CN109659958B - Power system and peak-load and frequency modulation method thereof - Google Patents
Power system and peak-load and frequency modulation method thereof Download PDFInfo
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Abstract
The invention discloses a power system and a peak-shaving frequency modulation method thereof, which comprises the following steps: acquiring control conditions and frequency variation of the power system; determining the maximum heat storage quantity of the phase-change heat storage station during the waist load period and the maximum heat release demand of the phase-change heat storage station during the valley period according to the control conditions; calculating peak shaving capacity increment of the power system according to the maximum heat storage quantity and the maximum heat release demand; and frequency modulation is carried out on the power system according to the low-frequency signal in the frequency variation. By implementing the method, the maximum peak load capacity increment of the power system is obtained aiming at the power system additionally provided with the phase change heat storage station, the distributed phase change heat storage station can make up the defects of the conventional frequency modulation mode due to the characteristics of slow response and large heat storage capacity, the rotating reserve capacity required by the power grid can be obviously reduced, the rotating reserve capacity saved due to the frequency modulation of the distributed phase change heat storage station can be used for power grid peak load regulation, accident reserve and the like, and the safety and the reliability of the operation of the power system can be further improved.
Description
Technical Field
The invention relates to the technical field of peak-shaving frequency modulation, in particular to a power system and a peak-shaving frequency modulation method thereof.
Background
In recent years, the development of cogeneration units is relatively fast, the installed capacity reaches 3 hundred million kilowatts and accounts for nearly 30 percent of the installed capacity of thermal power. In 2016, the United promulgation of State development and improvement Commission, energy agency, and the like, provides a 'cogeneration management method', and aims at the problem of the development lag of cogeneration, and the cogeneration centralized heating rate of large and medium-sized cities in the north is required to reach more than 60%. With the continuous promotion of energy conservation and emission reduction, the central heating area in China is still increased year by year, and more coal-fired units are predicted to be subjected to heat supply transformation or added with cogeneration units in the future.
The traditional unit adopts the operational mode of "decide electricity with the heat" in the heat supply period, the peak regulation fm ability is limited, current thermoelectric unit adopts the mode that increases heat accumulation device to improve thermoelectric unit's peak regulation fm ability usually, the heat accumulation device that increases can improve energy utilization rate through storing heat and giving out heat in different periods, but the current situation of supplying heat and generating electricity restriction each other does not change, because the restriction of conditions such as steam volume and flow in current heat accumulation device such as devices such as heat pump, the restriction between generated energy and the heat supply volume is more outstanding, peak regulation fm ability is limited.
Disclosure of Invention
In view of this, embodiments of the present invention provide an electric power system and a peak-shaving frequency modulation method thereof, so as to solve the problems in the prior art that the restriction on conditions such as steam amount and flow rate in heat storage devices such as heat pumps, etc., the restriction between the generated energy and the supplied heat amount is more prominent, and the peak-shaving frequency modulation capability is limited.
The technical scheme provided by the invention is as follows:
the embodiment of the invention provides a peak-shaving frequency modulation method of a power system, which comprises the following steps: acquiring control conditions and frequency variation of the power system; determining the maximum heat storage quantity of a phase change heat storage station in the power system in a waist load period and the maximum heat release requirement of a valley period according to the control conditions; calculating a peak shaving capacity increment of the power system according to the maximum heat storage capacity and the maximum heat release demand; and carrying out frequency modulation on the power system according to the low-frequency signal in the frequency variation.
Further, acquiring the control condition and the frequency variation of the power system comprises: and acquiring the constraint condition of a thermal motor set in the power system, the constraint condition of the phase change heat storage station, the boundary condition of the phase change heat storage station and the frequency variation of the power system.
Further, the constraint conditions of the thermoelectric power unit include: running constraint conditions, climbing rate constraint conditions and thermal load constraint conditions; the constraint conditions of the phase change heat storage station comprise: capacity constraints, heat balance constraints; the boundary conditions of the phase-change heat storage station comprise: the method comprises the following steps of heat storage capacity boundary condition, heat storage allowance boundary condition, maximum charging power boundary condition, maximum discharging power boundary condition, unit heat load demand boundary condition and peak load regulation capacity boundary condition at the next stage.
Further, determining the maximum heat storage amount in the phase change heat storage station waist load period and the maximum heat release demand in the valley period in the power system according to the control conditions includes: and determining the maximum heat storage quantity of the phase change heat storage station in the power system during the waist load period and the maximum heat release requirement of the phase change heat storage station in the power system during the valley period according to the constraint condition of the thermal generator set in the power system, the constraint condition of the phase change heat storage station and the boundary condition of the phase change heat storage station.
