CN113839396A - Dynamic reactive power compensation system and method for repairing line loss of power grid - Google Patents
Dynamic reactive power compensation system and method for repairing line loss of power grid Download PDFInfo
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Abstract
The invention discloses a dynamic reactive power compensation system and a method for repairing the line loss of a power grid, which comprises a reactive power compensation device for parameter acquisition, a dynamic constraint parameter module for repairing the line loss of the power grid, a dynamic reactive power compensation detection model for the line loss of the power grid and dynamic reactive power compensation control; the dynamic reactive power compensation system and the method for repairing the line loss of the power grid are characterized in that the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus are used as constraint parameters, a dynamic reactive power compensation detection model of the line loss of the power grid is constructed, the dynamic constraint parameter analysis of the line loss repair of the power grid is realized, the dynamic adjustment of the line loss repair of the power grid is carried out according to the positive-negative sequence conversion relation of resonance angular frequency, the frequency coupling characteristic quantity of the line loss of the power grid is obtained, and the line loss repair and the optimization detection of the power grid are carried out by combining a dynamic reactive power compensation device; the line loss of the power grid is integrally and effectively repaired, the management capability of stable operation of the power grid is improved, and the working condition stable operation capability of the network is improved.
Description
Technical Field
The invention relates to the technical field of power grids, in particular to a dynamic reactive power compensation system and method for repairing line loss of a power grid.
Background
The method comprises the following steps that a power grid is influenced by factors such as overload in the operation process, lines of the power grid are easy to damage, power grid restoration design is required, line loss node detection and positioning of the power grid are combined, power grid line loss restoration design is carried out, stable operation management capacity of the power grid is improved, line loss performance characteristics of the power grid are different in working condition modes such as power transformation, power transmission and power distribution of the power grid, line loss characteristic distribution of the power grid needs to be optimized, detected and analyzed, a correlation characteristic distribution set of the power grid line loss is established, and optimized positioning detection capacity of the power grid line loss is improved by combining a fuzzy correlation detection method; therefore, the dynamic reactive power compensation system and method for repairing the line loss of the power grid are provided.
Disclosure of Invention
The invention aims to provide a dynamic reactive power compensation system and a dynamic reactive power compensation method for repairing the line loss of a power grid, which effectively realize the repairing of the line loss of the power grid, improve the management capability of the stable operation of the power grid, improve the working condition stable operation capability of a network and solve the problems in the prior art.
In order to achieve the purpose, the invention provides the following technical scheme: the dynamic reactive power compensation system for repairing the line loss of the power grid comprises a reactive power compensation device for parameter acquisition, a dynamic constraint parameter module for repairing the line loss of the power grid, a dynamic reactive power compensation detection model for the line loss of the power grid and dynamic reactive power compensation control;
acquiring output dynamic parameters of the reactive power compensation device, providing positive and negative sequence coupling components of the dynamic reactive power compensation device, assuming zi (k) epsilon Rp multiplied by 1 as an output current response measurement value of an ith dynamic reactive power compensation device acquisition node, Hi (k) epsilon Rp multiplied by n as a corresponding measurement matrix,
for the output association coupling joint probability, the output association coupling joint probability distribution of the line loss of the power grid under the assumption of voltage disturbance meets the following conditions:
wherein:
under a certain frequency and a certain phase sequence, the output power compensation characteristic distribution of the line loss of the power grid is expressed by adopting a discrete tuple as { S1, S2, … and SL }, in the frequency coupling process, a voltage disturbance component can be obtained through the phase sequence of an alternating current side to obtain the output coupling frequency association degree sw (u) of the direct current voltage loop, and the phase-locked loop output is as follows:
wherein, aijRepresenting the out-coupling frequency factor of the dynamic reactive power compensation device, bjRepresenting the state parameters of coupling of different frequencies, beta is the trigger angle, and the correlation coefficient of the coupling current components of different frequencies is Mi[tl＞Mm∨Mn，Mm[tm＞Mj，Mn[tn＞MjAllocating a time slice to each state node of the line loss of the power grid, and adopting N2(u)＝{v|dG(u, v) ═ 2} represents the vector transformation from the phase sequence domain to the dq domain, where, (i ≠ m ≠ n ≠ j, and a ≠ b ≠ c) represents the correlation dimension of the d-axis and the q-axis of the line loss node of the power grid.
