AGC control system and control method for wind power participating in peak shaving frequency modulation
Technical Field
The invention relates to the technical field of active control of a power system, in particular to an AGC control system and a control method for realizing wind power generation increase by participating in peak shaving and frequency modulation of a power grid based on a two-stage scheduling coordination control framework after large-scale wind power grid connection.
Background
Wind power generation is a renewable energy power generation mode which is the most mature in technology and the best in economic benefit except hydropower at present. After the grid-connected operation of large-scale wind power, the influence of the randomness, the volatility and the intermittence of the wind power on the safe and stable operation of a power grid is gradually shown. Along with the construction of a plurality of ten million kilowatt-level wind power bases in China, the difficulty of completely consuming wind power of a power grid is gradually increased on the premise of ensuring safe and stable operation and ensuring active control performance, and meanwhile, higher requirements are provided for power grid dispatching and active control.
According to the requirements of the national new energy policy, the power grid receives wind power resources in a mode of priority scheduling and full acquisition after wind power integration. After large-scale wind power is connected to the grid, the wind power climbing and descending speed is too high, the 'reverse peak regulation' and the intermittent characteristic greatly increase the demand of the power grid on the conventional energy regulation reserve capacity, improve the performance requirement of resource regulation, and reduce the operation economy of the power grid. From the active control condition of the currently grid-connected wind power, although many wind power plants have the capacity of receiving remote control, due to the reasons of lack of wind power active control experience, maximum utilization of wind power resources and the like, the wind power active control is still in the stage of tracking a day-ahead plan, the day-ahead plan of the wind power plants is influenced by wind power prediction precision and a load prediction result of a whole grid system, the wind power active control is rough, and the utilization effect of the wind power resources is poor. Therefore, in order to fully realize the maximum utilization of wind power resources, the existing planned value control mode must be abandoned, the wind power plant is introduced into the conventional AGC control, the integration and the differential control of wind power and conventional energy are carried out, and the coordination control of the wind power and the conventional energy based on the wind power receiving capacity is realized.
The active control technology for wind power access in the power system currently has the following methods:
in the literature, "frequency control characteristics when a large amount of wind power is introduced into a power grid" (2008, 32 nd volume, 1 st period, 29 st page), frequency characteristics of asynchronous motors with different torque characteristics are tested by using a developed power disturbance device on the basis of deep analysis of the frequency characteristics of the asynchronous motors. A frequency characteristic model of comprehensive load containing the asynchronous motor is established based on a weighted comprehensive thought, and meanwhile, the output characteristic of wind power generation is analyzed. By analyzing a power grid including wind power generation, the deviation of frequency fluctuation becomes smaller under the condition of the same grid frequency modulation capability after the load frequency characteristic is considered.
According to the second document, "simulation research on frequency control of a doubly-fed variable speed wind turbine generator" (vol.31, No. 7, page 61 in power system automation), a frequency control link is added in power system simulation software based on a doubly-fed variable speed wind turbine generator model, according to control characteristics and a control process of the doubly-fed variable speed wind turbine generator, and when the system frequency changes, the doubly-fed variable speed wind turbine generator correspondingly increases or decreases active output by releasing or absorbing a part of kinetic energy in a rotor, so that the frequency control of the doubly-fed variable speed wind turbine generator is realized. The simulation result proves the effectiveness and the practicability of the frequency control link, and proves that the wind power plant can participate in the system frequency adjustment to a certain extent by adding the additional frequency control link.
The above documents disclose active power scheduling techniques after wind power access from different levels, such as wind turbine generator, wind farm model and characteristics, and electricity participation grid primary and secondary frequency control techniques.
In the third document, "wind power optimized scheduling method taking power grid safety constraints into account" (34, 15, page 71 of power system automation 2010), an optimized scheduling method for making a wind farm output plan according to constraints such as wind power prediction, power grid load prediction, inter-provincial tie line plan, power grid safety stability and the like is proposed. The method provided by the article is mainly used for coordinating and optimizing a grid-provincial dispatching mechanism to arrange a conventional energy unit, reserving a wind power output space to ensure that the active power output of a wind power plant stably runs in a safe area, and creating conditions for the maximum wind power acceptance of a power grid.
