CN105207209A - Alternating-current and direct-current power distribution network system load flow computing method based on droop control - Google Patents
Alternating-current and direct-current power distribution network system load flow computing method based on droop control Download PDFInfo
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Abstract
The invention provides an alternating-current and direct-current power distribution network system load flow computing method based on droop control. The method includes the following steps that firstly, initialization computing of a sagging curve is carried out; secondly, direct-current power of a direct-current power distribution system is updated through the Newton algorithm; thirdly, according to the updated direct-current power, a middle node voltage equation of an alternating-current power distribution system is solved, and droop characteristics are led into the alternating-current power distribution system; fourthly, whether alternating-current power flow and direct-current power flow converge or not is judged, if no, the second step continues for iterative computation till the alternating-current power flow and the direct-current power flow converge at the same time, and meanwhile a result is output. The invention provides the power flow mixing computing method suitable for a multi-terminal interconnection alternating-current and direct-current power distribution system adopting droop control, the gauss algorithm is adopted in the alternating-current power distribution system, and the Newton algorithm is adopted in the direct-current power distribution system. Meanwhile, the advantage that the gauss algorithm is little in calculation quantity and the advantage that the Newton algorithm is good in convergence are both taken into consideration, the problem that power flow does not converge is avoided, and the practicality level of power flow computing is improved.
Description
Technical Field
The invention relates to a power distribution network system load flow calculation method, in particular to an alternating current-direct current power distribution network system load flow calculation method based on droop control, and belongs to the technical field of power distribution system load flow calculation.
Background
With the rapid development of economy in China, the traditional alternating current power distribution network has a plurality of development bottlenecks due to the increasing high-density load. The alternating-current power distribution network faces a series of power quality problems of large line loss, tension of power supply corridors, aggravation of phenomena of instantaneous voltage drop, voltage fluctuation, harmonic waves of a power grid, three-phase imbalance and the like. Relevant researches show that the direct-current power distribution network has better performance than the alternating-current power distribution network in the aspects of transmission capacity, controllability, power supply quality improvement and the like. By adopting the direct-current power distribution technology, the power supply capacity can be improved under the conditions of the same insulation grade and the same current density, active power and reactive power can be controlled quickly and independently, the stability of power supply voltage is kept, the faults of an alternating-current power grid can be effectively isolated, and the higher and higher power quality requirements of users can be met. Meanwhile, the direct-current power distribution network also provides good access conditions for clean energy and energy storage power stations. The research of the direct current distribution network system has important social significance and wide application prospect. At present, the research on flexible AC/DC power distribution networks and engineering application thereof at home and abroad is in the starting stage, and a large number of theoretical and technical problems still exist.
With the increasing development of distributed power generation technology, more and more distributed power sources are connected to cause a plurality of power supply points in a power distribution network, in order to achieve the purpose that multiple power sources participate in power regulation, droop control is applied to a control system of a converter, and the application of droop control in an alternating current and direct current power distribution system has a plurality of problems to be solved.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides the alternating current-direct current distribution network system load flow calculation method based on droop control, and the practical level of load flow calculation in the current actual power grid and the future large power grid can be effectively improved by avoiding the problem that the load flow is not converged due to the fact that the load flow solution deviates from a droop curve greatly.
The technical scheme adopted for solving the technical problems is as follows: a droop control-based load flow calculation method for an alternating current-direct current power distribution network system is characterized by comprising the following steps:
(1) carrying out initial calculation on a droop curve;
(2) the direct current power distribution system updates the direct current power by adopting a Newton algorithm;
(3) solving a node voltage equation in the alternating current power distribution system according to the updated direct current power, and introducing droop characteristics into the alternating current power distribution system;
(4) and (3) judging whether the alternating current power flow and the direct current power flow are converged, if not, switching to the step (2) to continue iterative calculation until the alternating current power flow and the direct current power flow are simultaneously converged, and outputting a result at the same time.
Further, in step (1), the converter is regarded as a dc voltage-reactive power control mode, and the droop curve is initialized and calculated.