Further, calculating a peak shaver capacity increment of the power system according to the maximum heat storage capacity and the maximum heat release demand, comprising: calculating the downward peak regulation capacity of the phase change heat storage station in the power system in the valley period and the upward peak regulation capacity of the phase change heat storage station in the peak period according to the maximum heat storage quantity and the maximum heat release demand; and adding the downward peak shaving capacity and the upward peak shaving capacity to obtain the peak shaving capacity increment of the power system.
Further, frequency modulation is performed on the power system according to the low-frequency signal in the frequency variation, and the frequency modulation method includes: calculating a power deviation value according to the low-frequency signal, and obtaining a power regulating value according to the power deviation value; dividing the power adjusting value into four intervals according to the size of the power adjusting value; and carrying out frequency modulation on the power system according to the interval where the power regulation value is located.
Further, calculating a power deviation value according to the low-frequency signal, and obtaining a power adjustment value according to the power deviation value, including: and calculating a power deviation value according to the slowly-changed part in the low-frequency signal, and filtering and proportional-integral regulating the power deviation value to obtain a power regulating value.
Further, dividing the power adjustment value into four intervals according to the size of the power adjustment value, including: and dividing the power regulating value into a locking regulating area, a normal regulating area, a forenotice regulating area and a warning regulating area according to the magnitude of the absolute value of the power regulating value.
An embodiment of the present invention further provides an electric power system, where the electric power system includes: the phase-change heat storage station, the thermoelectric unit and the automatic power generation system are used for carrying out peak shaving and frequency modulation on the thermoelectric unit of the power system by using the peak shaving and frequency modulation method of the power system in any one of the embodiments.
The technical scheme provided by the invention has the following advantages:
the peak-shaving frequency modulation method of the power system provided by the embodiment of the invention is used for assisting a thermoelectric unit in the power system to perform peak-shaving frequency modulation by using an automatic power generation system aiming at the power system additionally provided with the distributed phase-change heat storage station, and when the heat generation amount of the thermoelectric unit is larger, the thermoelectric unit not only meets the heat load, but also stores redundant heat in the distributed phase-change heat storage station. When the heat generated by the thermoelectric unit does not meet the heat load, insufficient heat can be provided by the distributed phase-change heat storage station. The phase-change heat storage device can coordinate the thermoelectric generating set to participate in peak shaving of the power system, the maximum peak shaving capacity increment can be obtained, meanwhile, the phase-change heat storage station can complete AGC dispatching instructions in one minute, the response speed of frequency-modulation resources is lower than that of traditional generating sets, battery energy storage and the like, the phase-change heat storage station can be matched with other traditional generating sets, the AGC system coordinates and controls the respective output power, the frequency modulation of the power system is completed, the dynamic stability of the power grid frequency is achieved, and the power supply quality is guaranteed.
According to the power system provided by the embodiment of the invention, the distributed phase-change heat storage system is added in the thermoelectric unit, and the phase-change heat storage station has low response speed and strong power throughput capacity, and the adjusting direction can be changed in two directions. The distributed phase-change heat storage station has the characteristics of slow response and large heat storage capacity, so that the defects of a conventional frequency modulation mode can be overcome, the rotating reserve capacity required by a power grid can be obviously reduced, the rotating reserve capacity saved by the distributed phase-change heat storage station participating in frequency modulation can be used for power grid peak regulation, accident reserve and the like, and the operation safety and reliability of a power system can be further improved.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.
FIG. 1 is a flow chart of a method for peak and frequency modulation of a power system according to an embodiment of the invention;
FIG. 2 is a diagram of an operation mode of a thermoelectric power unit with a phase change heat storage station according to an embodiment of the present invention;
FIG. 3 is a graph showing the electrical and thermal characteristics of a thermoelectric power unit before and after the thermoelectric power unit is installed in a phase change heat storage station according to an embodiment of the present invention;
FIG. 4 is a flow chart of a method for peak shaving and frequency modulation of a power system according to an embodiment of the present invention;
FIG. 5 is a graph illustrating the variation of the regulation power of the phase-change thermal storage station in the forecast regulation area in the peak-shaving frequency modulation method of the power system according to the embodiment of the invention;
FIG. 6 is a graph of the variation of the PDV standard deviation in different phase-change heat storage station capacity fractions in the peak shaving frequency modulation method of the power system according to the embodiment of the invention;
fig. 7 is a graph of a change in the PDV standard deviation when the phase change heat storage station energy is not limited in the peak shaving method of the power system according to the embodiment of the present invention;
fig. 8 is a block diagram of a power system according to an embodiment of the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention provides a peak-shaving frequency modulation method of a power system, which comprises the following steps as shown in figure 1:
step S1: control conditions and frequency variation amounts of the power system are acquired. Specifically, the power system includes an Automatic power Generation system (AGC) and a thermoelectric unit additionally equipped with a distributed phase-change heat storage station, and obtains Control conditions of the phase-change heat storage station and the thermoelectric unit, and obtains a power grid frequency change value, which is a frequency change amount.