Further, by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of the direct current bus as constraint parameters, a dynamic reactive power compensation detection model of the line loss of the power grid is constructed, and the hysteresis compensation model of the line loss node is obtained and described as follows:
in the formula (I), the compound is shown in the specification,
dynamic compensation parameters representing line losses in the power network, CijFor the line loss capacitance value of the power grid, a digital discrete detection method is adopted, and the obtained combined association rule mining output statistics of the line loss of the power grid is as follows:
flg-M(z)＝(flg(z)，flg-x(z)，flg-y(z))＝(flg(z)，hx*flg(z)，hy*flg(z)) (5)
carrying out intelligent positioning of the line loss of the power grid in a proportional link of the PR controller to obtain an intelligent positioning training sequence of a line loss node of the power grid:
the dynamic reactive compensation device is used as a basic module to perform dynamic reactive compensation adjustment, and the restoration and positioning control of the line loss of the power grid are realized by adopting the dynamic reactive compensation device.
Further, on the basis that the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus are used as constraint parameters, a direct current side equivalent output voltage detection model of the operation of the distribution network is constructed, and the resonance link coefficient of the PR controller is assumed to be E-vl multiplied by B, so that the output instantaneous current v-r omega of the power grid is enabled to be r omegar，rrThe damping coefficient of resistance and the damping coefficient of capacitance current are r ═ rr+lgFundamental angular frequency factor B ═ kβk1BgThe inductance l ═ lskfkcAw/AcAnd then, the equivalent output function of the direct current side of the power grid is as follows:
in a resonance link, an inner loop feedback adjustment method is adopted to carry out adaptive compensation control on the line loss of the power grid, and the obtained parameter adjustment dynamic compensation model for repairing the line loss of the power grid is described as follows:
wherein, KP1、K11、KP2、K12Respectively describing dynamic coupling components of phase-locked loop and D/A conversion, s is the mutual impedance between converter stations, and the controller parameter KP1、K11、KP2、K2R, L is a capacitance current damping coefficient, neglects the disturbance effect of the network voltage, and meets the requirements
similarly, by adopting a steady-state compensation method of a parameter capacitance current damping coefficient, an output gain function of the line loss repair of the power grid is obtained and described as follows:
where idq represents the inertial gain factor, at the system instability pole, the closed loop stability adjustment function can be described as:
and Geq(s) represents the active damping coefficient of the capacitance current, dynamic constraint parameter analysis on the line loss repair of the power grid is realized according to the analysis, and the line loss repair of the power grid is realized according to the dynamic constraint parameter model construction.
Further, the reactive power compensation device carries out output dynamic parameter acquisition of the line loss of the power grid, optimization of a line loss repair model of the power grid is carried out on the basis that a constraint parameter model is constructed according to the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus, a line loss repair method of the power grid based on automatic detection of the dynamic reactive power compensation device is provided, and the obtained system stability adjustment coefficient is expressed as:
through carrying out the output compensation control of electric wire netting line loss with the double sampling, establish dynamic reactive compensation modulation gain control model, it is to obtain system transfer function:
wherein, s represents the frequency coupling coefficient, fsw represents the active power of the ac-dc side, and TSW is 1/fsw, so that a line loss distribution model of the distribution network operation is constructed, a steady-state error is introduced to perform the superposition of the same-frequency components, and the obtained phase sequence domain characteristic quantity of the line loss repair of the power grid is represented as:
Lx＝(1-k2)L11 (16)
Lmx＝k2L11 (17)
according to the positive-negative sequence conversion relation of the resonance angular frequency, the dynamic adjustment of the line loss of the power grid is carried out, and the obtained frequency coupling characteristic quantity of the line loss of the power grid is as follows:
and considering the influences of the magnetic leakage coefficient k1 and the current loop k beta of the line loss part, and combining an adjusting model of dynamic parameters to realize dynamic reactive compensation detection of the line loss of the power grid and repair the line loss of the power grid.