Further, in step (2), the dc distribution system uses a droop-controlled converter to incorporate a jacobian matrix for performing a uniform iterative calculation to correct the voltage, and updates the dc power according to the droop curve.
Further, in the step (3), the converter in the alternating current power distribution system obtains the updated direct current power, the converter is regarded as an active power-reactive power node by adopting a Gaussian algorithm and is incorporated into a node voltage equation for unified iterative calculation, and the droop characteristic is introduced into the alternating current power distribution system.
Further, the process of performing the initial calculation of the droop curve includes the following steps:
11) taking the converter as a Udc-Q node to perform primary load flow calculation, namely taking a direct current voltage Udc and a reactive power Q as known quantities, and solving active power and alternating current voltage, wherein the Udc takes a given direct current voltage reference value Udcref;
12) all node voltages satisfyAfter the dc power flow converges, wherein,for the k +1 th iteration direct current voltage calculation result of the ith node,for the calculation result of the k iteration direct current voltage of the ith node,dcgiven the allowed error;
after the direct current power flow is converged, calculating the direct current power of the converter node adopting droop controlTaking the reference value Pref of the direct current power as Pdcm, wherein PdcmIs the power of the mth converter, UdcmIs the DC voltage of the mth converter, j belongs to m and represents that the node is connected with the mth converter, UjFor other node voltages connected to the inverter, GmjN represents n direct current nodes in total for the node conductance connected with the converter;
13) determining a droop curve in combination with K, Udcref and Pref for a given droop curve of the converter, the expression for the droop curve being: pdc＝K(Udcref-Udc)+PrefIn the formula, K is a droop coefficient, Udcref is a direct-current voltage reference value, Pref is a direct-current power reference value, and Pdc is converter direct-current power.
Considering the sensitivity of a Newton method to an initial value, the invention adopts a droop curve initialization processing method based on a Udc-Q node, namely, considering that a direct current system has no reactive power transmission, firstly, a converter is taken as the Udc-Q node to carry out primary calculation, and the active power after the direct current power flow is converged is taken as a reference value, so that the droop curve is determined, and the problem that the power flow is not converged due to the fact that the power flow solution deviates from the droop curve greatly is solved.
Furthermore, the process of updating the direct current power by the direct current power distribution system by adopting the Newton algorithm comprises the following steps:
21) calculating a Jacobian matrix and a node power difference to form a correction equation shown in the formula (1):
in the formula,. DELTA.P1～ΔPnCalculating the power difference of each node by subtracting the load absorption power from the power injection power of each node; u shape1～UnFor each node voltage, Δ U1～ΔUnThe voltage residual of each node is taken as a variable to be solved; n is a radical of11～Nn,nFor the elements of the jacobian matrix,
the calculation is performed by using the formula (2) for the converter node considering the droop control, and the calculation is performed by using the formula (3) for other general nodes:
in the formula, GiiIs the self-conductance of the i-node, GijIs the mutual conductance between the node i and the node j;
22) solving the correction equation of the formula (1) to obtain the voltage residual error delta U of each node1～ΔUnCorrecting the DC voltage at each nodeFor the k +1 th iteration direct current voltage calculation result of the ith node,calculating the k iteration direct current voltage of the ith node;
23) according to the sagging curveUpdating converter DC power
According to the method, a Newton method is adopted to solve the direct current system, a current converter adopting droop control is incorporated into a system correction equation for uniform iteration, and the convergence of the algorithm is improved.
Further, the process of solving the node voltage equation in the ac power distribution system includes the steps of:
31) the AC power is updated under the condition of neglecting the loss, and the AC power of the converter is obtained
32) Calculating the node injection current of the converter Wherein,for the current calculation result of the current iteration (k + 1) of the converter,calculating a voltage calculation result for the kth iteration of the converter;
33) unifying converter nodes to AC distribution system node voltage equationSolving forWherein Y isaciThe admittance of the ith node of the alternating current distribution system is not changed along with the iterative process,the iterative calculation result of the (k + 1) th voltage of the ith node of the alternating current distribution system is used as a substitute quantity,the result is calculated for the current at the ith node of the AC distribution system at the (k + 1) th time.