Step S2: and determining the maximum heat storage quantity in the waist load period and the maximum heat release demand in the valley period of the phase change heat storage station in the power system according to the control conditions. Specifically, in order to obtain the maximum peak shaving capacity increment, the phase-change heat storage station in the power system needs to store heat during the waist load and peak load periods when in operation, and the heat is released when the power generation amount of the thermoelectric generator set in the power system is in the valley period.
Step S3: and calculating the peak shaving capacity increment of the power system according to the maximum heat storage quantity and the maximum heat release demand. Specifically, after determining the maximum heat storage quantity and the maximum heat release demand, determining the peak load regulation capacity increment of the power system according to the two values.
Step S4: and frequency modulation is carried out on the power system according to the low-frequency signal in the frequency variation. Specifically, a low-frequency signal in the frequency variation is decomposed, and the low-frequency signal is used as a control signal of the output of the thermoelectric unit provided with the distributed phase change heat storage station to modulate the frequency of the thermoelectric unit.
Through the steps S1 to S4, the peak-shaving frequency-modulation method for the power system according to the embodiment of the present invention is to use an automatic power generation system to assist the thermoelectric power unit in the power system to perform peak-shaving frequency modulation for the power system with the distributed phase-change heat storage station, and when the heat generated by the thermoelectric power unit is large, the excess heat is stored in the distributed phase-change heat storage station except for meeting the heat load. When the heat generated by the thermoelectric unit does not meet the heat load, insufficient heat can be provided by the distributed phase-change heat storage station. The phase-change heat storage device can coordinate the thermoelectric generating set to participate in peak shaving of the power system, the maximum peak shaving capacity increment can be obtained, meanwhile, the phase-change heat storage station can complete AGC dispatching instructions in one minute, the response speed of frequency-modulation resources is lower than that of traditional generating sets, battery energy storage and the like, the phase-change heat storage station can be matched with other traditional generating sets, the AGC system coordinates and controls the respective output power, the frequency modulation of the power system is completed, the dynamic stability of the power grid frequency is achieved, and the power supply quality is guaranteed.
As an optional implementation manner of this embodiment, the control conditions acquired in step S1 include: the method comprises the following steps of constraint conditions of a thermal motor set, constraint conditions of a phase change heat storage station and boundary conditions of the phase change heat storage station in the power system. Specifically, the constraints of the thermoelectric power unit include: running constraint conditions, climbing rate constraint conditions and thermal load constraint conditions; the constraint conditions of the phase change heat storage station comprise: capacity constraints, heat balance constraints; the boundary conditions of the phase-change heat storage station comprise: the method comprises the following steps of heat storage capacity boundary condition, heat storage allowance boundary condition, maximum charging power boundary condition, maximum discharging power boundary condition, unit heat load demand boundary condition and lower-stage peak regulation capacity boundary condition.
After the phase change heat storage station is additionally arranged in the thermoelectric unit, the operation constraint condition of the thermoelectric unit can be expressed by a formula (1),
wherein Ht,iThe thermal output at the t moment of the ith thermoelectric unit, Pt,iThe electric output at the t moment of the ith thermoelectric unit, Pel,minThe minimum electric output, k, of the thermoelectric generator set under pure condensing conditionv2The reduction amount of the electric power output per unit heat output is increased under the condition that the air input amount is not changed when the minimum electric power output is under the pure condensation working condition, hmedThe thermal output h is the thermal output h of the thermoelectric unit at the minimum technical output0Is a constant number, kmThe proportionality coefficient of electric power output and thermal power output h under back pressure working conditionh,maxThe thermal output is the thermal output of the thermoelectric unit when the maximum technical output is provided.
The ramp rate constraint condition of the thermoelectric power unit can be expressed by formula (2):
wherein, Pup,iAnd Pdown,iRespectively an upward and downward climbing rate constraint of the ith thermoelectric unit, Pt-1,iAnd the electric output at the moment t-1 of the ith thermoelectric unit.
The thermal load constraint of the thermoelectric power unit can be expressed by formula (3):
Hout,t+Hd,t＝Hload,t (3)
wherein Hout,tFor the heat-releasing power of the phase-change heat-storage station at time t, Hd,tSum of the heating powers directly supplied to the thermoelectric power units, Hload,tThe heat load requirement of the thermoelectric power unit.
