Disclosure of Invention
The invention provides a machine group distributed control method and system, an electronic device and a readable storage medium, which are used for solving the technical defects in the prior art.
The invention provides a machine set distributed control method, which comprises the following steps:
generating a control objective function based on the output voltage, the output current and the rated power of each unit;
obtaining adjacent unit information corresponding to each unit based on the communication connection among the units, and realizing consistent operation;
generating a deviation signal of a droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation;
and eliminating the frequency deviation of each unit based on the control objective function and the deviation signal of the droop curve.
According to the unit distributed control method provided by the embodiment of the invention, the control objective function is;
Δyi=yi *-(a1+b1yi *)yi
wherein, yi=f(Pi),yi *=f(Pi *);f(Pi),f(Pi *) Is a defined reference function; pi is calculated according to the output voltage and the output current of the ith unit; pi represents the rated power of the ith unit; coefficient a1,b1,a2,b2The value is determined by the defined reference mark function.
According to the unit distributed control method provided by the embodiment of the invention, when the output of each unit is distributed according to the rated capacity, the output of each unit meets the following conditions:
at this time, the defined reference function is set to f (P)i)=Pi *-1Pi(ii) a Coefficient a accordingly1,b1,a2,b2Is a1=a2=1,b1=b20, and satisfies:
in the formula, Dp,iAnd the damping coefficient of the ith unit.
According to the unit distributed control method provided by the embodiment of the invention, when the output of each unit is distributed according to the equal micro-increment rate, the output of each unit meets the following conditions:
λ1(P1)=λ2(P2)=...=λm(Pm)
the reference function defined at this time is f (P)i)=λi(Pi)
In the formula, λi(Pi) represents a gain function of the ith unit; at this time, the coefficient a1,b1,a2,b2Is a1=a2=0,b1=b2=1。
According to the unit distributed control method provided by the embodiment of the invention, the adjacent unit information corresponding to each unit is obtained based on the communication connection among the units, and the realization of the consistent operation is realized according to the following mode:
in the formula, Yi,YjRespectively representing the translation amounts of the ith station and the jth station set; dp,i,Dp,jRespectively representing the droop coefficients of the ith station and the jth station set; k is a radical ofiAnd (4) representing the frequency recovery coefficient of the ith unit.
According to the unit distributed control method provided by the embodiment of the invention, the deviation signal for generating the droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation is realized by an integral feedback link.
According to the unit distributed control method provided by the embodiment of the invention, the control equation for eliminating the frequency deviation of each unit based on the control objective function and the deviation signal of the droop curve is as follows:
Dp,i(ωi-ωb)=Δyi-ky,iYi
in the formula, ω
bRepresents a nominal angular frequency; omega
iMeasuring the angular frequency of the ith unit;
yi represents the translation amount of the droop curve of the ith unit.
The invention also provides a machine set distributed control system, which comprises:
the active power distribution unit is used for generating a control objective function based on the output voltage, the output current and the rated power of each unit;
the consistency control unit is used for obtaining the information of the adjacent units corresponding to each unit based on the communication connection among the units to realize the consistency operation;
the frequency recovery unit is used for generating a deviation signal of a droop curve based on a frequency recovery rated value of each unit after consistent operation in a steady state;
and the droop control unit is used for eliminating the frequency deviation of each unit based on the control objective function and the deviation signal of the droop curve.
The invention also provides an electronic device, which comprises a memory, a processor and a computer program stored on the memory and capable of running on the processor, wherein the processor executes the program to realize the steps of the unit distributed control method.
The invention also provides a non-transitory computer-readable storage medium having stored thereon a computer program which, when executed by a processor, performs the steps of the unit distributed control method as described in any one of the above.
The embodiment of the invention provides a unit active flexible allocation control method based on a consistency algorithm in consideration of the requirements of the unit in frequency recovery and active flexible allocation in an island mode, and the method is based on a point-to-point distributed communication architecture and realizes communication with lower cost; based on a distributed communication architecture, a frequency recovery and flexible output distribution control scheme is designed, and the effectiveness of the frequency recovery and flexible output distribution control scheme is theoretically analyzed. The control strategy provided by the embodiment of the invention can well realize system frequency recovery and active power output distribution according to a set rule, not only can distribute the active power output according to the rated capacity of a unit, but also can distribute the active power output according to the principle of equal micro-increment rate, and meets the requirements of fairness, economy and the like.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment of the invention discloses a machine component distributed control method, which is shown in figure 1 and comprises the following steps:
s1, generating a control objective function based on the output voltage, the output current and the rated power of each unit;
calculating to obtain P according to the output voltage and the output current of the ith unitiWhich is adjusted according to load variations; the rated power of the ith unit can be Pi *And (4) showing.