The invention adopts the Gaussian algorithm to solve the alternating current system, and introduces the droop characteristic of the converter into the alternating current system by taking the direct current power of the converter when the power of the converter is updated.
Further, the process of determining whether the ac power flow and the dc power flow converge includes the following steps:
41) judging the voltage of each node of the equationWhether or not, ifIf the current is converged, the DC power distribution system,for the k +1 th iteration direct current voltage calculation result of the ith node,for the calculation result of the k iteration direct current voltage of the ith node,dcgiven the allowed error;
42) equation of judgmentAnd if so, converging the power flow of the alternating current power distribution system, wherein,iteratively calculating the result for the (k + 1) th voltage of the ith node of the alternating current distribution system,iteratively calculating the result for the kth voltage at the ith node of the ac power distribution system,acis a given alternating current power flow iteration error;
43) and if the power flow of the direct current power distribution system or the power flow of the alternating current power distribution system is not converged, returning to direct current power flow solution to continue iterative calculation until the alternating current power flow and the direct current power flow are converged simultaneously, and outputting a result at the same time.
The convergence criterion of the alternating current power flow and the direct current power flow is judged, the calculation is stopped only when the alternating current and the direct current are converged at the same time, otherwise, the direct current power flow is returned to solve and recalculate, the Gaussian algorithm and the Newton algorithm are fully integrated, and the mixed calculation of the alternating current part and the direct current part in the alternating current and direct current power distribution network through power constraint is realized.
The invention has the following beneficial effects:
1) in the process of initializing and calculating the droop curve, the sensitivity of a Newton method to an initial value is considered, and a droop curve initialization processing method based on a Udc-Q node is adopted, namely, the converter is firstly taken as the Udc-Q node to calculate once in consideration of the fact that a direct-current system has no reactive power transmission. The active power after the direct current power flow convergence is used as a reference value, so that a droop curve is determined, and the problem that the power flow does not converge due to the fact that the power flow solution deviates from the droop curve greatly is solved.
2) The DC power distribution system is solved by adopting a Newton method, a current converter adopting droop control is included in a system correction equation for uniform iteration, and the convergence of the algorithm is improved.
3) The method is characterized in that a Gaussian algorithm is adopted to solve an alternating current distribution system, and when the power of a converter is updated, the droop characteristic of the converter is introduced into the alternating current system through taking the direct current power of the converter.
4) The convergence criterion of the alternating current power flow and the direct current power flow is judged, a Gaussian algorithm and a Newton algorithm are fully fused, and mixed calculation of the alternating current part and the direct current part in the alternating current-direct current power distribution network through power constraint is realized.
The invention provides a load flow hybrid calculation method suitable for a multi-end interconnected AC-DC power distribution system adopting droop control, wherein the AC power distribution system adopts a Gaussian algorithm, the DC power distribution system adopts a Newton method, and the advantages of small calculation amount of the Gaussian algorithm and good convergence of the Newton method are taken into consideration simultaneously, so that the problem of non-convergence of load flow caused by large deviation of load flow solution from a droop curve is avoided, and the practical level of load flow calculation in the current actual power distribution network and the future power distribution network is effectively improved.
Drawings
FIG. 1 is a flow chart of a method of the present invention;
FIG. 2 is a schematic structural diagram of an AC/DC power distribution network system for performing load flow calculation of the AC/DC power distribution network system according to the present invention;
FIG. 3 is a flow chart of a specific method for performing load flow calculation of the AC/DC power distribution network system according to the present invention;
fig. 4 is a schematic view of a droop curve determined in the process of carrying out load flow calculation on an alternating current and direct current distribution network system.
