CN111769567A - Power system line overload prevention control method based on dynamic security domain - Google Patents

Power system line overload prevention control method based on dynamic security domain Download PDF

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CN111769567A
CN111769567A CN202010694233.1A CN202010694233A CN111769567A CN 111769567 A CN111769567 A CN 111769567A CN 202010694233 A CN202010694233 A CN 202010694233A CN 111769567 A CN111769567 A CN 111769567A
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power
equipment
overload
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CN111769567B (en
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欧阳金鑫
龙晓轩
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Chongqing University
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    • 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
    • H02J3/04—Circuit arrangements for ac mains or ac distribution networks for connecting networks of the same frequency but supplied from different sources
    • H02J3/06—Controlling transfer of power between connected networks; Controlling sharing of load between connected networks
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H7/00—Emergency protective circuit arrangements specially adapted for specific types of electric machines or apparatus or for sectionalised protection of cable or line systems, and effecting automatic switching in the event of an undesired change from normal working conditions
    • H02H7/26—Sectionalised protection of cable or line systems, e.g. for disconnecting a section on which a short-circuit, earth fault, or arc discharge has occured
    • 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
    • H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381—Dispersed generators
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/10—Power transmission or distribution systems management focussing at grid-level, e.g. load flow analysis, node profile computation, meshed network optimisation, active network management or spinning reserve management
    • 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
    • H02J2203/00—Indexing scheme relating to details of circuit arrangements for AC mains or AC distribution networks
    • H02J2203/20—Simulating, e g planning, reliability check, modelling or computer assisted design [CAD]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
    • Y02B70/00—Technologies for an efficient end-user side electric power management and consumption
    • Y02B70/30—Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
    • Y02B70/3225—Demand response systems, e.g. load shedding, peak shaving
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
    • Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
    • Y04S20/00—Management or operation of end-user stationary applications or the last stages of power distribution; Controlling, monitoring or operating thereof
    • Y04S20/20—End-user application control systems
    • Y04S20/222—Demand response systems, e.g. load shedding, peak shaving

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Control Of Eletrric Generators (AREA)
  • Supply And Distribution Of Alternating Current (AREA)

Abstract

The invention discloses a dynamic security domain-based electric power system line overload prevention control method. Sequentially simulating the power of each line under the condition that the power system line is disconnected and screening an overload line through load flow calculation; if the overload line exists, dividing the controllable equipment into a sending end or a receiving end of the overload line according to the access position and the tide direction of the controllable equipment; calculating the maximum power adjustment amount of the controllable equipment to the overloaded circuit, constructing a dynamic security domain of the overloaded circuit, and judging the security of the overloaded circuit under the power adjustment of the controllable equipment according to the relation between the power of the overloaded circuit and the dynamic security domain; if the dynamic security domain cannot be met, the power of the controllable equipment is optimized and calculated, the operation mode of the controllable equipment is changed in advance according to the calculation result, the rapid power regulation capability and the line safety margin of the system can be exerted to the maximum extent, and equipment damage, power supply interruption and even large-area cascading failure caused by line overload are effectively avoided.

Description

Power system line overload prevention control method based on dynamic security domain
Technical Field
The invention relates to the field of protection and control of an electric power system, in particular to a dynamic security domain-based electric power system line overload prevention and control method.
Background
Faults and switching of elements of the power system easily cause the current of a return transmission line to exceed the long-term allowable current-carrying capacity, and overload occurs. After the circuit is overloaded, the heating power is greater than the heat dissipation power, so that the temperature of the lead is increased. If the temperature exceeds the maximum allowable working temperature of the circuit, short circuit is easily caused by the increase of sag, or the lead is easily damaged due to thermal oxidation. Currently, overload circuits can only be cut off by means of relay protection to avoid the circuit temperature exceeding the maximum allowable operating temperature. However, the protection action causes power supply interruption and voltage and frequency fluctuation, and may cause sudden change of state, failure and even disconnection of the generator, and large-area cascading failure.
The heating after the circuit overload is a slower process, and the overload is eliminated by quickly reducing the circuit power, so that the temperature can be prevented from exceeding the maximum allowable working temperature, and the safety of the circuit is ensured. Cutter and cutter loading are the most common methods currently used to eliminate line overload. However, load shedding can result in significant economic losses and power reliability problems. Because the generator is re-connected to the grid, the generator tripping is not beneficial to the fault recovery of the power system, and a large amount of loads and the generator are re-connected to the grid, impact can be generated on the power system, and even the safe and stable operation of the whole system is threatened.
The power supply power regulation is a more efficient method for eliminating line overload, and partial scholars propose that line current can be gradually reduced by regulating power supply power so as to avoid load shedding and large power oscillation. The time required for the temperature to reach the maximum allowable operating temperature after the line is overloaded is the allowable overload time of the line. Some scholars will reduce the line current below the long-term allowable ampacity for the allowed overload time as the target of overload control. The allowable overload time is determined by the heating power and the heat dissipation power of the line. The heating power is mainly affected by the line current. The heat dissipation power is not only affected by the environment, but also related to the line temperature. However, the existing method ignores the influence of the line power on heat generation and the influence of the line temperature on heat dissipation, and thus treats the allowable overload time as a constant value. Some scholars consider the difference of the allowed overload time under different line powers, but all calculate the allowed overload time with the initial overload power, and ignore the change of the line power. During the regulation of the mains power, the line current is constantly changing, which inevitably makes the permissible overload time dynamic. The existing calculation method for the allowable overload time not only causes waste of control resources, but also may cause damage to a line due to error and leakage of a control target.
At present, the regulation rate of controllable equipment in an electric power system is limited, and whether the overload circuit current can be reduced to be within the long-term allowable current-carrying capacity before the circuit temperature reaches the maximum allowable working temperature by means of the power regulation of the controllable equipment is determined, so that the overload safety recovery is lack of judgment basis. Meanwhile, if the power regulation of the controllable device cannot guarantee the safe recovery of the overloaded line, how to combine other methods to avoid the safety problem caused by the line overload is still lack of corresponding research. Therefore, how to accurately judge whether the line has overload risk and implement corresponding measures to eliminate the overload risk becomes a problem which needs to be solved by technical personnel in the field.
Disclosure of Invention
Therefore, the invention needs to solve the problem of how to accurately judge whether the line has overload risk and how to prevent the overload risk.