S2, obtaining adjacent unit information corresponding to each unit based on the communication connection among the units, and realizing consistent operation;
the consistency control algorithm is mainly adopted, the information of adjacent units is obtained by means of communication connection among the units, the consistency algorithm operation is realized, the problem of power robbery of the system units caused by introducing a frequency recovery mechanism can be solved, and the reliability and the accuracy of the system output distribution are guaranteed.
S3, generating a deviation signal of a droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation;
and S4, based on the control objective function and the deviation signal of the droop curve, eliminating the frequency deviation of each unit.
And S4 and S3 act together to realize the control of the system frequency. In S3, an integral feedback element is used to generate a droop curve deviation signal and provide the droop curve deviation signal to S4, so as to eliminate the frequency deviation.
The embodiment of the invention provides a unit active flexible allocation control method based on a consistency algorithm in consideration of the requirements of the unit in frequency recovery and active flexible allocation in an island mode, and the method is based on a point-to-point distributed communication architecture and realizes communication with lower cost; based on a distributed communication architecture, a frequency recovery and flexible output distribution control scheme is designed, and the effectiveness of the frequency recovery and flexible output distribution control scheme is theoretically analyzed. The control strategy provided by the embodiment of the invention can well realize system frequency recovery and active power output distribution according to a set rule, not only can distribute the active power output according to the rated capacity of a unit, but also can distribute the active power output according to the principle of equal micro-increment rate, and meets the requirements of fairness, economy and the like.
According to the unit distributed control method provided by the embodiment of the invention, the control objective function is;
Δyi=yi *-(a1+b1yi *)yi
wherein, yi=f(Pi),yi *=f(Pi *);f(Pi),f(Pi *) Is a defined reference function; pi is calculated according to the output voltage and the output current of the ith unit; pi represents the rated power of the ith unit; coefficient a1,b1,a2,b2The value is determined by the defined reference mark function.
According to the unit distributed control method provided by the embodiment of the invention, when the output of each unit is distributed according to the rated capacity, the output of each unit meets the following conditions:
at this time, the defined reference function is set to f (P)i)=Pi *-1Pi(ii) a Coefficient a accordingly1,b1,a2,b2Is a1=a2=1,b1=b20, and satisfies:
in the formula, Dp,iAnd the damping coefficient of the ith unit.
According to the unit distributed control method provided by the embodiment of the invention, when the output of each unit is distributed according to the equal micro-increment rate, the output of each unit meets the following conditions:
λ1(P1)=λ2(P2)=...=λm(Pm)
the reference function defined at this time is f (P)i)=λi(Pi)
In the formula, λi(Pi) represents a gain function of the ith unit; at this time, the coefficient a1,b1,a2,b2Is a1=a2=0,b1=b2=1。
According to the unit distributed control method provided by the embodiment of the invention, the adjacent unit information corresponding to each unit is obtained based on the communication connection among the units, and the realization of the consistent operation is realized according to the following mode:
in the formula, Yi,YjRespectively representing the translation amounts of the ith station and the jth station set; dp,i,Dp,jRespectively representing the droop coefficients of the ith station and the jth station set; k is a radical ofiAnd (4) representing the frequency recovery coefficient of the ith unit.
According to the unit distributed control method provided by the embodiment of the invention, the deviation signal for generating the droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation is realized by an integral feedback link.
According to the unit distributed control method provided by the embodiment of the invention, the control equation for eliminating the frequency deviation of each unit based on the control objective function and the deviation signal of the droop curve is as follows:
Dp,i(ωi-ωb)=Δyi-ky,iYi
in the formula, ω
bRepresents a nominal angular frequency; omega
iMeasuring the angular frequency of the ith unit;
yi represents the translation amount of the droop curve of the ith unit.
As shown in fig. 2, in order to further explain the unit distributed control system and the control method according to the embodiment of the present invention, the following specific embodiments are provided.