Detailed Description
In order to clearly explain the technical features of the present invention, the following detailed description of the present invention is provided with reference to the accompanying drawings. The following disclosure provides many different embodiments, or examples, for implementing different features of the invention. To simplify the disclosure of the present invention, the components and arrangements of specific examples are described below. Furthermore, the present invention may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed. It should be noted that the components illustrated in the figures are not necessarily drawn to scale. Descriptions of well-known components and processing techniques and procedures are omitted so as to not unnecessarily limit the invention.
The load flow calculation is the basis of analysis of the alternating current and direct current distribution network, and a load flow result can directly reflect the quality of a control strategy. Each transverter homoenergetic realizes the coordinated control of a plurality of transverters through drooping curve control voltage and power among the droop control, need not upper controller and communication network, and new transverter module can insert in a flexible way, has plug-and-play's effect. The Gaussian algorithm occupies a small memory and is easy to realize, but the method is to separately calculate the balance node from other nodes, if droop control is adopted, voltage updating of the balance node is involved, and if power fluctuation is large, the voltage fluctuation of the balance node is easy to cause overlarge, so that the iterative computation of the power flow is not converged. Compared with a Gaussian algorithm, the Newton method has good convergence, but the calculation process of the Newton method relates to the repeated solution of a Jacobian matrix, a large amount of memory is required to be occupied, and meanwhile, the iterative calculation time is long. In addition, the newton method is sensitive to the selection of the initial value, and particularly, when droop control is considered, the initial value needs to be reasonably calculated.
Considering that only active power is transmitted in the direct current distribution network system, if a Newton method is adopted for solving the load flow of the direct current system, the Jacobian matrix dimension of the direct current distribution network system is greatly reduced, and the occupied memory and the iterative computation time are also greatly reduced. And the alternating-current distribution network system can adopt a Gaussian algorithm, so that the complex Jacobian matrix calculation is avoided, and the program calculation efficiency is improved. Therefore, the invention provides a power flow hybrid calculation method suitable for a multi-end interconnection alternating current and direct current power distribution system adopting droop control, wherein the alternating current power distribution system adopts a Gaussian algorithm, the direct current power distribution system adopts a Newton method, and the advantages of small calculation amount of the Gaussian algorithm and good convergence of the Newton method are considered. Considering the sensitivity of the Newton method to the initial value, a droop curve initialization processing method based on the Vdc-Q node is provided, and the problem that the power flow is not converged due to the fact that the power flow solution deviates from the droop curve greatly is solved.
As shown in fig. 1, the method for calculating the power flow of the ac/dc power distribution network system based on droop control of the present invention includes the following steps:
(1) taking the converter as a direct-current voltage-reactive power control mode, and carrying out initialization calculation on a droop curve;
(2) the direct current power distribution system adopts a droop-controlled converter to be brought into a Jacobian matrix for carrying out unified iterative computation to correct voltage, and updates direct current power according to a droop curve;
(3) a converter in the alternating current power distribution system obtains updated direct current power, the converter is regarded as an active power-reactive power node by adopting a Gaussian algorithm and is incorporated into a node voltage equation for unified iterative calculation, and droop characteristics are introduced into the alternating current power distribution system;
(4) and (3) judging whether the alternating current power flow and the direct current power flow are converged, if not, switching to the step (2) to continue iterative calculation until the alternating current power flow and the direct current power flow are simultaneously converged, and outputting a result at the same time.
FIG. 2 is a schematic structural diagram of an AC/DC power distribution network system for performing load flow calculation of the AC/DC power distribution network system according to the present invention; fig. 3 is a flow chart of a specific method for performing load flow calculation of the ac/dc power distribution network system according to the present invention. As shown in fig. 1 and fig. 2, the specific process of the power flow calculation of the ac/dc power distribution network system based on droop control in the present invention is as follows:
step 1: and (3) performing primary load flow calculation by taking the converter as a Udc-Q node, namely solving active power and alternating voltage by taking the direct current voltage Udc and the reactive power Q as known quantities, wherein the Udc takes a given direct current voltage reference value Udcref.