The capacity constraint condition of the phase change heat storage station is expressed by formula (4):
wherein, PHRFor heat discharge power, P, of phase-change thermal storage stationsmax,rThe maximum heat release power of the phase change heat storage station. PHAFor storing heat power, P, of phase-change heat storage stationsmax,aThe maximum heat storage power of the phase change heat storage station.
The heat balance constraint condition of the phase change heat storage station is expressed by a formula (5):
wherein Hx,t、Hx,oThe heat storage capacity, eta of the phase-change heat storage station x at the initial state and the moment t respectivelya,x、ηr,xRespectively the heat storage efficiency and the heat release efficiency, P, of the phase-change heat storage station xa,x、Pr,xRespectively the heat storage power and the heat release power of the phase-change heat storage station x, Hs,xThe rated capacity of the phase change heat storage station.
As an optional implementation manner of this embodiment, according to control conditions such as the constraint condition of the thermoelectric power unit, the constraint condition of the phase change heat storage station, and the boundary condition of the phase change heat storage station, the maximum heat storage amount of the phase change heat storage station in the waist load period can be obtained, and is expressed by formula (6):
wherein S ismaxIs the maximum heat storage capacity of the phase-change heat storage station,
the maximum heat storage power of the phase change heat storage station at the time T during the waist load and peak load period is TFIndicating a waist load period.
The maximum heat release requirement of the phase change heat storage station in the valley period is expressed by the formula (7):
wherein the content of the first and second substances,
thermal power, T, to be compensated for a valley period-varying heat storage stationLIndicating a valley period.
As an optional implementation manner of this embodiment, in step S3, the calculating the peak shaving capacity increment of the power system according to the maximum heat storage amount and the maximum heat release demand includes: calculating the downward peak regulation capacity of the phase-change heat storage station in the valley period and the upward peak regulation capacity of the peak period in the phase-change heat storage station in the power system according to the maximum heat storage quantity and the maximum heat release demand; and adding the downward peak shaving capacity and the upward peak shaving capacity to obtain the peak shaving capacity increment of the power system.
Specifically, when the maximum heat storage amount H is calculateda,FAnd maximum exothermic demand Hr,LThen, compare Ha,FAnd Hr,LThe size of (2) can be divided into Ha,FIs less than Hr,LAnd Ha,FH or morer,LTwo cases calculate the peak shaver capacity increase of the power system.
When H is presenta,FIs less than Hr,LIn order to obtain the maximum peak regulation capacity increment, the distributed phase-change heat storage station needs to store heat in the waist load and peak load periods during operation, and releases heat when the generating capacity of the thermoelectric unit is in the valley period. At the moment, the distributed phase-change heat storage station is in a valley period, and the maximum average heat power of the supplementary heat supply is represented by formula (8):
wherein, TdownThe duration time H of supplying heat for the phase change heat storage station in the period when the generating capacity of the thermoelectric unit is in the valleya,PThe maximum heat storage capacity of the phase change heat storage station in the peak load period can be represented by formula (9):
TPindicating a peak-to-charge period.
The peak shaving capacity corresponding to the valley period is expressed by equation (10):
to meet the demand of the phase change heat storage station to release heat during the valley period, the average heat storage power reached during the peak period can be expressed by equation (11):
wherein, TupFor storing heat by phase changeAnd the station supplements the duration of heat supply when the power generation amount of the thermoelectric unit is in the peak period.
The peak shaver capacity in the peak period is expressed by the formula (12):
the peak shaving capacity increment can be obtained according to the above equations (8) to (12), and is expressed by equation (13):
when H is presenta,FH or morer,LDuring operation, in order to obtain the maximum peak regulation capacity increment, when the distributed phase-change heat storage station operates, when the distributed phase-change heat storage station is in the waist load period, the heat consumption requirement in the valley period is firstly met, and the rest heat is reused for meeting the heat consumption requirement in the peak period, because the phase-change heat storage is sufficient, the distributed phase-change heat storage station can reach the maximum heat release requirement in the valley period, and therefore the maximum average heat power supplemented in the valley period is represented by a formula (14):
wherein the content of the first and second substances,
is the thermal load level at time t.
The peak shaver capacity for the corresponding boost is expressed by equation (15):
as can be seen from equations (14) and (15), if the capacity and power of the distributed phase-change heat storage station are not limited, the minimum output of the power system can be reduced to the minimum value by adopting the heat storage supplement manner. After the distributed phase-change heat storage station meets the heat release requirement in the valley period, the rest heat is used for meeting the heat release requirement in the peak period, and the maximum thermal power average value capable of being supplemented in the peak period is represented by a formula (16):
the peak shaver capacity for the corresponding boost can be expressed by equation (17):
the peak shaving capacity increment can be obtained according to the above equations (14) to (17), and is expressed by equation (18):
the daily peak shaving capacity of the thermoelectric generator set after the distributed phase change heat storage station is additionally arranged can be obtained according to the formula (13) and the formula (18), and is expressed by the formula (19):
C＝C0+ΔC (19)
wherein, C0The daily peak regulation capacity of the thermoelectric unit without the distributed phase change heat storage station is shown.
