Disclosure of Invention
An object of the present disclosure is to provide a distributed residual error generator-based microgrid dynamic compensation control method and system, thereby overcoming, at least to some extent, one or more of the problems due to the limitations and disadvantages of the related art.
According to one aspect of the disclosure, a distributed residual error generator-based microgrid dynamic compensation control method is provided, which includes the following steps:
establishing a multi-inverter parallel model, namely obtaining a state space equation of an ith inverter when N inverters are connected in parallel according to a multi-inverter parallel topology and an interconnection relation between the ith inverter and a jth inverter;
a distributed residual error generator designing step, namely establishing a state space equation of the distributed residual error generator according to the state space equation of the ith inverter and obtaining a control model based on the distributed residual error generator;
a dynamic compensation controller design step of transforming the control model based on the distributed residual error generator to perturb diAnd calculating the dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control.
In an exemplary embodiment of the disclosure, the state space equation of the ith inverter when the N inverters are connected in parallel is as follows:
wherein N isiSet of adjacent inverters, x, for the ith inverteri=(ILi,d,ILi,q,Uci,d,Uci,q)TIs the state quantity of the system, xj=(ILj,d,ILj,q,Ucj,d,Ucj,q)TIs the state quantity of the neighboring system, ui=(Uti,d,Uti,q)TAs system input quantity, di=(Ioi,d,Ioi,q)TAs disturbance input of the system, yi=(ILi,d,ILi,q,Uci,d,Uci,q)TIs the output of the system.
In an exemplary embodiment of the present disclosure, the disturbance amount Ioj,dAnd Ioj,qThe current is composed of circulating current, local load current and common load currentAre formed by stacking, Icij,dAnd Icij,qFor circulating currents between the ith inverter and the jth inverter, Icji,dAnd Icji,qFor circulating currents between the jth inverter and the ith inverter, Iloadi,dAnd Iloadi,qIs the local load current of the ith inverter, Iloadj,dAnd Iloadj,qIs the local load current of the jth inverter, IPloadi,dAnd IPloadi,qIs the common load current of the ith inverter, IPloadj,dAnd IPloadj,qIs the common load current of the jth inverter.
In an exemplary embodiment of the present disclosure, the multi-inverter parallel model establishing step further includes:
and defining variables of each parameter in the multi-inverter parallel topology under a dq coordinate system.
In an exemplary embodiment of the present disclosure, in the step of designing the distributed residual error generator, a state space equation of the distributed residual error generator is:
wherein,
is the observer state quantity of the ith inverter, u
iIs the input quantity of the ith inverter,
observer state quantity, r, of adjacent inverters to the ith inverter
iIs the residual of the i-th inverter, y
iIs the output quantity of the ith inverter, L
iiIs the observer gain matrix to be designed.
In an exemplary embodiment of the present disclosure, the distributed residual generator designing step further includes:
state space equations for the distributed residual generator:
the conditions were determined by the lyapunov theorem of stability: v (t) is positive definite, dv (t)/dt is negative definite, when | | t | → ∞, there is v (t) → ∞, and a linear matrix inequality is obtained:
to LiiAnd solving to obtain a control model based on the distributed residual error generator.
In an exemplary embodiment of the disclosure, the linear matrix inequality is further constrained according to a pole configuration, wherein:
order (A)ii-LiiCi)→Aii,Pi→P,αi→ alpha and taui→ τ, the regional pole configuration inequality of the ith inverter can be obtained
To LiiAnd solving to obtain a control model based on the distributed residual error generator.
In an exemplary embodiment of the present disclosure, the distributed residual generator designing step further includes:
transforming the distributed residual generator based control model to perturb diFor the input model, the LMI calculation is used according to the model matching principle
min||G(s)yd-Trd(s)QGp(s)||∞;
And calculating a dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator.
According to one aspect of the present disclosure, there is provided a microgrid dynamic compensation control system based on a distributed residual error generator, comprising:
the multi-inverter parallel model establishing module is used for obtaining a state space equation of the ith inverter when the N inverters are connected in parallel according to the multi-inverter parallel topology and the interconnection relation between the ith inverter and the jth inverter;
the distributed residual error generator design module is used for establishing a state space equation of the distributed residual error generator according to the state space equation of the ith inverter and obtaining a control model based on the distributed residual error generator;
a dynamic compensation controller design module for transforming the distributed residual generator based control model to perturb diAnd calculating the dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control.
According to the microgrid dynamic compensation control method based on the distributed residual error generator in the exemplary embodiment of the disclosure, a state space equation of the distributed residual error generator is established through an obtained state space equation of an ith inverter when N inverters are connected in parallel, and a control model based on the distributed residual error generator is obtained; and converting the control model based on the distributed residual error generator into a model with disturbance di as input, calculating a dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control. On one hand, the dynamic voltage compensation controller is added into the inverter compensation control strategy, voltage fluctuation generated when the inverter and the load are cut in and cut off is restrained, plug and play of the inverter and the load are achieved, on the other hand, the circulating current problem is rapidly solved in combination with virtual impedance, power equalization is achieved, on the other hand, the voltage fluctuation problem of the inverter and the load which are cut in and cut off is solved, and comprehensive management of the micro-grid power quality problem by using the residual capacity of the inverter is achieved.
