absolute value delta f, converting a load action instruction into delta P by an unequal rate function, and controlling the load instruction Qc=delta P- (Pr+Pq-P0) of the energy storage system;
wherein P0 is the actual load of the combined cycle unit at the moment of primary frequency modulation action, pr is the actual power of the gas turbine, and Pq is the actual power of the steam turbine.
The energy storage system and the gas turbine control system simultaneously receive the same frequency signal, and the energy storage system receives the gas turbine power generation power signal. Specifically, the current network frequency signal, the power generation load of the gas-steam combined unit, the maximum power of the energy storage battery, the SOC and other related information need to be simultaneously sent to the combined cycle unit DCS and the battery energy storage control system, and particularly the network frequency signal needs to be homologous and cannot be transferred at all.
The gas-steam combined cycle unit DCS receives the power generated by the energy storage system and calculates the total power of the combined unit and the energy storage. Specifically, during primary frequency modulation, the current load value of the combined cycle unit needs to be recorded. .
And dividing the network frequency fluctuation size into sections, and combining the battery energy storage SOC values in different sections to give different control strategies. When the SOC is too large or too small, the battery energy storage acts at the first time, and the SOC is stabilized at about 50%. And the battery energy storage system is subjected to shallow charging and shallow discharging, and finally responds to balance overshoot caused by hysteresis of the steam turbine under the condition that the characteristics of the combined cycle unit are met.
Specifically, the absolute value |Δf| of the net frequency fluctuation amount Δf is divided into 3 sections:
interval 1: |Δf| <0.033Hz
Interval 2:0.033 hz= <|Δf| <0.06Hz
Interval 3:0.06 hz= <|Δf|
When the frequency of the |Deltaf| <0.033Hz is within the interval 1, the net frequency change is in the dead zone, and the gas turbine, the steam turbine and the energy storage system do not respond, so that the original state operation is kept.
When the frequency of 0.033 Hz= <|Δf| <0.1Hz is in the interval 2, the frequency is equivalent to small frequency disturbance, the reaction speed of the fuel engine is high, and the exhaust temperature is not greatly changed under the condition of small load fluctuation, so that the fuel engine can completely respond to a load instruction, and the energy storage device does not participate in regulation and is in a standby state; when the power variation of the combined unit reaches the delta P, the power variation of the combined unit is mainly regulated by a fuel engine, the moment time point is T0, the energy storage device starts to be put in, the energy storage instruction value is the difference value between the total load instruction of the combined unit and the current actual load of the unit, and the purpose is to absorb/release fluctuation caused by load increase/load decrease of the steam turbine.
When the load is in the interval 3, the load can generate larger fluctuation, in order to prevent the smoke exhaust temperature from rising too high due to the overlarge change of the load of the combustion engine, the load set value of the combustion engine is 90 percent delta P, and when the network frequency f is less than 50Hz and the SOC is more than 70 percent or the network frequency f is more than 50Hz and the SOC is less than 30 percent, the energy storage battery simultaneously acts; when 45% < SOC <55%, the energy storage battery does not follow the action at the action moment, and when the load of the combined cycle unit reaches 90% delta P, the energy storage battery starts to act, and the battery response is extremely fast, so that the 10% delta P requirement can be met instantly, and then, if the load of the steam turbine is gradually increased/reduced, the power of the battery is gradually reduced/increased, and finally the whole power of the unit reaches P0+delta P.
With primary frequency modulation action, Δf gradually decreases to the dead zone, Δp changes accordingly, and the output power of the circulating unit and the energy storage system decreases until the network frequency is recovered.
The primary frequency modulation control method for the combined battery energy storage of the gas steam cycle unit has the following advantages:
1. the primary frequency modulation of the gas-steam combined cycle unit is assisted by utilizing the battery energy storage, the battery energy storage and the turbine energy are balanced, the load is stabilized, the overshoot phenomenon is reduced, and the action qualification rate is improved.
2. The coupling degree between the gas turbine and the steam turbine is reduced, and the adjustment is more flexible.
3. The application can utilize the rapid charge and discharge performance of the energy storage system to balance the load fluctuation of the gas-steam combined cycle unit caused by the hysteresis of the steam turbine when responding to primary frequency modulation, and simultaneously solve the problem of insufficient integral electric quantity caused by the fact that the load-reducing speed of the unit is greater than the load-increasing speed.
Drawings
FIG. 1 is a flow chart of a method for controlling energy storage primary frequency modulation of a combined battery of a gas steam cycle unit.
Fig. 2, fig. 3, fig. 4, fig. 5, fig. 6 and fig. 7 correspond to 6 implementation manners of the method for controlling the primary frequency modulation of the combined battery energy storage of the gas steam cycle unit according to the application.
Detailed Description
In order to better understand the purpose, structure and function of the application, the application relates to a fuel gas steam cycle unit combined battery energy storage primary frequency modulation control method which is further described in detail below with reference to the accompanying drawings.
With the gradual increase of new energy sources of network access, the fluctuation of network frequency is more frequent, and if the gas-steam combined cycle unit can utilize the characteristics of rapidness and flexibility in adjustment to carry out reasonable primary frequency modulation, the method can bring great advantages for the stability of the network frequency. Therefore, the patent provides a control method for energy storage primary frequency modulation by using a gas steam cycle unit combined with a battery, which aims to improve the qualification rate of primary frequency modulation response of the unit.
As shown in figure 1, the application controls the charge and discharge of the battery according to the variation of the primary frequency modulation command and the residual battery power, so as to balance the overshoot of the steam turbine caused by the lifting load of the gas turbine, thereby improving the qualification rate of various indexes of the primary frequency modulation, saving the battery power and reducing the battery loss.