In practical application, the operation mode of the thermoelectric unit additionally provided with the distributed phase-change heat storage station is shown in fig. 2, the phase-change heat storage station stores heat by adopting the peak-shaving frequency modulation method of the power system when the thermoelectric unit supplies heat to a heat load, the operation intervals of the thermoelectric units before and after the addition of the distributed phase-change heat storage station are shown in fig. 3, a dotted line represents the thermoelectric unit additionally provided with the distributed phase-change heat storage station, a solid line represents the thermoelectric unit not additionally provided with the distributed phase-change heat storage station, and it can be seen that the thermoelectric unit additionally provided with the distributed phase-change heat storage station expands the electric heating operation interval of the unit. Meanwhile, the total peak regulation capacity of the thermoelectric unit additionally provided with the distributed phase-change heat storage station is 111.5MW obtained through experimental calculation, and is improved by about 2.6 times compared with the total peak regulation capacity of the thermoelectric unit for storing heat of the phase-change heat storage station.
As an alternative implementation manner of this embodiment, as shown in fig. 4, step S4 is to frequency modulate the power system according to the low-frequency signal in the frequency variation, and includes:
step S41: and calculating a power deviation value according to the low-frequency signal, and obtaining a power regulating value according to the power deviation value. Specifically, a power deviation value is calculated according to a slowly-varying part in the low-frequency signal, and the power deviation value is subjected to filtering and proportional-integral adjustment to obtain a power adjustment value.
Step S42: the power adjustment value is divided into four intervals according to the size of the power adjustment value. Specifically, the power adjustment value is divided into a lock adjustment area, a normal adjustment area, a forenotice adjustment area and a cautious adjustment area according to the magnitude of the absolute value of the power adjustment value.
Step S43: and carrying out frequency modulation on the power system according to the interval where the power regulation value is located. Specifically, in different intervals, the regulating quantity distributed to the phase change heat storage station by the automatic power generation system is calculated, so that the frequency regulating quantity of the thermoelectric unit is obtained.
Specifically, a Chebyshev analog low-pass filter can be adopted to decompose the frequency variation of the power grid into a high-frequency signal and a low-frequency signal, the phase change heat storage station can respond to the frequency modulation requirement of a minute level, one minute can be set as a boundary point of high and low frequencies, 30Hz is set as a cut-off frequency of low frequency, the low-frequency signal of the minute level is further decomposed into a fast-changing part and a slowly-changing part according to the characteristic that amplitude fluctuation exists in a pass band of the Chebyshev low-pass filter, the fluctuation range of the fast-changing part signal is large, and the fluctuation range of the slowly-changing part signal is small.
According to the peak-shaving frequency modulation method for the power system, the high-frequency signal and the fast-changing part are processed by the amplitude limiting device and then serve as frequency modulation control signals for the output of the traditional frequency modulation unit and other frequency modulation resources, and the slow-changing part is processed by the amplitude limiting device and then serves as frequency modulation control signals for the output of the thermoelectric unit provided with the distributed phase change heat storage station, so that the frequency modulation of the thermoelectric unit is achieved. The two types of frequency modulation resources are matched with each other, the respective output power is coordinately controlled through the automatic power generation system, the respective corresponding power grid frequency fluctuation is eliminated, the dynamic stability of the power grid frequency is achieved, and the power supply quality is guaranteed.
In the peak shaving and frequency modulation method for the Power system provided by the embodiment of the invention, the automatic Power generation system calculates a Power Deviation Value (PDV) according to a slowly varying part in the low-frequency signal, and obtains a Power Regulation Requirement (PRR) through filtering and proportional integral regulation according to the Power deviation value. The PDV represents unbalanced power between power generation and load in the region, namely when the load is disturbed or the output of the generator set deviates, the system frequency deviates from a reference value, and the exchange power on the connecting line deviates from a preset planned value, and the generator set increases or reduces the output total amount.
In the peak-shaving frequency modulation method for the power system provided by the embodiment of the invention, different control intervals are divided according to the absolute value of the power regulation value, namely a locking regulation area, a normal regulation area, a forenotice regulation area and a cautious regulation area, and specifically, the regulation quantity distributed to a phase-change heat storage station by an automatic power generation system is calculated in four different intervals, so that the frequency regulation quantity of the thermoelectric unit is obtained.
When the PRR is in the critical zone, the adjustment amount distributed to the phase change heat storage station by the AGC system is represented by the formula (20):
wherein, Δ Pc,xRepresenting the current power, P, of the phase change thermal storage stationa,xAnd Pr,xThe rated heat storage power and the rated heat release power of the phase change heat storage station.