In order to solve the technical problems, the invention adopts the following technical scheme:
the electric power system line overload prevention control method based on the dynamic security domain comprises the following steps:
s101, sequentially simulating the disconnection of each line in a target power system by using load flow calculation, calculating the power of each line, collecting the ambient temperature and the line temperature of each line, and executing the step S102;
s102, comparing the power of each line with the maximum allowable long-term operation power of the line, if the power of any line is larger than the maximum allowable long-term operation power of the line, judging that the line is an overloaded line, and executing a step S103, otherwise, executing a step S106;
s103, dividing the controllable equipment into sending-end controllable equipment or receiving-end controllable equipment of the overload line according to the power flow direction of the target power system and the access position of the controllable equipment in the target power system, and executing the step S104;
s104, calculating the maximum power regulating quantity of each transmitting-end controllable device and each receiving-end controllable device, calculating the maximum power regulating quantity of the controllable devices to the overload line, and executing the step S105;
s105, constructing a dynamic security domain of the overloaded line, judging whether the initial overloaded power of the overloaded line meets the corresponding dynamic security domain, if so, executing the step S101, otherwise, executing the step S106
And S106, calculating the equipment power capable of ensuring the safe recovery of the overload line according to the line overload prevention control optimization model, and adjusting all the equipment power to be equal to the calculated value so as to prevent the line overload.
Preferably, the devices connected to the target power system include a gas turbine, a synchronous generator and an electric gas conversion device, and in step S103, if the synchronous generator or the gas turbine provides power for the overload line, the synchronous generator or the gas turbine is a sending-end controllable device of the overload line; if the electric gas conversion equipment and the overload line absorb power from the same node at the same time, the electric gas conversion equipment is the sending end controllable equipment of the overload line; if the output power of the synchronous generator or the gas turbine does not flow through the overload circuit and is transmitted to the same node with the power of the overload circuit, the synchronous generator or the gas turbine is controlled equipment at the receiving end of the overload circuit; and if the power of the overload line is transmitted to the electric gas conversion equipment through a line, the electric gas conversion equipment is the receiving end electric gas conversion equipment of the overload line.
Preferably, in step S104, when the overloaded line is the r-th line, the controllable device in the target power system adjusts the maximum power of the overloaded line within any time period Δ t
Figure BDA0002590409360000021
Can be calculated from the following formula:
Figure BDA0002590409360000031
and is
Figure BDA0002590409360000032
Satisfies the following conditions:
Figure BDA0002590409360000033
in the formula (I), the compound is shown in the specification,
Figure BDA0002590409360000034
respectively representing the limit values of the power regulating quantity of the r-th line of the synchronous generator, the gas turbine and the electric gas conversion equipment in the target power system within delta t time;
Figure BDA0002590409360000035
the integrated maximum regulation speed of the overload line r power for the synchronous generator and gas turbine in the target power system.
Figure BDA0002590409360000036
Calculated as follows:
Figure BDA0002590409360000037
Figure BDA0002590409360000038
calculated as follows:
Figure BDA0002590409360000039
in the formula, Hsh,o、Hgj,oAnd Hck,oThe sensitivities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the sending end controllable equipment and the power of the overload circuit are respectively set; hsh,i、Hgj,iAnd Hck,iRespectively the h-th synchronous generator, the j-th gas turbine and the k-th electric gas conversion in the receiving end controllable equipmentA sensitivity of a device to the overloaded line power; ps0h,oAnd Ps0h,iAre each t0The active power output by the h-th synchronous generator in the sending-end controllable equipment and the receiving-end controllable equipment at any moment; pshd,oMaintaining the minimum active power for the h synchronous generator in the sending end controllable equipment; pg0j,oAnd Pg0j,iAre each t0The active power output by the jth gas turbine in the sending-end controllable equipment and the receiving-end controllable equipment at any moment; pguj,i(tm) For the jth gas turbine in the receiving end controllable equipment at tmAn upper power limit at a time; pc0k,oAnd Pc0k,iAre each t0The active power output by the kth electric gas conversion equipment in the sending end controllable equipment and the receiving end controllable equipment at any moment;
Figure BDA00025904093600000310
the maximum output active power of the kth electric gas conversion equipment in the sending end controllable equipment is obtained; n iss,oAnd ns,iThe number of synchronous generators in the sending end controllable equipment and the receiving end controllable equipment is respectively; n isg,oAnd ng,iThe number of gas turbines in the sending-end controllable equipment and the receiving-end controllable equipment respectively; n isc,oAnd nc,iThe number of the electric gas conversion equipment in the sending end controllable equipment and the receiving end controllable equipment is respectively;oandidistribution coefficients of power regulating quantities of the sending end controllable equipment and the receiving end controllable equipment are respectively;
Figure BDA0002590409360000041
and
Figure BDA0002590409360000042
the maximum landslide and the climbing speed of the h-th synchronous generator are respectively;
Figure BDA0002590409360000043
and
Figure BDA0002590409360000044
the maximum climbing speed and the maximum landslide speed of the jth gas turbine are respectively set; t is tm＝t0+Δt，t0The moment when the overload occurs on the overload line.
Preferably, the maximum output power of the kth electric gas conversion equipment in the sending end controllable equipment
Figure BDA0002590409360000045
Considering the constraint of the upper power limit of the electric power conversion equipment, the method can be calculated according to the following formula:
Figure BDA0002590409360000046
in the formula, phick,oThe conversion efficiency of the kth electric gas conversion equipment in the sending end controllable equipment is obtained; hgIs the heat value of natural gas;
Figure BDA0002590409360000047
the upper limit of the natural gas flow output by the kth electric gas conversion equipment in the sending end controllable equipment constrained by the upper limit of the power of the electric gas conversion equipment is calculated according to the following formula:
Figure BDA0002590409360000048
in the formula (I), the compound is shown in the specification,
Figure BDA0002590409360000049
the upper limit of the power of the kth electric gas conversion equipment in the sending end controllable equipment; picomk,o(t0) Is t0The air pressure of a kth electric gas conversion device in the controllable device at the sending end is accessed to a natural gas node at any moment; zcomk,oIs a constant related to the compression factor and the heating value of the natural gas; b iscomk,oIs a constant related to the heating value of natural gas and the temperature and efficiency of the electric gas conversion equipment.