It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure, as claimed
Detailed Description
Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals denote the same or similar parts in the drawings, and thus, a repetitive description thereof will be omitted.
Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of embodiments of the disclosure. One skilled in the relevant art will recognize, however, that the embodiments of the disclosure can be practiced without one or more of the specific details, or with other methods, components, materials, devices, steps, and so forth. In other instances, well-known structures, methods, devices, implementations, materials, or operations are not shown or described in detail to avoid obscuring aspects of the disclosure.
The block diagrams shown in the figures are functional entities only and do not necessarily correspond to physically separate entities. That is, these functional entities may be implemented in the form of software, or in one or more software-hardened modules, or in different networks and/or processor devices and/or microcontroller devices.
In the present exemplary embodiment, a distributed residual error generator-based microgrid dynamic compensation control method is provided, and referring to fig. 1, the distributed residual error generator-based microgrid dynamic compensation control method may include the following steps:
a multi-inverter parallel model establishing step S110, according to the multi-inverter parallel topology and the interconnection relation between the ith inverter and the jth inverter, obtaining a state space equation of the ith inverter when the N inverters are connected in parallel;
a distributed residual error generator designing step S120, wherein a state space equation of the distributed residual error generator is established according to the state space equation of the ith inverter, and a control model based on the distributed residual error generator is obtained;
a dynamic compensation controller designing step S130, converting the control model based on the distributed residual error generator to disturb diIs a model of the input, anAnd (4) calculating the dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control.
According to the microgrid dynamic compensation control method based on the distributed residual error generator in the exemplary embodiment of the disclosure, a state space equation of the distributed residual error generator is established through an obtained state space equation of an ith inverter when N inverters are connected in parallel, and a control model based on the distributed residual error generator is obtained; and converting the control model based on the distributed residual error generator into a model with disturbance di as input, calculating a dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control. On one hand, the dynamic voltage compensation controller is added into the inverter compensation control strategy, voltage fluctuation generated when the inverter and the load are cut in and cut off is restrained, plug and play of the inverter and the load are achieved, on the other hand, the circulating current problem is rapidly solved in combination with virtual impedance, power equalization is achieved, on the other hand, the voltage fluctuation problem of the inverter and the load which are cut in and cut off is solved, and comprehensive management of the micro-grid power quality problem by using the residual capacity of the inverter is achieved.
In the following, a method for controlling the microgrid dynamic compensation based on the distributed residual error generator in the present exemplary embodiment will be further described.
In step S110, according to the multi-inverter parallel topology and the interconnection relationship between the ith inverter and the jth inverter, a state space equation of the ith inverter when the N inverters are connected in parallel is obtained;
fig. 2 shows an inverter parallel topology, according to which variables are defined in the dq coordinate system. Wherein L isiAnd LjIs a filter inductance of the inverter, riAnd rjIs parasitic resistance of inductor, CiAnd CjIs a filter capacitor of an inverter, Uti,dAnd Uti,qFor station i to reverseOutput voltage of the device, Utj,dAnd Utj,qFor the jth inverter output voltage, Ili,dAnd Ili,qFor the I-th inverter inductor current, Ilj,dAnd Ilj,qFor the inductor current of the jth inverter, Uci,dAnd Uci,qFor the ith inverter capacitor voltage, Ucj,dAnd Ucj,qFor the capacitor voltage of the jth inverter, Ioi,dAnd Ioi,qFor the I-th inverter input current, Ioj,dAnd Ioj,qAnd inputting current for the jth inverter.
When the system is approximately stable, according to the interconnection relation between the ith inverter and the jth inverter, obtaining a state space equation of the ith inverter when the N inverters are connected in parallel:
wherein N isiSet of adjacent inverters, x, for the ith inverteri=(ILi,d,ILi,q,Uci,d,Uci,q)TIs the state quantity of the system, xj=(ILj,d,ILj,q,Ucj,d,Ucj,q)TIs the state quantity of the neighboring system, ui=(Uti,d,Uti,q)TAs system input quantity, di=(Ioi,d,Ioi,q)TAs disturbance input of the system, yi=(ILi,d,ILi,q,Uci,d,Uci,q)TIs the output of the system.
Disturbance variable Ioj,dAnd Ioj,qFormed by superposition of three parts of circulating current, local load current and common load current, Icij,dAnd Icij,qFor circulating currents between the ith inverter and the jth inverter, Icji,dAnd Icji,qFor circulating currents between the jth inverter and the ith inverter, Iloadi,dAnd Iloadi,qIs the local load current of the ith inverter, Iloadj,dAnd Iloadj,qLocal load current for jth inverter,IPloadi,dAnd IPloadi,qIs the common load current of the ith inverter, IPloadj,dAnd IPloadj,qIs the common load current of the jth inverter.