If all the phase change heat storage stations
If the sum is greater than the absolute value PRR, adjusting the adjustment quantity of the thermoelectric unit additionally provided with the phase change heat storage station according to the proportion; otherwise, the remaining adjustment is made by the conventional FM unit andand other frequency modulation resources issue power in proportion.
When the PRR is in the forenotice adjustment range, the adjustment amount allocated to the phase change thermal storage station by the AGC system is represented by equation (21):
wherein, Δ PTThe regulated power of all frequency modulation resources (including a traditional generator and a thermoelectric unit additionally provided with a phase change heat storage station) is represented, the total power is regulated up or down according to the direction calculation of the PRR, and the power is the PRREThe regulation demand is at an upper limit value in the forecast regulation zone. If PRR->ΔPTIf k is 0, the value of PRR is less than or equal to delta PTAt time k is the slope of the phase change thermal storage station regulating power change, as shown in fig. 5. If all the phase-change heat storage stations are
If the sum is greater than the absolute value PRR, adjusting the adjustment quantity of the thermoelectric unit additionally provided with the phase change heat storage station according to the proportion; otherwise, the remaining adjustment is delivered by the conventional generator set and other frequency modulation resources.
When the PRR is in the normal regulation region, the amount of regulation that the AGC system allocates to the phase change thermal storage station is represented by equation (22):
when the PRR is in the locking regulation area, the AGC system issues the adjustment quantity of the thermoelectric generator set which is allowed to be additionally provided with the phase change heat storage station according to the reported base point power. Thermoelectric generating set with additional phase change heat storage station comprehensively determines base point power according to self constraint conditions
Then, the power adjustment amount of the cogeneration unit with the phase change heat storage station is expressed by the formula (23):
in order to ensure that the PRR cannot exceed a locking area due to the output adjustment of a combined heat and power generation unit additionally provided with a phase change heat storage station, the adjustment quantity distributed to the phase change heat storage station by an AGC system is expressed by a formula (24) to a formula (26):
when in use
The method comprises the following steps:
when in use
The method comprises the following steps:
in other cases:
wherein, PRRDFor the upper limit value where the power regulation requirement is in the lock-out regulation region,
for the upward adjustment of the phase change heat storage station PRR when it is in the lock-up regulation zone,
the downward adjustment amount of the phase change heat storage station PRR in the locking adjusting area is obtained.
Specifically, simulation is carried out aiming at the peak-load frequency modulation method of the power system, and the base point power is determined according to the table 1
TABLE 1
| Residual capacity of phase change heat storage station | Base point power |
| Below 1/3 | Negative value (Heat storage state) |
| Greater than 1/3 and less than 2/3 | Zero |
| Higher than 2/3 | Positive values (exothermic state) |
And (3) exiting the traditional frequency modulation unit in sequence from small to large according to the frequency modulation capacity during simulation, complementing the reduced frequency modulation capacity of the unit by using the output of the distributed phase change heat storage station, and keeping the total frequency modulation capacity of the system unchanged. The frequency modulation effect is measured by PDV, and when the numerical value is smaller, the smaller the change amplitude of the PDV is, the better the effect of participating in peak modulation of the electric power system is. The corresponding PDV standard deviation trend of different phase change thermal storage station occupation ratios obtained by simulation is shown in fig. 6. Fig. 6 shows that as the proportion of the distributed phase-change heat storage stations in the frequency modulation capacity increases, the PDV standard deviation decreases first and then increases, which indicates that the proportion of the distributed phase-change heat storage stations in the frequency modulation capacity is not more reasonable.
When the energy of the distributed phase-change heat storage station is not limited during simulation, the frequency modulation effect of the simulation control strategy is as shown in fig. 7. Due to the fact that no energy limitation exists, the effect that the control strategy considers the characteristics of the phase change heat storage station in detail is reflected. Except for the point that the occupation ratio of the phase change heat storage station is 100%, the standard deviation of the PDV tends to be gradually reduced along with the increase of the occupation ratio of the phase change heat storage station, and the reduction range is very large, so that the good frequency modulation effect is embodied under the strategy of allocating and installing the heat and power cogeneration unit with the phase change heat storage station to bear the regulating quantity flexibly based on the PRR located section.