Preferably, the first and second electrodes are formed of a metal,oandicalculated according to the following formula:
Figure BDA00025904093600000410
in the formula, the most controllable device at the sending end and the receiving endThe sum of the high-power regulating variables is respectively
Figure BDA00025904093600000411
And
Figure BDA00025904093600000412
Figure BDA0002590409360000051
in the formula (I), the compound is shown in the specification,
Figure BDA0002590409360000052
maximum power regulating quantities of a h synchronous generator, a j gas turbine and a k electric gas conversion device in the sending end controllable device in delta t time are respectively set;
Figure BDA0002590409360000053
the maximum power regulating quantities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the receiving end controllable equipment in delta t time are respectively.
Preferably, the maximum power adjustment amount of the synchronous generator in the sending-end controllable device and the receiving-end controllable device in the Δ t time is calculated according to the following formula:
Figure BDA0002590409360000054
the maximum power regulating quantity of the gas turbine in the delta t time in the sending end controllable equipment and the receiving end controllable equipment is calculated according to the following formula:
Figure BDA0002590409360000055
the maximum power regulating quantity of the electric conversion equipment in the sending end controllable equipment and the receiving end controllable equipment in delta t time is calculated according to the following formula:
Figure BDA0002590409360000056
preferably, the jth gas turbine in the controlled end equipment is at tmUpper power limit P of timeguj,i(tm) Considering the constraint of the node voltage, the method comprises the following steps:
Figure BDA0002590409360000057
in the formula, pigj,i(t0) Is t0The pressure of a jth gas turbine in the receiving-end controllable equipment is connected to a natural gas node at any moment;
Figure BDA0002590409360000058
the air pressure of the combustion chamber of the jth gas turbine in the receiving-end controllable equipment is measured; phi is agj,iThe energy conversion efficiency of the jth gas turbine in the receiving-end controllable equipment is obtained; hgIs the heat value of natural gas.
Preferably, when the overload line is the r-th line, the dynamic security domain P of the r-th lineL0rConstructed according to the following formula:
Figure BDA0002590409360000061
in the formula, the coefficient C can be calculated as follows:
Figure BDA0002590409360000062
in the formula, Tmax,LrThe maximum allowable temperature of the r line; t isa,LrThe environment absolute temperature of the r line; t is0,LrThe temperature of the r line in normal operation; rhoLr、ULr、
Figure BDA0002590409360000065
QLrThe resistivity, voltage, radius and reactive power of the r line are respectively; mLr、NLrThe convection heat dissipation coefficient and the radiation heat dissipation coefficient of the r line, B1、B2、B3、B4Is a constant related to the parameters of the line r itself:
Figure BDA0002590409360000063
in the formula, xLrIs the density of the r-th line, cLrIs the specific heat capacity of the r-th line.
Preferably, in step S106, the line overload prevention control optimization model is:
Figure BDA0002590409360000064
wherein, ash、bsh、cshCost factor for the h-th synchronous generator in the target power system, dgjIs the cost factor, P, of the jth gas turbine in the target power systemsh、Pgj、PckThe power of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the target power system, nsIs the total number of synchronous generators in the target power system, ngIs the total number of gas turbines in the target power system, nkMu is the unit electricity price, sigma is the unit cost of natural gas,
Figure BDA0002590409360000071
the efficiency of the kth electric gas conversion equipment in the target power system;
the active power of each synchronous generator, each gas turbine and each electric gas conversion device meets the following conditions:
Figure BDA0002590409360000072
wherein, PlyThe power absorbed for the y-th node load of the target power system, y is 1,2, …, ny,nyThe number of nodes of the target power system is shown, Re represents a real part, Y is an admittance matrix of the target power system, and U is a node voltage matrix of the target power system.
In order to ensure the safety of the overload circuit, the comprehensive maximum adjusting speed, the adjusting quantity limit value of the overload circuit and the initial overload power determined by the synchronous generator, the gas turbine and the electric gas conversion equipment always meet the dynamic safety domain:
Figure BDA0002590409360000073
the node voltage of the power system should satisfy:
Uy,min≤Uy≤Uy,max
wherein, UyIs the voltage of the y-th node, Uy,max、Uy,minRespectively, the upper and lower limits of the voltage at node y.
The power of the electrical gas conversion equipment should meet the constraints of the natural gas system, namely:
Figure BDA0002590409360000074
wherein, FqIs the output flow of the qth natural gas source, nqNumber of natural gas sources, FloadFlow rate, phi, consumed by natural gas loads other than gas turbinesckFor the conversion efficiency of the kth electrical gas-converting apparatus, phigjThe conversion efficiencies of the jth gas turbine are respectively.
Compared with the prior art, the invention has the following advantages:
1. compared with the generator tripping load in the prior art, the generator tripping load control method has the advantages that the control of an overload circuit is realized by adopting the power regulation of controllable equipment, the economic loss caused by the generator tripping load and the impact on an electric coupling system are avoided, and the running stability of the system is improved.
2. Compared with the control method based on the fixed maximum overload time in the prior art, the method considers the influence of the current, the parameters and the environmental factors of the line on the temperature rise of the line, more accurately reflects the safety of the line, and avoids the damage to the overload line when the actually allowed overload time is less than a fixed value.
3. Compared with the control method for calculating the maximum overload time based on the line static power in the prior art, the method provided by the invention considers the change of the line power in the overload control process, and more accurately reflects the dynamic temperature rise process of the line in the overload process, so that more accurate allowable overload time is obtained, and misjudgment caused by the time obtained based on the line static power is avoided.
4. The method can quickly judge the safety of the overload circuit only by the information of the overload power of the circuit, the power regulation capability of the controllable equipment, the influence on the overload circuit, the circuit parameters, the environmental parameters and the like, and does not need to model the dynamic temperature rise process of the circuit, and is easy to realize, thereby improving the applicability of the judging method.
5. Aiming at the problem that the regulating capacity of the controllable equipment has a limit value, the invention provides an overload prevention method and an optimization model, and the power of each controllable equipment can be adjusted in advance according to the optimization model, so that the overload risk is avoided, and the running stability of the electric coupling system is improved.