According to the wind power optimal scheduling method provided by the third document, balance between system operation economy and maximum access of wind power is achieved by reasonably arranging a day-ahead plan, and safe and stable operation of a power grid after wind power access is guaranteed by tracking a safe region curve through a wind power plant. Active power control technologies of a power grid and a wind power plant after wind power access are disclosed from different aspects such as grid province resource coordination, resource calling mode optimization, grid safety and the like, but the active power control technologies of the wind power plant are not discussed by analyzing coordination of wind power and conventional energy from the aspects of real-time control and AGC.
Four documents of System control of large scale wind Power by use of Automatic Generation Control (AGC), Quality and Security of Electric Power Delivery Systems,2003, CIGRE/PES 2003, CIGRE/IEEE PES International Symposium 8-10Oct.2003, On pages (15-21), propose to introduce the deviation of the actual generated Power of wind Power and the planned generated Power into AGC control, and to analyze the wind Power access and System control problems from the Power market perspective.
The fourth literature is mainly used for analyzing the problem of deviation balance between the actual wind power output and the planned output from the perspective of the power market, when the actual wind power output and the planned output of the wind power plant have deviation, AGC is introduced to the deviation part, other energy sources are automatically called by AGC to meet the requirement of power deviation, and the absorption, power balance and frequency stability of wind power resources are realized. The problem discussed in the fourth document is limited to deviation between actual output and planned output of the wind power plant, the main idea is to discuss the completion of planning of the wind power plant, and the problem of wind power consumption when the safety and stability of a power grid are affected after the large-scale wind power plant is accessed is not researched.
The fifth document 'Research On Active Power Real-Time Dispatching of Wind Farm Integration' (Power and Energy Engineering Conference (APPEE), 2010Asia-Pacific,28-31March 2010, On page(s): 1-4) analyzes the Power characteristics of a large-scale Wind Farm, and proposes an elastic Dispatching method for accessing the large-scale Wind Farm to a Power grid.
The fifth document analyzes and reduces adverse effects of wind power intermittency on a power grid after large-scale wind power is accessed from the perspective of reserving adjustment capacity for the wind power plant, but the requirement that the wind power plant reserves a part of adjustment capacity according to an ultra-short-term load forecasting result is contrary to the basic requirement that wind power resources are consumed as much as possible in the current new energy development policy.
Document VI, Large-scale wind power active control considering section safety constraints (Power grid technology, 2015(4): 1014-plus 1018), provides an active control method for a large-scale wind power hierarchical section, and according to the characteristics of tree-shaped, multilayer nesting and active power unidirectionality of the large-scale wind power output section, under the condition of a given section hierarchical structure, the distribution of multilayer section regulation power is realized by adopting a method of wide-area wind power distribution regulation power, depth-first search of an out-of-limit section and power generation capacity transfer, so that the utilization rate of the power grid section and the power grid operation economy can be improved, and the regulation and control pressure of a dispatcher can be reduced.
The sixth document starts from a power grid structure and power grid safety constraints, and utilizes the power transmission capacity of a power transmission channel as much as possible on the premise of meeting the power grid safety constraints, so that the maximum utilization of wind power resources is realized.
The patent 'a divide-province two-stage coordinated wind power generation increasing control method' discloses a divide-province dispatch overall coordination control strategy, wherein the divide-province dispatch side carries out overall optimization to obtain the power generation index of the whole network, then the power generation index is distributed to each province dispatch, and the province dispatch controls a single wind power plant to realize the wind power coordination increasing function.
Disclosure of Invention
The technical problem to be solved by the invention is that based on a split-dispatching-provincial-dispatching two-stage dispatching coordination Control framework, on the basis that wind power consumption indexes of all provinces are obtained through calculation of a split-dispatching AGC (Automatic Generation Control) system, wind power is used for participating in peak regulation and frequency modulation according to ACE (Area Control Error) of a whole network Control Area, wind power Generation increase is further realized, and the wind power consumption capacity of a power grid is improved.