The peak-load modulation method for the power system provided by the embodiment of the invention constructs a thermoelectric unit operation constraint condition, a phase change heat storage station capacity constraint condition, a thermoelectric unit ramp rate constraint condition, a thermal load constraint condition and a distributed phase change heat storage station heat balance constraint condition after the distributed phase change heat storage station is additionally arranged. Control boundary conditions such as heat storage capacity, heat storage allowance, maximum heat charging power, maximum heat release power, unit heat load demand, peak shaving capacity at the next stage and the like are constructed, and the maximum heat storage quantity of the distributed phase change heat storage station in a waist load period and the maximum heat release demand of the distributed phase change heat storage station in a valley period are analyzed and compared. The method comprises the steps of constructing a maximum heat storage quantity in a waist load period and a maximum heat release demand in a valley period according to the distributed phase-change heat storage station, and determining an operation strategy adopted by the distributed phase-change heat storage station and an increased scheduling peak shaving capacity increment of the distributed phase-change heat storage station. And (4) analyzing the effect of improving the peak regulation capacity after the phase change heat storage station is additionally arranged on the thermoelectric unit by combining simulation and actual experiments.
The embodiment of the invention provides a peak-shaving frequency modulation method of an electric power system, which provides a method for carrying out secondary frequency division on frequency variation. Aiming at the characteristic that the Chebyshev filter has amplitude fluctuation in a passband, the method further decomposes the minute-level low-frequency signal into a fast-changing part and a slowly-changing part according to the change rate, the fluctuation range of the fast-changing part signal is large, and the fluctuation range of the slowly-changing part signal is small. The method is characterized in that the output of a thermoelectric unit additionally provided with a phase change heat storage station is coordinated and controlled with a traditional unit, so that an optimal coordination mode is realized; a method for directly sending an instruction to an automatic generation system (AGC) system comprising a distributed phase-change heat storage station by a control center for meeting capacity requirements of a thermoelectric generating set additionally provided with the distributed phase-change heat storage station for participating in frequency modulation and a control strategy of the AGC system. When a thermoelectric unit additionally provided with a phase change heat storage station participates in frequency modulation, the AGC system fully exerts the energy storage performance characteristics and avoids the constraint of limited total capacity according to the characteristic of low power regulation speed. And issuing a strategy for adjusting the target output of a cogeneration unit or a traditional unit additionally provided with a phase change heat storage station and other frequency modulation resources based on the PRR located interval. And analyzing the effect of a control strategy for improving the frequency modulation capability after the phase change heat storage station is additionally arranged by combining the operation data of the actual power grid.
An embodiment of the present invention further provides an electric power system, as shown in fig. 8, the electric power system includes: the system comprises a phase change heat storage station 1, a thermoelectric unit 2 and an automatic power generation system 3, wherein the automatic power generation system 3 carries out peak shaving and frequency modulation on the thermoelectric unit 2 of the power system by using the peak shaving and frequency modulation method of the power system in any embodiment.
The basic objective of the automatic power generation system 3 when the peak shaving frequency modulation is performed on the thermoelectric unit 2 of the power system is to ensure the balance between the generated output and the load, ensure the system frequency as a rated value, enable the net area tie line tide to be equal to the plan and minimize the regional operation cost. And the phase change heat storage station 1 and the thermoelectric unit 2 adjust output to track an AGC control instruction, compensate load disturbance and unit output deviation, and recover the system frequency to a reference value and the tie line power to a planned value.
According to the power system provided by the embodiment of the invention, the distributed phase-change heat storage station 1 is added into the thermoelectric unit 2, and the phase-change heat storage station 1 has low response speed and strong power throughput capacity, and the adjusting direction can be changed in two directions, so that the power system can be combined with a conventional frequency modulation power supply to serve as an effective means for assisting the peak modulation of a traditional unit. The slow response and the large heat storage capacity of the distributed phase-change heat storage station 1 enable the distributed phase-change heat storage station to make up for the defects of a conventional frequency modulation mode, the rotating reserve capacity required by a power grid can be remarkably reduced, the rotating reserve capacity saved due to the fact that the distributed phase-change heat storage station 1 participates in frequency modulation can be used for power grid peak shaving, accident reserve and the like, and the safety and the reliability of operation of a power system can be further improved.
The principle and the implementation mode of the invention are explained by applying specific embodiments in the invention, and the description of the embodiments is only used for helping to understand the method and the core idea of the invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, there may be variations in the specific embodiments and the application scope, and in summary, the content of the present specification should not be construed as a limitation to the present invention. All the simple modifications of the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims (7)
1. A peak-shaving frequency modulation method of an electric power system is characterized by comprising the following steps:
acquiring control conditions and frequency variation of the power system;
determining the maximum heat storage quantity of the phase change heat storage station in the power system during the waist load period and the maximum heat release requirement of the phase change heat storage station in the valley period according to the control conditions;
calculating a peak shaving capacity increment of the power system according to the maximum heat storage capacity and the maximum heat release demand;
performing frequency modulation on the power system according to the low-frequency signal in the frequency variation;
wherein, according to the low frequency signal in the frequency variation, frequency modulation is performed on the power system, and the method comprises the following steps:
calculating a power deviation value according to a slowly-changed part in the low-frequency signal, and filtering and proportional-integral regulating the power deviation value to obtain a power regulating value;
dividing the power adjusting value into four intervals according to the size of the power adjusting value;
and carrying out frequency modulation on the power system according to the interval where the power regulation value is located.