Drawings
For purposes of promoting a better understanding of the objects, aspects and advantages of the invention, reference will now be made in detail to the present invention as illustrated in the accompanying drawings, in which:
fig. 1 is a flowchart illustrating a method for preventing and controlling overload of a power system line based on a dynamic security domain according to an embodiment of the present disclosure;
fig. 2 is a block diagram of an exemplary electrical coupling system according to an embodiment of the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
As shown in fig. 1, the method for preventing and controlling overload of a power system line based on a dynamic security domain includes the following steps:
s101, sequentially simulating the disconnection of each line in a target power system by using load flow calculation, calculating the power of each line, collecting the ambient temperature and the line temperature of each line, and executing the step S102, wherein the power of the e-th line is calculated by taking the e-th line as an examplePLeCollecting the ambient temperature T of each linea,LeAnd line temperature T0,LeWherein e is 1,2, …, nL，nLThe number of transmission lines;
s102, comparing the power of each line with the maximum allowable long-term operation power of the line, if the power of any line is larger than the maximum allowable long-term operation power of the line, judging that the line is an overloaded line, and executing a step S103, otherwise, executing a step S106;
s103, dividing the controllable equipment into sending-end controllable equipment or receiving-end controllable equipment of the overload line according to the power flow direction of the target power system and the access position of the controllable equipment in the target power system, and executing the step S104;
s104, calculating the maximum power regulating quantity of each transmitting-end controllable device and each receiving-end controllable device, calculating the maximum power regulating quantity of the controllable devices to the overload line, and executing the step S105;
s105, constructing a dynamic security domain of the overloaded line, judging whether the initial overloaded power of the overloaded line meets the corresponding dynamic security domain, if so, executing the step S101, otherwise, executing the step S106
And S106, calculating the equipment power capable of ensuring the safe recovery of the overload line according to the line overload prevention control optimization model, and adjusting all the equipment power to be equal to the calculated value so as to prevent the line overload.
In the method for preventing and controlling the line overload of the electric power system based on the dynamic security domain, the line security domain is constructed to reflect the security of the line overload; according to the influence of the initial power of the overload line and the power adjustment of the controllable equipment on the power of the overload line, whether the overload risk exists in the line is judged quickly; and for the line with overload risk, an overload prevention method and an optimization model based on a line dynamic security domain are provided, so that the overload security risk is eliminated.
In specific implementation, the devices connected to the target power system include a Gas Turbine (GT), a Synchronous Generator (SG) and an electric gas conversion device (P2G), and in step S103, if the synchronous generator or the gas turbine provides power for the overload line, the synchronous generator or the gas turbine is a sending-end controllable device of the overload line; if the electric gas conversion equipment and the overload line absorb power from the same node at the same time, the electric gas conversion equipment is the sending end controllable equipment of the overload line; if the output power of the synchronous generator or the gas turbine does not flow through the overload circuit and is transmitted to the same node with the power of the overload circuit, the synchronous generator or the gas turbine is controlled equipment at the receiving end of the overload circuit; and if the power of the overload line is transmitted to the electric gas conversion equipment through a line, the electric gas conversion equipment is the receiving end electric gas conversion equipment of the overload line.
In specific implementation, in step S104, when the overload line is the r-th line in step S104, the controllable device in the target power system adjusts the maximum power of the overload line within any time period Δ t
Figure BDA0002590409360000091
Can be calculated from the following formula:
Figure BDA0002590409360000092
and is
Figure BDA0002590409360000093
Satisfies the following conditions:
Figure BDA0002590409360000094
in the formula (I), the compound is shown in the specification,
Figure BDA0002590409360000095
respectively representing the limit values of the power regulating quantity of the r-th line of the synchronous generator, the gas turbine and the electric gas conversion equipment in the target power system within delta t time;
Figure BDA0002590409360000096
for synchronizing generators and gas in a targeted power systemThe integrated maximum speed of regulation of the power of the turbine on said overload line r.
Figure BDA0002590409360000097
Calculated as follows:
Figure BDA0002590409360000101
Figure BDA0002590409360000102
calculated as follows:
Figure BDA0002590409360000103
in the formula, Hsh,o、Hgj,oAnd Hck,oThe sensitivities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the sending end controllable equipment and the power of the overload circuit are respectively set; hsh,i、Hgj,iAnd Hck,iThe sensitivities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the receiving end controllable equipment and the power of the overload circuit are respectively set; ps0h,oAnd Ps0h,iAre each t0The active power output by the h-th synchronous generator in the sending-end controllable equipment and the receiving-end controllable equipment at any moment; pshd,oMaintaining the minimum active power for the h synchronous generator in the sending end controllable equipment; pg0j,oAnd Pg0j,iAre each t0The active power output by the jth gas turbine in the sending-end controllable equipment and the receiving-end controllable equipment at any moment; pguj,i(tm) For the jth gas turbine in the receiving end controllable equipment at tmAn upper power limit at a time; pc0k,oAnd Pc0k,iAre each t0The active power output by the kth electric gas conversion equipment in the sending end controllable equipment and the receiving end controllable equipment at any moment;
Figure BDA0002590409360000104
for the kth station in the sending-end controllable equipmentThe maximum output active power of the gas equipment; n iss,oAnd ns,iThe number of synchronous generators in the sending end controllable equipment and the receiving end controllable equipment is respectively; n isg,oAnd ng,iThe number of gas turbines in the sending-end controllable equipment and the receiving-end controllable equipment respectively; n isc,oAnd nc,iThe number of the electric gas conversion equipment in the sending end controllable equipment and the receiving end controllable equipment is respectively;oandidistribution coefficients of power regulating quantities of the sending end controllable equipment and the receiving end controllable equipment are respectively;
Figure BDA0002590409360000105
and
Figure BDA0002590409360000106
the maximum landslide and the climbing speed of the h-th synchronous generator are respectively;
Figure BDA0002590409360000107
and
Figure BDA0002590409360000108
the maximum climbing speed and the maximum landslide speed of the jth gas turbine are respectively set; t is tm＝t0+Δt，t0The moment when the overload occurs on the overload line.