Further, a multi-frequency coupling adjustment method is adopted to perform dynamic reactive compensation control on the line loss of the power grid, harmonic resonance characteristic quantities of the line loss of the power grid are extracted, and according to difference characteristic quantities of current mutation and the like of a phase-locked loop and a direct current bus of the power grid, the characteristic form of the multi-frequency coupling adjustment is as follows:
the power consumption of the line loss repairing process of the power grid is as follows:
Pshort＝IshortVDD (21)
under the action of digital control delay, the output current loss Pleakage of the line loss of the power grid, the hysteresis compensation of the wave trap is as follows:
Pleakage＝IleakageVDD (22)
the digital discrete part sampling characteristic value of the dynamic reactive compensator is as follows:
mu is the magnetic leakage coefficient of the phase-locked loop, the result of the automatic detection of the dynamic reactive power compensation device is input into an expert compensation system to carry out the line loss repair control of the power grid, and the obtained line loss repair damping coefficient of the power grid meets the following requirements:
in the formula, S represents an open-loop transfer function of the system, the number of unstable poles is calculated, and the state adjustment coefficient for repairing the line loss of the power grid is obtained as follows:
u0＝-sgn(Mn)ρ(t)sgn(s) (25)
according to the phase-locked loop of the power grid, the current sudden change and other different characteristic quantities of the direct current bus, the static power consumption Pspc and the dynamic power consumption Pdpc are calculated, namely:
Pspc＝VddIdd (26)
in the formula: pdpc is the leakage current of the power grid, and alpha is the maximum lag angle; c is a node capacitor for charging and discharging; v is the rectified voltage of the hysteresis compensation link; f is the amplitude compensation frequency. And (4) according to the model design, the line loss of the power grid is repaired and optimized and detected by combining the dynamic reactive power compensation device.
The invention provides another technology, which comprises a dynamic reactive power compensation method for repairing the line loss of the power grid, and the method comprises the following steps:
s1: the method comprises the steps of constructing a dynamic reactive power compensation detection model of the line loss of the power grid by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters, and realizing dynamic constraint parameter analysis on line loss repair of the power grid;
s2: according to the positive-negative sequence conversion relation of the resonance angular frequency, carrying out dynamic adjustment on the line loss repair of the power grid to obtain the frequency coupling characteristic quantity of the line loss of the power grid;
s3: and (4) carrying out line loss repair and optimized detection on the power grid by combining a dynamic reactive power compensation device.
Compared with the prior art, the invention has the following beneficial effects:
the dynamic reactive power compensation system and the method for repairing the line loss of the power grid are combined with the detection and the positioning of line loss nodes of the power grid to carry out the design of repairing the line loss of the power grid, thereby improving the management capability of stable operation of the power grid; the method comprises the steps of taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters, constructing a dynamic reactive power compensation detection model of the line loss of the power grid, realizing dynamic constraint parameter analysis on line loss repair of the power grid, carrying out dynamic adjustment on line loss repair of the power grid according to the positive-negative sequence conversion relation of resonance angular frequency to obtain the frequency coupling characteristic quantity of the line loss of the power grid, and carrying out line loss repair and optimization detection of the power grid by combining a dynamic reactive power compensation device; the line loss of the power grid is integrally and effectively repaired, the management capability of stable operation of the power grid is improved, and the working condition stable operation capability of the network is improved.