In step S120, according to a state space equation of the ith inverter, establishing a state space equation of the distributed residual error generator, and obtaining a control model based on the distributed residual error generator;
aiming at a micro-grid multi-inverter interconnection system, designing a distributed residual error generator, namely a state space equation of the distributed residual error generator:
wherein,
is the observer state quantity of the ith inverter, u
iIs the input quantity of the ith inverter,
observer state quantity, r, of adjacent inverters to the ith inverter
iIs the residual of the i-th inverter, y
iIs the output quantity of the ith inverter, L
iiIs the observer gain matrix to be designed.
Obtaining a matrix inequality according to the Lyapunov principle stability theorem, wherein the Lyapunov principle stability theorem is as follows: v (t) is positive, dV (t)/dt is negative, and when | | t | → ∞, there are V (t) → ∞; solving by LMI to obtain Lii。
Since there is no L in the distributed observeriiIs limited to satisfy only H∞L of the Performance indexiiThe values are usually large and inconvenient to use, and the linear matrix inequality is further constrained according to a pole configuration, where:
order (A)ii-LiiCi)→Aii,Pi→P,αi→ alpha and taui→ τ, the regional pole configuration inequality of the ith inverter can be obtained
FIG. 3 shows a distributed residual generator, using LMI to solve the linear matrix inequality, calculating LiiA distributed residual generator is obtained. Wherein, Ki(s) is equivalent to the droop control loop and the voltage-current double closed loop of the original inverter, GiAnd(s) is an inverter as a controlled object.
In step S130, the distributed residual generator based control model is transformed to perturb diAnd calculating the dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control.
FIG. 4 shows a disturbance diFor input model matching form schematic, without considering original controller Ki(s) in the case of a disturbance d, the distributed residual generator shown in FIG. 3 is transformed to that shown in FIG. 4iIs a model matching form of the input.
FIG. 5 shows a schematic diagram of a dynamic compensation control structure based on a distributed residual error generator, using LMI to solve min | | G(s) according to a model matching principleyd-Trd(s)QGp(s)||∞Obtaining dynamic compensation controller Q(s)。
The distributed residual error generator is constructed by collecting the control input quantity and output quantity of each inverter and the state quantity of the adjacent inverters, and the dynamic compensation controller Q(s) is added on the basis, so that the schematic diagram of the dynamic compensation control structure based on the distributed residual error generator shown in fig. 5 is obtained.
Fig. 6 shows a microgrid dynamic compensation control strategy based on a distributed residual error generator, and dynamic compensation control based on the distributed residual error generator is added on the basis of the original droop control of an inverter.
In summary, the dynamic voltage compensation controller is added to the inverter compensation control strategy, voltage fluctuation generated when the inverter and the load are cut in and cut off is suppressed, plug and play of the inverter and the load is achieved, on the other hand, the problem of circulation is rapidly solved by combining virtual impedance, power equalization is achieved, on the other hand, the problem of voltage fluctuation when the inverter and the load are cut in and cut off is solved, and comprehensive management of the problem of electric energy quality of the microgrid by using the residual capacity of the inverter is achieved.
In addition, in the present exemplary embodiment, a microgrid dynamic compensation control system based on a distributed residual error generator is also provided. Referring to fig. 7, the distributed residual error generator-based microgrid dynamic compensation control system 700 includes a multi-inverter parallel model building module 710, a distributed residual error generator design module 720, and a dynamic compensation controller design module 730, wherein:
the multi-inverter parallel model establishing module 710 is used for obtaining a state space equation of an ith inverter when the N inverters are connected in parallel according to the multi-inverter parallel topology and the interconnection relationship between the ith inverter and the jth inverter;
the distributed residual error generator design module 720 is used for establishing a state space equation of the distributed residual error generator according to the state space equation of the ith inverter and obtaining a control model based on the distributed residual error generator;
a dynamic compensation controller design module 730 for transforming the distributed residual generator based control model to perturb diAnd calculating the dynamic compensation controller Q(s) to obtain a dynamic compensation control model based on the distributed residual error generator, and adding the dynamic compensation control model into a droop control generation compensation control strategy to perform micro-grid dynamic compensation control.
It should be noted that although in the above detailed description several modules or units of the microgrid dynamic compensation control system based on a distributed residual error generator are mentioned, this division is not mandatory. Indeed, the features and functionality of two or more modules or units described above may be embodied in one module or unit, according to embodiments of the present disclosure. Conversely, the features and functions of one module or unit described above may be further divided into embodiments by a plurality of modules or units.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or program product. Thus, various aspects of the invention may be embodied in the form of: an entirely hardware embodiment, an entirely software embodiment (including firmware, microcode, etc.) or an embodiment combining hardware and software aspects that may all generally be referred to herein as a "circuit," module "or" system.
Furthermore, the above-described figures are merely schematic illustrations of processes involved in methods according to exemplary embodiments of the invention, and are not intended to be limiting. It will be readily understood that the processes shown in the above figures are not intended to indicate or limit the chronological order of the processes. In addition, it is also readily understood that these processes may be performed synchronously or asynchronously, e.g., in multiple modules.
Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.
It will be understood that the present disclosure is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is to be limited only by the terms of the appended claims.