In specific implementation, the maximum output power of the kth electric gas conversion equipment in the sending end controllable equipment
Figure BDA0002590409360000109
Considering the constraint of the upper power limit of the electric power conversion equipment, the method can be calculated according to the following formula:
Figure BDA00025904093600001010
in the formula, phick,oThe conversion efficiency of the kth electric gas conversion equipment in the sending end controllable equipment is obtained; hgIs the heat value of natural gas;
Figure BDA0002590409360000111
for upper power constraints of electric-to-gas apparatusThe upper limit of the natural gas flow output by the kth electric gas conversion device in the sending end controllable device is calculated according to the following formula:
Figure BDA0002590409360000112
in the formula (I), the compound is shown in the specification,
Figure BDA0002590409360000113
the upper limit of the power of the kth electric gas conversion equipment in the sending end controllable equipment; picomk,o(t0) Is t0The air pressure of a kth electric gas conversion device in the controllable device at the sending end is accessed to a natural gas node at any moment; zcomk,oIs a constant related to the compression factor and the heating value of the natural gas; b iscomk,oIs a constant related to the heating value of natural gas and the temperature and efficiency of the electric gas conversion equipment.
In the specific implementation process, the first-stage reactor,oandicalculated according to the following formula:
Figure BDA0002590409360000114
wherein the sum of the maximum power adjustment amounts of the sending-end controllable device and the receiving-end controllable device is
Figure BDA0002590409360000115
And
Figure BDA0002590409360000116
Figure BDA0002590409360000117
in the formula (I), the compound is shown in the specification,
Figure BDA0002590409360000118
maximum power regulating quantities of a h synchronous generator, a j gas turbine and a k electric gas conversion device in the sending end controllable device in delta t time are respectively set;
Figure BDA0002590409360000119
the maximum power regulating quantities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the receiving end controllable equipment in delta t time are respectively.
In specific implementation, the maximum power regulating quantity of the synchronous generator in the sending end controllable device and the receiving end controllable device in delta t time is calculated according to the following formula:
Figure BDA0002590409360000121
the maximum power regulating quantity of the gas turbine in the delta t time in the sending end controllable equipment and the receiving end controllable equipment is calculated according to the following formula:
Figure BDA0002590409360000122
the maximum power regulating quantity of the electric conversion equipment in the sending end controllable equipment and the receiving end controllable equipment in delta t time is calculated according to the following formula:
Figure BDA0002590409360000123
in specific implementation, the jth gas turbine in the receiving-end controllable equipment is at tmUpper power limit P of timeguj,i(tm) Considering the constraint of the node voltage, the method comprises the following steps:
Figure BDA0002590409360000124
in the formula, pigj,i(t0) Is t0The pressure of a jth gas turbine in the receiving-end controllable equipment is connected to a natural gas node at any moment;
Figure BDA0002590409360000125
the air pressure of the combustion chamber of the jth gas turbine in the receiving-end controllable equipment is measured; phi is agj,iThe energy conversion efficiency of the jth gas turbine in the receiving-end controllable equipment is obtained; hgIs the heat value of natural gas.
In specific implementation, when the overload line is the r-th line, the dynamic security domain P of the r-th lineL0rConstructed according to the following formula:
Figure BDA0002590409360000126
in the formula, the coefficient C can be calculated as follows:
Figure BDA0002590409360000127
in the formula, Tmax,LrThe maximum allowable temperature of the r line; t isa,LrThe environment absolute temperature of the r line; t is0,LrThe temperature of the r line in normal operation; rhoLr、ULr、
Figure BDA0002590409360000131
QLrThe resistivity, voltage, radius and reactive power of the r line are respectively; mLr、NLrThe convection heat dissipation coefficient and the radiation heat dissipation coefficient of the r line, B1、B2、B3、B4Is a constant related to the parameters of the line r itself:
Figure BDA0002590409360000132
in the formula, xLrIs the density of the r-th line, cLrIs the specific heat capacity of the r-th line.
In step S106, the line overload prevention control optimization model is:
Figure BDA0002590409360000133
wherein, ash、bsh、cshCost factor for the h-th synchronous generator in the target power system, dgjFor the generation of the jth gas turbine in the target power systemCoefficient of merit, Psh、Pgj、PckThe power of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the target power system, nsIs the total number of synchronous generators in the target power system, ngIs the total number of gas turbines in the target power system, nkMu is the unit electricity price, sigma is the unit cost of natural gas,
Figure BDA0002590409360000134
the efficiency of the kth electric gas conversion equipment in the target power system;
the active power of each synchronous generator, each gas turbine and each electric gas conversion device meets the following conditions:
Figure BDA0002590409360000135
wherein, PlyThe power absorbed for the y-th node load of the target power system, y is 1,2, …, ny,nyThe number of nodes of the target power system is shown, Re represents a real part, Y is an admittance matrix of the target power system, and U is a node voltage matrix of the target power system.
In order to ensure the safety of the overload circuit, the comprehensive maximum adjusting speed, the adjusting quantity limit value of the overload circuit and the initial overload power determined by the synchronous generator, the gas turbine and the electric gas conversion equipment always meet the dynamic safety domain:
Figure BDA0002590409360000141
the node voltage of the power system should satisfy:
Uy,min≤Uy≤Uy,max
wherein, UyIs the voltage of the y-th node, Uy,max、Uy,minRespectively, the upper and lower limits of the voltage at node y.
The power of the electrical gas conversion equipment should meet the constraints of the natural gas system, namely:
Figure BDA0002590409360000142
wherein, FqIs the output flow of the qth natural gas source, nqNumber of natural gas sources, FloadFlow rate, phi, consumed by natural gas loads other than gas turbinesckFor the conversion efficiency of the kth electrical gas-converting apparatus, phigjThe conversion efficiencies of the jth gas turbine are respectively.
Compared with the prior art, the invention has the following advantages:
1. compared with the generator tripping load in the prior art, the generator tripping load control method has the advantages that the control of an overload circuit is realized by adopting the power regulation of controllable equipment, the economic loss caused by the generator tripping load and the impact on an electric coupling system are avoided, and the running stability of the system is improved.
2. Compared with the control method based on the fixed maximum overload time in the prior art, the method considers the influence of the current, the parameters and the environmental factors of the line on the temperature rise of the line, more accurately reflects the safety of the line, and avoids the damage to the overload line when the actually allowed overload time is less than a fixed value.
3. Compared with the control method for calculating the maximum overload time based on the line static power in the prior art, the method provided by the invention considers the change of the line power in the overload control process, and more accurately reflects the dynamic temperature rise process of the line in the overload process, so that more accurate allowable overload time is obtained, and misjudgment caused by the time obtained based on the line static power is avoided.