Drawings
Fig. 1 is an equivalent circuit model diagram of a dynamic reactive power compensation device of the present invention;
FIG. 2 is a control block diagram of reactive compensation of the present invention;
FIG. 3 is a graph of the output power gain of the grid of the present invention;
FIG. 4 is a diagram illustrating a line loss feature distribution value extraction result according to the present invention;
FIG. 5 is a graph of the line loss repair output of the present invention;
FIG. 6 is a schematic diagram of the output result of parameter adjustment for simulation optimization according to the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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 dynamic reactive power compensation system for repairing the line loss of the power grid comprises a reactive power compensation device for parameter acquisition, a dynamic constraint parameter module for repairing the line loss of the power grid, a dynamic reactive power compensation detection model for the line loss of the power grid and dynamic reactive power compensation control;
acquiring parameters based on the dynamic reactive power compensation device:
dynamic reactive compensation is adopted to carry out output dynamic parameter acquisition of the line loss of the power grid of the device, positive and negative sequence coupling components of the dynamic reactive compensation device are given, zi (k) epsilon Rp multiplied by 1 is assumed to be an output current response measured value of an ith dynamic reactive compensation device acquisition node, Hi (k) epsilon Rp multiplied by n is a corresponding measuring matrix,
for the output association coupling joint probability, the output association coupling joint probability distribution of the line loss of the power grid under the assumption of voltage disturbance meets the following conditions:
wherein:
under a certain frequency and a certain phase sequence, the output power compensation characteristic distribution of the line loss of the power grid is expressed by adopting a discrete tuple as { S1, S2, … and SL }, in the frequency coupling process, a voltage disturbance component can be obtained through the phase sequence of an alternating current side to obtain the output coupling frequency association degree sw (u) of the direct current voltage loop, and the phase-locked loop output is as follows:
wherein, aijRepresenting the out-coupling frequency factor of the dynamic reactive power compensation device, bjRepresenting the state parameters of coupling of different frequencies, beta is the trigger angle, and the correlation coefficient of the coupling current components of different frequencies is Mi[tl＞Mm∨Mn，Mm[tm＞Mj，Mn[tn＞MjAllocating a time slice to each state node of the line loss of the power grid, and adopting N2(u)＝{v|dG(u, v) ═ 2} represents the vector transformation from the phase sequence domain to the dq domain, wherein, (i ≠ m ≠ n ≠ j, a ≠ b ≠ c) represents the correlation dimension of the d axis and the q axis of the line loss node of the power grid, the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus are used as constraint parameters, a dynamic reactive power compensation detection model of the line loss of the power grid is constructed, and the hysteresis compensation model of the line loss node is described as follows:
in the formula (I), the compound is shown in the specification,
dynamic compensation parameters representing line losses in the power network, CijFor the line loss capacitance value of the power grid, a digital discrete detection method is adopted, and the obtained combined association rule mining output statistics of the line loss of the power grid is as follows:
flg-M(z)＝(flg(z)，flg-x(z)，flg-y(z))＝(flg(z)，hx*f1g(z)，hy*flg(z)) (5)
carrying out intelligent positioning of the line loss of the power grid in a proportional link of the PR controller to obtain an intelligent positioning training sequence of a line loss node of the power grid:
the dynamic reactive compensation device is used as a basic module to perform dynamic reactive compensation adjustment, and the restoration and positioning control of the line loss of the power grid are realized by adopting the dynamic reactive compensation device.
The dynamic constraint parameter module for repairing the line loss of the power grid comprises:
the method comprises the steps of constructing a dynamic reactive power compensation detection model of the line loss of the power grid by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters to obtain an equivalent circuit model of a dynamic reactive power compensation device as shown in figure 1, constructing a direct current side equivalent output voltage detection model of the operation of a distribution network according to the equivalent circuit model of the dynamic reactive power compensation device shown in figure 1, and assuming that the resonance link coefficient of a PR (pulse-width modulation) controller is E-vl-B, enabling the output instantaneous current v-r-omega of the power grid to be r-omega-Br，rrThe damping coefficient of resistance and the damping coefficient of capacitance current are r ═ rr+lgFundamental angular frequency factor B ═ kβk1BgThe inductance l ═ lskfkcAw/AcAnd then, the equivalent output function of the direct current side of the power grid is as follows:
in a resonance link, an inner loop feedback adjustment method is adopted to carry out adaptive compensation control on the line loss of the power grid, and the obtained parameter adjustment dynamic compensation model for repairing the line loss of the power grid is described as follows:
wherein, KP1、K11、KP2、K12For describing the dynamic coupling components of the phase locked loop and the digital-to-analog conversion, respectively. s is the mutual impedance between converter stations due to the controller parameter KP1、K11、KP2、K2R, L is a capacitance current damping coefficient, neglects the disturbance effect of the network voltage, and meets the requirements
similarly, by adopting a steady-state compensation method of a parameter capacitance current damping coefficient, an output gain function of the line loss repair of the power grid is obtained and described as follows:
where idq represents the inertial gain factor, at the system instability pole, the closed loop stability adjustment function can be described as:
and Geq(s) represents the active damping coefficient of the capacitance current, dynamic constraint parameter analysis on the line loss repair of the power grid is realized according to the analysis, and the line loss repair of the power grid is realized according to the dynamic constraint parameter model construction.