The technical scheme adopted by the invention is as follows: an AGC control system for wind power participating in peak regulation and frequency modulation is based on a 'split-modulation-provincial-modulation' coordination control framework, wherein the 'split-modulation-provincial-modulation' coordination control framework comprises a split-modulation AGC control end and a provincial-modulation wind power control end;
the shunting AGC control end comprises a main control module for controlling the conventional area of the interconnected power grid and a wind power control module for controlling a wind power plant;
the wind power saving and regulating control end comprises a plurality of wind power saving and regulating control modules, and each wind power saving and regulating control module is used for controlling the wind power of a plurality of wind power plants in one control area;
a virtual wind turbine generator model corresponding to each control area wind power plant is established in a wind power control module of the shunting AGC control end and is used as an AGC control object of the wind power control module;
each provincial wind power control module counts control parameter data of a wind power plant in a control area and uploads the control parameter data to a corresponding virtual wind turbine generator model of the wind power control module; the wind power control module acquires corresponding control parameter data through each virtual wind turbine generator model and forwards wind power control command data to the corresponding provincial dispatching wind power control module;
and each provincial wind power regulation control module carries out wind power control on the wind power plant in the control area according to the received wind power control command data.
Further, the control parameter data of the wind farm in the control area of the provincial and regional wind power control module includes: and controlling the actual output, the adjusting range and the AGC controllable signals of a plurality of wind power plants in the area. And updating the control parameter data into the control parameters of the corresponding virtual wind turbine generator model after uploading.
The main control module of the control end of the sub-modulation AGC implements the conventional area control of the control area of the sub-modulation AGC in the interconnected power grid, and the control target is to maintain the frequency of the power grid of the control area within the control range, or maintain the exchange power of the control area and other adjacent sub-modulation AGC control areas to be a given plan value, or simultaneously meet the two control targets. The above-described conventional zone control is prior art.
The wind power control module of the sub-modulation AGC sends control command data to the virtual wind power generator set, wherein the control command data comprises control targets of the sub-modulation AGC of each province, and the sub-modulation AGC sends the control command data to each corresponding province-modulation wind power control module through each virtual wind power generator set model according to control parameter data acquired from the virtual wind power generator set and a power generation index tracking mode or a peak-modulation frequency-modulation control mode;
in a power generation index tracking mode, a control target is wind power generation index data corresponding to each provincial control area calculated according to a set time interval;
and under the peak-load and frequency modulation control mode, the control target is the sum of the wind power generation index data and the local AEC frequency modulation component.
An AGC control method for wind power participating peak shaving frequency modulation based on the AGC control system for wind power participating peak shaving frequency modulation comprises the following steps:
s1, establishing a 'dispatching-provincial dispatching' coordination control system architecture, acquiring control parameters of a plurality of wind power plants in a control area corresponding to each provincial dispatching wind power control module, and updating each virtual wind turbine generator model according to the acquired control parameters;
s2, the wind power control module of the sub-modulation AGC sends control command data to each corresponding provincial modulation wind power control module through each virtual wind power generator set model according to a power generation index tracking mode or a peak-modulation frequency modulation control mode;
in the power generation index tracking mode, the control command data sent by the wind power control module to the virtual wind turbine generator set model comprises real-time wind power generation indexes; under the peak-shaving frequency-modulation control mode, the control command data sent to the virtual wind turbine generator set model by the wind power control module comprises real-time wind power generation indexes and ACE apportionment amount of a control area;
and S3, each provincial wind power control module acquires control command data from the corresponding virtual wind turbine generator model, and performs AGC (automatic gain control) on each wind power plant in the corresponding control area according to the control command data.
Preferably, step S2 of the present invention includes:
s21, wind power generation indexes of the virtual wind turbine generator corresponding to the provincial dispatching wind power control modules are calculated by the wind power control modules of the AGC control ends in a dispatching mode at set time intervals;
s22, the wind power control module judges whether each virtual wind turbine model simultaneously meets the output stability condition and the power generation index stability condition: if the real-time wind power generation index is not met, the wind power control module issues control command data comprising the real-time wind power generation index to the corresponding virtual wind turbine generator according to the power generation index tracking mode; and if the real-time wind power generation indexes and the ACE apportionment amount of the control area are met simultaneously, the wind power control module issues control command data comprising the real-time wind power generation indexes and the ACE apportionment amount of the control area to the corresponding virtual wind power generation set according to the peak-shaving frequency-modulation control mode.