4. The method can quickly judge the safety of the overload circuit only by the information of the overload power of the circuit, the power regulation capability of the controllable equipment, the influence on the overload circuit, the circuit parameters, the environmental parameters and the like, and does not need to model the dynamic temperature rise process of the circuit, and is easy to realize, thereby improving the applicability of the judging method.
5. Aiming at the problem that the regulating capacity of the controllable equipment has a limit value, the invention provides an overload prevention method and an optimization model, and the power of each controllable equipment can be adjusted in advance according to the optimization model, so that the overload risk is avoided, and the running stability of the electric coupling system is improved.
Taking the typical electrical coupling system in fig. 2 as an example, the rated voltage of the system is 135kV, the nodes 1,2, 23, and 27 are connected to the synchronous generator, and the capacities are 100MVA, 80MVA, 60MVA, and 50MVA, respectively. The nodes 13 and 22 are connected to the gas turbine, and the capacities are 50MVA and 40MVA respectively. The nodes 17 and 28 are connected into the electric switching equipment, and the maximum power is 1.5 MW. The synchronous generator represents a synchronous generator, the gas turbine represents a gas turbine, and the electric gas conversion equipment represents electric gas conversion. Line L6-10The initial temperature of (a) was 50 ℃, MAT was 70 ℃, PLCP was 44.5A, and the long-term allowable power of the line was 10.5 MW. The ambient temperature was 30 ℃.
Taking the system shown in fig. 2 as an example, when the system is in normal operation, the powers of the synchronous generator 1, the synchronous generator 2, the synchronous generator 3 and the synchronous generator 4 are 62.13MW, 60.97MW, 19.19MW and 37.01MW, respectively; the power of the gas turbine 1 and the power of the gas turbine 2 are respectively 21.59MW and 26.91 MW; the power of the electric gas conversion device 1 and the power of the electric gas conversion device 2 are respectively 0.27MW and 0.59 MW. When the line L is6-9Out of operation, line L6-10The power of the line is 18.02MW, which exceeds the long-term allowable power of the line, and at the moment, according to the criterion of a dynamic security domain, the value on the right side of the unequal number is 7.19, which indicates that the safety of the overloaded line cannot be ensured in the current operation mode. In practice, however, the line temperature will rise to the maximum tolerated temperature at 2.06min, and at this point the line power is still greater than the long-term allowed power, and the line temperature will continue to rise, compromising line safety.
Taking the system shown in fig. 2 as an example, after the method is adopted, the powers of the synchronous generator 1, the synchronous generator 2, the synchronous generator 3 and the synchronous generator 4 are 55.68MW, 55.78MW, 25.28MW and 35.64MW respectively; the power of the gas turbine 1 and the power of the gas turbine 2 are respectively 21.59MW and 33.13 MW; the power of the electric gas conversion device 1 and the power of the electric gas conversion device 2 are respectively 0.51MW and 0.79 MW. When the line L is6-9Out of operation, line L6-10Has a power of 14.42MW and a value of 17.23 to the right of the unequal sign, which indicates that the optimization results in a safe line. And, in fact, is controllableUnder the power regulation effect of the equipment, the temperature of the line begins to fall after rising to 67.60 ℃, the maximum tolerance temperature of the line cannot be reached, and the line is safe. The safety domain provided by the invention can accurately reflect the safety of the overload line, and the overload prevention method provided by the invention can effectively prevent the overload risk of the line and ensure the safety of the system operation.
The invention constructs a line security domain to reflect the security of line overload; according to the influence of the initial power of the overload line and the power adjustment of the controllable equipment on the power of the overload line, whether the overload risk exists in the line is judged quickly; and for the line with overload risk, an overload prevention method and an optimization model based on a line dynamic security domain are provided, so that overload security risk is eliminated. The method can quickly judge the safety of the overload circuit only by the information of the overload power of the circuit, the power regulation capability of the controllable equipment, the influence on the overload circuit, the circuit parameters, the environmental parameters and the like, and does not need to model the dynamic temperature rise process of the circuit, and is easy to realize, thereby improving the applicability of the judging method. Aiming at the problem that the adjusting capacity of the controllable equipment has a limit value, the invention provides an overload prevention method and an optimization model, and the power of each controllable equipment can be adjusted in advance according to the optimization model, so that the overload risk is avoided, and the running stability of the electric coupling system is improved.
Finally, it is noted that the above-mentioned embodiments illustrate rather than limit the invention, and that, while the invention has been described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (9)

1. The electric power system line overload prevention control method based on the dynamic security domain is characterized by comprising the following steps:
s101, sequentially simulating the disconnection of each line in a target power system by using load flow calculation, calculating the power of each line, collecting the ambient temperature and the line temperature of each line, and executing the step S102;
s102, comparing the power of each line with the maximum allowable long-term operation power of the line, if the power of any line is larger than the maximum allowable long-term operation power of the line, judging that the line is an overloaded line, and executing a step S103, otherwise, executing a step S106;
s103, dividing the controllable equipment into sending-end controllable equipment or receiving-end controllable equipment of the overload line according to the power flow direction of the target power system and the access position of the controllable equipment in the target power system, and executing the step S104;
s104, calculating the maximum power regulating quantity of each transmitting-end controllable device and each receiving-end controllable device, calculating the maximum power regulating quantity of the controllable devices in the target power system to the overload circuit, and executing the step S105;
s105, constructing a dynamic security domain of the overloaded line, judging whether the initial overloaded power of the overloaded line meets the corresponding dynamic security domain, if so, executing the step S101, otherwise, executing the step S106
And S106, calculating the equipment power capable of ensuring the safe recovery of the overload line according to the line overload prevention control optimization model, and adjusting all the equipment power to be equal to the calculated value so as to prevent the line overload.
2. The method for preventing and controlling line overload of power system based on dynamic security domain as claimed in claim 1, wherein the devices connected to the target power system include a gas turbine, a synchronous generator and an electric gas conversion device, and in step S103, if the synchronous generator or the gas turbine provides power for the overload line, the synchronous generator or the gas turbine is the sending controllable device of the overload line; if the electric gas conversion equipment and the overload line absorb power from the same node at the same time, the electric gas conversion equipment is the sending end controllable equipment of the overload line; if the output power of the synchronous generator or the gas turbine does not flow through the overload circuit and is transmitted to the same node with the power of the overload circuit, the synchronous generator or the gas turbine is controlled equipment at the receiving end of the overload circuit; and if the power of the overload line is transmitted to the electric gas conversion equipment through a line, the electric gas conversion equipment is the receiving end electric gas conversion equipment of the overload line.