The dynamic reactive power compensation detection model of the line loss of the power grid comprises the following steps:
a control block diagram of reactive power compensation in the power grid line loss repair is shown in fig. 2, the dynamic reactive power compensation device is adopted to acquire output dynamic parameters of the power grid line loss, and optimization of a power grid line loss repair model is performed on the basis of constructing a constraint parameter model according to the frequency coupling characteristic of the power grid line loss and the capacitance difference characteristic of a direct-current bus, a power grid line loss repair method based on automatic detection of the dynamic reactive power compensation device is provided, and a system stability adjustment coefficient is obtained and expressed as:
through carrying out the output compensation control of electric wire netting line loss with the double sampling, establish dynamic reactive compensation modulation gain control model, it is to obtain system transfer function:
wherein, s represents the frequency coupling coefficient, fsw represents the active power of the ac-dc side, and TSW is 1/fsw, so that a line loss distribution model of the distribution network operation is constructed, a steady-state error is introduced to perform the superposition of the same-frequency components, and the obtained phase sequence domain characteristic quantity of the line loss repair of the power grid is represented as:
Lx＝(1-k2)L11 (16)
Lmx＝k2L11 (17)
according to the positive-negative sequence conversion relation of the resonance angular frequency, the dynamic adjustment of the line loss of the power grid is carried out, and the obtained frequency coupling characteristic quantity of the line loss of the power grid is as follows:
and considering the influences of the magnetic leakage coefficient k1 and the current loop k beta of the line loss part, and combining an adjusting model of dynamic parameters to realize dynamic reactive compensation detection of the line loss of the power grid and repair the line loss of the power grid.
Difference characteristic quantity extraction and line loss restoration:
the dynamic reactive compensation control of the line loss of the power grid is carried out by adopting a multi-frequency coupling adjustment method, the harmonic resonance characteristic quantity of the line loss of the power grid is extracted, and according to the difference characteristic quantities of current mutation and the like of a phase-locked loop and a direct-current bus of the power grid, the characteristic form of the multi-frequency coupling adjustment is as follows:
the power consumption of the line loss repairing process of the power grid is as follows:
Pshort＝IshortVDD (21)
under the action of digital control delay, the output current loss Pleakage of the line loss of the power grid, the hysteresis compensation of the wave trap is as follows:
Pleakage＝IleakageVDD (22)
the digital discrete part sampling characteristic value of the dynamic reactive compensator is as follows:
in the formula, S represents an open-loop transfer function of the system, the number of unstable poles is calculated, and the state adjustment coefficient for repairing the line loss of the power grid is obtained as follows:
u0＝-sgn(Mn)ρ(t)sgn(s) (25)
according to the phase-locked loop of the power grid, the current sudden change and other different characteristic quantities of the direct current bus, the static power consumption Pspc and the dynamic power consumption Pdpc are calculated, namely:
Pspc＝VddIdd (26)
in the formula: pdpc is the leakage current of the power grid, and alpha is the maximum lag angle; c is a node capacitor for charging and discharging; v is the rectified voltage of the hysteresis compensation link; f is the amplitude compensation frequency. And (4) according to the model design, the line loss of the power grid is repaired and optimized and detected by combining the dynamic reactive power compensation device.