Further, the output stabilizing condition is as follows: and (3) rolling and calculating whether the output of the virtual wind turbine generator and the adjustment target controlled by the AGC last time enter a target dead zone or not at a set time interval, and if the output of the virtual wind turbine generator and the adjustment target controlled by the AGC last time enter the control target dead zone and the maintaining time exceeds a set duration threshold, determining that the virtual wind turbine generator meets the output stable condition and has better operation precision. The control target maintenance duration threshold may be set to 20 s.
The power generation index stabilization condition is as follows: and calculating to obtain the power generation index of the virtual wind turbine generator according to the total wind power generation index of the dispatching control area, and if the upper deviation and the lower deviation of the calculated power generation index and the installed capacity of the virtual wind turbine generator do not exceed a given threshold value, determining that the virtual wind turbine generator meets the power generation index stability condition.
Preferably, S21 includes:
s211, calculating the wind power generation index I of the whole sub-modulation AGC control areawind-all:
Iwind-all=Vforecast-Ptie-line-plan-Vh-reg-Vreserve-reg-Vreserve-plant+Vpump (1)
In the formula, VforecastFor load prediction of the partial modulation, Ptie-line-planFor the division-call-line planning, Vh-regFor regulating the power of the sub-regulating system to minimum, Vreserve-regFor reserve rotation, Vreserve-plantThe power is output from the spare power plant; vpumpPumping water for power generation;
s212, according to the device capacity proportion distribution of a plurality of provinces in the dispatching AGC control area, calculating the wind power generation index I of the virtual wind turbine generator set corresponding to each provincewind-pro:
In the formula, Cwind-iThe total installed capacity of wind power corresponding to the ith province is adjusted, and n is the number of virtual wind generating sets in the dispatching control area; i iswind-pro-iAnd the index is the wind power generation index of the ith province.
Preferably, in S22, in the power generation index tracking mode, the real-time wind power generation index in the control command data issued by the sub-wind-regulation control module to each virtual wind turbine generator is the wind power generation index I of the virtual wind turbine generator corresponding to the corresponding provincial regulationwind-pro。
Preferably, in S22, in the peak-load and frequency-modulation control mode, the sub-wind-modulation control module sends control command data to the corresponding virtual wind turbine generator, and the real-time wind power generation index is the wind power generation index I of the virtual wind turbine generator corresponding to the corresponding provincial-load and frequency-modulation control modewind-pro(ii) a The method for calculating the ACE apportionment amount of the control area comprises the following steps:
s221, calculating the real-time ACE of the split-modulation control area by the split-modulation AGC main control module according to the control mode of the current split-modulation control area;
s222, if the calculated real-time ACE is smaller than a preset negative direction secondary emergency threshold value, the frequency modulation increasing and transmitting adjustment quantity of all the virtual wind turbine generators in the peak and frequency modulation control mode is ACEwind:
ACEwind=K×ACE (4)
In the formula, K is a wind power frequency modulation distribution factor and is a positive number smaller than 1;
the frequency modulation increasing and generating adjustment quantity P of each virtual wind turbine generator participating in peak shaving frequency modulationregComprises the following steps:
in the formula, Preg-iDistributing the obtained frequency modulation and power increase regulating quantity for the ith virtual wind turbine generator participating in peak regulation and frequency modulation; ciThe installed capacity of the ith virtual wind turbine generator participating in peak shaving frequency modulation is obtained; n is the number of virtual wind turbine generators participating in peak shaving frequency modulation;
the provincial modulation wind power control modules corresponding to the virtual wind power generation sets participating in peak modulation and frequency modulation carry out AGC control on the wind power plant in the control areagendesComprises the following steps:
Pgendes=Pindex+Preg (6)
in the formula, PindexIs the base point power of the virtual wind turbine generator, and the value of the base point power is equal to the wind power generation index I of the virtual wind turbine generatorwind-pro. At this moment, the total regulating quantity of the conventional water-fire electric machine set is as follows:
ACEgeneral=α×(1-K)×ACE (7)
wherein alpha is an adjustment coefficient.
Considering the uncertainty of the rate, the adjustment precision and the wind resource in the process of the wind power participating in the frequency modulation of the power grid, when the distribution is carried out, the alpha coefficient must be set to be larger than 1, and when the shortage of the power generation of the power grid is ensured, the power balance of the power grid is ensured to be met through the combined adjustment of the wind power and the conventional unit.