Step 2: all node voltages satisfyAfter the dc power flow converges, wherein,for the k +1 th iteration direct current voltage calculation result of the ith node,for the calculation result of the k iteration direct current voltage of the ith node,dcgiven the allowed error;
after the direct current power flow is converged, calculating the direct current power of the converter node adopting droop controlTaking the reference value Pref of the direct current power as Pdcm, wherein PdcmIs the power of the mth converter, UdcmIs the DC voltage of the mth converter, j belongs to m and represents that the node is connected with the mth converter, UjFor other node voltages connected to the inverter, GmjN represents a total of n dc nodes for the node conductance associated with the inverter.
Step 3: the droop curve is determined in connection with K, Udcref and Pref for a given droop curve of the converter, as shown in fig. 4, the determined droop curve has the expression: pdc＝K(Udcref-Udc)+PrefIn the formula, K is a droop coefficient, Udcref is a direct-current voltage reference value, Pref is a direct-current power reference value, and Pdc is converter direct-current power. Particularly, when the K is 0, the constant voltage control is converted into the constant voltage control, and when the algorithm is designed, the K value is set to be 0, so that the constant voltage control can realize a processing mode unified with the droop voltage control.
Step 4: calculating a Jacobian matrix and a node power difference to form a correction equation shown in the formula (1):
in the formula,. DELTA.P1～ΔPnCalculating the power difference of each node by subtracting the load absorption power from the power injection power of each node; u shape1～UnFor each node voltage, Δ U1～ΔUnThe voltage residual of each node is taken as a variable to be solved; n is a radical of11～Nn,nAre jacobian matrix elements.
The calculation is performed by using the formula (2) for the converter node considering the droop control, and the calculation is performed by using the formula (3) for other general nodes:
in the formula, GiiIs the self-conductance of the i-node, GijIs the mutual conductance between the i node and the j node.
Step 5: solving the correction equation of the formula (1) to obtain the voltage residual error delta U of each node1～ΔUnCorrecting the DC voltage at each nodeFor the k +1 th iteration direct current voltage calculation result of the ith node,and (5) performing the k-th iteration direct-current voltage calculation result for the ith node.
Step 6: according to the sagging curveUpdating converter DC power
Step 7: the AC power is updated under the condition of neglecting the loss, and the AC power of the converter is obtained
Step 8: calculating the node injection current of the converterWherein,for the current calculation result of the current iteration (k + 1) of the converter,and calculating the voltage calculation result for the k iteration of the converter.
Step 9: unifying converter nodes to AC distribution system node voltage equationSolving, wherein, YaciThe admittance of the ith node of the alternating current distribution system is not changed along with the iterative process,the iterative calculation result of the (k + 1) th voltage of the ith node of the alternating current distribution system is used as a substitute quantity,the result is calculated for the current at the ith node of the AC distribution system at the (k + 1) th time.
Step 10: judging the voltage of each node of the equationWhether or not, ifIf the current is converged, the DC power distribution system,for the k +1 th iteration direct current voltage calculation result of the ith node,for the calculation result of the k iteration direct current voltage of the ith node,dcgiven the allowed error.
Step 11: equation of judgmentAnd if so, converging the power flow of the alternating current power distribution system, wherein,iteratively calculating the result for the (k + 1) th voltage of the ith node of the alternating current distribution system,iteratively calculating the result for the kth voltage at the ith node of the ac power distribution system,acis the given alternating current power flow iteration error.
Step 12: and if the direct current power distribution system power flow or the alternating current power distribution system power flow is not converged, returning to Step4 to continue iterative calculation until the alternating current power flow and the direct current power flow are converged simultaneously, and outputting the result simultaneously.
The foregoing is only a preferred embodiment of the present invention, and it will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the principle of the invention, and such modifications and improvements are also considered to be within the scope of the invention.