The dynamic reactive power compensation method for repairing the line loss of the power grid comprises the following steps:
the method comprises the following steps: the method comprises the steps of constructing a dynamic reactive power compensation detection model of the line loss of the power grid by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters, and realizing dynamic constraint parameter analysis on line loss repair of the power grid;
step two: according to the positive-negative sequence conversion relation of the resonance angular frequency, carrying out dynamic adjustment on the line loss repair of the power grid to obtain the frequency coupling characteristic quantity of the line loss of the power grid;
step three: and (4) carrying out line loss repair and optimized detection on the power grid by combining a dynamic reactive power compensation device. The dynamic reactive power compensation system and method for repairing the line loss of the power grid.
The simulation test and result analysis of the dynamic reactive power compensation system and method for repairing the line loss of the power grid are as follows:
the simulation software adopts MATLAB7.0, the value of the alternating current side filter inductance of the power grid is between 1.4 and 2.8, the frequency coupling coefficient is 0.23, the initial power loss is 1.68kW/h, the amplitude of the negative sequence disturbance voltage with the fundamental frequency voltage of 200V is 300V, the amplitude of the current response is 12A, Rp1 is 45 omega, Cr is 14.6pF, Ro is 30 omega, and the optimized parameter adjustment output is shown in figure 6.
According to the parameter setting result, the automatic detection of the dynamic reactive power compensation device and the line loss repair of the power grid are carried out, the power gain of the power grid is obtained as shown in figure 3, according to the calculation result of the output power gain of the power grid of figure 3, the dynamic reactive power compensation control of the line loss of the power grid is carried out by adopting a multi-frequency coupling adjustment method, the harmonic resonance characteristic quantity of the line loss of the power grid is extracted, the line loss characteristic extraction is realized, the line loss characteristic distribution value is obtained as shown in figure 4, the figure 4 is analyzed, the extraction of the line loss characteristic of the power grid can be effectively realized by adopting the method, the identification capability of the characteristic distribution is strong, the line loss repair and optimization detection are carried out according to the difference characteristic quantity of current mutation and the like of a phase-locked loop and a direct current bus of the power grid by combining the dynamic reactive power compensation device, the line loss repair result is tested, as shown in figure 5, the analysis of figure 5 shows that the method can effectively realize the positioning and repair of the line loss of the power grid, the repairing result is accurate and reliable.
In summary, the following steps: the dynamic reactive power compensation system and the method for repairing the line loss of the power grid are combined with the detection and the positioning of line loss nodes of the power grid to carry out the design of repairing the line loss of the power grid, thereby improving the management capability of stable operation of the power grid; the method comprises the steps of taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters, constructing a dynamic reactive power compensation detection model of the line loss of the power grid, realizing dynamic constraint parameter analysis on line loss repair of the power grid, carrying out dynamic adjustment on line loss repair of the power grid according to the positive-negative sequence conversion relation of resonance angular frequency to obtain the frequency coupling characteristic quantity of the line loss of the power grid, and carrying out line loss repair and optimization detection of the power grid by combining a dynamic reactive power compensation device; the line loss of the power grid is integrally and effectively repaired, and the working condition stable operation capacity of the network is improved.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (6)
1. The dynamic reactive power compensation system for repairing the line loss of the power grid is characterized in that: the system comprises a reactive power compensation device for parameter acquisition, a dynamic constraint parameter module for power grid line loss restoration, a dynamic reactive power compensation detection model for power grid line loss and dynamic reactive power compensation control;
acquiring output dynamic parameters of the reactive power compensation device, providing positive and negative sequence coupling components of the dynamic reactive power compensation device, assuming zi (k) epsilon Rp multiplied by 1 as an output current response measurement value of an ith dynamic reactive power compensation device acquisition node, Hi (k) epsilon Rp multiplied by n as a corresponding measurement matrix,
for the output association coupling joint probability, the output association coupling joint probability distribution of the line loss of the power grid under the assumption of voltage disturbance meets the following conditions:
wherein:
the output power compensation characteristic distribution of the line loss of the power grid is expressed as { S1, S2, … and SL } by adopting discrete tuples, in the frequency coupling process, the voltage disturbance component can be obtained through the phase sequence of an alternating current side to obtain the output coupling frequency association degree sw (u) of the direct current voltage loop, and the phase-locked loop outputs:
wherein, aijRepresenting the out-coupling frequency factor of the dynamic reactive power compensation device, bjRepresenting the state parameters of coupling of different frequencies, beta is the trigger angle, and the correlation coefficient of the coupling current components of different frequencies is Mi[tl＞Mm∨Mn，Mm[tm＞Mj，Mn[tn＞MjAllocating a time slice to each state node of the line loss of the power grid, and adopting N2(u)＝{v|dG(u, v) ═ 2} represents the vector transformation from the phase sequence domain to the dq domain, where, (i ≠ m ≠ n ≠ j, and a ≠ b ≠ c) represents the correlation dimension of the d-axis and the q-axis of the line loss node of the power grid.