After the control targets are obtained from the virtual wind turbine generators, the provincial wind power regulation control modules distribute the control targets according to the installed capacity proportion of each wind power plant in the control area, and the method belongs to the prior art.
Furthermore, for the virtual wind turbine generator set in the peak-shaving frequency modulation mode, the sub-shaving wind power control module acquires control parameters of an AGC (automatic gain control) control area of the corresponding province in real time, if the actual output enters a target control dead zone within set time, the AGC is considered to be qualified in tracking, and the corresponding virtual wind turbine generator set continuously participates in peak-shaving frequency modulation; otherwise, the corresponding provincial dispatching AGC control area wind resource is considered to be insufficient, the control mode of the corresponding virtual wind turbine generator is switched to a power generation index tracking mode, namely the virtual wind turbine generator does not participate in peak-regulation frequency modulation in the next peak-regulation frequency modulation period. The above-mentioned setting time may be set to 60 seconds.
Advantageous effects
The AGC control method for wind power participation peak shaving frequency modulation is based on a two-stage coordination control framework of split-province modulation, wind power participation tracking wind power generation indexes are designed, and according to the ACE condition of a whole network main control area, when output is increased for negative needs, the adjustment state of a virtual wind turbine generator set is judged in real time, so that a wind power plant bears the frequency modulation amount for increasing the output, frequency adjustment requirements are met, wind power generation is increased, and the wind power absorption level is further improved.
Drawings
FIG. 1 is a schematic diagram of a system architecture according to the present invention;
FIG. 2 is a schematic flow chart of the method of the present invention.
Detailed Description
The following further description is made in conjunction with the accompanying drawings and the specific embodiments.
Example 1
Referring to fig. 1, the AGC control system for wind power participating in peak shaving frequency modulation of the present invention is based on a "split-modulation-provincial-modulation" coordination control architecture, which includes a split-modulation AGC control end and a provincial-modulation wind power control end;
the shunting AGC control end comprises a main control module for controlling the conventional area of the interconnected power grid and a wind power control module for controlling a wind power plant;
the wind power saving and regulating control end comprises a plurality of wind power saving and regulating control modules, and each wind power saving and regulating control module is used for controlling the wind power of a plurality of wind power plants in one control area;
a virtual wind turbine generator model corresponding to each control area wind power plant is established in a wind power control module of the shunting AGC control end and is used as an AGC control object of the wind power control module;
each provincial wind power control module counts control parameter data of a wind power plant in a control area and uploads the control parameter data to a corresponding virtual wind turbine generator model of the wind power control module; the wind power control module acquires corresponding control parameter data through each virtual wind turbine generator model and forwards wind power control command data to the corresponding provincial dispatching wind power control module;
and each provincial wind power regulation control module carries out wind power control on the wind power plant in the control area according to the received wind power control command data.
The control parameter data of the wind power plant in the control area of the provincial dispatching wind power control module comprises the following data: and controlling the actual output, the adjusting range and the AGC controllable signals of a plurality of wind power plants in the area. And updating the control parameter data into the control parameters of the corresponding virtual wind turbine generator model after uploading.
The main control module of the control end of the sub-modulation AGC implements the conventional area control of the control area of the sub-modulation AGC in the interconnected power grid, and the control target is to maintain the frequency of the power grid of the control area within the control range, or maintain the exchange power of the control area and other adjacent sub-modulation AGC control areas to be a given plan value, or simultaneously meet the two control targets. The above-described conventional zone control is prior art.
The wind power control module of the sub-modulation AGC sends control command data to the virtual wind power generator set, wherein the control command data comprises control targets of the sub-modulation AGC of each province, and the sub-modulation AGC sends the control command data to each corresponding province-modulation wind power control module through each virtual wind power generator set model according to control parameter data acquired from the virtual wind power generator set and a power generation index tracking mode or a peak-modulation frequency-modulation control mode;
in a power generation index tracking mode, a control target is wind power generation index data corresponding to each provincial control area calculated according to a set time interval;
and under the peak-load and frequency modulation control mode, the control target is the sum of the wind power generation index data and the frequency modulation component of the area AEC.