In fig. 1, an AGC command Pagc issued by a schedule, a unit load P0 at the time of issuing the command, a battery SOC, and a battery maximum power Pe are read first. And judging that the difference between the AGC command and the current unit load is in a certain interval. And executing the strategy according to different areas.
Fig. 2, 3, 4, 5, 6,7 correspond to 6 implementations, respectively. The black thickest line is a primary frequency modulation action instruction, the black thin line is the combined unit power, and the black dotted line is the circulating unit-energy storage total power (approximate change condition is not practical).
Fig. 2, 3 are graphs of frequency variation absolute values between 0.033-0.08 Hz. The energy storage system is used for balancing fluctuation power after stabilizing, so that the integral output is stable.
Fig. 4 and 5 show that the absolute value of the frequency change is larger than 0.08Hz, and fig. 4 shows that when the primary frequency modulation action needs to increase the load, the SOC value of the battery is higher, and the energy storage battery participates in regulation from the initial moment. Fig. 5 shows that when the primary frequency modulation action needs load reduction, the SOC value of the battery is lower, the energy storage battery participates in regulation from the initial moment, as shown in the graph, the solid curve line is the combined power without energy storage, the broken line is the total power after energy storage is increased, the response speed of the energy storage of the battery is faster, the response speed is the command when the fuel engine does not act, the power of the fuel engine and the power of the fuel engine are overlapped when the fuel engine does not act, until the stable value is reached, and the power can be absorbed or released by the energy storage system to keep stable no matter the load of the latter half-range turbine rises or falls.
Fig. 6,7 are graphs performed when the absolute value of the frequency change is greater than 0.08Hz and the battery SOC size is 45% -55%. When the primary frequency modulation action is performed, the battery SOC is in a range of 45% -55%, and when the load of the combined cycle unit is increased to 90% delta P in FIG. 6, the energy storage system acts to supplement 10% delta P power, and as the load of the combined cycle unit continues to increase, the power of the energy storage system gradually decreases, so that the overall output is stable; when the load of the combined cycle unit is reduced to 90% delta P in FIG. 7, the energy storage system acts to supplement 10% delta P power, and as the load of the combined cycle unit is continuously reduced, the power of the energy storage system is gradually increased, so that the overall output is stable.
It will be understood that the application has been described in terms of several embodiments, and that various changes and equivalents may be made to these features and embodiments by those skilled in the art without departing from the spirit and scope of the application. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the application without departing from the essential scope thereof. Therefore, it is intended that the application not be limited to the particular embodiment disclosed, but that the application will include all embodiments falling within the scope of the appended claims.
Claims (1)
1. The primary frequency modulation control method for the combined battery energy storage of the gas steam cycle unit is characterized by comprising the following steps of:
selecting the rated power of the energy storage battery to be 2% of the rated power of the combined unit, and finishing the release of the capacity within 0.5-1 hour; determining the action condition of each device according to the change range of the network frequency absolute value delta f, converting a load action instruction into delta P by an unequal rate function, wherein the energy storage system load instruction Qc=delta P- (Pr+Pq-P0), wherein P0 is the actual load of the combined cycle unit at the primary frequency modulation action moment, pq is the actual power of a steam turbine, and Pr is the actual power of a gas turbine;
the energy storage system and the gas turbine control system simultaneously receive the same frequency signal, the energy storage system receives the gas turbine power generation power signal, and the gas steam combined cycle unit DCS receives the power generated by the energy storage system and counts the total power of the combined unit and the energy storage;
the absolute value |Δf| of the net frequency fluctuation amount Δf is divided into 3 sections:
interval 1: |Δf| <0.033Hz
Interval 2:0.033 hz= <|Δf| <0.06Hz
Interval 3:0.06 hz= <|Δf|
When the frequency of the |delta f| <0.033Hz is in the interval 1, the net frequency change is in the dead zone, and the gas turbine, the steam turbine and the energy storage system do not respond, so that the original state operation is kept;
when 0.033 hz= <|Δf| <0.1Hz is in interval 2, the combustion engine completely responds to the load instruction, and the energy storage device does not participate in regulation; when the power variation of the combined unit reaches the delta P, the power variation of the combined unit is mainly regulated by a fuel engine, the time point is T0, the energy storage device is started to be put into operation, and the energy storage instruction value is the difference value between the total load instruction of the combined unit and the current actual load of the unit;
when 0.1 Hz= </deltaf| is in the interval 3, the set value of the load of the fuel engine is 90% deltaP, and when the network frequency f <50Hz and the SOC is more than 70% or the network frequency f >50Hz and the SOC is less than 30%, the energy storage battery acts simultaneously; when 45% < SOC <55%, the energy storage battery does not follow the action at the action moment, and when the load of the combined cycle unit reaches 90% delta P, the energy storage battery starts to act, if the load of the turbine is gradually increased/decreased, the power of the battery is gradually decreased/increased, and finally the overall power of the unit reaches P0+delta P;
with primary frequency modulation action, Δf gradually decreases to the dead zone, Δp changes accordingly, and the output power of the circulating unit and the energy storage system decreases until the network frequency is recovered.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311030489.2A CN117081104A (en) | 2023-08-16 | 2023-08-16 | Primary frequency modulation control method for energy storage of combined battery of gas steam cycle unit |
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| CN202311030489.2A CN117081104A (en) | 2023-08-16 | 2023-08-16 | Primary frequency modulation control method for energy storage of combined battery of gas steam cycle unit |
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