2. The system of claim 1, wherein: and (2) constructing a dynamic reactive power compensation detection model of the line loss of the power grid by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of the direct-current bus as constraint parameters, and obtaining a line loss node hysteresis compensation model description as follows:
in the formula (I), the compound is shown in the specification,
dynamic compensation parameters representing line losses in the power network, CijFor the line loss capacitance value of the power grid, a digital discrete detection method is adopted, and the obtained combined association rule mining output statistics of the line loss of the power grid is as follows:
flg-M(z)＝(flg(z)，flg-x(z)，flg-y(z))
＝(flg(z)，hx*flg(z)，hy*flg(z)) (5)
carrying out intelligent positioning of the line loss of the power grid in a proportional link of the PR controller to obtain an intelligent positioning training sequence of a line loss node of the power grid:
the dynamic reactive compensation device is used as a basic module to perform dynamic reactive compensation adjustment, and the restoration and positioning control of the line loss of the power grid are realized by adopting the dynamic reactive compensation device.
3. The system of claim 1, wherein: the dynamic reactive compensation detection model of the line loss of the power grid is constructed by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters, and the direct current side equivalent output voltage detection model of the operation of a distribution network is constructed by assuming that the resonance link coefficient of a PR controller is E-vl-B, so that the output instantaneous current v-r omega of the power grid isr，rrThe damping coefficient of resistance and the damping coefficient of capacitance current are r ═ rr+lgFundamental angular frequency factor B ═ kβk1BgThe inductance l ═ lskfkcAw/AcAnd then, the equivalent output function of the direct current side of the power grid is as follows:
in a resonance link, an inner loop feedback adjustment method is adopted to carry out adaptive compensation control on the line loss of the power grid, and the obtained parameter adjustment dynamic compensation model for repairing the line loss of the power grid is described as follows:
wherein, KP1、K11、KP2、K12Respectively describing dynamic coupling components of phase-locked loop and D/A conversion, s is the mutual impedance between converter stations, and the controller parameter KP1、K11、KP2、K2R, L is a capacitance current damping coefficient, neglects the disturbance effect of the network voltage, and meets the requirements
similarly, by adopting a steady-state compensation method of a parameter capacitance current damping coefficient, an output gain function of the line loss repair of the power grid is obtained and described as follows:
where idq represents the inertial gain factor, at the system instability pole, the closed loop stability adjustment function can be described as:
and Geq(s) represents the active damping coefficient of the capacitance current, dynamic constraint parameter analysis on the line loss repair of the power grid is realized according to the analysis, and the line loss repair of the power grid is realized according to the dynamic constraint parameter model construction.