Example 2
Referring to fig. 2, the AGC control method for wind power participating in peak shaving frequency modulation based on the AGC control system for wind power participating in peak shaving frequency modulation includes:
s1, establishing a 'dispatching-provincial dispatching' coordination control system architecture, acquiring control parameters of a plurality of wind power plants in a control area corresponding to each provincial dispatching wind power control module, and updating each virtual wind turbine generator model according to the acquired control parameters;
s2, the wind power control module of the sub-modulation AGC sends control command data to each corresponding provincial modulation wind power control module through each virtual wind power generator set model according to a power generation index tracking mode or a peak-modulation frequency modulation control mode;
in the power generation index tracking mode, the control command data sent by the wind power control module to the virtual wind turbine generator set model comprises real-time wind power generation indexes; under the peak-shaving frequency-modulation control mode, the control command data sent to the virtual wind turbine generator set model by the wind power control module comprises real-time wind power generation indexes and ACE apportionment amount of a control area;
and S3, each provincial wind power control module acquires control command data from the corresponding virtual wind turbine generator model, and performs AGC (automatic gain control) on each wind power plant in the corresponding control area according to the control command data.
Step S2 includes:
s21, wind power generation indexes of the virtual wind turbine generator corresponding to the provincial dispatching wind power control modules are calculated by the wind power control modules of the AGC control ends in a dispatching mode at set time intervals;
s22, the wind power control module judges whether each virtual wind turbine model simultaneously meets the output stability condition and the power generation index stability condition: if the real-time wind power generation index is not met, the wind power control module issues control command data comprising the real-time wind power generation index to the corresponding virtual wind turbine generator according to the power generation index tracking mode; and if the real-time wind power generation indexes and the ACE apportionment amount of the control area are met simultaneously, the wind power control module issues control command data comprising the real-time wind power generation indexes and the ACE apportionment amount of the control area to the corresponding virtual wind power generation set according to the peak-shaving frequency-modulation control mode.
The output stable conditions are as follows: and (3) rolling and calculating whether the output of the virtual wind turbine generator and the adjustment target controlled by the AGC last time enter a target dead zone or not at a set time interval, and if the output of the virtual wind turbine generator and the adjustment target controlled by the AGC last time enter the control target dead zone and the maintaining time exceeds a set duration threshold, determining that the virtual wind turbine generator meets the output stable condition and has better operation precision. The control target maintenance duration threshold may be set to 20 s.
The power generation index stabilization conditions are as follows: and calculating to obtain the power generation index of the virtual wind turbine generator according to the total wind power generation index of the dispatching control area, and if the upper deviation and the lower deviation of the calculated power generation index and the installed capacity of the virtual wind turbine generator do not exceed a given threshold value, determining that the virtual wind turbine generator meets the power generation index stability condition.
Step S21 includes:
s211, calculating the wind power generation index I of the whole sub-modulation AGC control areawind-all:
Iwind-all=Vforecast-Ptie-line-plan-Vh-reg-Vreserve-reg-Vreserve-plant+Vpump (1)
In the formula, VforecastFor load prediction of the partial modulation, Ptie-line-planFor the division-call-line planning, Vh-regFor regulating the power of the sub-regulating system to minimum, Vreserve-regFor reserve rotation, Vreserve-plantThe power is output from the spare power plant; vpumpPumping water for power generation;
s212, according to the device capacity proportion distribution of a plurality of provinces in the dispatching AGC control area, calculating the wind power generation index I of the virtual wind turbine generator set corresponding to each provincewind-pro:
In the formula, Cwind-iThe total installed capacity of wind power corresponding to the ith province is adjusted, and n is the number of virtual wind generating sets in the dispatching control area; i iswind-pro-iAnd the index is the wind power generation index of the ith province.