2. The method of claim 1, wherein obtaining the control condition and the frequency variation of the power system comprises:
and acquiring the constraint condition of a hot electric machine set in the power system, the constraint condition of the phase change heat storage station, the boundary condition of the phase change heat storage station and the frequency variation of the power system.
3. The peak-shaving frequency modulation method for an electric power system according to claim 2,
the constraint conditions of the thermoelectric power unit comprise: running constraint conditions, climbing rate constraint conditions and thermal load constraint conditions;
the constraint conditions of the phase change heat storage station comprise: capacity constraints, heat balance constraints;
the boundary conditions of the phase-change heat storage station comprise: the method comprises the following steps of heat storage capacity boundary condition, heat storage allowance boundary condition, maximum charging power boundary condition, maximum discharging power boundary condition, unit heat load demand boundary condition and lower-stage peak regulation capacity boundary condition.
4. The peak-shaving frequency modulation method for the power system according to claim 2, wherein determining the maximum heat storage amount in the phase-change heat storage station waist load period and the maximum heat release demand in the valley period in the power system according to the control condition comprises:
and determining the maximum heat storage quantity of the phase change heat storage station in the power system during the waist load period and the maximum heat release requirement of the phase change heat storage station in the power system during the valley period according to the constraint condition of the thermal generator set in the power system, the constraint condition of the phase change heat storage station and the boundary condition of the phase change heat storage station.
5. The method of claim 1, wherein calculating the peak shaving capacity increment of the power system according to the maximum heat storage capacity and the maximum heat release demand comprises:
calculating downward peak shaving capacity of a phase change heat storage station in the power system in a valley period and upward peak shaving capacity of a peak period according to the maximum heat storage quantity and the maximum heat release demand;
and adding the downward peak shaving capacity and the upward peak shaving capacity to obtain the peak shaving capacity increment of the power system.
6. The method of claim 1, wherein dividing the power adjustment value into four intervals according to the magnitude of the power adjustment value comprises:
and dividing the power regulating value into a locking regulating area, a normal regulating area, a forenotice regulating area and a warning regulating area according to the magnitude of the absolute value of the power regulating value.
7. An electrical power system, comprising: a phase-change heat storage station, a thermoelectric unit and an automatic power generation system,
the automatic power generation system performs peak shaving on a thermoelectric power unit of a power system by using the peak shaving method of the power system according to any one of claims 1 to 6.
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Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106356895A (en) * | 2016-10-24 | 2017-01-25 | 国家电网公司 | Method for promoting wind power generation by heat storage of combined heat and power plant |
| CN108039736A (en) * | 2017-11-14 | 2018-05-15 | 国网辽宁省电力有限公司 | A kind of large capacity heat accumulation storing up electricity coordinated scheduling method for improving wind-powered electricity generation and receiving ability |
| CN108256670A (en) * | 2017-12-22 | 2018-07-06 | 甘肃省电力公司风电技术中心 | Photo-thermal power generation and thermoelectricity unit combined adjusting peak Optimized model based on cogeneration of heat and power |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
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-
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106356895A (en) * | 2016-10-24 | 2017-01-25 | 国家电网公司 | Method for promoting wind power generation by heat storage of combined heat and power plant |
| CN108039736A (en) * | 2017-11-14 | 2018-05-15 | 国网辽宁省电力有限公司 | A kind of large capacity heat accumulation storing up electricity coordinated scheduling method for improving wind-powered electricity generation and receiving ability |
| CN108256670A (en) * | 2017-12-22 | 2018-07-06 | 甘肃省电力公司风电技术中心 | Photo-thermal power generation and thermoelectricity unit combined adjusting peak Optimized model based on cogeneration of heat and power |
Non-Patent Citations (3)
| Title |
|---|
| Research on the Control Strategy of Phase-Change Heat Storage Station with Automatic Generation System in Power Network Peak Regulation and Frequency Modulation;Qingqi Zhao,et al.;《2018 Chinese Control And Decision Conference (CCDC)》;20180709;第4315-4320页 * |
| 含储能资源参与的自动发电控制策略研究;胡泽春等;《中国电机工程学报》;20141015;第34卷(第29期);第5080-5086页 * |
| 配置储热后热电机组调峰能力分析;吕泉等;《电力***自动化》;20140610;第38卷(第11期);全文 * |
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