The active power distribution unit is shown in fig. 3, Pi is calculated according to the output voltage and the output current of the ith unit, and is adjusted according to load change; pi *The rated power of the ith unit is represented; y isi=f(Pi),yi *=f(Pi *) (ii) a Coefficient a1,b1,a2,b2The value is determined by a self-defined reference function; output Δ yi=yi *-(a1+b1yi *)yiIs the difference between the reference input and the actual input. f (P)i),f(Pi *) The reference function is self-defined, and generally is a linear function, and the selection method is more and is determined according to specific requirements.
Taking the power allocation needed to satisfy two typical requirements of fairness of output and economy as an example, it is explained as follows.
a) If the output of each unit in the autonomous micro-energy network is distributed according to rated capacity, the output of each unit needs to meet the following requirements:
the objective function is now set to f (P)i)=Pi *-1Pi(ii) a The coefficient correspondingly takes the value a1=a2=1,b1=b20, and satisfies:
in the formula, Dp, i is the damping coefficient of the ith unit. The scheme of distributing the output according to the rated capacity can meet reasonable system output configuration and ensure the fair output of each power generator.
b) If all units in the autonomous micro energy network are distributed according to the principle of equal micro-increment rate, the output of all units needs to meet the following requirements:
λ1(P1)=λ2(P2)=...=λm(Pm)
the reference function defined at this time is f (P)i)=λi(Pi) In the formula ofi(Pi) represents a gain function of the ith unit; when the coefficient is a1=a2=0,b1=b21. Because the direct current side of the unit is always renewable energy, the higher the utilization rate of the renewable energy and the lower the comprehensive cost, the power generation cost function can be expressed as the normalized power generation cost function
Wherein C represents the cost of comprehensive power generation, kcRepresenting the cost factor, P representing the active power, PmaxThe cost function is thus in quadratic form for maximum output. The incremental rate is defined as the derivative of the cost of electricity generation to the output, and can therefore be expressed as
λi(Pi)=αiPi-βi
In the formula, alphai,βiCoefficients associated with the ith machine component cost function. The system output is distributed according to the principle of equal micro-increment rate, the construction cost, the maintenance cost and the operation cost of the distributed power supply are fully considered, and economical and efficient operation can be realized.
In addition, if the system needs to distribute the output according to other mechanisms, only the objective function needs to be changed and the corresponding coefficient needs to be selected in the active distribution unit. Therefore, the active power distribution flexibility of the system is higher, and the control is simpler and more convenient.
The consistency control unit uses an average consistency algorithm and the consistency unit is shown in fig. 4.
The consistency control unit can be designed as
In the formula, Yi,YjRepresenting the translation amount of the ith station and the jth station set;Dp,i,Dp,jthe droop coefficients of the ith station and the jth station unit are represented; k is a radical ofiAnd (4) representing the frequency recovery coefficient of the ith unit.
Since Yi in the above formula is translation amount and is a number, when the autonomous micro energy grid enters a steady state, the derivative of the autonomous micro energy grid is 0, and the autonomous micro energy grid can be obtained
In the formula Iij(i ≠ j) ≦ 0 for the elements in the Laplace matrix L, L is
When the communication topology of the autonomous micro energy network meets the spanning tree condition, the matrix L is a symmetric matrix, the addition of elements of each row of the matrix L is equal to 0, namely the condition is met
li1+li2+…lim=0
The consistency control unit may be designed to:
in the above formula, Dp, iky, i are extracted and converted into
Let gi be Dp, iky, i (gi >0), yield
Where i is 1,2, … m, the above formula can be expressed in a matrix form
Let matrix G be diag { G ═ GiIs transformed into
Since the frequencies of the units are all equal, Δ yi(Dp,iky,i)-1Is in direct proportion to the variation of the unit frequency and the proportionality coefficients of the units are equal, then delta yi(Dp,iky,i)-1And are also equal. From the above formula
Further obtain the
So that the communication topology includes a spanning tree and at least one node has a reference value, i.e. gi ≠ 0, then there is a non-singular matrix L + G. The embodiment of the invention adopts a non-directional graph model, gi (i ═ 1,2, … m) is greater than 0, and L + G is a non-singular matrix when no isolated node exists. The left and right sides of the above formula are multiplied by (L + G) -1 to obtain
The left and right sides of the above formula are multiplied by Dp, i to obtain
Δyi=ky,iYi
Further, can obtain
Dp,i(ωi-ωb)=0
In steady state, ω i ═ ω b, i.e., the system frequency can be restored to the nominal value.