Claims (8)
1. A droop control-based load flow calculation method for an alternating current-direct current power distribution network system is characterized by comprising the following steps:
(1) carrying out initial calculation on a droop curve;
(2) the direct current power distribution system updates the direct current power by adopting a Newton algorithm;
(3) solving a node voltage equation in the alternating current power distribution system according to the updated direct current power, and introducing droop characteristics into the alternating current power distribution system;
(4) and (3) judging whether the alternating current power flow and the direct current power flow are converged, if the alternating current power flow or the direct current power flow is not converged, continuing to perform iterative calculation in the step (2) until the alternating current power flow and the direct current power flow are converged simultaneously, and outputting a result at the same time.
2. The method for calculating the power flow of the ac/dc power distribution network system based on droop control as claimed in claim 1, wherein in the step (1), the converter is regarded as a dc voltage-reactive power control mode, and the droop curve is initialized and calculated.
3. The method for calculating the power flow of the ac/dc power distribution network system based on the droop control as claimed in claim 2, wherein in the step (2), the dc power distribution system uses the converter for the droop control to incorporate the jacobian matrix for the unified iterative calculation to correct the voltage, and updates the dc power according to the droop curve.
4. The method for calculating the power flow of the alternating current-direct current power distribution network system based on the droop control as claimed in claim 3, wherein in the step (3), the converter in the alternating current power distribution system obtains the updated direct current power, a Gaussian algorithm is adopted to take the converter as an active power-reactive power node to be included in a node voltage equation for unified iterative calculation, and the droop characteristic is introduced into the alternating current power distribution system.
5. The AC/DC distribution network system power flow calculation method based on droop control as claimed in any one of claims 1 to 4, wherein the process of performing initial calculation of the droop curve comprises the following steps:
11) consider the inverter as UdcCarrying out primary power flow calculation on a Q node to solve active power and alternating voltage, wherein UdcTaking a given DC voltage reference value Udcref；
12) All node voltages satisfyAfter the dc power flow converges, wherein,for the k +1 th iteration direct current voltage calculation result of the ith node,for the calculation result of the k iteration direct current voltage of the ith node,dcgiven the allowed error;
after the direct current power flow is converged, calculating the direct current power of the converter node adopting droop controlTaking a DC power reference value Pref＝PdcmWherein P isdcmIs the power of the mth converter, UdcmIs the DC voltage of the mth converter, j belongs to m and represents that the node is connected with the mth converter, UjFor other node voltages connected to the inverter, GmjN represents n direct current nodes in total for the node conductance connected with the converter;
13) k, U for a given sag curve of a converterdcrefAnd PrefDetermining a droop curve, wherein the expression of the droop curve is as follows: pdc＝K(Udcref-Udc)+PrefWhere K is the sag coefficient, UdcrefIs a DC voltage reference value, PrefIs a DC power reference value, PdcIs the inverter direct current power.
6. The power flow calculation method of the alternating current-direct current power distribution network system based on the droop control as claimed in claim 5, wherein the process that the direct current power distribution system adopts a Newton algorithm to update the direct current power comprises the following steps:
21) calculating a Jacobian matrix and a node power difference to form a correction equation shown in the formula (1):
in the formula,. DELTA.P1～ΔPnCalculating the power difference of each node by subtracting the load absorption power from the power injection power of each node; u shape1～UnFor each node voltage, Δ U1～ΔUnThe voltage residual of each node is taken as a variable to be solved; n is a radical of11～Nn,nFor the elements of the jacobian matrix,
the calculation is performed by using the formula (2) for the converter node considering the droop control, and the calculation is performed by using the formula (3) for other general nodes:
in the formula, GiiIs the self-conductance of the i-node, GijIs the mutual conductance between the node i and the node j;
22) solving the correction equation of the formula (1) to obtain the voltage residual error delta U of each node1～ΔUnCorrecting the DC voltage at each nodeFor the k +1 th iteration direct current voltage calculation result of the ith node,calculating the k iteration direct current voltage of the ith node;
23) according to the sagging curveUpdating converter DC power
7. The method for calculating the power flow of the alternating current and direct current power distribution network system based on the droop control as claimed in claim 6, wherein the process of solving the node voltage equation in the alternating current power distribution system comprises the following steps:
31) the AC power is updated under the condition of neglecting the loss, and the AC power of the converter is obtained
32) Calculating the node injection current of the converterWherein,for the current calculation result of the current iteration (k + 1) of the converter,calculating a voltage calculation result for the kth iteration of the converter;
33) unifying converter nodes to AC distribution system node voltage equationSolving, wherein, YaciThe admittance of the ith node of the alternating current distribution system is not changed along with the iterative process,the iterative calculation result of the (k + 1) th voltage of the ith node of the alternating current distribution system is used as a substitute quantity,the result is calculated for the current at the ith node of the AC distribution system at the (k + 1) th time.