3. The method according to claim 1, wherein in step S104, when the overloaded line is the r-th line, the controllable device in the target power system adjusts the maximum power of the overloaded line by the maximum power adjustment amount in any time period Δ t
Figure FDA0002590409350000011
Can be calculated from the following formula:
Figure FDA0002590409350000012
and is
Figure FDA0002590409350000013
Satisfies the following conditions:
Figure FDA0002590409350000014
in the formula (I), the compound is shown in the specification,
Figure FDA0002590409350000021
respectively representing the limit values of the power regulating quantity of the r-th line of the synchronous generator, the gas turbine and the electric gas conversion equipment in the target power system within delta t time;
Figure FDA0002590409350000022
the integrated maximum regulation speed of the overload line r power for the synchronous generator and gas turbine in the target power system.
Figure FDA0002590409350000023
Calculated as follows:
Figure FDA0002590409350000024
Figure FDA0002590409350000025
calculated as follows:
Figure FDA0002590409350000026
in the formula, Hsh,o、Hgj,oAnd Hck,oThe sensitivities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the sending end controllable equipment and the power of the overload circuit are respectively set; hsh,i、Hgj,iAnd Hck,iThe sensitivities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the receiving end controllable equipment and the power of the overload circuit are respectively set; ps0h,oAnd Ps0h,iAre each t0The active power output by the h-th synchronous generator in the sending-end controllable equipment and the receiving-end controllable equipment at any moment; pshd,oMaintaining the minimum active power for the h synchronous generator in the sending end controllable equipment; pg0j,oAnd Pg0j,iAre each t0The active power output by the jth gas turbine in the sending-end controllable equipment and the receiving-end controllable equipment at any moment; pguj,i(tm) For the jth gas turbine in the receiving end controllable equipment at tmAn upper power limit at a time; pc0k,oAnd Pc0k,iAre each t0The active power output by the kth electric gas conversion equipment in the sending end controllable equipment and the receiving end controllable equipment at any moment;
Figure FDA0002590409350000027
the maximum output active power of the kth electric gas conversion equipment in the sending end controllable equipment is obtained; n iss,oAnd ns,iThe number of synchronous generators in the sending end controllable equipment and the receiving end controllable equipment is respectively; n isg,oAnd ng,iAre respectively asThe number of gas turbines in the sending-end controllable equipment and the receiving-end controllable equipment; n isc,oAnd nc,iThe number of the electric gas conversion equipment in the sending end controllable equipment and the receiving end controllable equipment is respectively;oandidistribution coefficients of power regulating quantities of the sending end controllable equipment and the receiving end controllable equipment are respectively;
Figure FDA0002590409350000028
and
Figure FDA0002590409350000029
the maximum landslide and the climbing speed of the h-th synchronous generator are respectively;
Figure FDA00025904093500000210
and
Figure FDA00025904093500000211
the maximum climbing speed and the maximum landslide speed of the jth gas turbine are respectively set; t is tm＝t0+Δt，t0The moment when the overload occurs on the overload line.
4. The dynamic security domain-based power system line overload prevention control method as claimed in claim 3, wherein the maximum output power of the kth electrical to gas device in the sending-end controllable device
Figure FDA0002590409350000031
Considering the constraint of the upper power limit of the electric power conversion equipment, the method can be calculated according to the following formula:
Figure FDA0002590409350000032
in the formula, Pckn,oThe rated power of the kth electric gas conversion equipment in the sending end controllable equipment is obtained; phi is ack,oThe conversion efficiency of the kth electric gas conversion equipment in the sending end controllable equipment is obtained; hgIs the heat value of natural gas;
Figure FDA0002590409350000033
the upper limit of the natural gas flow output by the kth electric gas conversion equipment in the sending end controllable equipment constrained by the upper limit of the power of the electric gas conversion equipment is calculated according to the following formula:
Figure FDA0002590409350000034
in the formula (I), the compound is shown in the specification,
Figure FDA0002590409350000035
the upper limit of the power of the kth electric gas conversion equipment in the sending end controllable equipment; picomk,o(t0) Is t0The air pressure of a kth electric gas conversion device in the controllable device at the sending end is accessed to a natural gas node at any moment; zcomk,oIs a constant related to the compression factor and the heating value of the natural gas; b iscomk,oIs a constant related to the heating value of natural gas and the temperature and efficiency of the electric gas conversion equipment.
5. A dynamic security domain based power system line overload prevention control method as defined in claim 3,oandicalculated according to the following formula:
Figure FDA0002590409350000036
wherein the sum of the maximum power adjustment amounts of the sending-end controllable device and the receiving-end controllable device is
Figure FDA0002590409350000037
And Δ Pi max(Δt)；
Figure FDA0002590409350000041
In the formula (I), the compound is shown in the specification,
Figure FDA0002590409350000042
maximum power regulating quantities of a h synchronous generator, a j gas turbine and a k electric gas conversion device in the sending end controllable device in delta t time are respectively set;
Figure FDA0002590409350000043
the maximum power regulating quantities of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the receiving end controllable equipment in delta t time are respectively.
6. The dynamic security domain-based power system line overload prevention control method as claimed in claim 5, wherein the maximum power adjustment amount of the synchronous generators in the sending-end controllable device and the receiving-end controllable device within the Δ t time is calculated according to the following formula:
the maximum power regulating quantity of the gas turbine in the delta t time in the sending end controllable equipment and the receiving end controllable equipment is calculated according to the following formula:
Figure FDA0002590409350000045
the maximum power regulating quantity of the electric conversion equipment in the sending end controllable equipment and the receiving end controllable equipment in delta t time is calculated according to the following formula:
Figure FDA0002590409350000046
7. the dynamic security domain-based power system line overload prevention control method as claimed in claim 5, wherein the jth gas turbine in the controlled end device is at tmUpper power limit P of timeguj,i(tm) Considering the constraint of the node voltage, the method comprises the following steps:
Figure FDA0002590409350000047
in the formula, pigj,i(t0) Is t0The pressure of a jth gas turbine in the receiving-end controllable equipment is connected to a natural gas node at any moment;
Figure FDA0002590409350000048
the air pressure of the combustion chamber of the jth gas turbine in the receiving-end controllable equipment is measured; phi is agj,iThe energy conversion efficiency of the jth gas turbine in the receiving-end controllable equipment is obtained; hgIs the heat value of natural gas.