The frequency can be recovered from the above analysis to obtain a rated value, and it can be known that
Can obtain the product
When the objective function is expressed as f (P)i)=Pi *-1PiCoefficient of a1=a2=1;b1=b2The target function and coefficient are substituted into the above formula when the value is 0
P is designed by designing parameters of the autonomous micro energy networki *-1Dp,iEach unit can perform power distribution according to rated capacity, with the same (i 1, 2.. m).
When the objective function is expressed as f (P)i)=λi(Pi) Coefficient of a1=a2=0;b1=b2Substituted into the formula 1
At this time, the micro-increment rates of all the units are equal, and the fact that all the units can distribute active power according to the principle of the equal micro-increment rates is shown.
Therefore, the unit distributed control method provided by the embodiment of the invention can realize the frequency recovery and the active power flexible distribution of the autonomous micro-energy network system.
The embodiment of the invention discloses a machine set distributed control system, which is shown in figure 5 and comprises the following components:
the active power distribution unit 10 is used for generating a control objective function based on the output voltage, the output current and the rated power of each unit;
the consistency control unit 20 is configured to obtain information of adjacent units corresponding to each unit based on the communication connection between the units, so as to implement consistent operation; the consistency control unit 20 mainly employs a consistency control algorithm. The consistency control unit 20 obtains information of adjacent units by means of communication connection among the units, realizes consistency algorithm operation, can solve the problem of power robbery of system units caused by introducing a frequency recovery mechanism, and ensures reliability and accuracy of system output distribution.
The frequency recovery unit 30 is used for generating a deviation signal of a droop curve based on frequency recovery rated values of the units in a steady state after the units operate in a consistent manner;
and the droop control unit 40 is used for eliminating the frequency deviation of each unit based on the control objective function and the deviation signal of the droop curve.
Fig. 6 illustrates a physical structure diagram of an electronic device, which may include: a processor (processor)310, a communication Interface (communication Interface)320, a memory (memory)330 and a communication bus 340, wherein the processor 310, the communication Interface 320 and the memory 330 communicate with each other via the communication bus 340. Processor 310 may invoke logic instructions in memory 330 to perform a component distributed control method comprising:
s1, generating a control objective function based on the output voltage, the output current and the rated power of each unit;
s2, obtaining adjacent unit information corresponding to each unit based on the communication connection among the units, and realizing consistent operation;
s3, generating a deviation signal of a droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation;
and S4, based on the control objective function and the deviation signal of the droop curve, eliminating the frequency deviation of each unit.
In addition, the logic instructions in the memory may be implemented in the form of software functional units and may be stored in a computer readable storage medium when sold or used as a stand-alone product. Based on such understanding, the technical solution of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present invention. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), a magnetic disk or an optical disk, and other various media capable of storing program codes.
In another aspect, the present invention also provides a computer program product comprising a computer program stored on a non-transitory computer readable storage medium, the computer program comprising program instructions which, when executed by a computer, the computer is capable of performing a set of computer distributed control methods, the methods comprising:
s1, generating a control objective function based on the output voltage, the output current and the rated power of each unit;
s2, obtaining adjacent unit information corresponding to each unit based on the communication connection among the units, and realizing consistent operation;
s3, generating a deviation signal of a droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation;
and S4, based on the control objective function and the deviation signal of the droop curve, eliminating the frequency deviation of each unit.
In yet another aspect, the present invention also provides a non-transitory computer readable storage medium having stored thereon a computer program that, when executed by a processor, is implemented to perform a set of distributed control methods, the method comprising:
s1, generating a control objective function based on the output voltage, the output current and the rated power of each unit;
s2, obtaining adjacent unit information corresponding to each unit based on the communication connection among the units, and realizing consistent operation;
s3, generating a deviation signal of a droop curve based on the frequency recovery rated value of each unit in the steady state after the consistent operation;
and S4, based on the control objective function and the deviation signal of the droop curve, eliminating the frequency deviation of each unit.
The above-described system embodiments are merely illustrative, and the units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of the present embodiment. One of ordinary skill in the art can understand and implement it without inventive effort.
Through the above description of the embodiments, those skilled in the art will clearly understand that each embodiment can be implemented by software plus a necessary general hardware platform, and certainly can also be implemented by hardware. With this understanding in mind, the above-described technical solutions may be embodied in the form of a software product, which can be stored in a computer-readable storage medium such as ROM/RAM, magnetic disk, optical disk, etc., and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute the methods described in the embodiments or some parts of the embodiments.
Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.