In S22, in the power generation index tracking mode, the sub-wind-regulation control module sends real-time wind power generation indexes in the control command data to each virtual wind turbine generator, that is, the wind power generation indexes I of the virtual wind turbine generators corresponding to the corresponding provincial regulationswind-pro。
In S22, in the peak-load and frequency-modulation control mode, the real-time wind power generation index is the wind power generation index I of the virtual wind turbine generator corresponding to the corresponding province-modulation in the control command data sent by the sub-wind-modulation control module to the corresponding virtual wind turbine generatorwind-pro(ii) a The method for calculating the ACE apportionment amount of the control area comprises the following steps:
s221, calculating the real-time ACE of the split-modulation control area by the split-modulation AGC main control module according to the control mode of the current split-modulation control area;
s222, if the calculated real-time ACE is smaller than a preset negative direction secondary emergency threshold value, the frequency modulation increasing and transmitting adjustment quantity of all the virtual wind turbine generators in the peak and frequency modulation control mode is ACEwind:
ACEwind=K×ACE (4)
In the formula, K is a wind power frequency modulation distribution factor and is a positive number smaller than 1;
the frequency modulation increasing and generating adjustment quantity P of each virtual wind turbine generator participating in peak shaving frequency modulationregComprises the following steps:
in the formula, Preg-iDistributing the obtained frequency modulation and power increase regulating quantity for the ith virtual wind turbine generator participating in peak regulation and frequency modulation; ciThe installed capacity of the ith virtual wind turbine generator participating in peak shaving frequency modulation is obtained;
the provincial modulation wind power control modules corresponding to the virtual wind power generation sets participating in peak modulation and frequency modulation carry out AGC control on the wind power plant in the control areagendesComprises the following steps:
Pgendes=Pindex+Preg (6)
in the formula, PindexIs the base point power of the virtual wind turbine generator, and the value of the base point power is equal to the wind power generation index I of the virtual wind turbine generatorwind-pro. At this moment, the total regulating quantity of the conventional water-fire electric machine set is as follows:
ACEgeneral=α×(1-K)×ACE (7)
wherein alpha is an adjustment coefficient.
Considering the uncertainty of the rate, the adjustment precision and the wind resource in the process of the wind power participating in the frequency modulation of the power grid, when the distribution is carried out, the alpha coefficient must be set to be larger than 1, and when the shortage of the power generation of the power grid is ensured, the power balance of the power grid is ensured to be met through the combined adjustment of the wind power and the conventional unit.
After the control targets are obtained from the virtual wind turbine generators, the provincial wind power regulation control modules distribute the control targets according to the installed capacity proportion of each wind power plant in the control area, and the method belongs to the prior art.
Furthermore, for the virtual wind turbine generator set in the peak-shaving frequency modulation mode, the sub-shaving wind power control module acquires control parameters of an AGC (automatic gain control) control area of the corresponding province in real time, if the actual output enters a target control dead zone within set time, the AGC is considered to be qualified in tracking, and the corresponding virtual wind turbine generator set continuously participates in peak-shaving frequency modulation; otherwise, the corresponding provincial dispatching AGC control area wind resource is considered to be insufficient, the control mode of the corresponding virtual wind turbine generator is switched to a power generation index tracking mode, namely the virtual wind turbine generator does not participate in peak-regulation frequency modulation in the next peak-regulation frequency modulation period. The above-mentioned setting time may be set to 60 seconds.
The AGC control method for wind power participation peak shaving frequency modulation is based on a two-stage coordination control framework of split-province modulation, wind power participation tracking wind power generation indexes are designed, and according to the ACE condition of a whole network main control area, when output is increased for negative needs, the adjustment state of a virtual wind turbine generator set is judged in real time, so that a wind power plant bears the frequency modulation amount for increasing the output, frequency adjustment requirements are met, wind power generation is increased, and the wind power absorption level is further improved.
Example 3
With reference to fig. 1 and fig. 2, when the present invention is implemented, a main control area (main control module) is first established in the split AGC application, the conventional area control of the interconnected network is implemented, and the conventional unit is used to implement the conventional frequency and tie line power control. And a wind power control area (wind power control module) is established in the sub-modulation AGC application, and the control area mainly implements indirect control on wind power of each province in the sub-modulation. And establishing virtual wind turbine generators corresponding to each provincial dispatching in the wind power control area, wherein each provincial dispatching corresponds to one virtual wind turbine generator. And establishing a wind power control area in the provincial dispatching AGC to implement wind power control, wherein the wind power control area of the provincial dispatching AGC takes a wind power plant as a control object.
The provincial dispatching AGC forms the wind power control parameter information of a provincial dispatching total by counting the actual output, the regulating range and AGC controllable signals of each wind power plant in the wind power control area, and sends the wind power control parameter information to the dispatching control end to be used as the control parameter of the virtual control unit established in the dispatching AGC wind power control area.