4. The system of claim 1, wherein: the reactive power compensation device carries out output dynamic parameter acquisition of the line loss of the power grid, optimization of a line loss repair model of the power grid is carried out on the basis that a constraint parameter model is constructed according to the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct-current bus, a power grid line loss repair method based on automatic detection of the dynamic reactive power compensation device is provided, and the obtained system stability regulation coefficient is expressed as:
through carrying out the output compensation control of electric wire netting line loss with the double sampling, establish dynamic reactive compensation modulation gain control model, it is to obtain system transfer function:
wherein, s represents the frequency coupling coefficient, fsw represents the active power of the ac-dc side, and TSW is 1/fsw, so that a line loss distribution model of the distribution network operation is constructed, a steady-state error is introduced to perform the superposition of the same-frequency components, and the obtained phase sequence domain characteristic quantity of the line loss repair of the power grid is represented as:
Lx＝(l-k2)L11 (16)
Lmx＝k2L11 (17)
according to the positive-negative sequence conversion relation of the resonance angular frequency, the dynamic adjustment of the line loss of the power grid is carried out, and the obtained frequency coupling characteristic quantity of the line loss of the power grid is as follows:
and considering the influences of the magnetic leakage coefficient k1 and the current loop k beta of the line loss part, and combining an adjusting model of dynamic parameters to realize dynamic reactive compensation detection of the line loss of the power grid and repair the line loss of the power grid.
5. The system of claim 1, wherein: the dynamic reactive compensation control of the line loss of the power grid is carried out by adopting a multi-frequency coupling adjustment method, the harmonic resonance characteristic quantity of the line loss of the power grid is extracted, and according to the difference characteristic quantities of current mutation and the like of a phase-locked loop and a direct-current bus of the power grid, the characteristic form of the multi-frequency coupling adjustment is as follows:
the power consumption of the line loss repairing process of the power grid is as follows:
Pshort＝IshortVDD (21)
under the action of digital control delay, the output current loss Pleakage of the line loss of the power grid, the hysteresis compensation of the wave trap is as follows:
Pleakage＝IleakageVDD (22)
the digital discrete part sampling characteristic value of the dynamic reactive compensator is as follows:
mu is the magnetic leakage coefficient of the phase-locked loop, the result of the automatic detection of the dynamic reactive power compensation device is input into an expert compensation system to carry out the line loss repair control of the power grid, and the obtained line loss repair damping coefficient of the power grid meets the following requirements:
in the formula, S represents an open-loop transfer function of the system, the number of unstable poles is calculated, and the state adjustment coefficient for repairing the line loss of the power grid is obtained as follows:
u0＝-sgn(Mn)ρ(t)sgn(s) (25)
according to the phase-locked loop of the power grid, the current sudden change and other different characteristic quantities of the direct current bus, the static power consumption Pspc and the dynamic power consumption Pdpc are calculated, namely:
Pspc＝VddIdd (26)
in the formula: pdpc is the leakage current of the power grid, and alpha is the maximum lag angle; c is a node capacitor for charging and discharging; v is the rectified voltage of the hysteresis compensation link; f is the amplitude compensation frequency. And (4) according to the model design, the line loss of the power grid is repaired and optimized and detected by combining the dynamic reactive power compensation device.
6. The method of dynamic reactive power compensation of grid line loss restoration according to claim 1, characterized by: the method comprises the following steps:
s1: the method comprises the steps of constructing a dynamic reactive power compensation detection model of the line loss of the power grid by taking the frequency coupling characteristic of the line loss of the power grid and the capacitance difference characteristic of a direct current bus as constraint parameters, and realizing dynamic constraint parameter analysis on line loss repair of the power grid;
s2: according to the positive-negative sequence conversion relation of the resonance angular frequency, carrying out dynamic adjustment on the line loss repair of the power grid to obtain the frequency coupling characteristic quantity of the line loss of the power grid;
s3: and (4) carrying out line loss repair and optimized detection on the power grid by combining a dynamic reactive power compensation device.
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| CN116760055A (en) * | 2023-06-07 | 2023-09-15 | 东南大学 | Dynamic reactive compensation method based on neural network |
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| CN115441452A (en) * | 2022-09-22 | 2022-12-06 | 费莱(浙江)科技有限公司 | Dynamic compensation method and system based on harmonic separation detection |
| CN116760055A (en) * | 2023-06-07 | 2023-09-15 | 东南大学 | Dynamic reactive compensation method based on neural network |
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