8. The method for calculating the power flow of the alternating current/direct current power distribution network system based on the droop control as claimed in claim 7, wherein the step of judging whether the alternating current power flow and the direct current power flow are converged comprises the following steps:
41) judging the voltage of each node of the equationWhether or not, ifIf the current is converged, the DC power distribution system,for the k +1 th iteration direct current voltage calculation result of the ith node,for the calculation result of the k iteration direct current voltage of the ith node,dcgiven the allowed error;
42) equation of judgmentAnd if so, converging the power flow of the alternating current power distribution system, wherein,iteratively calculating the result for the (k + 1) th voltage of the ith node of the alternating current distribution system,iteratively calculating the result for the kth voltage at the ith node of the ac power distribution system,acis a given alternating current power flow iteration error;
43) and if the power flow of the direct current power distribution system or the power flow of the alternating current power distribution system is not converged, returning to direct current power flow solution to continue iterative calculation until the alternating current power flow and the direct current power flow are converged simultaneously, and outputting a result at the same time.
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Cited By (8)
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| CN106682363A (en) * | 2017-01-22 | 2017-05-17 | 东南大学 | Benders decomposition based droop control island micro-grid power flow calculation method |
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| CN106682363A (en) * | 2017-01-22 | 2017-05-17 | 东南大学 | Benders decomposition based droop control island micro-grid power flow calculation method |
| CN106682363B (en) * | 2017-01-22 | 2019-08-13 | 东南大学 | The one type sagging control isolated island micro-capacitance sensor tidal current computing method that this is decomposed to moral |
| CN107769213A (en) * | 2017-10-31 | 2018-03-06 | 贵州电网有限责任公司电力科学研究院 | A kind of more transverters alternating current-direct current distribution power system load flow calculation method in parallel |
| CN107769213B (en) * | 2017-10-31 | 2020-09-01 | 贵州电网有限责任公司电力科学研究院 | Load flow calculation method for multi-converter parallel AC/DC power distribution network |
| CN109995037A (en) * | 2017-12-29 | 2019-07-09 | 湖南工业大学 | Tractive power supply system tidal current analysis method, system and the storage medium of meter and AC-DC coupling |
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| CN108808715B (en) * | 2018-06-07 | 2021-07-27 | 国电南瑞科技股份有限公司 | Multi-terminal flexible direct system static safety analysis method considering direct current network fault power |
| CN109617079A (en) * | 2018-12-18 | 2019-04-12 | 华南理工大学 | A kind of existence and method for analyzing stability of direct-flow distribution system flow solution |
| CN110912140A (en) * | 2019-12-13 | 2020-03-24 | 福州大学 | Direct-current power distribution network load flow calculation method considering refined model of water electrolysis hydrogen production system |
| CN110912140B (en) * | 2019-12-13 | 2023-04-28 | 福州大学 | Power distribution network tide calculation method considering refined model of electrolytic water hydrogen production system |
| CN113794206A (en) * | 2021-11-16 | 2021-12-14 | 华东交通大学 | Alternating current-direct current hybrid power grid load flow calculation method considering VSC control strategy |
| CN116073390A (en) * | 2023-04-06 | 2023-05-05 | 广东电网有限责任公司珠海供电局 | Tidal current calculation method, device, terminal and medium of voltage active support mixing system |
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