8. A dynamic security domain-based power system line overload prevention control method as claimed in claim 1, wherein when the overloaded line is the r-th line, the dynamic security domain P of the r-th lineL0rConstructed according to the following formula:
Figure FDA0002590409350000051
in the formula, the coefficient C can be calculated as follows:
Figure FDA0002590409350000052
in the formula, Tmax,LrThe maximum allowable temperature of the r line; t isa,LrThe environment absolute temperature of the r line; t is0,LrThe temperature of the r line in normal operation; rhoLr、ULr、
Figure FDA0002590409350000053
QLrThe resistivity, voltage, radius and reactive power of the r line are respectively; mLr、NLrThe convection heat dissipation coefficient and the radiation heat dissipation coefficient of the r line, B1、B2、B3、B4As a function of the parameters of the line r itselfConstant:
Figure FDA0002590409350000054
in the formula, xLrIs the density of the r-th line, cLrIs the specific heat capacity of the r-th line.
9. The dynamic security domain-based power system line overload prevention control method according to claim 1, wherein in step S106, the line overload prevention control optimization model is:
Figure FDA0002590409350000055
wherein, ash、bsh、cshCost factor for the h-th synchronous generator in the target power system, dgjIs the cost factor, P, of the jth gas turbine in the target power systemsh、Pgj、PckThe power of the h synchronous generator, the j gas turbine and the k electric gas conversion equipment in the target power system, nsIs the total number of synchronous generators in the target power system, ngIs the total number of gas turbines in the target power system, nkMu is the unit electricity price, sigma is the unit cost of natural gas,
Figure FDA0002590409350000061
the efficiency of the kth electric gas conversion equipment in the target power system;
the active power of each synchronous generator, each gas turbine and each electric gas conversion device meets the following conditions:
Figure FDA0002590409350000062
wherein, PlyThe power absorbed for the y-th node load of the target power system, y is 1,2, …, ny,nyIs a target electricityThe node number of the force system, Re represents a real part, Y is a target power system admittance matrix, and U is a target power system node voltage matrix.
In order to ensure the safety of the overload circuit, the comprehensive maximum adjusting speed, the adjusting quantity limit value of the overload circuit and the initial overload power determined by the synchronous generator, the gas turbine and the electric gas conversion equipment always meet the dynamic safety domain:
Figure FDA0002590409350000063
the node voltage of the power system should satisfy:
Uy,min≤Uy≤Uy,max
wherein, UyIs the voltage of the y-th node, Uy,max、Uy,minRespectively, the upper and lower limits of the voltage at node y.
The power of the electrical gas conversion equipment should meet the constraints of the natural gas system, namely:
Figure FDA0002590409350000064
wherein, FqIs the output flow of the qth natural gas source, nqNumber of natural gas sources, FloadFlow rate, phi, consumed by natural gas loads other than gas turbinesckFor the conversion efficiency of the kth electrical gas-converting apparatus, phigjThe conversion efficiencies of the jth gas turbine are respectively.
The output flow of the natural gas source is limited, and the requirements of:
Fq,min≤Fq≤Fq,max
wherein, Fq,max、Fq,minThe upper limit and the lower limit of the output flow of the qth gas source are respectively set;
in order to ensure the normal and stable transportation of natural gas, the node pressure range of the natural gas system is as follows:
πm,min≤πm≤πm,max
wherein, pim,max、πm,m i nThe upper and lower limits of the pressure at the mth node, m is 1,2, …, nm，nmThe number of the natural gas system nodes.
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Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112688323A (en) * 2021-01-13 2021-04-20 重庆大学 Power system cascading failure blocking method based on active minimum generator tripping
CN112688322A (en) * 2021-01-13 2021-04-20 重庆大学 Power system overload coordination control method considering dynamic safety of line
CN112801428A (en) * 2021-04-08 2021-05-14 国网江苏省电力有限公司苏州供电分公司 Probability early warning-based lightning loss prevention control method
CN113161983A (en) * 2021-03-29 2021-07-23 重庆大学 Power transmission line self-adaptive overload protection method considering dynamic thermal characteristics
CN114583822A (en) * 2022-03-18 2022-06-03 国网伊犁伊河供电有限责任公司 Overload tripping method and device for automatic bus transfer device combined with power supply risk of power grid

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105262086A (en) * 2015-11-17 2016-01-20 天津大学 Security domain-based method for determining N-1 overload component set
CN110380447A (en) * 2019-07-22 2019-10-25 重庆大学 A kind of lower electric-gas interconnection energy resource system drop Risk Scheduling method of blower failure

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105262086A (en) * 2015-11-17 2016-01-20 天津大学 Security domain-based method for determining N-1 overload component set
CN110380447A (en) * 2019-07-22 2019-10-25 重庆大学 A kind of lower electric-gas interconnection energy resource system drop Risk Scheduling method of blower failure

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
陈晖 等: ""基于静态安全域的交直流协调安全控制"", 《广东电力》 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN112688323A (en) * 2021-01-13 2021-04-20 重庆大学 Power system cascading failure blocking method based on active minimum generator tripping
CN112688322A (en) * 2021-01-13 2021-04-20 重庆大学 Power system overload coordination control method considering dynamic safety of line
CN113161983A (en) * 2021-03-29 2021-07-23 重庆大学 Power transmission line self-adaptive overload protection method considering dynamic thermal characteristics
CN113161983B (en) * 2021-03-29 2022-06-03 重庆大学 Power transmission line self-adaptive overload protection method considering dynamic thermal characteristics
CN112801428A (en) * 2021-04-08 2021-05-14 国网江苏省电力有限公司苏州供电分公司 Probability early warning-based lightning loss prevention control method
CN114583822A (en) * 2022-03-18 2022-06-03 国网伊犁伊河供电有限责任公司 Overload tripping method and device for automatic bus transfer device combined with power supply risk of power grid

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