After the sub-modulation, provincial-modulation AGC framework design and the virtual wind turbine generator modeling are completed, wind power generation increasing control is carried out on a sub-modulation AGC side, two control modes, namely a power generation index tracking mode and a peak-modulation frequency modulation control mode, are designed, the sub-modulation AGC carries out judgment on output stability and power generation index stability according to the operation state control parameters of the virtual wind turbine generator, and automatic switching of the control modes of the virtual wind turbine generator is achieved.
After each province dispatch is put into the wind power control function, the sub-dispatching AGC firstly calculates the total wind power generation index of the sub-dispatching control area according to the set time interval (for example, once every 5 minutes):
Iwind-all=Vforecast-Ptie-line-plan-Vh-reg-Vreserve-reg-Vreserve-plant+Vpump (1)
obtaining the power generation index I of the overall tonewind-allAnd then, distributing according to the installed capacity proportion of a plurality of provinces to obtain the wind power generation index of each province:
after the wind power generation indexes of all provincial dispatches are calculated, the dispatching AGC automatically sets the control targets of the virtual wind turbine generators according to the control modes of the virtual wind turbine generators corresponding to all provincial dispatches. If the control mode of the virtual wind turbine generator is the tracking index control mode, the control target of the virtual wind turbine generator is the wind power generation index I obtained through calculationwind-pro(ii) a If the control mode of the virtual wind turbine generator is a peak-shaving frequency-modulation control mode, the following calculation is carried out:
and the sub-modulation AGC calculates the real-time ACE (area Control error) of the sub-modulation Control area according to the Control mode adopted by the sub-modulation main Control area. Taking TBC (Tie-Line Bias Control, Tie-Line deviation Control mode) as an example, the ACEs of the split Control area in TBC mode are:
ACE=Treal-Tsche+B×△f (3)
in the formula: t isrealActual transmission power of the external tie line for the control area; t isschePlanning transmission power for the control area external links; b is a control region frequency offset systemCounting; and delta f is the frequency deviation of the power grid.
At this time, if the ACE is smaller than a negative direction secondary emergency threshold value (for example, -200MW) preset by the power grid, calculating the integral ACE adjustment amount in the split-dispatching control area as follows:
ACEwind=K×ACE (4)
the frequency modulation increasing and generating adjustment quantity P of each virtual wind turbine generator participating in peak shaving frequency modulationregComprises the following steps:
the provincial modulation wind power control modules corresponding to the virtual wind power generation sets participating in peak modulation and frequency modulation carry out AGC control on the wind power plant in the control areagendesComprises the following steps:
Pgendes=Pindex+Preg (6)
in the formula, PindexIs the base point power of the virtual wind turbine generator, and the value of the base point power is equal to the wind power generation index I of the virtual wind turbine generatorwind-pro. At this moment, the total regulating quantity of the conventional water-fire electric machine set is as follows:
ACEgeneral=α×(1-K)×ACE (7)
wherein alpha is an adjustment coefficient.
Considering the uncertainty of the rate, the adjustment precision and the wind resource in the process of the wind power participating in the frequency modulation of the power grid, when the distribution is carried out, the alpha coefficient must be set to be larger than 1, and when the shortage of the power generation of the power grid is ensured, the power balance of the power grid is ensured to be met through the combined adjustment of the wind power and the conventional unit.
And (3) after the sub-modulation AGC obtains a control target in the wind power peak-modulation frequency-modulation mode according to the formula (6), the control target is issued to the provincial modulation wind power AGC through the virtual wind power generator set, and the provincial modulation wind power AGC controls a single wind power plant.
And (3) simultaneously detecting control parameter data of the virtual wind turbine generator by the sub-modulation AGC, tracking the actual tracking condition of the AGC in the peak-modulation frequency modulation mode, if the output of the virtual wind turbine generator enters a target control dead zone, considering that the tracking is qualified, continuing the peak-modulation frequency modulation, and if the output of the virtual wind turbine generator cannot reach a given target within a specified time (for example, 60s), considering that wind resources are insufficient, and not entering the peak-modulation frequency modulation mode in the next period.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.